Science.gov

Sample records for aging watershed dams

  1. Small watershed response to porous rock check dams in a semiarid watershed

    NASA Astrophysics Data System (ADS)

    Nichols, Mary; Polyakov, Viktor; Nearing, Mark

    2016-04-01

    Rock check dams are used throughout the world as technique for mitigating erosion problems on degraded lands. Increasingly, they are being used in restoration efforts on rangelands in the southwestern US, however, their impact on watershed response and channel morphology is not well quantified. In 2008, 37 porous rock structures were built on two small (4.0 and 3.1 ha) instrumented watersheds on an alluvial fan at the base of the Santa Rita Mountains in southern Arizona, USA. 35 years of historical rainfall and runoff, and sediment data are available to compare with 7 years of data collected after check dam construction. In addition, post construction measurements of channel geometry and longitudinal channel profiles were compared with pre-construction measurements to characterize the impact of check dams on sediment retention and channel morphology. The primary impact of the check dams is was retention of channel sediment and reduction in channel gradient; however response varied between the proximal watersheds with 80% of the check dams on one of the watersheds filled to 100% of their capacity after 7 runoff seasons. In addition, initial impact on precipitation runoff ratios is was not persistent. The contrasting watershed experiences lower sediment yields and only 20% of the check dams on this watershed are were filled to capacity and continue to influence runoff during small events. Within the watersheds the mean gradient of the channel reach immediately upstream of the structures has been reduced by 35% (from 0.061 to 0.039) and 34% on (from 0.071 to 0.047).

  2. Floods n' Dams: A Watershed Model.

    ERIC Educational Resources Information Center

    Milne, Andrew; Etches, John

    1996-01-01

    Describes an activity meant to illustrate flooding in a watershed as it impinges on human activities. Shows how flood protection can be provided using the natural holding capacity of basins elsewhere in the water system to reduce the impact on the settled flood plain. The activity works well with intermediate and senior level students but can be…

  3. 75 FR 61417 - South River Watershed Dam No. 10A, Augusta County, VA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Natural Resources Conservation Service South River Watershed Dam No. 10A, Augusta County, VA AGENCY... not being prepared for the rehabilitation of South River Watershed Dam No. 10A, Augusta...

  4. Temporospatial Patterns of Manganese Concentrations in a Hydropower Dam Watershed

    NASA Astrophysics Data System (ADS)

    Munger, Z.; Schreiber, M. E.

    2014-12-01

    Concentrations of manganese (Mn) downstream of a hydropower dam are strongly influenced by seasonal reservoir dynamics. During warm months reservoirs experience stratification that results in the depletion of dissolved oxygen at depth and the concurrent release of dissolved Mn from the sediment into the water column. After being released from the dam these Mn rich waters are mixed with oxygenated river water and the Mn may become oxidized and removed from the water column over time. Previous studies have largely focused on patterns of Mn distribution within the first 20 km or less downstream of a dam. However, water quality issues at our field site extend much further downstream. The primary goal of our work was to investigate how seasonal dynamics in the reservoir couple with heterogeneity at the watershed scale to drive temporal and spatial patterns across large distances. Mn concentrations were monitored downstream of a hydropower dam in southwest Virginia over a two year period that covered the Roanoke River between Leesville Dam and a water treatment plant 150 km downstream. Data that we have collected over the past two years show that Mn concentrations are highest near the dam during reservoir stratification in late summer and fall and decrease with distance downstream. A mass balance of the first 19 km downstream from the dam suggests loss of Mn via sedimentation and filtering of particulates. Mn concentrations appear to reach a consistent minimum at 50 km downstream. However, after the 50 km inflection, Mn concentrations increase with distance downstream. Along the downstream reach (>50 km), Mn concentrations in the river also exhibit a better correlation with stream discharge and the suspended particle load. Tributaries to this reach are also characterized by higher concentrations of Mn than observed in the first 50 km which appear to be driving these increases in concentration. These results provide new insights into the temporospatial patterns of Mn

  5. Nonpoint source pollution management for the multipurpose dam watersheds.

    PubMed

    Choi, J-Y

    2008-01-01

    Main pollution sources in multipurpose dam watersheds in Korea are highland fields, stream banks, livestock farms, roads, and construction sites. Specifically, highland fields are the major nonpoint pollution sources. Excessive organic chemicals such as fertilizer and pesticide can be exuded from the land, and the area is likely to be eroded by heavy rain. Fallow, conservative cultivation, and covering can be alternatives for soil protection and reinforcement. In addition to these, construction of detour waterways and improvement of irrigation method can minimize the impact of runoff. In the case of slope in 15% degree or more, prohibiting cultivation and restoring the surface is preferred to improving cultivation method in order to control nonpoint pollution sources efficiently.

  6. Prediction of precipitation in Golestan dam watershed using climate signals

    NASA Astrophysics Data System (ADS)

    Ruigar, Hossein; Golian, Saeed

    2016-02-01

    Global and regional scale climate teleconnection signals, including sea level pressure (SLP) and sea surface temperature (SST), are the main factors influencing the earth's climate oscillations and are among the most important indices used to predict climatic variables. In this research, the effect of teleconnection signals on monthly maximum 1-day precipitation is examined using artificial neural network (ANN) and 40 years of rainfall data for the Madarsoo watershed located at the upstream of Golestan dam in Northern Iran. The Pearson correlation coefficient was used to determine the correlation between monthly maximum 1-day precipitation and climate signals with different lags. Different ANN models with various combinations of inputs, i.e., correlated SLP and SST with different lags, were then used for forecasting precipitation. Results revealed acceptable performance of ANN in forecasting monthly maximum 1-day precipitation using SST/SLP datasets. For instance, the performance indices including root mean square error (RMSE), correlation ( R), and Nash-Sutcliffe (CNS) coefficients for monthly maximum 1-day precipitation of Tangrah rain gauge in August were found to be 6.12, 0.95, and 0.945 mm, respectively, for the test period.

  7. Dam removal, connectivity, and aquatic resources in the St. Regis River Watershed, New York

    USGS Publications Warehouse

    McKenna, James E.; Hanak, Kaitlin; DeVilbiss, Katharine; David, Anthony; Johnson, James H.

    2015-10-09

    The decommissioning and planned removal of the Hogansburg Dam on the St. Regis River in New York has stimulated interest in the potential effects of that barrier removal on the St. Regis watershed. There will be immediate and systemic effects of the Hogansburg Dam removal, which may include inundation of habitats below the dam or dewatering of habitats above the dam, possibly affecting local fish assemblages and (or) local native mussel assemblages; and expansion of stream network connectivity, which has the potential to open a large area of the watershed to migratory aquatic species. Information was collected about biota, water quality, sediment distribution, riverbed dimensions in the vicinity of the dam, and habitat characteristics of headwater sample sites. Complete fish assemblages were collected, but species of special concern associated with the connectivity changes included, American Eel, Atlantic Salmon, Brook Trout, Eastern Sand Darter, and Lake Sturgeon. Freshwater mussels in the vicinity of the dam also were examined and may be at risk of exposure (without a rescue plan) after dam removal. Reservoir sediment will be transported downstream and will alter aquatic habitat as it moves through the system. The dam removal will open more than 440 kilometers of stream habitat to migratory species, allowing them to more easily complete their life cycles. Fish assemblages above the dam may be altered by migrating fishes, but resident Brook Trout are not expected to be adversely affected.

  8. Effect of Check Dams on Erosion and Flow Dynamics on Small Semi-Arid Watersheds

    NASA Astrophysics Data System (ADS)

    Polyakov, V.; Nearing, M.; Nichols, M.; McClaran, M. P.

    2012-12-01

    Erosion dynamics in semi-arid environments is defined by high magnitude, low frequency rainfalls that produce runoff with high sediment concentration. Check dams were shown to be an effective sedimentation mitigation technique on small watersheds. Constructed of rocks, or other materials placed across the flow and anchored into the bottom and sides of the channel, these barriers produce upstream and downstream effects. By impounding runoff they reduce flow velocity, increase infiltration and allow sediment settling thus decreasing channel slope. Decreased sediment load downstream of the dam may result in accelerated channel scouring. While the effect of check dams on channel stability has been studied extensively their impact on overall watershed sediment balance is not well known. In 2008 a total of 37 loose rock semi permeable check dams were installed on two small (4.0 and 3.1 ha) watersheds located on the alluvial fan of the Santa Rita Mountains in southern Arizona, USA. Each watershed was equipped with high resolution weighing type rain gauge a supercritical flow flume and sediment sampler. Hyetographs, hydrographs, and sediment load data for the watersheds were collected since 1975. The erosion dynamics and flow characteristics following the check dam installation were compared with historical records. The volume of the sediment retained upstream of each dam was calculated through survey. After 4 years the check dams were filled to over 80% of their capacity and no significant increase in downstream scouring has been observed. Maximum 30-min intensity (I30) was overall best predictor variable for total runoff. After check dam installation the number ratio of runoff to rainfall events has been reduced by half. However, runoff peak rates were not significantly effected.

  9. 76 FR 50170 - Pohick Creek Watershed Dam No. 8, Fairfax County, Virginia; Finding of No Significant Impact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Natural Resources Conservation Service Pohick Creek Watershed Dam No. 8, Fairfax County, Virginia; Finding... Creek Watershed Dam No. 8, Fairfax County, Virginia. FOR FURTHER INFORMATION CONTACT: John A....

  10. Semiarid watershed response to low-tech porous rock check dams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rock check dams are used throughout the world as a technique for mitigating erosion problems on degraded lands. Increasingly, they are being used in restoration efforts on rangelands in the southwestern US; however, their impact on watershed response and channel morphology is not well quantified. In...

  11. Sediments deposition due to soil erosion in the watershed region of Mangla dam.

    PubMed

    Butt, Mohsin Jamil; Mahmood, Rashed; Waqas, Ahmad

    2011-10-01

    Soil erosion is the most important reason of sedimentation load of water reservoirs in the world. In Pakistan, Mangla dam is one of the most important water reservoirs used for the production of electricity and for the supply of water for irrigation purposes. However, the capacity of Mangla dam reservoir has reduced by more than 20% since its construction. This study highlights the impact of rainfall on soil erosion and consequently on sedimentation deposition in Mangla dam reservoir. Sedimentation, annual rainfall, and normal rainfall data of 39 years were used in this study. Shuttle Radar Topographic Mission data were used to calculate the total drainage area of the Mangla watershed region. The sedimentation data of Mangla reservoir from 1967 to 2005 were retrieved from Water and Power Development Authority in Pakistan. The meteorological observatories in the Mangla watershed region are identified. Annual rainfall data from 1967 to 2005 for the meteorological observatories in the Mangla watershed regions were retrieved from Pakistan Meteorological Department (PMD). In addition, normal rainfall data for the years 1949 to 1978 and for the years 1979 to 2008 were also retrieved from PMD. The impact of annual rainfall is observed on sedimentation load in Mangla dam. The correlation coefficient between annual rainfall and sedimentation load is 0.94. This study shows that with an increase in rainfall, the soil erosion of the area increases which subsequently is responsible for the increase in the rate of sedimentation load in Mangla dam. This study further demonstrates that better soil management can reduce the sedimentation load in the Mangla reservoir.

  12. Economics of integrated watershed management in the presence of a dam

    NASA Astrophysics Data System (ADS)

    Lee, Yoon; Yoon, Taeyeon; Shah, Farhed A.

    2011-10-01

    This paper presents an optimal control model of integrated watershed management in the presence of a dam. Management efforts focus on upstream soil conservation, reservoir-level sediment removal, and downstream damage control from water pollution. Increased soil conservation potentially benefits farmers and also has the external benefit of reducing sediment accumulation in the reservoir. Sediment is released downstream of the reservoir using the hydrosuction sediment removal system (HSRS). This sediment release extends reservoir life and provides nutrients to downstream farmers who then use less fertilizer. Also included in the functions of the dam manager are the provision of water to downstream farms, the control of instream flow to mitigate downstream damages from water pollution, and the use of water treatment to meet quality standards for water supplied directly from the reservoir to residential users. An illustrative application of the model to Lake Aswan, located between Egypt and Sudan, indicates substantial benefits from far-sighted behavior and cooperation across all agents. Moving from the baseline case that reflects the status quo to the socially optimal solution increases watershed net present value by more than $500 billion. Other scenarios with varying types of collaboration among the agents are also explored. Interestingly, while decisions with respect to soil conservation do impact the welfare of upstream farmers, the benefits to reservoir management and agriculture in Egypt are modest compared to benefits Egypt gets from improved control of instream flow. Also, subject to technical limits, increasing reservoir life through practice of HSRS is economically desirable.

  13. Inception point for embankment dam stepped spillways

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stepped spillways applied to embankment dams have become a common design practice with the rehabilitation of aging watershed dams, especially those experiencing a hazard classification change from low to high hazard. Previous research on stepped spillways focused on gravity dams where aerated flow ...

  14. Relationship between age of dam with calving ease and birth weight of Simmental calves.

    PubMed

    Burfening, P J

    1988-04-01

    Records from 123,656 Simmental calves (75% and 88% Simmental) were used to study the effect of age of dam on calving ease and birth weight. Calving ease was scored from 1 to 4 (1 = unassisted, 2 to 4 = various levels of assistance). Scores were recorded so that the percentage of assisted births could be calculated. Mean percentage of assisted births and birth weights for each age of dam in months, sex and Simmental percentage subclass were subjected to statistical analysis. Although sex and Simmental percentage occasionally interacted with age of dam for percentage of assisted births, in general, as age of dam increased the percentage of assisted births decreased in dams normally classified as 2-yr-olds (21 mo to 33 mo of age), whereas birth weight remained fairly constant. These results suggest that including age of dam in months in the mixed-model equations for sire evaluation for calving ease could improve the accuracy of these procedures.

  15. Effect of dams' parity and age on daughters' milk yield in Norwegian Red cows.

    PubMed

    Storli, K S; Heringstad, B; Salte, R

    2014-10-01

    The effect of age and parity of dams on their daughters' milk yield is not well known. Lactation data from 276,000 cows were extracted from the Norwegian Dairy Herd Recording System and analyzed using a linear animal model to estimate effects of parity and age within parity of dam. The 305-d milk yield of daughters decreased as parity of dam increased. Daughters of first-parity dams produced 149 kg more milk than did daughters of seventh-parity dams. We also observed an effect of age of dam within parity on 305-d milk yield of daughters in first lactation. Dams that were young at first calving gave birth to daughters with a higher milk yield compared with older dams within the same parity. The effect of age within parity of dam was highest for second-parity dams. Extensive use of heifers would have a systematic effect, and age and parity of dam should be included in the model when planning a future strategy.

  16. K-Ar ages of Pleistocene lava dams in the Grand Canyon in Arizona

    PubMed Central

    Dalrymple, G. Brent; Hamblin, W. K.

    1998-01-01

    At least 13 times during the Pleistocene Epoch lava flowed into the inner gorge of the Grand Canyon and formed lava dams, as high as 600 m, that temporarily blocked the flow of the Colorado River. K-Ar ages on these lava dams indicate that the seven youngest formed within a short period of time between about 0.6 and 0.4 mega-annum (Ma). The physiography of the lava dam remnants within the canyon shows that each dam was destroyed by erosion, the Colorado River rapidly reaching its pre-existing grade level, before the next dam was emplaced by new eruptions. The total time for emplacement and destruction for an individual lava dam was probably as little as 0.01–0.02 million years. The K-Ar ages of the two oldest dams, the Lava Butte dam (0.577 ± 0.054 Ma) and the Prospect dam (0.684 ± 0.051 Ma) are somewhat younger than the physiography of their remnants suggest. PMID:9707546

  17. K-Ar ages of Pleistocene lava dams in the Grand Canyon in Arizona.

    PubMed

    Dalrymple, G B; Hamblin, W K

    1998-08-18

    At least 13 times during the Pleistocene Epoch lava flowed into the inner gorge of the Grand Canyon and formed lava dams, as high as 600 m, that temporarily blocked the flow of the Colorado River. K-Ar ages on these lava dams indicate that the seven youngest formed within a short period of time between about 0.6 and 0.4 mega-annum (Ma). The physiography of the lava dam remnants within the canyon shows that each dam was destroyed by erosion, the Colorado River rapidly reaching its pre-existing grade level, before the next dam was emplaced by new eruptions. The total time for emplacement and destruction for an individual lava dam was probably as little as 0. 01-0.02 million years. The K-Ar ages of the two oldest dams, the Lava Butte dam (0.577 +/- 0.054 Ma) and the Prospect dam (0.684 +/- 0.051 Ma) are somewhat younger than the physiography of their remnants suggest.

  18. Influence of dams and habitat condition on the distribution of redhorse (Moxostoma) species in the Grand River watershed, Ontario

    USGS Publications Warehouse

    Reid, S.M.; Mandrak, N.E.; Carl, L.M.; Wilson, C.C.

    2008-01-01

    Redhorse, Moxostoma spp., are considered to be negatively affected by dams although this assertion is untested for Canadian populations. One hundred and fifty-one sites in the Grand River watershed were sampled to identify factors influencing the distribution of redhorse species. Individual species of redhorse were captured from 3 to 32% of sites. The most widespread species were golden redhorse, M. erythrurum (30%) and greater redhorse, M. valenciennesi (32%), while river redhorse, M. carinatum, was only found along the lower Grand River. Redhorse were absent from the highly fragmented Speed River sub-watershed and upper reaches of the Conestogo River and the Grand River. Redhorse species richness was positively correlated to river fragment size and upstream drainage area. Generalized additive models (GAMs) were applied to evaluate the influence of river fragment length, connectivity and habitat on species distribution. Principal component analysis reduced habitat data to three axes representing: channel structure, substrate, and pool, riffle and run habitats (PC1); gradient and drainage area (PC2); and cover (PC3). GAMs indicate that PC2 was important for predicting black redhorse and greater redhorse site occupancy and PC1 was important for golden redhorse. River fragment length was important for predicting site occupancy for shorthead redhorse, but not other species. ?? 2006 Springer Science+Business Media, Inc.

  19. Poult performance as influenced by age of dam, genetic line, and dietary vitamin E.

    PubMed

    Siegel, P B; Blair, M; Gross, W B; Meldrum, B; Larsen, C; Boa-Amponsem, K; Emmerson, D A

    2006-05-01

    An experiment was conducted to measure the effects of age of dam, genetic line, and dietary levels of vitamin E on growth and immunocompetence of poults. Age of dam was defined as younger (in early egg production) and older (past peak production); line consisted of a commercial sire and dam line; and dietary vitamin E was supplemented into the diet at 10 and 300 IU/kg of feed. Traits measured included body, liver, gizzard, and yolk sac weights at hatch; BW and feed conversion to 9, 28, and 42 d; response to SRBC, Phaseolus vulgaris agglutinin-P, and Escherichia coli administered at 28 d of age; and response to a cold stress on d 5 posthatch. Differences among genetic lines were evident with growth greater for poults from the sire than from the dam line. Performance of poults from older dams was generally superior to that of poults from younger dams. The higher level of vitamin E resulted in a greater than 7-fold increase in blood plasma vitamin E and reduced mortality. There were interactions among the main effects in which the fitness of poults from younger dams was enhanced by the higher level of vitamin E and the effect of breeder age differed among genetic lines.

  20. Multiple flow processes accompanying a dam-break flood in a small upland watershed, Centralia, Washington

    USGS Publications Warehouse

    Costa, John E.

    1994-01-01

    On October 5, 1991, following 35 consecutive days of dry weather, a 105-meter long, 37-meter wide, 5.2-meter deep concrete-lined watersupply reservoir on a hillside in the eastern edge of Centralia, Washington, suddenly failed, sending 13,250 cubic meters of water rushing down a small, steep tributary channel into the city. Two houses were destroyed, several others damaged, mud and debris were deposited in streets, on lawns, and in basements over four city blocks, and 400 people were evacuated. The cause of failure is believed to have been a sliding failure along a weak seam or joint in the siltstone bedrock beneath the reservoir, possibly triggered by increased seepage into the rock foundation through continued deterioration of concrete panel seams, and a slight rise (0.6 meters) in the pool elevation. A second adjacent reservoir containing 18,900 cubic meters of water also drained, but far more slowly, when a 41-cm diameter connecting pipe was broken by the landslide. The maximum discharge resulting from the dam-failure was about 71 cubic meters per second. A reconstructed hydrograph based on the known reservoir volume and calculated peak discharge indicates the flood duration was about 6.2 minutes. Sedimentologic evidence, high-water mark distribution, and landforms preserved in the valley floor indicate that the dam failure flood consisted of two flow phases: an initial debris flow that deposited coarse bouldery sediment along the slope-area reach as it lost volume, followed soon after by a water-flood that achieved a stage about one-half meter higher than the debris flow. The Centralia dam failure is one of three constructed dams destroyed by rapid foundation failure that defines the upper limits of an envelope curve of peak flood discharge as a function of potential energy for failed constructed dams worldwide.

  1. Integrated assessment of the effects of dams on irrigation sustainability in a data scarce watershed

    NASA Astrophysics Data System (ADS)

    Yoshida, T.; Masumoto, T.; Kudo, R.

    2014-12-01

    Several development projects are currently under way in developing countries to meet growing demand for water and energy. However, due to the lack of the hydro-meteorological data, some projects were conducted without rigorous check of water balance and the potential changes in the flow regime likely to be induced by reservoirs, and their implications for irrigation projects and ecosystems. To cope with this issues, we carried out analysis by using a hydrological model and quasi-observed rainfall data. A distributed water circulation model was introduced as a tool to implement the analysis. Given daily meteorological data, the model calculates spatial distribution of surface runoff, evapotranspiration, river flow and water demand. In addition, it represents operation of water use facilities, and return flow from irrigated areas. We performed a case study in the Pursat River Basin in Cambodia, where multiple projects are ongoing. We first calculated river discharge with observed rain data and calibrated it. Next, we performed a water balance analysis of the basin using the compiled model with 7 years of rainfall data. Because 20-30 years of data is generally required for water resources planning, we thus prepared 25 years of data by using a climate model with a statistically corrected bias. We determined a reference year for irrigation planning from the long-term data such that annual precipitation of 5-year return period. We selected a scenario for irrigated areas from the Water Balance Study Report (JICA, 2013) to project the future water demand, and checked the water balance under no-dam conditions. The results revealed that water supply was more than adequate to meet water demand in the reference year. We finally incorporated the future dam operations into the calculations and evaluated the impact of the dams on river flows and irrigation projects. Even under the changed flow regimes, the water balance was satisfied in the reference year. However, river flows

  2. Seasonal And Intra-seasonal Hydrological Responses To Change In Climate Pattern And Small Dams of the Faga Watershed In Burkina-Faso

    NASA Astrophysics Data System (ADS)

    Mamounata, K.

    2015-12-01

    In response to the increasing demand for food linked to the substantial growth of population in Burkina Faso, irrigation has been widely used by the farming community to support agricultural production. Thus a promising option for water resources development in such a context is to increase the number of small dams. It is assumed that the great number of small dams may have effect on sub-basins' hydrological dynamic. This study aims to assess the seasonal and the intra-seasonal change in river basins hydrology with the case study of the Faga River sub-basin located in Burkina-Faso, West Africa, using Water Simulation Model (WaSiM). For this watershed the number of small dams is slightly very important (More than 60) and their impact on the watershed runoff has been estimated simultaneously with the change in climate pattern. The coefficient of variation for rainfall in this sub-basin from 1982 to 2010 is 0.097 and the stream flow presents a seasonal average of 25.58Km3 per month for the same period. The intra-seasonal climate variation for the same period is estimated at 0.087 in the scenario where any dam has not been considered. Results based on simulation including the five important dams over the sub-basin show that the overall effect of small dams is on average a 20.76% in runoff. Projections using the Representative Concentration Pathways (RCP) 4.5 and 8.5 climate scenarios with increase of 25% of dams' number show a probable decrease of about 29.54% and 35.25% of the average during the next fifty years runoff. The study findings show that small dams reduce significantly the runoff from their watershed and the uncertainties related to the sustainability of the resource seems to be increasing during the same period. Therefore, despite the very large number of water storage infrastructures, reservoirs operating strategies have to be achieved for water sustainability within the Faga sub-basin.

  3. Seasonality of soil erosion under mediterranean conditions at the Alqueva Dam watershed.

    PubMed

    Ferreira, Vera; Panagopoulos, Thomas

    2014-07-01

    The Alqueva reservoir created the largest artificial lake of Western Europe in 2010. Since then, the region has faced challenges due to land-use changes that may increase the risk of erosion and shorten the lifetime of the reservoir, increasing the need to promote land management sustainability. This paper investigates the aspect of seasonality of soil erosion using a comprehensive methodology that integrates the Revised Universal Soil Loss Equation (RUSLE) approach, geographic information systems, geostatistics, and remote-sensing. An experimental agro-silvo pastoral area (typical land-use) was used for the RUSLE factors update. The study confirmed the effect of seasonality on soil erosion rates under Mediterranean conditions. The highest rainfall erosivity values occurred during the autumn season (433.6 MJ mm ha(-1) h(-1)), when vegetation cover is reduced after the long dry season. As a result, the autumn season showed the highest predicted erosion (9.9 t ha(-1)), contributing 65 % of the total annual erosion. The predicted soil erosion for winter was low (1.1 t ha(-1)) despite the high rainfall erosivity during that season (196.6 MJ mm ha(-1) h(-1)). The predicted annual soil loss was 15.1 t ha(-1), and the sediment amount delivery was 4,314 × 10(3) kg. Knowledge of seasonal variation would be essential to outline sustainable land management practices. This model will be integrated with World Overview of Conservation Approaches and Technologies methods to support decision-making in that watershed, and it will involve collaboration with both local people and governmental institutions.

  4. Retention of institutional knowledge and technical capacity for repair and rehabilitation of NRCS-assisted watershed dams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA Natural Resources Conservation Service (NRCS) along with project sponsors have constructed more than 11,000 dams across the U.S. The peak of construction was in the 1960's with the dams primarily designed with a 50 year planned service life. Over the next two decades, an average of one da...

  5. Socioeconomic and Institutional Dimensions of Dam Removals: The Wisconsin Experience

    PubMed

    Born; Genskow; Filbert; Hernandez-Mora; Keefer; White

    1998-05-01

    / There are tens of thousands of small dams in the United States; many of these aging structures are deteriorating. Governments and dam owners face decisions regarding repair or removal of these structures. Along with the many benefits society derives from dams and their impoundments, numerous recent ecological studies are revealing the extensive alteration and degradation of river ecosystems by dams. Dam removal-a principal restoration strategy-is an infrequent event. The major reasons for removal have been public safety and the high costs associated with repair; the goal of river ecosystem restoration now warrants greater attention. Substantial study is being given to the environmental aspects of dams and dam removals, but very little attention has been given to the socioeconomic and institutional dimensions associated with the removal of dams, although these factors play a significant role in the removal decision-making process. Based on a case study of dam removals in Wisconsin-where more than 30 of the state's 3600 small dams have been removed in the past few decades-legal, financial, and socioeconomic issues associated with dam removal are documented and assessed. Dam removal has been complex and contentious, with limited community-based support for removal and loss of the impounded waters. In cases examined here, the estimated costs of repairing a dam averaged more than three times the cost of removal. The availability of governmental financing has been a key determinant in removal decisions. Watershed-scale ecological considerations are not major factors for most local interests. As watershed management and restoration increasingly include dam removal options as part of an integrated strategy, more attention will need to be focused on socioeconomic factors and stakeholder perspectives-variables that strongly influence the viability of this management alternative.KEY WORDS: Dam removal; River restoration; Institutions; Stakeholders

  6. ENHANCED RECOVERY METHODS FOR 85KR AGE-DATING GROUNDWATER: ROYAL WATERSHED, MAINE

    EPA Science Inventory

    Potential widespread use of 85Kr, having a constant input function in the northern hemisphere, for groundwater age-dating would advance watershed investigations. The current input function of tritium is not sufficient to estimate young modern recharge waters. While tri...

  7. Spatial multicriteria decision analysis of flood risks in aging-dam management in China: a framework and case study.

    PubMed

    Yang, Meng; Qian, Xin; Zhang, Yuchao; Sheng, Jinbao; Shen, Dengle; Ge, Yi

    2011-05-01

    Approximately 30,000 dams in China are aging and are considered to be high-level risks. Developing a framework for analyzing spatial multicriteria flood risk is crucial to ranking management scenarios for these dams, especially in densely populated areas. Based on the theories of spatial multicriteria decision analysis, this report generalizes a framework consisting of scenario definition, problem structuring, criteria construction, spatial quantification of criteria, criteria weighting, decision rules, sensitivity analyses, and scenario appraisal. The framework is presented in detail by using a case study to rank dam rehabilitation, decommissioning and existing-condition scenarios. The results show that there was a serious inundation, and that a dam rehabilitation scenario could reduce the multicriteria flood risk by 0.25 in the most affected areas; this indicates a mean risk decrease of less than 23%. Although increased risk (<0.20) was found for some residential and commercial buildings, if the dam were to be decommissioned, the mean risk would not be greater than the current existing risk, indicating that the dam rehabilitation scenario had a higher rank for decreasing the flood risk than the decommissioning scenario, but that dam rehabilitation alone might be of little help in abating flood risk. With adjustments and improvement to the specific methods (according to the circumstances and available data) this framework may be applied to other sites.

  8. Age and extent of a giant glacial-dammed lake at Yarlung Tsangpo gorge in the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Liu, Weiming; Lai, Zhongping; Hu, Kaiheng; Ge, Yonggang; Cui, Peng; Zhang, Xiaogang; Liu, Feng

    2015-10-01

    Many glacier dams on major rivers at the southeastern edge of the Tibetan Plateau had been previously determined through remote sensing and glacier terminal position calculation. It was hypothesized that such damming substantially impeded river incision into the plateau interior. Investigation on the large glacial-dammed lake at the entrance of Tsangpo gorge is critical for understanding this hypothesis. So far, the issues, such as age, lake surface elevation, and stages of this dammed lake, are still in debate. Our field survey of lacustrine deposits and loess distribution along the middle Yarlung Tsangpo River and its tributary, Nyang River, suggested that the lake surface elevation was at about 3180 m asl. The 23 quartz optically stimulated luminescence (OSL) and 4 organic AMS 14C ages all fall into the Last Glacial period (~ 41-13 ka). The OSL and 14C ages are in general agreement with each other where applicable. There might be only one long damming event because the ages of lacustrine deposits from 2970 to 3100 m asl are similar, and every lacustrine section is sustained for a long time. The estimated lake surface area was 1089 km2, and the volume was ~ 170 km3, which differ from previous estimations which suggested two-stage (about early Holocene and 1.5 ka) lakes, and the largest lake surface elevation reached 3500 m.

  9. Exposure age and climate controls on weathering in deglaciated watersheds of western Greenland

    NASA Astrophysics Data System (ADS)

    Scribner, C. A.; Martin, E. E.; Martin, J. B.; Deuerling, K. M.; Collazo, D. F.; Marshall, A. T.

    2015-12-01

    Fine-grained sediments deposited by retreating glaciers weather faster than the global average and this weathering can impact the global carbon cycle and oceanic fluxes of nutrients and radiogenic isotopes. Much work has focused on subglacial and proglacial weathering of continental ice sheets, but little is known about weathering and resulting fluxes from deglacial watersheds, which are disconnected from the ice sheets and discharge only annual precipitation and permafrost melt. We investigate the effects of exposure age and precipitation on weathering intensity in four deglacial watersheds on Greenland that form a transect from the coast near Sisimiut toward the Greenland Ice Sheet (GrIS) near Kangerlussuaq based on evaluations of major ion compositions, Sr isotope ratios, and mineral saturation states of waters and sediments. The transect is underlain by Archean orthogneiss and is characterized by gradients in moraine ages (∼7.5-8.0 ky inland to ∼10 ky at the coast) and water balance (-150 mm/yr inland to +150 mm/yr at the coast). Anion compositions are generally dominated by HCO3, but SO4 becomes increasingly important toward the coast, reflecting a switch from trace carbonate dissolution to sulfide mineral oxidation. Coastal watersheds have a higher proportion of dissolved silica, higher Na/Cl, Si/Ca, and lower Ca/Sr ratios than inland watersheds, indicating an increase in the relative proportion of silicate weathering and an increase in the extent of weathering toward the coast. More extensive weathering near the coast is also apparent in differences in the 87Sr/86Sr ratios of stream water and bedload (Δ87Sr/86Sr), which decreases from 0.017 inland to 0.005 at the coast, and in increased saturation states relative to amorphous SiO2 and quartz. The steep weathering gradient from inland to coastal watersheds reflects enhanced weathering compared to that expected from the 2 to 3 ky difference in exposure age caused by elevated coastal precipitation. The

  10. Evolution of groundwater age in a mountain watershed over a period of thirteen years

    NASA Astrophysics Data System (ADS)

    Manning, Andrew H.; Clark, Jordan F.; Diaz, Stephanie H.; Rademacher, Laura K.; Earman, Sam; Niel Plummer, L.

    2012-08-01

    We compile a unique 13-year record of groundwater age for 11 springs in Sagehen basin, a watershed in the Sierra Nevada Mountains of California, USA. Chlorofluorocarbon (CFC), sulfur hexafluoride (SF6), and tritium (3H) data collected in prior studies from 1997 to 2003 are re-interpreted and combined with new data collected in 2009 and 2010. The age record is analyzed to explore the potential value of groundwater age monitoring for (1) providing additional constraints on the age distribution in mixed-age samples, and (2) identifying temporal changes in groundwater recharge. Motivation for this study is provided by a lack of knowledge of how groundwater recharge and discharge (stream baseflow) in mountain watersheds might respond to climate change, and a resulting need to better understand mountain aquifer residence times, storage, and recharge. Piston-flow ages for the springs generally range from 10 to 50 yr. The plausibility of different age mixing models is tested by comparing observed temporal variations in age with those simulated using simple numerical models, and by examining plots comparing the concentrations of different age tracers. We find that most spring waters are best characterized by a bimodal mixing model consisting of a new (<1 yr old) fraction and a fraction that is older, but still modern (recharged after 1950). Identification of this mixing model would not have been possible without data from multiple age tracers and data from multiple years. Computed mean ages vary substantially (often by 3-7 yr) between sampling events for most springs, including those with ages of 20-50 yr. Mean age variations are likely controlled by variations in the magnitude of the new fraction, which is positively correlated with annual snowpack water content. Most springs show overall upward trends in mean age for the sampling period, consistent with decreasing recharge rates in response to diminishing snowpack. Groundwater age monitoring appears to be a potentially

  11. A Geostatistical Approach to Watershed Sources of Aged Riverine Organic Matter to the Hudson-Mohawk River System

    NASA Astrophysics Data System (ADS)

    Longworth, B. E.; Petsch, S. T.; Raymond, P. A.; Bauer, J. E.

    2006-12-01

    A number of rivers transport highly-aged (~103 to 104 yrs B.P.) particulate organic matter (POM), however, the sources of this material remain a matter of debate. Weathering, erosion and transport of streambed and interfluve material export terrestrial organic matter (OM) to streams, and this terrestrial OM is the primary POM constituent in most fast-flowing, shaded headwater systems. The age and composition of exported POM should therefore reflect the abundance and distribution of OM sources within the watershed. Here, we examine the relationship between watershed carbon sources and streamwater POM using Δ14C and C:N ratios of suspended particulates, streambed sediments and watershed materials in fourteen small headwater watersheds of the Hudson River, an intermediate sized, temperate, passive margin river in the northeastern USA. These sites vary widely in lithology (OM-rich shales, OM-lean carbonate/siltstone facies, and OM-free crystalline rocks), land use types (forested and agricultural), and morphology (slope, elevation and aspect). Using GIS-based statistical modeling, we developed predictors of POM export based on these watershed factors. Regression analysis using mapped distributions of watershed OM of differing radiocarbon and elemental compositions as predictors of POM composition reveal that both OM-rich watershed lithologies and agricultural land use are strong predictors of aged riverine OM, but does not allow definitive separation of these two sources. In addition, a simple isotope mass balance approach further demonstrates that while erosion and transport of watershed materials can account for the source of aged POM in headwater systems, additional sources or processes are required to explain the depleted Δ14C of POM in the Hudson and Mohawk mainstems.

  12. Metal binding in soil cores and sediments in the vicinity of a dammed agricultural and industrial watershed.

    PubMed

    Kanbar, Hussein Jaafar; Hanna, Nour; El Samrani, Antoine G; Kazpard, Véronique; Kobaissi, Ahmad; Harb, Nafez; Amacha, Nabil

    2014-12-01

    The environment is witnessing a downgrade caused by the amelioration of the industrial and agricultural sectors, namely, soil and sediment compartments. For those reasons, a comparative study was done between soil cores and sediments taken from two locations in the Qaraaoun reservoir, Lebanon. The soil cores were partitioned into several layers. Each layer was analyzed for several physicochemical parameters, such as functional groups, particle size distribution, ζ-potential, texture, pH, electric conductivity, total dissolved solids, organic matter, cation exchange capacity, active and total calcareous, available sodium and potassium, and metal content (cadmium, copper, and lead). The metal content of each site was linked to soil composition and characteristics. The two sites showed distinguishable characteristics for features such as organic matter, pH, mineral fraction, calcareous, and metal content. The samples taken toward the south site (Q1), though contain lower organic matter than the other but are more calcareous, showed higher metal content in comparison to the other site (Q2) (average metal content of Q1 > Q2; for Cd 3.8 > 1.8 mg/kg, Cu 28.6 > 21.9 mg/kg, Pb 26.7 > 19 mg/kg). However, the metal content in this study did not correlate as much to the organic matter; rather, it was influenced by the location of the samples with respect to the dam, the reservoir's hydrodynamics, the calcareous nature of the soil, and the variation of the industrial and agricultural influence on each site.

  13. Growth of age-0 steelhead (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) in the Pine River watershed, Alcona County, Michigan

    SciTech Connect

    Bellgraph, Brian J.; Thompson, Bradley E.; Hayes, Daniel B.; Riley, Timothy S.

    2006-12-01

    We sampled ten sites within the Pine River watershed, Alcona County, Michigan. In 2001, age-0 steelhead (Oncorhynchus mykiss) were collected to determine growth rates. In 2002, emergence dates of steelhead were determined by observational studies and age-0 steelhead and brook trout (Salvelinus fontinalis) were collected to determine growth rates. Steelhead emergence occurred from late June to mid-July 2002. Growth rates of both species varied among branches within the watershed (P<0.05). Steelhead growth varied from 0.24 to 0.42 mm/day and brook trout growth varied from 0.22 to 0.37 mm/day.

  14. Groundwater noble gas, age, and temperature signatures in an Alpine watershed: Valuable tools in conceptual model development

    USGS Publications Warehouse

    Manning, A.H.; Caine, J.S.

    2007-01-01

    [1] Bedrock groundwater in alpine watersheds is poorly understood, mainly because of a scarcity of wells in alpine settings. Groundwater noble gas, age, and temperature data were collected from springs and wells with depths of 3-342 m in Handcart Gulch, an alpine watershed in Colorado. Temperature profiles indicate active groundwater circulation to a maximum depth (aquifer thickness) of about 200 m, or about 150 m below the water table. Dissolved noble gas data show unusually high excess air concentrations (>0.02 cm3 STP/g, ??Ne > 170%) in the bedrock, consistent with unusually large seasonal water table fluctuations (up to 50 m) observed in the upper part of the watershed. Apparent 3H/3He ages are positively correlated with sample depth and excess air concentrations. Integrated samples were collected from artesian bedrock wells near the trunk stream and are assumed to approximate flow-weighted samples reflecting bedrock aquifer mean residence times. Exponential mean ages for these integrated samples are remarkably consistent along the stream, four of five being from 8 to 11 years. The tracer data in combination with other hydrologic and geologic data support a relatively simple conceptual model of groundwater flow in the watershed in which (1) permeability is primarily a function of depth; (2) water table fluctuations increase with distance from the stream; and (3) recharge, aquifer thickness, and porosity are relatively uniform throughout the watershed in spite of the geological complexity of the Proterozoic crystalline rocks that underlie it. Copyright 2007 by the American Geophysical Union.

  15. Projection of future climate change impacts on nonpoint source pollution loads for a forest dominant dam watershed by reflecting future vegetation canopy in a Soil and Water Assessment Tool model.

    PubMed

    Park, Min J; Park, Jong Y; Shin, Hyung J; Lee, Mi S; Park, Geun A; Jung, In K; Kim, Seong J

    2010-01-01

    This study is to assess the future impact of climate change on hydrological behavior considering future vegetation canopy prediction and its propagation to nonpoint source pollution (NPS) loads. The SWAT (Soil and Water Assessment Tool) model was used for the assessment. For a forest dominant ChungjuDam watershed of South Korea, the MIROC3.2hires climate data of SRES A1B and B1 scenarios were adopted and downscaled for the watershed. The future vegetation canopy information was projected by the monthly relationship between Terra MODIS (MODerate resolution Imaging Spectroradiometer) LAI (Leaf Area Index) and temperature. The future predicted LAI increased up to 1.9 in 2080s April and October because of the temperature increase 3.6 degrees C and 5.3 degrees C respectively. By reflecting the future LAI changes, the future estimated percent changes of maximum annual dam inflow, SS, T-N, and T-P were + 42.5% in 2080s A1B,-35.6% in 2020s A1B,+73.7% in 2080s A1B and-21.0% in 2080s B1 scenario respectively. The increase of T-N load was from the increase of subsurface lateral flows and the groundwater recharges by the future rainfall increase. The decrease of T-P load was by decrease of sediment load during wet days because the effect of LAI increase is greater than the increase of rainfall.

  16. Multiple constraints on the age of a Pleistocene lava dam across the Little Colorado River at Grand Falls, Arizona

    USGS Publications Warehouse

    Duffield, W.; Riggs, N.; Kaufman, D.; Champion, D.; Fenton, C.; Forman, S.; McIntosh, W.; Hereford, R.; Plescia, J.; Ort, M.

    2006-01-01

    The Grand Falls basalt lava flow in northern Arizona was emplaced in late Pleistocene time. It flowed 10 km from its vent area to the Little Colorado River, where it cascaded into and filled a 65-m-deep canyon to form the Grand Falls lava dam. Lava continued ???25 km downstream and ???1 km onto the far rim beyond where the canyon was filled. Subsequent fluvial sedimentation filled the reservoir behind the dam, and eventually the river established a channel along the margin of the lava flow to the site where water falls back into the pre-eruption canyon. The ca. 150 ka age of the Grand Falls flow provided by whole-rock K-Ar analysis in the 1970s is inconsistent with the preservation of centimeter-scale flow-top features on the surface of the flow and the near absence of physical and chemical weathering on the flow downstream of the falls. The buried Little Colorado River channel and the present-day channel are at nearly the same elevation, indicating that very little, if any, regional downcutting has occurred since emplacement of the flow. Newly applied dating techniques better define the age of the lava dam. Infrared-stimulated luminescence dating of silty mudstone baked by the lava yielded an age of 19.6 ?? 1.2 ka. Samples from three noneroded or slightly eroded outcrops at the top of the lava flow yielded 3He cosmogenic ages of 16 ?? 1 ka, 17 ?? 1 ka, and 20 ?? 1 ka. A mean age of 8 ?? 19 ka was obtained from averaging four samples using the 40Ar/39Ar step-heating method. Finally, paleomagnetic directions in lava samples from two sites at Grand Falls and one at the vent area are nearly identical and match the curve of magnetic secular variation at ca. 15 ka, 19 ka, 23 ka, and 28 ka. We conclude that the Grand Falls flow was emplaced at ca. 20 ka. ?? 2006 Geological Society of America.

  17. Technical background information for the ORNL environmental and safety report. Volume 2. A description of the aquatic ecology of the White Oak Creek Watershed and the Clinch River below Melton Hill Dam

    SciTech Connect

    Loar, J.M.; Solomon, J.A.; Cada, G.F.

    1981-10-01

    In order to characterize the aquatic communities in the vicinity of Oak Ridge National Laboratory (ORNL), a biological sampling program was initiated in March 1979 and continued until June 1980. The periphyton, benthic macroinvertebrate, and fish communities were sampled at four sites in White Oak Creek watershed above White Oak Lake. In addition to these communities, phytoplankton, zooplankton, and ichthyoplankton were routinely collected at sites in White Oak Lake, White Oak Creek embayment below the dam, and in the Clinch River above and below the confluence with White Oak Creek. Also, muscle tissue of several fish species, including sauger and striped bass from the Clinch River, was analyzed for seven trace elements (Cd, Cr, Cu, Pb, Hg, Ni, and Zn). Data on the taxonomic composition, abundance, and temporal distribution of each community are presented for each of three study areas: upper White Oak Creek watershed, White Oak Lake, and the Clinch River (including White Oak Creek embayment). The spatial distribution of major taxonomic groups in each area was examined using analysis of variance techniques and dissimilarity indices. Results obtained from this study are compared with those of previous surveys of White Oak Creek when equivalent sampling methodologies were used. Attempts were also made to document changes that have occurred since the 1950-1953 survey.

  18. Advancing knowledge gained from sediment budgets through sediment age dating and fingerprinting in small watersheds

    NASA Astrophysics Data System (ADS)

    Skalak, K.; Benthem, A.; Gellis, A.; Harvey, J. W.; Hupp, C. R.; Larsen, L.; Noe, G. B.; Pizzuto, J. E.; Schenk, E.

    2013-12-01

    Dynamics and long-term trajectories of fine sediment generally remain poorly quantified in rivers, which have implications for nutrient and contaminant transport and remediation strategies. Here we focus on two streams within the Chesapeake Bay watershed, Difficult Run and Accotink Creek. These streams have varying degrees of urbanization and diverse best management practices, making possible a comparison of sediment sources, sinks, and residence times to illuminate how land management impacts fine sediment transport. Bank erosion and floodplain accumulation in Difficult Run has been previously determined and is ongoing in Accotink Creek. Current work advances sediment budgets by quantifying the role of in-channel fine sediment storage in the bed and margins. To understand the relative storage timescales for various geomorphic features (floodplain, in-channel, etc.) and develop age distributions, sediment is dated using radionuclides of varying half-lives such as Pb-210, Cs-137, Be-7, bomb radiocarbon, and optically stimulated luminescence (OSL). To determine the source of sediment that is transported in suspension, sediment fingerprinting has been completed in Difficult Run and initiated in Accotink Creek. Furthermore, the present study furthers our understanding of fine sediment dynamics by fingerprinting sources of stored sediment and evaluating how they evolve over storm events and stream size. For this, we sampled sediment in storage zones before and after storm events of a specified magnitude to determine their chemical signatures with respect to various source-tracking elements and isotopes. This study represents the first such work to integrate sediment dating, sediment fingerprinting and an analysis of storage zones to understand fine sediment dynamics and long-term trajectories.

  19. Modeling bed material transport through colonial-age mill dam impoundments, northern Delaware

    NASA Astrophysics Data System (ADS)

    Pearson, A.; Pizzuto, J. E.

    2013-12-01

    Two hundred -year old colonial mill dam impoundments of the White Clay and Red Clay Creeks in northern Delaware are barely 20% 'filled' with sediment. Field evidence suggests that gravel-sized bed material supplied from upstream is able to pass through these impoundments, implying that the impoundment morphology has reached an equilibrium morphology controlled by the prevailing hydraulic regime. We assess this hypothesis using backwater modeling to compute local boundary shear stresses and the Wilcock-Crowe sediment transport equation to determine bed material transport rates in a representative impoundment with a ~ 2 m high dam and a 1.5 km-long impoundment. While previous conceptual models suggest that cobbles could only be transported through impoundments during catastrophic storm events or after impoundments had completely filled, our analysis demonstrates that transport rates of cobbles during the 2 year flow are significant. Even smaller discharges can be effective: the 0.5 year discharge moves coarse-grained bed material (11.2 - 32 mm) at moderate rates outside the impoundment and at low rates within the impoundment, suggesting net accumulation. Larger flows (5-25 year) transport material at similar rates both outside and within the impoundment. Averaged over time, this regime would keep the bed of the stream in quasi-equilibrium, with lower flows filling the impoundment and higher flows removing the accumulated sediment. This behavior is reminiscent of the response and recovery cycle described for quasi-equilibrium stream channels, suggesting that these impounded channels behave as graded streams with a reduced slope rather than as stagnant quasi-lacustrine systems incapable of transporting the sediment supplied from upstream. The current morphology (only 20% filled by sand and gravel) may not have existed in the past. Cores from floodplains adjacent to the impoundments reveal deposits of laminated mud suggesting a former fine-grained impoundment fill that

  20. Natural Dams as Tipping Points in Himalayan Erosion (Invited)

    NASA Astrophysics Data System (ADS)

    Korup, O.

    2010-12-01

    Natural dams result from hillslope, glacial, volcanic, and other sediment inputs that temporarily overwhelm the transport capacity along a given river reach. Such blockages are tipping points in which fluvial erosion and sediment transport rapidly switch to aggradation and vice versa even in the most powerful of rivers, thus eventually modulating both rates and duration of river incision into bedrock. Conspicuous clusters of hundreds of large natural dams occur in several major watersheds draining the Himalayan syntaxes and the southern Himalayan front, including the Indus, Yarlung Tsangpo, Sutlej, Kali Gandaki, and Arun. The Indus features the largest concentration of giant landslide dams known worldwide, whereas the Yarlung Tsangpo seems largely devoid of comparable landslide dams. Glacial dams such as river-blocking moraines are limited to headwaters where topography intersects the regional snowline. By forming dams and protective alluvial fill, glaciers and landslides help retard headward fluvial bedrock incision into parts of the Tibetan Plateau interior, limiting its dissection in addition to effects of upstream aridity and localized rock uplift. A growing number of radiometric age constraints on widely exposed lake sediments and backwater terraces support the notion that large tracts of these rivers had been repeatedly ponded for as long as several tens of thousands of years during the Late Quaternary. High local topographic relief in buffers along these rivers characterizes conspicuous knickzones, and helps pinpoint first-order differences in the type and potential longevity of these natural dams. Patterns of low-temperature thermochronometric data corroborate that peaks in mean local relief, spatially coinciding with peaks in long-term exhumation rates, act as a regionally consistent downstream limit to the preservation potential of natural dams. If indeed glacier and landslide dams act as a negative feedback in response to fluvial dissection of parts of

  1. Using dissolved gases to observe the evolution of groundwater age in a mountain watershed over a period of thirteen years

    USGS Publications Warehouse

    Manning, Andrew H.

    2011-01-01

    Baseflows in snowmelt-dominated mountain streams are critical for sustaining ecosystems and water resources during periods of greatest demand. Future climate predictions for mountainous areas throughout much of the western U.S. include increasing temperatures, declining snowpacks, and earlier snowmelt periods. The degree to and rate at which these changes will affect baseflows in mountain streams remains unknown, largely because baseflows are groundwater-fed and the relationship between climate and groundwater recharge/discharge rates in mountain watersheds is uncertain. We use groundwater age determinations from multiple dissolved gas tracers (CFCs, SF6, and 3H/3He) to track changes in groundwater age over a period of thirteen years in the Sagehen Creek watershed, Sierra Nevada Mountains, CA. Data were collected from springs and wells in 2009 and 2010 and combined with those obtained in prior studies from 1997 to 2003. Apparent ages range from 0 to >60 years. Comparison between variations in age and variations in snow water equivalent (SWE) and mean annual air temperature reveals the degree of correlation between these climate variables and recharge rate. Further, comparison of apparent ages from individual springs obtained at different times and using different tracers helps constrain the age distribution in the sampled waters. The age data are generally more consistent with an exponential age distribution than with piston-flow. However, many samples, even those with relatively old mean ages, must have a disproportionately large very young fraction that responds directly to annual SWE variations. These findings have important implications for how future baseflows may respond to decreasing SWE.

  2. APPARENT 85KRYPTON AGES OF GROUNDWATER WITHIN THE ROYAL WATERSHED, MAINE, USA

    EPA Science Inventory

    85Kr activities were determined in 264 domestic and municipal wells from 2002-2004 in the Royal watershed (361 km2), Maine. Gas extraction for 85Kr from wells was effected directly via a well-head methodology permitting efficient widespread analys...

  3. Using dissolved organic matter age and composition to detect permafrost thaw in boreal watersheds of interior Alaska

    USGS Publications Warehouse

    O'Donnell, Jonathan A.; Aiken, George R.; Walvoord, Michelle Ann; Raymond, Peter A.; Butler, Kenna; Dornblaser, Mark M.; Heckman, Katherine

    2014-01-01

    Recent warming at high latitudes has accelerated permafrost thaw, which can modify soil carbon dynamics and watershed hydrology. The flux and composition of dissolved organic matter (DOM) from soils to rivers are sensitive to permafrost configuration and its impact on subsurface hydrology and groundwater discharge. Here, we evaluate the utility of DOM composition and age as a tool for detecting permafrost thaw in three rivers (Beaver, Birch, and Hess Creeks) within the discontinuous permafrost zone of interior Alaska. We observed strong temporal controls on Δ14C content of hydrophobic acid isolates (Δ14C-HPOA) across all rivers, with the most enriched values occurring during spring snowmelt (75 ± 8‰) and most depleted during winter flow (−21 ± 8‰). Radiocarbon ages of winter flow samples ranged from 35 to 445 yr BP, closely tracking estimated median base flow travel times for this region (335 years). During spring snowmelt, young DOM was composed of highly aromatic, high molecular-weight compounds, whereas older DOM of winter flow had lower aromaticity and molecular weight. We observed a significant correlation between Δ14C-HPOA and UV absorbance coefficient at 254 nm (α254) across all study rivers. Usingα254 as an optical indicator for Δ14C-HPOA, we also observed a long-term decline in α254 during maximum annual thaw depth over the last decade at the Hess Creek study site. These findings suggest a shift in watershed hydrology associated with increasing active layer thickness. Further development of DOM optical indicators may serve as a novel and inexpensive tool for detecting permafrost degradation in northern watersheds.

  4. Linking High Frequency Variations in Stream Water DOC to Ages of Water Sources in Peat-Dominated Montane Watersheds

    NASA Astrophysics Data System (ADS)

    Tunaley, C.; Tetzlaff, D.; Lessels, J. S.; Soulsby, C.

    2015-12-01

    We combined time series of inferred DOC (from optical sensors) and stable isotopes in streams and watershed source areas to assess the link between water age and C fluxes. We monitored temporal dynamics of FDOM for 2 yrs at nested scales (0.9, 3.0 and 30km2) in a montane Scottish watershed. FDOM was strongly correlated (r2 ~ 0.8) with DOC allowing inference of 15 min timeseries. Marked seasonality was observed, with highest DOC concentrations (~25 mg l-1) in summer events and lower concentrations (~5mg l-1) in winter. During events, anticlockwise hysteresis was observed; consistent with expansion of the riparian saturation zone, increasing hydrological connectivity across peat soils and mobilizing DOC. Lag times for peak discharge and DOC were 1-12 hrs depending on event characteristics and antecedent conditions. Isotope time series from precipitation, streams and catchment source waters (overland flow and hillslope drainage) were also generated. These allowed us to model the non-stationary characteristics of their ages. Stream water age ranges from 3 months at high flows when overland flow dominates runoff to 4 yrs under baseflow. Overland flow age was a dominant influence on DOC transport. Highest concentrations occurred in small summer events with relatively young (<1 month old) overland flow waters generated after dry antecedent conditions, reflecting displacement of DOC-rich soil water. With wetting up in late summer/fall, overland flow is younger (< 1 week) diluting soil water DOC. Similar patterns occur across scales, though at 0.9km2 the dominance of a large peatland limits hysteresis, and maintains more constant DOC levels. At larger scales, DOC was more responsive but decreased more rapidly, reflecting a greater, but more transient influence of young overland flow. This shows the importance of riparian wetlands in regulating the quality and age of streams and the need to incorporate these sensitive areas in land management strategies.

  5. Subdaily Hydrologic Variability by Dams

    NASA Astrophysics Data System (ADS)

    Costigan, K. H.; Ruffing, C.; Smith, J. M.; Daniels, M. D.

    2012-12-01

    The effects dams have on hydrologic, geomorphic, and ecologic regimes has been well characterized using mean daily discharge. Subdaily discharge variation (herein flashiness) has not been well characterized for a variety of dam, watershed, and land cover characteristics. The hourly hydrologic records for 30 sites across the continental United States were analyzed for flashiness using the Richards-Baker Index, coefficient of daily variation, percent of total flow variation, and the percent of the year when daily discharge is greater than mean daily discharge. The goal of this analysis is to evaluate the role of catchment variables such as mean slope and land use conditions across receiving watersheds in predicting flashiness; compare flashiness metrics across sites to identify relationships between dam related variables such as type and size; and determine the most appropriate temporal extent for assessing flashiness in streamflow. Our approach relies on data at the watershed scale with a fine temporal grain to determine flashiness over a decade of operation for each dam.

  6. Age of dam and sex of calf adjustments and genetic parameters for gestation length in Charolais cattle.

    PubMed

    Crews, D H

    2006-01-01

    To estimate adjustment factors and genetic parameters for gestation length (GES), AI and calving date records (n = 40,356) were extracted from the Canadian Charolais Association field database. The average time from AI to calving date was 285.2 d (SD = 4.49 d) and ranged from 274 to 296 d. Fixed effects were sex of calf, age of dam (2, 3, 4, 5 to 10, > or = 11 yr), and gestation contemporary group (year of birth x herd of origin). Variance components were estimated using REML and 4 animal models (n = 84,332) containing from 0 to 3 random maternal effects. Model 1 (M1) contained only direct genetic effects. Model 2 (M2) was G1 plus maternal genetic effects with the direct x maternal genetic covariance constrained to zero, and model 3 (M3) was G2 without the covariance constraint. Model 4 (M4) extended G3 to include a random maternal permanent environmental effect. Direct heritability estimates were high and similar among all models (0.61 to 0.64), and maternal heritability estimates were low, ranging from 0.01 (M2) to 0.09 (M3). Likelihood ratio tests and parameter estimates suggested that M4 was the most appropriate (P < 0.05) model. With M4, phenotypic variance (18.35 d2) was partitioned into direct and maternal genetic, and maternal permanent environmental components (hd2 = 0.64 +/- 0.04, hm2 = 0.07 +/- 0.01, r(d,m) = -0.37 +/- 0.06, and c2 = 0.03 +/- 0.01, respectively). Linear contrasts were used to estimate that bull calves gestated 1.26 d longer (P < 0.02) than heifers, and adjustments to a mature equivalent (5 to 10 yr old) age of dam were 1.49 (P < 0.01), 0.56 (P < 0.01), 0.33 (P < 0.01), and -0.24 (P < 0.14) d for GES records of calves born to 2-, 3-, 4-, and > or = 11-yr-old cows, respectively. Bivariate animal models were used to estimate genetic parameters for GES with birth and adjusted 205-d weaning weights, and postweaning gain. Direct GES was positively correlated with direct birth weight (BWT; 0.34 +/- 0.04) but negatively correlated with maternal

  7. Paleoreconstruction of organic carbon inputs to an oxbow lake in the Mississippi River watershed: Effects of dam construction and land use change on regional inputs

    USGS Publications Warehouse

    Bianchi, Thomas S.; Galy, Valier; Rosenheim, Brad E.; Shields, Michael; Cui, Xingquan; Van Metre, Peter C.

    2015-01-01

    We use a dated sediment core from Lake Whittington (USA) in the lower Mississippi River to reconstruct linkages in the carbon cycling and fluvial sediment dynamics over the past 80 years. Organic carbon (OC) sources were characterized using bulk (δ13C, ramped pyrolysis-oxidation (PyrOx) 14C, δ15N, and TN:OC ratios) and compound-specific (lignin phenols and fatty acids, including δ13C and 14C of the fatty acids) analyses. Damming of the Missouri River in the 1950s, other hydrological modifications to the river, and soil conservation measures resulted in reduced net OC export, in spite of increasing OC concentrations. Decreasing δ13C values coincided with increases in δ15N, TN:OC ratios, long-chain fatty acids, and lignin-phenol concentrations, suggesting increased inputs of soil-derived OC dominated by C3 vegetation, mainly resulting from changes in farming practices and crop distribution. However, ramped PyrOx 14C showed no discernible differences downcore in thermochemical stability, indicating a limited impact on soil OC turnover.

  8. Paleoreconstruction of organic carbon inputs to an oxbow lake in the Mississippi River watershed: Effects of dam construction and land use change on regional inputs

    NASA Astrophysics Data System (ADS)

    Bianchi, Thomas S.; Galy, Valier; Rosenheim, Brad E.; Shields, Michael; Cui, Xingqian; Van Metre, Peter

    2015-10-01

    We use a dated sediment core from Lake Whittington (USA) in the lower Mississippi River to reconstruct linkages in the carbon cycling and fluvial sediment dynamics over the past 80 years. Organic carbon (OC) sources were characterized using bulk (δ13C, ramped pyrolysis-oxidation (PyrOx) 14C, δ15N, and TN:OC ratios) and compound-specific (lignin phenols and fatty acids, including δ13C and 14C of the fatty acids) analyses. Damming of the Missouri River in the 1950s, other hydrological modifications to the river, and soil conservation measures resulted in reduced net OC export, in spite of increasing OC concentrations. Decreasing δ13C values coincided with increases in δ15N, TN:OC ratios, long-chain fatty acids, and lignin-phenol concentrations, suggesting increased inputs of soil-derived OC dominated by C3 vegetation, mainly resulting from changes in farming practices and crop distribution. However, ramped PyrOx 14C showed no discernible differences downcore in thermochemical stability, indicating a limited impact on soil OC turnover.

  9. Evaporation Ponds or Recharge Structures ? the Role of Check Dams in Arkavathy River Basin, India

    NASA Astrophysics Data System (ADS)

    Jeremiah, K.; Srinivasan, V.; R, A.

    2014-12-01

    "Watershed development" has been the dominant paradigm for water management in India for the last two decades. Current spending on watershed development programmes rivals spending on large dams. In practice, watershed development involves a range of soil and water conservation measures including building check dams, gully plugs, contour bunds etc. Despite their dominance in water management paradigms, relatively little empirical data exists on these structures. Importantly, even though the benefits of individual watershed structures are recognized, the cumulative impact of building hundreds of such structures on hydrologic partitioning of a watershed remains unknown. We investigated the role of check dams in two small milli-watersheds in the Arkavathy River basin in South India. We conducted a comprehensive census of all check dams in the two milli-watersheds with a total area of 26 sq km. 40 check dams (representing a density of 1.35/sq km of watershed area) were geotagged, photographed, measured and their condition was recorded. We then selected twelve check dams and monitored the water stored using capacitance sensors. We also set up Automatic Weather Stations in each watershed. Inflows, evaporation and infiltration were calculated at each site to evaluate how check dams alter hydrologic partitioning in the watershed as a whole.

  10. 106. DAM EARTH DIKE SUBMERSIBLE DAMS & DIKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    106. DAM - EARTH DIKE - SUBMERSIBLE DAMS & DIKE CONN. AT MOVABLE DAM (ML-8-52/2-FS) March 1940 - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

  11. Deep Groundwater Contributions as a Primary Control on Stream Chemistry and Apparent Age in a Large Alpine Watershed in the Southern Rocky Mountains of Colorado

    NASA Astrophysics Data System (ADS)

    Frisbee, M. D.; Phillips, F. M.; Campbell, A. R.

    2008-12-01

    Considerable advances have been made in understanding runoff generation at small-scales yet our understanding of runoff generation in large watersheds greater than 1000 km2 remains poor. Small-scale runoff mechanisms are well documented in the literature including: overland flow, subsurface runoff, bypass flow, unsaturated flow, etc. Yet, despite the great variety in runoff mechanisms observed at the hillslope scale, chemical fluxes derived from runoff often become damped as the observed watershed scale increases. Hydrologists continue to explain this behavior using small-scale runoff mechanisms which are often related to shallow subsurface features or processes despite residence time studies which indicate that chemicals can be temporally persistent in watersheds. In doing so, we ignore the importance of deep groundwater contributions. As a matter of fact, recent studies seem to reject the "increasing deep groundwater" hypothesis whereby stream chemistry would continue to increase if the contributions from deep groundwater continue to increase and have instead embraced an "integration process hypothesis". This hypothesis suggests that variations in stream chemistry follow the central limit theorem as scale increases; large scatter at small scales and convergence on a median value as scale increases. A critical problem exists with the integration process hypothesis with regards to the contributions of deep groundwater to streamflow generation and its effect on residence times. For example, if a conservative chemical constituent in deep groundwater approaches some invariant concentration as scale increases, then it would follow that a conservative environmental tracer would approach an invariant apparent age since both processes reflect mixing. This implies that the apparent age of streamflow will become scale invariant. Current research in a large alpine watershed of the San Juan Mountains of southern Colorado suggests otherwise. Deep groundwater components in this

  12. Debris flows from failures Neoglacial-age moraine dams in the Three Sisters and Mount Jefferson wilderness areas, Oregon

    USGS Publications Warehouse

    O'Connor, J. E.; Hardison, J.H.; Costa, J.E.

    2001-01-01

    The highest concentration of lakes dammed by Neoglacial moraines in the conterminous United States is in the Mount Jefferson and Three Sisters Wilderness Areas in central Oregon. Between 1930 and 1980, breakouts of these lakes have resulted in 11 debris flows. The settings and sequences of events leading to breaching and the downstream flow behavior of the resulting debris flows provide guidance on the likelihood and magnitude of future lake breakouts and debris flows.

  13. Geophysical methods for the assessment of earthen dams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dams and levees are an integral part of the fluvial system in watersheds. Their stability is of utmost concern to the Nation and to those directly impacted should failure occur. There are some 88,000 dams and 110,000 miles of levees in the USA. Many of those are earthen embankments and structures su...

  14. 107. DAM EARTH DIKE SUBMERSIBLE DAMS PLANS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    107. DAM - EARTH DIKE - SUBMERSIBLE DAMS - PLANS & SECTIONS (ML-8-52/3-FS) March 1940 - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

  15. Preliminary estimates of residence times and apparent ages of ground water in the Chesapeake Bay watershed, and water-quality data from a survey of springs

    USGS Publications Warehouse

    Focazio, Michael J.; Plummer, L. Neil; Bohlke, John K.; Busenberg, Eurybiades; Bachman, L. Joseph; Powars, David S.

    1998-01-01

    Knowledge of the residence times of the ground-water systems in Chesapeake Bay watershed helps resource managers anticipate potential delays between implementation of land-management practices and any improve-ments in river and estuary water quality. This report presents preliminary estimates of ground-water residence times and apparent ages of water in the shallow aquifers of the Chesapeake Bay watershed. A simple reservoir model, published data, and analyses of spring water were used to estimate residence times and apparent ages of ground-water discharge. Ranges of aquifer hydraulic characteristics throughout the Bay watershed were derived from published literature and were used to estimate ground-water residence times on the basis of a simple reservoir model. Simple combinations of rock type and physiographic province were used to delineate hydrogeomorphic regions (HGMR?s) for the study area. The HGMR?s are used to facilitate organization and display of the data and analyses. Illustrations depicting the relation of aquifer characteristics and associated residence times as a continuum for each HGMR were developed. In this way, the natural variation of aquifer characteristics can be seen graphically by use of data from selected representative studies. Water samples collected in September and November 1996, from 46 springs throughout the watershed were analyzed for chlorofluorocarbons (CFC?s) to estimate the apparent age of ground water. For comparison purposes, apparent ages of water from springs were calculated assuming piston flow. Additi-onal data are given to estimate apparent ages assuming an exponential distribution of ages in spring discharge. Additionally, results from previous studies of CFC-dating of ground water from other springs and wells in the watershed were compiled. The CFC data, and the data on major ions, nutrients, and nitrogen isotopes in the water collected from the 46 springs are included in this report. The apparent ages of water

  16. Geomorphic evolution to large check-dam removal on a mountain river in Taiwan

    NASA Astrophysics Data System (ADS)

    Wang, H.; Kuo, W.

    2012-12-01

    As aging dams become obsolete or economically inefficient, dam removal has become an important aspect of river restoration in recent years. While various efforts are ongoing to enhance our understanding, studies documenting the physical and ecological responses to dam removal are still lacking, particularly for removal of large dams in mountain river and following major flood, where the size of watersheds and the amount of reservoir sediment released can be much greater than for most previously studied dam removals. This presentation documents the geomorphic evolution to removal of a large dam on a coarse-grained, steep (an order of magnitude greater than on the Marmot) mountain channel in Taiwan. The Chijiawan creek is the only habitat in Taiwan of the endangered Formosan landlocked salmon. Its habitat has been cut significantly since the 1960s following construction of check dams designed to prevent reservoir sedimentation downstream. The largest and lowermost barrier on Chijiawan creek is the 15m high, "No. 1 Check Dam" built in 1971. Forty years later, the dam had backfilled with about an estimated 0.2 million m3 sediment and its toe had been scoured about 4m below its foundation, raising a significant risk of dam failure. For these reasons, the Shei-Pa National Park removed the dam in late May 2011. To monitor the channel response to dam removal, we conducted surveys of grain size distributions, cross-sectional and longitudinal profiles, analyzed the stage and turbidity records, and carried out repeat photography. Channel changes were greatest immediately following removal as a result of the high stream power, steep energy slope, and unconsolidated alluvial fill behind the dam. Headcut propagation caused immediate removal of the sand-grade sediment and progressive channel widening. One month after dam removal, a minor flood event with the estimated peak discharge of 20 m3/s excavated a big wedge of sediment from the impoundment. Two months after dam removal

  17. Geomorphic impacts, age and significance of two giant landslide dams in the Nepal Himalayas: Ringmo-Phoksundo (Dolpo District) and Dhampu-Chhoya (Mustang District).

    NASA Astrophysics Data System (ADS)

    Fort, Monique; Braucher, Regis; Bourlès, Didier; Guillou, Valery; Nath Rimal, Lila; Gribenski, Natacha; Cossart, Etienne

    2014-05-01

    Large catastrophic slope failures have recently retained much attention in the northern dry Himalayas (1). They play a prominent role in the denudation history of active orogens at a wide range of spatial and time scales (2), and they impact durably landforms and process evolution in upstream catchments. Their occurrence mostly results from three different potential triggers: earthquakes, post-glacial debuttressing, and permafrost melting. We focus on two examples of giant rock slope failures that occurred across and north of the Higher Himalaya of Nepal and assess their respective influence on the regional, geomorphic evolution. The Ringmo rockslide (4.5 km3) results from the collapse of a mountain wall (5148 m) cut into palaeozoic dolomites of the Tethysian Himalayas. It caused the damming of the Suli Gad River at the origin of the Phoksumdo Lake (3600 m asl). The presence of glacial till at the very base of the sequence suggests the rockslide event is post-glacial, a field assumption confirmed by cosmogenic dating. Two consistent 36Cl ages of 20,885 ±1675 argue for a single, massive event of paraglacial origin that fits well with the last chronologies available on the Last Glacial Maximum in the Nepal Himalaya. The persistence of the Phoksumdo Lake is due to its dam stability (i.e. high lime content of landslide components) and to low sediment flux from the arid, upper Suli Gad catchment. The Dhampu-Chhoya rock avalanche (about 1 km3, area extent 10 km2) was derived from the northward failure of the Kaiku ridge, uphold by north-dipping, upper crystallines of the Higher Himalaya. It dammed the Kali Gandaki River, with complex interactions with the Late Pleistocene ice tongues derived from the Dhaulagiri (8167 m) and Nilgiris (7061 m) peaks. Both the rock avalanche and glaciers controlled the existence and level of the "Marpha Lake" (lacustrine deposits up to Kagbeni). Again, consistent 10Be ages of 29,680 ± 1015 ka obtained from two large blocks (>1000 m3

  18. Watershed Seasons

    ERIC Educational Resources Information Center

    Endreny, Anna

    2007-01-01

    All schools are located in "watersheds," land that drains into bodies of water. Some watersheds, like the one which encompasses the school discussed in this article, include bodies of water that are walking distance from the school. The watershed cited in this article has a brook and wetland within a several-block walk from the school. This…

  19. Modeling an ancient Iranian dam system

    NASA Astrophysics Data System (ADS)

    Ertsen, Maurits; De Schacht, Tijs

    2013-04-01

    In Iran, along the northern and eastern fringes of the Pasargadae plain, five dam remains from the Achaemenid period (550-330 BCE) present an important footprint of the human impact and reshaping of the region. The dams are predominantly found in dry wadi beds. In the framework of the Joint Iranian-French Archaeological Project at Pasargadae, these dam sites were studied and excavated. Located 22 km to the north of Pasargadae in a small wadi, the Sad-i Didegan dam has a watershed of circa 46 square km, small compared with catchments of other known Achaemenid dams. It is an earth built gravity dam of circa 90 m wide, 21 m high and with a crown length of about 150 m. In the lower body of the dam, remains of a feeder canal and an accessible control infrastructure at the downstream flank of the dam were found. To the northwest, the dam site of Sad-i Shahidabad can be found, another large Achaemenid dam, which stored water from the perennial river of the Rud-i Polvar. This dam also had a similar canal and control structure. Close to the Sad-i Didegan area is a large earthwork, found to cross the watershed divide between Didegan and Shahidabad, consisting of a wide V-shaped trench of remarkable size: up to 100 m wide, a total length of at least 900 m and a maximum present day depth of 7.5 m. Even though the construction of the system in this case clearly was left unfinished, the remains echo the major investment of available labor. Given the contemporaneity of both dam sites, it is clear evidence of the more regionally and elaborately planned character of the hydrological endeavors in the Pasargadae area. Only through further study and future fieldwork (also obtaining absolute dating material), this impressive feature will be fully understood. This contribution proposes a possible use of the two dam system using a modern control simulation model. This analysis will also shed light on the question why the system probably never functioned.

  20. Groundwater Quality, Age, and Probability of Contamination, Eagle River Watershed Valley-Fill Aquifer, North-Central Colorado, 2006-2007

    USGS Publications Warehouse

    Rupert, Michael G.; Plummer, L. Niel

    2009-01-01

    The Eagle River watershed is located near the destination resort town of Vail, Colorado. The area has a fastgrowing permanent population, and the resort industry is rapidly expanding. A large percentage of the land undergoing development to support that growth overlies the Eagle River watershed valley-fill aquifer (ERWVFA), which likely has a high predisposition to groundwater contamination. As development continues, local organizations need tools to evaluate potential land-development effects on ground- and surface-water resources so that informed land-use and water management decisions can be made. To help develop these tools, the U.S. Geological Survey (USGS), in cooperation with Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority, conducted a study in 2006-2007 of the groundwater quality, age, and probability of contamination in the ERWVFA, north-central Colorado. Ground- and surface-water quality samples were analyzed for major ions, nutrients, stable isotopes of hydrogen and oxygen in water, tritium, dissolved gases, chlorofluorocarbons (CFCs), and volatile organic compounds (VOCs) determined with very low-level laboratory methods. The major-ion data indicate that groundwaters in the ERWVFA can be classified into two major groups: groundwater that was recharged by infiltration of surface water, and groundwater that had less immediate recharge from surface water and had elevated sulfate concentrations. Sulfate concentrations exceeded the USEPA National Secondary Drinking Water Regulations (250 milligrams per liter) in many wells near Eagle, Gypsum, and Dotsero. The predominant source of sulfate to groundwater in the Eagle River watershed is the Eagle Valley Evaporite, which is a gypsum deposit of Pennsylvanian age located predominantly in the western one-half of Eagle County.

  1. The effect of age at separation from the dam and presence of social companions on play behavior and weight gain in dairy calves.

    PubMed

    Valníčková, B; Stěhulová, I; Šárová, R; Špinka, M

    2015-08-01

    Play behavior positively affects welfare of farm animals, yet impoverished social environment during early ontogeny may limit the opportunity or motivation to play. This study investigated the independent and the combined effects of the presence of the dam during the colostrum feeding period and subsequent group housing on play behavior and growth in dairy calves. Forty female calves were allocated to 1 of 4 treatments according to a 2×2 factorial design. The treatments were with or without mother during the 4d after birth and companion housing (single pens or grouped housing in pens of 4 calves between 1 and 8wk of age). After 8wk of age all calves were housed in groups of 4 calves. Play behavior of the calves was observed at 2, 5, and 12wk of age in the following situations: 6 h of spontaneous behavior in the home pen, a 15-min open-field test, and a 15-min social test with an unfamiliar calf. Additionally, play behavior after grouping or relocation at 8wk of age was recorded during two 2-h sessions. There were no significant effects of the mother by companion interaction either on the amount of play behavior in any of the tests or on the body weights of the calves. Presence of the mother after birth did not increase later playfulness, with the exception of higher spontaneous play at 12wk of age. When calves were housed in groups of 4, they played more in the home pen on wk 2 and 5 than individually housed calves of the same age. In contrast, individually housed calves were more playful during open-field tests and social tests on wk 2 and 5. At 8wk, single calves that were placed in a new pen with 3 unfamiliar calves played more than twice as much as grouped calves that were just moved to a new pen with familiar companions. These results show that single-housed calves are deprived of natural levels of play, as demonstrated by both their lower spontaneous play behavior and the higher rebound effect when they are exposed to larger spaces or larger spaces plus

  2. A Whole-Genome Screen of a Quantitative Trait of Age-Related Maculopathy in Sibships from the Beaver Dam Eye Study

    PubMed Central

    Schick, James H.; Iyengar, Sudha K.; Klein, Barbara E.; Klein, Ronald; Reading, Karlie; Liptak, Rachel; Millard, Christopher; Lee, Kristine E.; Tomany, Sandra C.; Moore, Emily L.; Fijal, Bonnie A.; Elston, Robert C.

    2003-01-01

    Age-related maculopathy (ARM) is a leading cause of visual impairment among the elderly in Western populations. To identify ARM-susceptibility loci, we genotyped a subset of subjects from the Beaver Dam (WI) Eye Study and performed a model-free genomewide linkage analysis for markers linked to a quantitative measure of ARM. We initially genotyped 345 autosomal markers in 325 individuals (N=263 sib pairs) from 102 pedigrees. Ten regions suggestive of linkage with ARM were observed on chromosomes 3, 5, 6, 12, 15, and 16. Prior to fine mapping, the most significant regions were an 18-cM region on chromosome 12, near D12S1300 (P=.0159); a region on chromosome 3, near D3S1763, with a P value of .0062; and a 6-cM region on chromosome 16, near D16S769, with a P value of .0086. After expanding our analysis to include 25 additional fine-mapping markers, we found that a 14-cM region on chromosome 12, near D12S346 (located at 106.89 cM), showed the strongest indication of linkage, with a P value of .004. Three other regions, on chromosomes 5, 6, and 15, that were nominally significant at P⩽.01 are also appropriate for fine mapping. PMID:12717633

  3. Global phosphorus retention by river damming.

    PubMed

    Maavara, Taylor; Parsons, Christopher T; Ridenour, Christine; Stojanovic, Severin; Dürr, Hans H; Powley, Helen R; Van Cappellen, Philippe

    2015-12-22

    More than 70,000 large dams have been built worldwide. With growing water stress and demand for energy, this number will continue to increase in the foreseeable future. Damming greatly modifies the ecological functioning of river systems. In particular, dam reservoirs sequester nutrient elements and, hence, reduce downstream transfer of nutrients to floodplains, lakes, wetlands, and coastal marine environments. Here, we quantify the global impact of dams on the riverine fluxes and speciation of the limiting nutrient phosphorus (P), using a mechanistic modeling approach that accounts for the in-reservoir biogeochemical transformations of P. According to the model calculations, the mass of total P (TP) trapped in reservoirs nearly doubled between 1970 and 2000, reaching 42 Gmol y(-1), or 12% of the global river TP load in 2000. Because of the current surge in dam building, we project that by 2030, about 17% of the global river TP load will be sequestered in reservoir sediments. The largest projected increases in TP and reactive P (RP) retention by damming will take place in Asia and South America, especially in the Yangtze, Mekong, and Amazon drainage basins. Despite the large P retention capacity of reservoirs, the export of RP from watersheds will continue to grow unless additional measures are taken to curb anthropogenic P emissions.

  4. Global phosphorus retention by river damming

    PubMed Central

    Maavara, Taylor; Parsons, Christopher T.; Ridenour, Christine; Stojanovic, Severin; Dürr, Hans H.; Powley, Helen R.; Van Cappellen, Philippe

    2015-01-01

    More than 70,000 large dams have been built worldwide. With growing water stress and demand for energy, this number will continue to increase in the foreseeable future. Damming greatly modifies the ecological functioning of river systems. In particular, dam reservoirs sequester nutrient elements and, hence, reduce downstream transfer of nutrients to floodplains, lakes, wetlands, and coastal marine environments. Here, we quantify the global impact of dams on the riverine fluxes and speciation of the limiting nutrient phosphorus (P), using a mechanistic modeling approach that accounts for the in-reservoir biogeochemical transformations of P. According to the model calculations, the mass of total P (TP) trapped in reservoirs nearly doubled between 1970 and 2000, reaching 42 Gmol y−1, or 12% of the global river TP load in 2000. Because of the current surge in dam building, we project that by 2030, about 17% of the global river TP load will be sequestered in reservoir sediments. The largest projected increases in TP and reactive P (RP) retention by damming will take place in Asia and South America, especially in the Yangtze, Mekong, and Amazon drainage basins. Despite the large P retention capacity of reservoirs, the export of RP from watersheds will continue to grow unless additional measures are taken to curb anthropogenic P emissions. PMID:26644553

  5. Global phosphorus retention by river damming.

    PubMed

    Maavara, Taylor; Parsons, Christopher T; Ridenour, Christine; Stojanovic, Severin; Dürr, Hans H; Powley, Helen R; Van Cappellen, Philippe

    2015-12-22

    More than 70,000 large dams have been built worldwide. With growing water stress and demand for energy, this number will continue to increase in the foreseeable future. Damming greatly modifies the ecological functioning of river systems. In particular, dam reservoirs sequester nutrient elements and, hence, reduce downstream transfer of nutrients to floodplains, lakes, wetlands, and coastal marine environments. Here, we quantify the global impact of dams on the riverine fluxes and speciation of the limiting nutrient phosphorus (P), using a mechanistic modeling approach that accounts for the in-reservoir biogeochemical transformations of P. According to the model calculations, the mass of total P (TP) trapped in reservoirs nearly doubled between 1970 and 2000, reaching 42 Gmol y(-1), or 12% of the global river TP load in 2000. Because of the current surge in dam building, we project that by 2030, about 17% of the global river TP load will be sequestered in reservoir sediments. The largest projected increases in TP and reactive P (RP) retention by damming will take place in Asia and South America, especially in the Yangtze, Mekong, and Amazon drainage basins. Despite the large P retention capacity of reservoirs, the export of RP from watersheds will continue to grow unless additional measures are taken to curb anthropogenic P emissions. PMID:26644553

  6. Floodplain Hyporheic Response under Dam Release Hydrographs

    NASA Astrophysics Data System (ADS)

    Zhou, T.; Ward, A. S.; O'Connor, B. L.; Endreny, T. A.

    2012-12-01

    Hydropower operations cause altered hydrograph patterns downstream of dams, which regulates the direction and magnitude of floodplain and riverbed hyporheic flux. Periodic adjustments in river stage changes temporal and spatial patterns in hydraulic pressure, initiates propagation of lateral and vertical hyporheic flux, and affects the riparian ecological system by changing the hyporheic penetration distance, hyporheic flux rate, and thermal conditions in river banks. While this issue has been largely neglected by watershed scientists and managers, there is the potential to use hyporheic metrics in setting dam release rules and restoring downstream river reaches. In order to evaluate the hyporheic feedbacks of various dam release patterns, this study applied a computational fluid dynamics (CFD) model to simulate the interaction of open water hydrographs on porous media lateral hyporheic exchange for the Green River, Utah, downstream of Flaming Gorge Dam. The CFD initially represented the river as a straight channel with a thick porous media extending from the channel banks and bottom. The dam release hydrographs changed the patterns of hyporheic flux at the river banks, the penetration distance of the hyporheic flux, the subsurface thermal patterns, and the residence time of water in the subsurface. The results suggest the undulating river stage downstream of dam releases can initiate patterns of hyporheic exchange similar to those induced by restoration of river bed morphology.

  7. DAM Safety and Deformation Monitoring in Dams

    NASA Astrophysics Data System (ADS)

    Kalkan, Y.; Bilgi, S.; Potts, L.; Miiama, J.; Mahgoub, M.; Rahman, S.

    2013-12-01

    Water is the life and necessity to water is increasing day by day with respect to the World population, rising of living standards and destruction of nature. Thus, the importance of water and water structures have been increasing gradually. Dams are among the most important engineering structures used for water supplies, flood controls, agricultural purposes as well as drinking and hydroelectric power. There are about 150.000 large size dams in the World. Especially after the Second World War, higher and larger capacity dams have been constructed. Dams create certain risks like the other manmade structures. No one knows precisely how many dam failures have occurred in the World, whereas hundreds of dam failures have occurred throughout the U.S. history. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. These physical data are measured and monitored by the instruments and equipment. Dams and their surroundings have to be monitored by using essential methods at periodic time intervals in order to determine the possible changes that may occur over the time. Monitoring programs typically consist of; surveillance or visual observation. These programs on dams provide information for evaluating the dam's performance related to the design intent and expected changes that could affect the safety performance of the dam. Additionally, these programs are used for investigating and evaluating the abnormal or degrading performance where any remedial action is necessary. Geodetic and non-geodetic methods are used for monitoring. Monitoring the performance of the dams is critical for producing and maintaining the safe dams. This study provides some information, safety and the techniques about the deformation monitoring of the

  8. Watershed Investigations

    ERIC Educational Resources Information Center

    Bodzin, Alec; Shive, Louise

    2004-01-01

    Investigating local watersheds presents middle school students with authentic opportunities to engage in inquiry and address questions about their immediate environment. Investigation activities promote learning in an investigations interdisciplinary context as students explore relationships among chemical, biological, physical, geological, and…

  9. Baseline studies in the Elwha River ecosystem prior to dam removal: Introduction to the special issue

    USGS Publications Warehouse

    Duda, Jeffrey J.; Freilich, Jerry; Schreiner, Edward G.

    2008-01-01

    The planned removal of two dams that have been in place for over 95 years on the Elwha River provides a unique opportunity to study dam removal effects. Among the largest dams ever considered for removal, this project is compelling because 83% of the watershed lies undisturbed in Olympic National Park. Eighteen million cubic meters of sediment have accumulated in and will be released from the reservoirs, and there is potential for rehabilitating depressed Pacific salmon runs. Researchers from academia, non-profit organizations, federal and state governments, and the Lower Elwha Klallam Tribe are currently assessing baseline ecological conditions of the Elwha River as part of dam removal studies. We introduce dam removal topics, provide a brief history of the dams, and summarize the ecology of the Elwha River basin as an introduction to a special issue devoted to research in the watershed.

  10. Research and design of Renwick Dam stepped spillway

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The United States Department of Agricultural (USDA) Natural Resources Conservation Service (NRCS) has financially and technically assisted with the construction of nearly 11,000 small watershed dams in the U.S. By 2017, half of these structures will reach the end of their planned service life due t...

  11. Focusing on dam safety

    SciTech Connect

    Lagassa, G.

    1993-01-01

    With increased relicensing activity and a federal emphasis on safety, dam repair and refurbishment is a growing business. Providers of goods and services are gearing up to meet the dam repair and rehabilitation needs that result.

  12. Correlation of bulk sedimentary and compound-specific δ13C values indicates minimal pre-aging of n-alkanes in a small tropical watershed

    NASA Astrophysics Data System (ADS)

    Lane, Chad S.; Horn, Sally P.; Taylor, Zachary P.; Kerr, Matthew T.

    2016-08-01

    Inherent to sedimentary compound-specific isotopic proxies of paleoecological and paleoclimate change is the assumption that biomarkers are coeval with the surrounding sedimentary matrix. Compound-specific radiocarbon analyses of lake and nearshore marine sediments have indicated a potential offset between the ages of terrestrial biomarkers and their surrounding sediments that could confound efforts to establish strong chronological control for compound-specific isotopic data. We conducted high-resolution compound-specific δ13C analyses of n-alkanes (δ13Calkane) in a well-studied sediment core from Laguna Castilla, Dominican Republic, and compared the results to bulk sedimentary δ13C (δ13Cbulk), fossil pollen, and sediment geochemistry to assess potential 'pre-aging' of alkanes in the terrestrial environment prior to deposition. We found significant positive correlations between δ13Cbulk values and δ13Calkane values, indicating little or no temporal lag in the response of δ13Calkane values to vegetation change and thus little or no offset in the age of terrestrially-derived compounds and the organic fraction of the sedimentary matrix. While this study highlights the need for further research into the variables affecting age offsets between proxy data, we propose the comparison of δ13Cbulk and δ13Calkane values as a method to assess potential age offsets between compound-specific and other proxy datasets, particularly in small watersheds with sediment records containing a high proportion of allochthonous organic matter. This method is more available to researchers than obtaining numerous compound-specific radiocarbon analyses, which are costly and not a routine service offered by radiocarbon facilities.

  13. Hoover Dam Learning Packet.

    ERIC Educational Resources Information Center

    Bureau of Reclamation (Dept. of Interior), Washington, DC.

    This learning packet provides background information about Hoover Dam (Nevada) and the surrounding area. Since the dam was built at the height of the Depression in 1931, people came from all over the country to work on it. Because of Hoover Dam, the Colorado River was controlled for the first time in history and farmers in Nevada, California, and…

  14. Chemistry and age of groundwater in bedrock aquifers of the Piceance and Yellow Creek watersheds, Rio Blanco County, Colorado, 2010-12

    USGS Publications Warehouse

    McMahon, P.B.; Thomas, J.C.; Hunt, A.G.

    2013-01-01

    Fourteen monitoring wells completed in the Uinta and Green River Formations in the Piceance Creek and Yellow Creek watersheds in Rio Blanco County, Colorado, were sampled for chemical, isotopic, and groundwater-age tracers to provide information on the overall groundwater quality, the occurrence and distribution of chemicals that could be related to the development of underlying natural-gas reservoirs, and to better understand groundwater residence times in the flow system. Methane concentrations in groundwater ranged from less than 0.0005 to 387 milligrams per liter. The methane was predominantly biogenic in origin, although the biogenic methane was mixed with thermogenic methane in water from seven wells. Three BTEX compounds (benzene, toluene, and ethylbenzene) were detected in water from six of the wells, but none of the concentrations exceeded Federal drinking-water standards. The presence of thermogenic methane in the aquifers indicates a connection and vulnerability to chemicals in deeper geologic units. Helium-4 data indicate that groundwater had ages ranging from less than 1,000 years to greater than 50,000 years. The presence of old groundwater in parts of the aquifers indicates that these aquifers may not be useful for large-scale water supply because of low recharge rates.

  15. Modelling global nutrient retention by river damming: Phosphorus and silicon

    NASA Astrophysics Data System (ADS)

    Maavara, Taylor; Dürr, Hans; Van Cappellen, Philippe

    2014-05-01

    The phosphorus to silicon (P:Si) nutrient ratio is a key variable affecting ecosystem health in many aquatic environments. River damming represents a major anthropogenic perturbation of natural material flows along the aquatic continuum, with the potential to profoundly modify absolute and relative nutrient availabilities in surface waters. In this study, a multi-tiered approach for estimating global nutrient retention in man-made reservoirs is presented. We illustrate its application to the global riverine flux of reactive Si, using a database of dissolved reactive Si (DSi) budgets for 24 natural lakes and 22 artificial reservoirs. The database includes information on bedrock geology, surface water pH, water residence time, reservoir age and function, climate, and trophic status. Statistical analyses (ANOVA, t-test, PCA, linear plus non-linear regressions) are used to identify the best predictors of DSi retention and delineate how reservoir properties modulate nutrient dynamics. Results indicate that (1) reservoirs retain significantly less DSi than natural lakes, and (2) the water residence time, reservoir age and function (e.g., hydroelectrical production, irrigation, flood control) are the main system variables controlling DSi retention by dams. Next, a biogeochemical Si model is used to reproduce the previously derived statistical trends for DSi retention. Calibration of the model yields a relationship that enables one to predict annual in-reservoir siliceous productivity as a function of the external reactive Si supply. The model further accounts for the transition from reservoirs where reactive Si retention is primarily due to burial of allochtonous Si to those where in-reservoir DSi uptake by diatoms dominates. Finally, the statistical and mechanistic relationships are extrapolated to estimate that 25-28 Tg SiO2 yr-1 are retained worldwide by dams, or 7% of the annual reactive Si load to watersheds. We are currently applying the same multi-tiered approach

  16. Watershed Science.

    ERIC Educational Resources Information Center

    Green, Tom

    1996-01-01

    Presents activities from an interdisciplinary project studying local watersheds that incorporate a broad spectrum of disciplines including science, math, geography, English, computer science, and political science. Enables students to understand how precipitation changes chemically as it interacts with the soils and human-altered landscape as it…

  17. Ecosystem Response During the Removal of the Elwha River Dams

    NASA Astrophysics Data System (ADS)

    Pess, G. R.; McHenry, M.; Liermann, M. C.; Moses, R.; Denton, K.; McMillan, J.; Brenkman, S.; Duda, J.; Peters, R.; Anderson, J.; Quinn, T.

    2015-12-01

    Over the last century, the two dams blocked the upstream movement of anadromous fish to over 90% of the Elwha River watershed on the Olympic Peninsula of Washington State. These dams also restricted the downstream movement of sediment, wood, and other organic materials to the lower river and estuary. Populations of all Pacific salmon species and steelhead in the Elwha became critically low, habitat complexity decreased below the dams, and downstream coastal habitats became sediment starved. Simultaneous deconstruction of the two dams began in September 2011 was completed in September of 2014. The recent removal of the dams has been an opportunity to explore linkages among changes in sediment supply, salmonid populations, and ecosystem attributes. Preliminary findings focus on the delivery of millions of metric tonnes of sediment to the main river, its floodplain, and nearshore, the re-establishment of a natural wood delivery regime, the re-colonization of the upper watershed by anadromous fish, insights into functional relationships among salmonid populations and life history strategies, and the associated effects of all these elements on the aquatic and terrestrial foodwebs. This talk will provide an overview of the Elwha restoration project, and highlight recent changes observed during dam removal.

  18. Sediment Budgeting in Dam-Affected Rivers: Assessing the Influence of Damming, Tributaries, and Alluvial Valley Sediment Storage on Sediment Regimes

    NASA Astrophysics Data System (ADS)

    Wilcox, A. C.; Dekker, F. J.; Riebe, C. S.

    2014-12-01

    Although sediment supply is recognized as a fundamental driver of fluvial processes, measuring how dams affect sediment regimes and incorporating such knowledge into management strategies remains challenging. To determine the influences of damming, tributary supply, and valley morphology and sediment storage on downstream sediment supply in a dryland river, the Bill Williams River (BWR) in western Arizona, we measured basin erosion rates using cosmogenic nuclide analysis of beryllium-10 (10Be) at sites upstream and downstream of a dam along the BWR, as well as from tributaries downstream of the dam. Riverbed sediment mixing calculations were used to test if the dam, which blocks sediment supply from the upper 85% of the basin's drainage area, increases the proportion of tributary sediment to residual upstream sediment in mainstem samples downstream of the dam. Erosion rates in the BWR watershed are more than twice as large in the upper catchment (136 t km-2 yr-1) than in tributaries downstream of Alamo Dam (61 t km-2 yr-1). Tributaries downstream of the dam have little influence on mainstem sediment dynamics. The effect of the dam on reducing sediment supply is limited, however, because of the presence of large alluvial valleys along the mainstem BWR downstream of the dam that store substantial sediment and mitigate supply reductions from the upper watershed. These inferences, from our 10Be derived erosion rates and mixing calculations, are consistent with field observations of downstream changes in bed material size, which suggest that sediment-deficit conditions are restricted to a 10 km reach downstream of the dam, and limited reservoir bathymetry data. Many studies have suggested that tributary sediment inputs downstream of dams play a key role in mitigating dam-induced sediment deficits, but here we show that in a dryland river with ephemeral tributaries, sediment stored in alluvial valleys can also play a key role and in some cases trumps the role of

  19. Loess Plateau check dams can potentially sequester eroded soil organic carbon

    NASA Astrophysics Data System (ADS)

    Zhang, Haicheng; Liu, Shuguang; Yuan, Wenping; Dong, Wenjie; Xia, Jiangzhou; Cao, Yaojun; Jia, Yanwei

    2016-06-01

    Check dams are special soil and water conservation structures in the Loess Plateau, China. They play an important role in intercepting sediments and soil organic carbon (SOC). However, the decomposition of intercepted SOC and the environmental regulations at check dams have not been investigated. We conducted several paired field experiments at both check dams and slope lands in the Yanhe Watershed of the Loess Plateau to examine the characteristics of SOC decomposition at check dams. On average, the SOC mineralization rate in slope lands was approximately three times higher than in check dams. Increased soil moisture and compaction in check dams can constrain carbon mineralization by limiting the oxygen availability of SOC and can isolate substrate carbon from heterotrophic microorganisms. Our results indicate that check dams display a considerable potential for eroded SOC sequestration via reducing the soil respiration rate and highlight the important implications of lateral carbon redistribution and human engineering projects when estimating regional or global ecosystem carbon cycles.

  20. PERSPECTIVE ON LANDSLIDE DAMS.

    USGS Publications Warehouse

    Schuster, Robert L.; Costa, John E.; ,

    1986-01-01

    The most common types of mass movements that form landslide dams are rock and soil slumps and slides; mud, debris, and earth flows: and rock and debris avalanches. The most common initiation mechanisms for dam-forming landslides are excessive rainfall and snow melt, and earthquakes. Most landslide dams are remarkable short-lived. In a sample of 63 documented cases, 22 percent of the landslide dams failed in less than 1 day after formation, and half failed within 10 days. Overtopping was by far the most frequent cause of landslide-dam failure. Backwater flooding behind landslide dams can inundate communities and valuable agricultural land. Floods from the failure of landslide dams are smaller than floods from constructed dams impounding bodies of water with the same potential energy, but larger than floods from failure of ice dams. Secondary effects of landslide-dam failures include additional landslides as reservoir levels drop rapidly, aggradation of valleys upstream and downstream of the dams, and avulsive channel changes downstream.

  1. Optimizing the Dammed: water supply losses and fish habitat gains from dam removal in California

    NASA Astrophysics Data System (ADS)

    Null, S. E.; Medellin-Azuara, J.; Lund, J. R.

    2012-12-01

    Dams provide water supply, flood protection, and hydropower generation benefits, but have also harmed native species by altering the natural flow regime and degrading aquatic and riparian habitat. Restoring some river reaches to free-flowing conditions may restore substantial environmental benefits, but at some economic cost. This study uses a systems analysis approach to evaluate removing rim dams in California's Central Valley to highlight dams that could be removed as well as existing dams that are most beneficial for providing water supply and hydropower benefits. CALVIN, an economic-engineering optimization model was used to evaluate water storage and scarcity from removing dams. A warm and dry climate model (GFDL CM2.1 A2 emissions scenario) for a 30 year period centered at 2085, and double population scenario for year 2050 water demands represent future conditions. Tradeoffs between water scarcity to urban, agricultural, and instream flow requirements were compared with additional river miles accessible to anadromous species following dam removal. Results show that existing infrastructure is most beneficial if operated as a system (ignoring many current political and institutional constraints). Removing all rim dams is not beneficial for California, but a subset of existing dams are potentially promising candidates for removal from an optimized water supply and free-flowing river perspective. Incorporating environmental considerations into decision-making may lead to better solutions than focusing only on human benefits such as water supply, flood protection, hydropower generation, and recreation. Similarly, improving environmental flows can come at substantially lower economic cost, when viewed and operated as a system.Ratio of Surface Storage to Mean Annual Flow by Watershed

  2. Estimating Age Distributions of Base Flow in Watersheds Underlain by Single and Dual Porosity Formations Using Groundwater Transport Simulation and Weighted Weibull Functions

    NASA Astrophysics Data System (ADS)

    Sanford, W. E.

    2015-12-01

    Age distributions of base flow to streams are important to estimate for predicting the timing of water-quality responses to changes in distributed inputs of nutrients or pollutants at the land surface. Simple models of shallow aquifers will predict exponential age distributions, but more realistic 3-D stream-aquifer geometries will cause deviations from an exponential curve. In addition, in fractured rock terrains the dual nature of the effective and total porosity of the system complicates the age distribution further. In this study shallow groundwater flow and advective transport were simulated in two regions in the Eastern United States—the Delmarva Peninsula and the upper Potomac River basin. The former is underlain by layers of unconsolidated sediment, while the latter consists of folded and fractured sedimentary rocks. Transport of groundwater to streams was simulated using the USGS code MODPATH within 175 and 275 watersheds, respectively. For the fractured rock terrain, calculations were also performed along flow pathlines to account for exchange between mobile and immobile flow zones. Porosities at both sites were calibrated using environmental tracer data (3H, 3He, CFCs and SF6) in wells and springs, and with a 30-year tritium record from the Potomac River. Carbonate and siliciclastic rocks were calibrated to have mobile porosity values of one and six percent, and immobile porosity values of 18 and 12 percent, respectively. The age distributions were fitted to Weibull functions. Whereas an exponential function has one parameter that controls the median age of the distribution, a Weibull function has an extra parameter that controls the slope of the curve. A weighted Weibull function was also developed that potentially allows for four parameters, two that control the median age and two that control the slope, one of each weighted toward early or late arrival times. For both systems the two-parameter Weibull function nearly always produced a substantially

  3. Earthquake-dammed lakes in New Zealand

    SciTech Connect

    Adams, J.

    1981-05-01

    Eleven small lakes were formed by landslides caused by the 1929 Buller earthquake; four others were formed by other historic earthquakes in New Zealand. At least nine other New Zealand lakes are also dammed by landslides and were probably formed by prehistoric earthquakes. When recognized by morphology, synchronous age, and areal distribution, earthquake-dammed lakes could provide an estimate of paleoseismicity for the past few hundred or thousand years.

  4. 16. Parker Dam, only top fourth of dam visible, at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Parker Dam, only top fourth of dam visible, at 320' high, Parker Dam is one of the highest in the world. Much of this height is because dam penetrates well below river bottom to fasten to bedrock. - Parker Dam, Spanning Colorado River between AZ & CA, Parker, La Paz County, AZ

  5. Population density, biomass, and age-class structure of the invasive clam Corbicula fluminea in rivers of the lower San Joaquin River watershed, California

    USGS Publications Warehouse

    Brown, L.R.; Thompson, J.K.; Higgins, K.; Lucas, L.V.

    2007-01-01

    Corbicula fluminea is well known as an invasive filter-feeding freshwater bivalve with a variety of effects on ecosystem processes. However. C. fluminea has been relatively unstudied in the rivers of the western United States. In June 2003, we sampled C. fluminea at 16 sites in the San Joaquin River watershed of California, which was invaded by C. fluminea in the 1940s. Corbicula fluminea was common in 2 tributaries to the San Joaquin River, reaching densities of 200 clams??m-2, but was rare in the San Joaquin River. Biomass followed a similar pattern. Clams of the same age were shorter in the San Joaquin River than in the tributaries. Distribution of clams was different in the 2 tributaries, but the causes of the difference are unknown. The low density and biomass of clams in the San Joaquin River was likely due to stressful habitat or to water quality, because food was abundant. The success of C. fluminea invasions and subsequent effects on trophic processes likely depends on multiple factors. As C. fluminea continues to expand its range around the world, questions regarding invasion success and effects on ecosystems will become important in a wide array of environmental settings.

  6. Evaluation of high-frequency mean streamwater transit-time estimates using groundwater age and dissolved silica concentrations in a small forested watershed

    USGS Publications Warehouse

    Peters, Norman E.; Burns, Douglas A.; Aulenbach, Brent T.

    2014-01-01

    Many previous investigations of mean streamwater transit times (MTT) have been limited by an inability to quantify the MTT dynamics. Here, we draw on (1) a linear relation (r 2 = 0.97) between groundwater 3H/3He ages and dissolved silica (Si) concentrations, combined with (2) predicted streamwater Si concentrations from a multiple-regression relation (R 2 = 0.87) to estimate MTT at 5-min intervals for a 23-year time series of streamflow [water year (WY) 1986 through 2008] at the Panola Mountain Research Watershed, Georgia. The time-based average MTT derived from the 5-min data was ~8.4 ± 2.9 years and the volume-weighted (VW) MTT was ~4.7 years for the study period, reflecting the importance of younger runoff water during high flow. The 5-min MTTs are normally distributed and ranged from 0 to 15 years. Monthly VW MTTs averaged 7.0 ± 3.3 years and ranged from 4 to 6 years during winter and 8–10 years during summer. The annual VW MTTs averaged 5.6 ± 2.0 years and ranged from ~5 years during wet years (2003 and 2005) to >10 years during dry years (2002 and 2008). Stormflows are composed of much younger water than baseflows, and although stormflow only occurs ~17 % of the time, this runoff fraction contributed 39 % of the runoff during the 23-year study period. Combining the 23-year VW MTT (including stormflow) with the annual average baseflow for the period (~212 mm) indicates that active groundwater storage is ~1,000 mm. However, the groundwater storage ranged from 1,040 to 1,950 mm using WY baseflow and WY VW MTT. The approach described herein may be applicable to other watersheds underlain by granitoid bedrock, where weathering is the dominant control on Si concentrations in soils, groundwater, and streamwater.

  7. Hydrologic response of streams restored with check dams in the Chiricahua Mountains, Arizona

    USGS Publications Warehouse

    Norman, Laura M.; Brinkerhoff, Fletcher C.; Gwilliam, Evan; Guertin, D. Phillip; Callegary, James B.; Goodrich, David C.; Nagler, Pamela L.; Gray, Floyd

    2016-01-01

    In this study, hydrological processes are evaluated to determine impacts of stream restoration in the West Turkey Creek, Chiricahua Mountains, southeast Arizona, during a summer-monsoon season (June–October of 2013). A paired-watershed approach was used to analyze the effectiveness of check dams to mitigate high flows and impact long-term maintenance of hydrologic function. One watershed had been extensively altered by the installation of numerous small check dams over the past 30 years, and the other was untreated (control). We modified and installed a new stream-gauging mechanism developed for remote areas, to compare the water balance and calculate rainfall–runoff ratios. Results show that even 30 years after installation, most of the check dams were still functional. The watershed treated with check dams has a lower runoff response to precipitation compared with the untreated, most notably in measurements of peak flow. Concerns that downstream flows would be reduced in the treated watershed, due to storage of water behind upstream check dams, were not realized; instead, flow volumes were actually higher overall in the treated stream, even though peak flows were dampened. We surmise that check dams are a useful management tool for reducing flow velocities associated with erosion and degradation and posit they can increase baseflow in aridlands.

  8. Watersheds: Where We Live.

    ERIC Educational Resources Information Center

    Vandas, Steve

    1997-01-01

    Presents information about watersheds including water quantity, water quality, floods and floodplains. Lists resources for learning more about watersheds as well as Internet resources. Includes a foldout that can be used to teach children about watersheds and floodplains. (JRH)

  9. Divergent patterns of abundance and age-class structure of headwater stream tadpoles in burned and unburned watersheds

    USGS Publications Warehouse

    Hossack, B.R.; Corn, P.S.; Fagre, D.B.

    2006-01-01

    Wildfire is a potential threat to many species with narrow environmental tolerances like the Rocky Mountain tailed frog (Ascaphus montanus Mittleman and Myers, 1949), which inhabits a region where the frequency and intensity of wildfires are expected to increase. We compared pre- and post-fire counts of tadpoles in eight streams in northwestern Montana to determine the effects of wildfire on A. montanus. All streams were initially sampled in 2001, 2 years before four of them burned in a large wildfire, and were resampled during the 2 years following the fire. Counts of tadpoles were similar in the two groups of streams before the fire. After the fire, tadpoles were almost twice as abundant in unburned streams than in burned streams. The fire seemed to have the greatest negative effect on abundance of age-1 tadpoles, which was reflected in the greater variation in same-stream age-class structure compared with those in unburned streams. Despite the apparent effect on tadpoles, we do not expect the wildfire to be an extirpation threat to populations in the streams that we sampled. Studies spanning a chronosequence of fires, as well as in other areas, are needed to assess the effects of fires on streams with A. montanus and to determine the severity and persistence of these effects.

  10. 9. Excavation work at Pleasant Dam (now called Waddell Dam). ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Excavation work at Pleasant Dam (now called Waddell Dam). Photographer unknown, July, 22, 1926. Source: Maricopa County Municipal Water Conservation District Number One (MWD). - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  11. 51. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM -- TAINTER GATE -- GENERAL ARRANGEMENT. M-L 26(R) 45/1 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

  12. River Restoration by Dam Removal: Assessing Riverine Re-Connectivity Across New England

    NASA Astrophysics Data System (ADS)

    Magilligan, F. J.; Nislow, K. H.; Graber, B.; Sneddon, C.; Fox, C.; Martin, E.

    2014-12-01

    The impacts of dams in New England are especially acute as it possesses one of the highest densities of dams in the US, with the NID documenting more than 4,000 dams, and state agency records indicating that >14,000 dams are peppered throughout the landscape. This large number of dams contributes to pervasive watershed fragmentation, threatening the ecological integrity of rivers and streams, and in the case of old, poorly maintained structures, posing a risk to lives and property. These concerns have generated active dam removal efforts throughout New England. To best capture the geomorphic, hydrologic, and potential ecological effects of dam removal at a regional level, we have compiled a dataset of 127 removed dams in New England, which includes information about structural characteristics, georectified locations, and key watershed attributes (including basin size, distance to next upstream obstacle, and number of free-flowing river kms opened up). Our specific research questions address (1) what is the spatial distribution of removed dams and how does this pattern relate to stated management goals of restoring critical habitat for native resident freshwater and diadromous fish, (2) what are the structural or management commonalities in dam types that have been removed, and (3) what has been the incremental addition of free-flowing river length? Rather than reflecting an overall management prioritization strategy, results indicate that dam removals are characterized more by opportunistic removals. For example, despite a regional emphasis on diadromous fish protection and restoration, most removals are inland rather than coastal settings. Most of the removed dams were small (~ 45% < 4 m) although ~10% of the removed dams were 6-8 m high. However, despite the predominant removal of small dams, these dams were not restricted to headwater locations; most (38%) occurred in medium-sized watersheds having upstream drainage areas between 100-1,000 km2 with 8% formerly

  13. Dammed or Damned?

    ERIC Educational Resources Information Center

    Hirsch, Philip

    1988-01-01

    Summarizes issues raised at a workshop on "People and Dams" organized by the Society for Participatory Research in Asia. Objectives were to (1) understand problems created by dams for people, (2) consider forces affecting displaced populations and rehabilitation efforts, and (3) gain a perspective on popular education efforts among affected…

  14. Model analysis of check dam impacts on long-term sediment and water budgets in southeast Arizona, USA

    USGS Publications Warehouse

    Norman, Laura M.; Niraula, Rewati

    2016-01-01

    The objective of this study was to evaluate the effect of check dam infrastructure on soil and water conservation at the catchment scale using the Soil and Water Assessment Tool (SWAT). This paired watershed study includes a watershed treated with over 2000 check dams and a Control watershed which has none, in the West Turkey Creek watershed, Southeast Arizona, USA. SWAT was calibrated for streamflow using discharge documented during the summer of 2013 at the Control site. Model results depict the necessity to eliminate lateral flow from SWAT models of aridland environments, the urgency to standardize geospatial soils data, and the care for which modelers must document altering parameters when presenting findings. Performance was assessed using the percent bias (PBIAS), with values of ±2.34%. The calibrated model was then used to examine the impacts of check dams at the Treated watershed. Approximately 630 tons of sediment is estimated to be stored behind check dams in the Treated watershed over the 3-year simulation, increasing water quality for fish habitat. A minimum precipitation event of 15 mm was necessary to instigate the detachment of soil, sediments, or rock from the study area, which occurred 2% of the time. The resulting watershed model is useful as a predictive framework and decision-support tool to consider long-term impacts of restoration and potential for future restoration.

  15. 1. GORGE HIGH DAM. THIS THIN ARCH DAM WITH A ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. GORGE HIGH DAM. THIS THIN ARCH DAM WITH A GRAVITY SECTION IS THE THIRD DAM BUILT BY SEATTLE CITY LIGHT TO PROVIDE WATER FOR GORGE POWERHOUSE AND WAS COMPLETED IN 1961, 1989. - Skagit Power Development, Gorge High Dam, On Skagit River, 2.9 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  16. Paired watershed study design

    SciTech Connect

    Clausen, J.C.; Spooner, J.

    1993-09-01

    The purpose of the fact sheet is to describe the paired watershed approach for conducting nonpoint source (NPS) water quality studies. The basic approach requires a minimum of two watersheds - control and treatment - and two periods of study - calibration and treatment. The basis of the paired watershed approach is that there is a quantifiable relationship between paired water quality data for the two watersheds, and that this relationship is valid until a major change is made in one of the watersheds.

  17. A river might run through it again: criteria for consideration of dam removal and interim lessons from California.

    PubMed

    Pejchar, L; Warner, K

    2001-11-01

    Resource managers are increasingly being challenged by stakeholder groups to consider dam removal as a policy option and as a tool for watershed management. As more dam owners face high maintenance costs, and rivers as spawning grounds for anadromous fish become increasingly valuable, dam removal may provide the greatest net benefit to society. This article reviews the impact of Endangered Species Act listings for anadromous fish and recent shifts in the Federal Energy Regulatory Commission's hydropower benefit-costs analysis and discusses their implications for dam removal in California. We propose evaluative criteria for consideration of dam removal and apply them to two case studies: the Daguerre and Englebright Dams on the Yuba River and the Scott and Van Horne Dams on the South Eel River, California.

  18. A river might run through it again: criteria for consideration of dam removal and interim lessons from California.

    PubMed

    Pejchar, L; Warner, K

    2001-11-01

    Resource managers are increasingly being challenged by stakeholder groups to consider dam removal as a policy option and as a tool for watershed management. As more dam owners face high maintenance costs, and rivers as spawning grounds for anadromous fish become increasingly valuable, dam removal may provide the greatest net benefit to society. This article reviews the impact of Endangered Species Act listings for anadromous fish and recent shifts in the Federal Energy Regulatory Commission's hydropower benefit-costs analysis and discusses their implications for dam removal in California. We propose evaluative criteria for consideration of dam removal and apply them to two case studies: the Daguerre and Englebright Dams on the Yuba River and the Scott and Van Horne Dams on the South Eel River, California. PMID:11568839

  19. Using Runoff Hydrograph Model for Early Detecting Landslide Dam Failure

    NASA Astrophysics Data System (ADS)

    Chompuchan, C.; Chen, W. L.; Lin, C. Y.

    2014-12-01

    In mountainous areas, many studies explored that during extreme rainfall event induced landslide dams failure and consequently caused the catastrophe damage of lives and infrastructures at the downstream of the watershed. The detection of initial landslide dam formation and the estimation of its occurrence position in the upstream were essential to warn the residents and evacuate in advance. The devices currently used, such as wire sensor, geophone sensor, and infrared cameras (CCD) are classified as the post-event type sensor, which only has a shorter response time, and can just hardly satisfy the requirement which people expect from precaution system. To predict disasters earlier and increase response time, this study used the change point derived from comparing theoretical and observing runoff hydrograph. Chishan River watershed was selected as a case study. Grid Rational Algorithm for Predicting Hydrograph (GRAPH), the dynamic rainfall - runoff model, was used to calibrate watershed runoff hydrograph parameter. The landslide dams were simulated at difference distances along the river, and the runoff hydrographs were compared. Then, the rainfall data and landslide dam failure during Typhoon Morakot in August 2009 was verified the model.The result showed that, during the initial landslide dam formation, the observed accumulate and peak flow hydrograph reduced significantly in comparison with theoretical flow. This model can be applied to establish an efficient warning system for debris flow occurring precaution. In addition, this study has been improved for a longer response time by integrating traditional observation system and runoff hydrograph warning systems and can provide to the references of related authorities.

  20. Suspended sediment yield in Texas watersheds

    NASA Astrophysics Data System (ADS)

    Coonrod, Julia Ellen Allred

    The Texas Water Development Board collected suspended sediment samples across the state of Texas for approximately 60 years. Until this research, no comprehensive analysis of the data had been conducted. This study compiles the suspended sediment data along with corresponding streamflow and rainfall. GIS programs are developed which characterize watersheds corresponding to the sediment gauging stations. The watersheds are characterized according to topography, climate, soils, and land use. All of the data is combined to form several SAS data sets which can subsequently be analyzed using regression. Annual data for all of the stations across the state are classified temporally and spatially to determine trends in the sediment yield. In general, the suspended sediment load increases with increasing runoff but no correlation exists with rainfall. However, the annual average rainfall can be used to classify the watersheds according to climate, which improves the correlation between sediment load and runoff. The watersheds with no dams have higher sediment loads than watersheds with dams. Dams in the drier parts of Texas reduce the sediment load more than dams in the wetter part of the state. Sediment rating curves are developed separately for each basin in Texas. All but one of the curves fall into a band which varies by about two orders of magnitude. The study analyzes daily time series data for the Lavaca River near Edna station. USGS data are used to improve the sediment rating curve by the addition of physically related variables and interaction terms. The model can explain an additional 41% of the variability in sediment concentration compared to a simple bivariate regression of sediment load and flow. The TWDB daily data for the Lavaca River near Edna station are used to quantify temporal trends. There is a high correlation between sediment load and flowrate for the Lavaca River. The correlation can be improved by considering a flow-squared term and by

  1. The Spatially-Distributed Agroecosystem-Watershed (Ages-W) Hydrologic/Water Quality (H/WQ) model for assessment of conservation effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    AgroEcoSystem-Watershed (AgES-W) is a modular, Java-based spatially distributed model which implements hydrologic/water quality (H/WQ) simulation components under the Object Modeling System (OMS3) environmental modeling framework. AgES-W has recently been enhanced with the addition of nitrogen (N) a...

  2. First-year dam removal activities in the Elwha River - dam removal, sediment dispersal, and fish relocations

    NASA Astrophysics Data System (ADS)

    Duda, J. J.; McMillan, J. R.; Moses, R.; McHenry, M.; Pess, G. R.; Brenkman, S.; Peters, R.; Zimmerman, M.; Warrick, J. A.; Curran, C. A.; Magirl, C. S.; Beirne, M.; Rubin, S.

    2012-12-01

    After years of anticipation, volumes of Environmental Impact Statements, unprecedented mitigation projects, and the multifaceted collection of pre-dam removal data, the deconstruction phase of the Elwha River restoration project officially began on September 17th, 2011. With their simultaneous decommissioning, the removal of the 64 m tall Glines Canyon Dam and 33 m tall Elwha Dam represents one of the largest such projects of its kind in North America. The nearly 19 million m3 of sediment residing in the dammed reservoirs is being eroded by the river in one of the largest controlled releases of sediment into a river and marine waters in recorded history. The release of sediment and the halting of deconstruction and reservoir draw down activities during "fish windows" are largely determining a deconstruction schedule expected to last about 2 years. High suspended sediment concentrations, modeled to exceed 10,000 mg/L during the highest flows and to exceed 500 mg/L for 39% of the time in year 4 of the project (15% is the recorded background level entering the upper reservoir), could last for up to 3-5 years following dam removal depending on hydrological conditions. Anadromous fish, including three federally listed species (Puget Sound Chinook salmon, steelhead, and bull trout), reside in the river downstream of the Elwha dam for part of their life cycle. All five species of Pacific salmon and steelhead, either locally extirpated (sockeye) or persisting below the impassable Elwha Dam in degraded spawning and rearing habitat, are expected to recolonize the watershed to degrees that will vary spatially and temporally due to life history characteristics and levels of human intervention. During the first year of dam removal, adult coho salmon and steelhead were relocated from areas of high turbidity downstream of the Elwha Dam site to two tributaries upstream, where some of them successfully spawned. Additionally, steelhead were observed to naturally migrate past the

  3. Modeling and sediment study in the watershed Medjerda, Tunisia

    NASA Astrophysics Data System (ADS)

    Kotti, Fatma; Mahé, Gil; Habaieb, Hamadi; Dieulin, Claudine; Hermassi, Taoufik

    2015-04-01

    Water projects have experienced a major expansion in the late 1980s, and we now have sufficient perspective to assess their actual performance and their socio-environmental impacts (Payan, 2007). This study focuses on the great watershed of Tunisia namely Medjerda which has an area of about 23,600 km2. In the main river of Medjerda some dams have been created for water retention: Sidi Salem Dam (the largest in the country), El Aroussia dam, and others on tributaries Mellegue Bouhertma, Siliana, Beni Mtir, Lakhemess and Kasseb. Since the construction of dams, essentially Sidi Salem and Siliana, the Medjerda river has undergone significant changes in morphology. The monitoring of the flow of the major hydrological stations in the pre-estuarine zone downstream from Sidi Salem dam is used to measure the impact of the constructions on hydrological regimes: reduction in average rates, reduction in volumes sold, altered seasonal pattern, and most of all reduction of the sediment transport, which the highest values are related to extreme events. In this context, the balance of sediment monitoring appears indispensable for the quantification of sediment transport at the outlet. Our approach is to calculate a specific flow rate relative to the area of the basin for every structure built in the Medjerda watershed, from the information available on transport and sedimentation rates known, combined with contours of each sub watershed. There are about ten dams spread throughout Medjerda watershed. The methodology is primarily developed for the Mellegue dam because we have at this station a long data set from 1955 until 2005. Other stations will be studied later on. The main objective of this study is to provide a series of annual variation of theoretical contributions. These calculated values will be compared with the actual measured sedimentary series. Two cores in the sediments of the pre-estuarine area are performed to determine past variability in sediment inputs over a time

  4. Laboratory experiments on dam-break flow of water-sediment mixtures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dams induce sedimentation and store significant amounts of sediment as they age; therefore, dam failures often involve the release of sediment-laden water to the downstream floodplain. In particular, tailings dams, which are constructed to impound mining wastes, can cause devastating damage when the...

  5. Effect of Rubber Dam on Arterial Oxygen Saturation in Children

    PubMed Central

    Nara, Asha; Chour, Rashmi; Narasimman, Jamini; Latti, Pooja; Srinidhi, P B

    2015-01-01

    Background: The placement of rubber dam has the potential to alter the airflow through nasal and oral cavities. Pediatric dentist should be aware whether the use of a rubber dam affects the oxygen saturation (SpO2) in children. To assess the effect of rubber dam on arterial blood SpO2 in children of 6-12 years age. Materials and Methods: Totally, 60 ASA Class I patients of 6-12 years age, randomly allocated in two groups: Group A: Rubber dam isolation of maxilla and Group B: Isolation of the mandible. A pulse oximeter was used to detect SpO2. To establish a baseline, each patient’s SpO2 was recorded every 30 s for 2 min. A rubber dam was then placed which extended over the nose. Class I cavity and glass ionomer cements restoration were performed. The rubber dam was cut to expose the nasal cavities SpO2 were recorded every 30 s for 5 min throughout the procedure. A two-way ANOVA test was applied. Results: In both groups there was no significant difference in SpO2 after rubber dam placement with nose covered or uncovered (P > 0.05). Conclusion: There was no significant change in SpO2 after rubber dam isolation with nose covered or uncovered in children of 6-12 years age. PMID:26124600

  6. Sediment from hydraulic mining detained by Englebright and small dams in the Yuba basin

    NASA Astrophysics Data System (ADS)

    James, L. Allan

    2005-10-01

    Recent initiatives to find ways to reintroduce anadromous fish to the Central Valley of California have identified the Yuba River as one of the best potential watersheds for expanding spawning habitat of spring-run chinook salmon and steelhead trout. Salmon spawning in the Yuba River would require substantial modifications or removal of Englebright Dam, a large dam (86 million m3 capacity) built by the U.S. Army Corps of Engineers in 1941. An extensive on-going feasibility study by local, state, and federal organizations, therefore, is examining aspects of various dam-treatment scenarios that range from no action to complete dam removal. This paper examines the extraordinary history of the watershed and resulting conditions pertinent to the feasibility of altering Englebright Dam. It seeks to accomplish four goals. First, historical geomorphic changes in the watershed are outlined that influence the physical context of the feasibility study. The Yuba watershed is centered in the hydraulic gold-mining region made famous by G.K. Gilbert (Gilbert, G.K., 1917. Hydraulic-mining débris in the Sierra Nevada. U.S. Geol. Survey Prof. Paper 105 154 pp.), and Englebright Dam was built as a débris dam to control the sediment from hydraulic mining. Second, recent findings of high concentrations of mercury in sediment and fish tissues in the watershed are briefly reviewed. Much mercury was applied during the 20th century. Third, historic data on 20th century hydraulic mining are presented that document numerous small dams built in the Yuba basin to detain mining sediment. Finally, field measurements of the texture and lithology of modern bed materials in the Yuba River basin are presented that demonstrate reworked sediment from mining is an important component of the modern sediment load and fine spawning gravels. The complex anthropogenic geomorphic changes in the Yuba basin present a challenge with regards to responsible treatment of Englebright Dam. If toxic sediment is

  7. Island Watershed Activity.

    ERIC Educational Resources Information Center

    Benson, Rod

    2003-01-01

    Describes a 90-minute "Island Watershed" activity to help earth science students understand the concept of the water cycle. Introduces a surface waters unit appropriate for students in grades 7-10. Includes watershed project guidelines. (Author/KHR)

  8. How big of an effect do small dams have? Using geomorphological footprints to quantify spatial impact of low-head dams and identify patterns of across-dam variation

    USGS Publications Warehouse

    Fencl, Jane S.; Mather, Martha E.; Costigan, Katie H.; Daniels, Melinda D.

    2015-01-01

    Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (<7.6 m high) fragment United States rivers. Despite potential adverse impacts of these ubiquitous disturbances, the spatial impacts of low-head dams on geomorphology and ecology are largely untested. Progress for research and conservation is impaired by not knowing the magnitude of low-head dam impacts. Based on the geomorphic literature, we refined a methodology that allowed us to quantify the spatial extent of low-head dam impacts (herein dam footprint), assessed variation in dam footprints across low-head dams within a river network, and identified select aspects of the context of this variation. Wetted width, depth, and substrate size distributions upstream and downstream of six low-head dams within the Upper Neosho River, Kansas, United States of America were measured. Total dam footprints averaged 7.9 km (3.0–15.3 km) or 287 wetted widths (136–437 wetted widths). Estimates included both upstream (mean: 6.7 km or 243 wetted widths) and downstream footprints (mean: 1.2 km or 44 wetted widths). Altogether the six low-head dams impacted 47.3 km (about 17%) of the mainstem in the river network. Despite differences in age, size, location, and primary function, the sizes of geomorphic footprints of individual low-head dams in the Upper Neosho river network were relatively similar. The number of upstream dams and distance to upstream dams, but not dam height, affected the spatial extent of dam footprints. In summary, ubiquitous low-head dams individually and cumulatively altered lotic ecosystems. Both characteristics of individual dams and the context of neighboring dams affected low-head dam impacts within the river network. For these reasons, low-head dams require a different, more integrative, approach for research and management than the individualistic

  9. How Big of an Effect Do Small Dams Have? Using Geomorphological Footprints to Quantify Spatial Impact of Low-Head Dams and Identify Patterns of Across-Dam Variation

    PubMed Central

    Costigan, Katie H.; Daniels, Melinda D.

    2015-01-01

    Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (<7.6 m high) fragment United States rivers. Despite potential adverse impacts of these ubiquitous disturbances, the spatial impacts of low-head dams on geomorphology and ecology are largely untested. Progress for research and conservation is impaired by not knowing the magnitude of low-head dam impacts. Based on the geomorphic literature, we refined a methodology that allowed us to quantify the spatial extent of low-head dam impacts (herein dam footprint), assessed variation in dam footprints across low-head dams within a river network, and identified select aspects of the context of this variation. Wetted width, depth, and substrate size distributions upstream and downstream of six low-head dams within the Upper Neosho River, Kansas, United States of America were measured. Total dam footprints averaged 7.9 km (3.0–15.3 km) or 287 wetted widths (136–437 wetted widths). Estimates included both upstream (mean: 6.7 km or 243 wetted widths) and downstream footprints (mean: 1.2 km or 44 wetted widths). Altogether the six low-head dams impacted 47.3 km (about 17%) of the mainstem in the river network. Despite differences in age, size, location, and primary function, the sizes of geomorphic footprints of individual low-head dams in the Upper Neosho river network were relatively similar. The number of upstream dams and distance to upstream dams, but not dam height, affected the spatial extent of dam footprints. In summary, ubiquitous low-head dams individually and cumulatively altered lotic ecosystems. Both characteristics of individual dams and the context of neighboring dams affected low-head dam impacts within the river network. For these reasons, low-head dams require a different, more integrative, approach for research and management than the individualistic

  10. How Big of an Effect Do Small Dams Have? Using Geomorphological Footprints to Quantify Spatial Impact of Low-Head Dams and Identify Patterns of Across-Dam Variation.

    PubMed

    Fencl, Jane S; Mather, Martha E; Costigan, Katie H; Daniels, Melinda D

    2015-01-01

    Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (<7.6 m high) fragment United States rivers. Despite potential adverse impacts of these ubiquitous disturbances, the spatial impacts of low-head dams on geomorphology and ecology are largely untested. Progress for research and conservation is impaired by not knowing the magnitude of low-head dam impacts. Based on the geomorphic literature, we refined a methodology that allowed us to quantify the spatial extent of low-head dam impacts (herein dam footprint), assessed variation in dam footprints across low-head dams within a river network, and identified select aspects of the context of this variation. Wetted width, depth, and substrate size distributions upstream and downstream of six low-head dams within the Upper Neosho River, Kansas, United States of America were measured. Total dam footprints averaged 7.9 km (3.0-15.3 km) or 287 wetted widths (136-437 wetted widths). Estimates included both upstream (mean: 6.7 km or 243 wetted widths) and downstream footprints (mean: 1.2 km or 44 wetted widths). Altogether the six low-head dams impacted 47.3 km (about 17%) of the mainstem in the river network. Despite differences in age, size, location, and primary function, the sizes of geomorphic footprints of individual low-head dams in the Upper Neosho river network were relatively similar. The number of upstream dams and distance to upstream dams, but not dam height, affected the spatial extent of dam footprints. In summary, ubiquitous low-head dams individually and cumulatively altered lotic ecosystems. Both characteristics of individual dams and the context of neighboring dams affected low-head dam impacts within the river network. For these reasons, low-head dams require a different, more integrative, approach for research and management than the individualistic approach

  11. How Big of an Effect Do Small Dams Have? Using Geomorphological Footprints to Quantify Spatial Impact of Low-Head Dams and Identify Patterns of Across-Dam Variation.

    PubMed

    Fencl, Jane S; Mather, Martha E; Costigan, Katie H; Daniels, Melinda D

    2015-01-01

    Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (<7.6 m high) fragment United States rivers. Despite potential adverse impacts of these ubiquitous disturbances, the spatial impacts of low-head dams on geomorphology and ecology are largely untested. Progress for research and conservation is impaired by not knowing the magnitude of low-head dam impacts. Based on the geomorphic literature, we refined a methodology that allowed us to quantify the spatial extent of low-head dam impacts (herein dam footprint), assessed variation in dam footprints across low-head dams within a river network, and identified select aspects of the context of this variation. Wetted width, depth, and substrate size distributions upstream and downstream of six low-head dams within the Upper Neosho River, Kansas, United States of America were measured. Total dam footprints averaged 7.9 km (3.0-15.3 km) or 287 wetted widths (136-437 wetted widths). Estimates included both upstream (mean: 6.7 km or 243 wetted widths) and downstream footprints (mean: 1.2 km or 44 wetted widths). Altogether the six low-head dams impacted 47.3 km (about 17%) of the mainstem in the river network. Despite differences in age, size, location, and primary function, the sizes of geomorphic footprints of individual low-head dams in the Upper Neosho river network were relatively similar. The number of upstream dams and distance to upstream dams, but not dam height, affected the spatial extent of dam footprints. In summary, ubiquitous low-head dams individually and cumulatively altered lotic ecosystems. Both characteristics of individual dams and the context of neighboring dams affected low-head dam impacts within the river network. For these reasons, low-head dams require a different, more integrative, approach for research and management than the individualistic approach

  12. Elk River Watershed - Flood Study

    NASA Astrophysics Data System (ADS)

    Barnes, C. C.; Byrne, J. M.; MacDonald, R. J.; Lewis, D.

    2014-12-01

    Flooding has the potential to cause significant impacts to economic activities as well as to disrupt or displace populations. Changing climate regimes such as extreme precipitation events increase flood vulnerability and put additional stresses on infrastructure. Potential flooding from just under 100 (2009 NPRI Reviewed Facility Data Release, Environment Canada) toxic tailings ponds located in Canada increase risk to human safety and the environment. One such geotechnical failure spilt billions of litres of toxic tailings into the Fraser River watershed, British Columbia, when a tailings pond dam breach occurred in August 2014. Damaged and washed out roadways cut access to essential services as seen by the extensive floods that occurred in Saskatchewan and Manitoba in July 2014, and in Southern Alberta in 2013. Recovery efforts from events such as these can be lengthy, and have substantial social and economic impacts both in loss of revenue and cost of repair. The objective of this study is to investigate existing conditions in the Elk River watershed and model potential future hydrological changes that can increase flood risk hazards. By analyzing existing hydrology, meteorology, land cover, land use, economic, and settlement patterns a baseline is established for existing conditions in the Elk River watershed. Coupling the Generate Earth Systems Science (GENESYS) high-resolution spatial hydrometeorological model with flood hazard analysis methodology, high-resolution flood vulnerability base line maps are created using historical climate conditions. Further work in 2015 will examine possible impacts for a range of climate change and land use change scenarios to define changes to future flood risk and vulnerability.

  13. Dams and Intergovernmental Transfers

    NASA Astrophysics Data System (ADS)

    Bao, X.

    2012-12-01

    Gainers and Losers are always associated with large scale hydrological infrastructure construction, such as dams, canals and water treatment facilities. Since most of these projects are public services and public goods, Some of these uneven impacts cannot fully be solved by markets. This paper tried to explore whether the governments are paying any effort to balance the uneven distributional impacts caused by dam construction or not. It showed that dam construction brought an average 2% decrease in per capita tax revenue in the upstream counties, a 30% increase in the dam-location counties and an insignificant increase in downstream counties. Similar distributional impacts were observed for other outcome variables. like rural income and agricultural crop yields, though the impacts differ across different crops. The paper also found some balancing efforts from inter-governmental transfers to reduce the unevenly distributed impacts caused by dam construction. However, overall the inter-governmental fiscal transfer efforts were not large enough to fully correct those uneven distributions, reflected from a 2% decrease of per capita GDP in upstream counties and increase of per capita GDP in local and downstream counties. This paper may shed some lights on the governmental considerations in the decision making process for large hydrological infrastructures.

  14. What's in a Watershed?

    ERIC Educational Resources Information Center

    Vandas, Steve

    1997-01-01

    Discusses watersheds and floods. Includes an insert that provides a visual example of many different watersheds, illustrates a flood and different ways that flood plains are developed, and contains activities designed to assist students in learning about watersheds and floods. Lists water resources available on the World Wide Web. (JRH)

  15. Hydrologic response of streams restored with check dams in the Chiricahua Mountains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, hydrological processes are evaluated to determine impacts of stream restoration in the West Turkey Creek, Chiricahua Mountains, southeast Arizona, during a summer-monsoon season (June–October of 2013). A paired-watershed approach was used to analyze the effectiveness of check dams to ...

  16. Technical background information for the environmental and safety report, Volume 4: White Oak Lake and Dam

    SciTech Connect

    Oakes, T.W.; Kelly, B.A.; Ohnesorge, W.F.; Eldridge, J.S.; Bird, J.C.; Shank, K.E.; Tsakeres, F.S.

    1982-03-01

    This report has been prepared to provide background information on White Oak Lake for the Oak Ridge National Laboratory Environmental and Safety Report. The paper presents the history of White Oak Dam and Lake and describes the hydrological conditions of the White Oak Creek watershed. Past and present sediment and water data are included; pathway analyses are described in detail.

  17. 52. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM -- TAINTER GATE HOIST-ASSEMBLY -- PLANS AND ELEVATIONS. M-L 26(R) 46/2 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

  18. ECHETA DAM RIPRAP ON RESERVOIR SIDE OF THE DAM AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ECHETA DAM RIP-RAP ON RESERVOIR SIDE OF THE DAM AT BREACH. VIEW TO NORTH-NORTHEAST. - Echeta Dam & Reservoir, 2.9 miles east of Echeta Road at Echeta Railroad Siding at County Road 293, Echeta, Campbell County, WY

  19. 32. AERIAL VIEW OF TIETON DAM, UPSTREAM FACE OF DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. AERIAL VIEW OF TIETON DAM, UPSTREAM FACE OF DAM (Trashrack-structure for outlet at lower left in reservoir, spillway at upper left. Reservoir nearly empty due to drought.) - Tieton Dam, South & East of State Highway 12, Naches, Yakima County, WA

  20. Owyhee River intracanyon lava flows: does the river give a dam?

    USGS Publications Warehouse

    Ely, Lisa L.; Brossy, Cooper C.; House, P. Kyle; Safran, Elizabeth B.; O'Connor, Jim E.; Champion, Duane E.; Fenton, Cassandra R.; Bondre, Ninad R.; Orem, Caitlin A.; Grant, Gordon E.; Henry, Christopher D.; Turrin, Brent D.

    2013-01-01

    to fill the blocked valley. Variations in this primary process of incision through the lava dams could be influenced by additional independent factors such as regional uplift, drainage integration, or climate that affect the relative base level, discharge, and sediment yield within the watershed. By redirecting the river, tributaries, and subsequent lava flows to different parts of the canyon, lava dams create a distinct valley morphology of flat, broad basalt shelves capping steep cliffs of Tertiary sediment. This stratigraphy is conducive to landsliding and extends the effects of intracanyon lava flows on channel geomorphology beyond the lifetime of the dams.

  1. Dam health diagnosis and evaluation

    NASA Astrophysics Data System (ADS)

    Wu, Zhongru; Su, Huaizhi

    2005-06-01

    Based on the bionics principle in the life sciences field, we regard a dam as a vital and intelligent system. A bionics model is constructed to observe, diagnose and evaluate dam health. The model is composed of a sensing system (nerve), central processing unit (cerebrum) and decision-making implement (organism). In addition, the model, index system and engineering method on dam health assessment are presented. The proposed theories and methods are applied to evaluate dynamically the health of one concrete dam.

  2. Bed Sediment Monitoring of Multiple Contiguous Small Dam Removals

    NASA Astrophysics Data System (ADS)

    Galster, J. C.; Wyrick, J. R.

    2010-12-01

    Dam removal is crucial for reconnecting river habitats, restoring passage of fish and other aquatic organisms, and restoring the free flow of water and sediment. However, removal of obsolete dams is often resisted due to concerns of releasing sediment and initiating channel instability. Two dams on the Musconetcong River in northern New Jersey have been removed as part of a watershed-wide effort to remove or breach all major obstructions to restore the river to its original free-flowing state. The two dams were consecutively situated 1 kilometer apart and their removals provided an opportunity to study the geomorphic response in the form of bed elevation changes and sediment size through pre- and post-removal monitoring. Initial geomorphic surveys of the riverbed in the vicinity of and between the two dams have shown areas of erosion and deposition. These surveys have established a set of control points along the river channel between the two dams, and confirm the downstream movement of a sediment plume and localized areas of erosion. At the upstream dam, comparisons pre- and post-dam removal surveys show greater than 100 cubic meters of sediment being both eroded and deposited within the site. Most but not all of the erosion occurred around the newly exposed sediment bar upstream of the former dam, where the thalweg has reestablished itself following the dam’s removal. Areas that were excavated during removal have experienced deposition. Most of the deposition occurred downstream and on the left-hand bank. Due to the two low flow culverts in the former dam, a mid-channel sediment bar formed but has subsequently eroded. At the downstream dam site, erosion has removed up to 1.1 m of sediment from the bed in places while depositing up to 0.5 m sediment in others. As sediment from the former impoundment migrated through the project site, areas excavated during the removal became areas of deposition following the removal, and; alternately, areas in the channel

  3. Using hydraulic modeling to address social impacts of small dam removals in southern New Jersey.

    PubMed

    Wyrick, Joshua R; Rischman, Brian A; Burke, Christopher A; McGee, Craig; Williams, Chasity

    2009-07-01

    Small relic mill dams are common in the watersheds of southern New Jersey, dotting the landscape with many small neighborhood lakes. Originally built in the late 1800s, most of these dams have become increasingly unable to handle current design storms due to increased urbanization of the watersheds. Several of these dams have also been classified as "high hazard" by the New Jersey Department of Environmental Protection Dam Safety Division because their failure has the potential for loss of life or extensive property damage. The current private owners are generally unable to afford the high repair costs needed to rehabilitate the dams to current safety standards, and are therefore more inclined to remove them. This research analyses both the physical and social impacts of the removal of two small dams in southern New Jersey, and integrates the two seemingly disparate concepts. Using hydraulic modeling and previous case studies, it is predicted that there will be limited effects to the hydrological and biological characteristics of the stream corridor. A survey distributed to the affected homeowners that live on these lakes shows that the community, however, expects significant impacts to the bio-physical characteristics of the stream corridor, as well financial impacts to their property value and social impacts to their recreational activities. The current study exposes the widening gap between policy makers and landowners, and highlights where complete stakeholder interaction could and should occur.

  4. Influence of a large dam on the longitudinal patterns of fish assemblages in Qingyi Stream

    PubMed Central

    SUI, Xiao-Yun; LU, Zhi; YAN, Yun-Zhi; CHEN, Yi-Feng; JIA, Yin-Tao

    2014-01-01

    Using seasonally collected data (2009-2010) from 15 sampling sites that represent first- to fifth-order streams within the Qingyi watershed, we examined the spatio-temporal patterns of fish assemblages along two longitudinal gradients to explore the effects of a large dam on fish assemblages at the watershed scale. No significant variation was observed in either species richness or assemblage structure across seasons. Species richness significantly varied according to stream order and gradient. Dam construction appeared to decrease species richness upstream substantially, while a significant decrease between gradients only occurred within fourth-order streams. Along the gradient without the large dam, fish assemblage structures presented distinct separation between two neighboring stream orders, with the exception of fourth-order versus fifth-order streams. However, the gradient disrupted by a large dam displayed the opposite pattern in the spatial variation of fish assemblages related with stream orders. Significant between-gradient differences in fish assemblage structures were only observed within fourth-order streams. Species distributions were determined by local habitat environmental factors, including elevation, substrate, water depth, current discharge, wetted width, and conductivity. Our results suggested that dam construction might alter the longitudinal pattern in fish species richness and assemblage structure in Qingyi Stream, despite the localized nature of the ecological effect of dams. PMID:25297075

  5. Recovery of a mixed bedrock-alluvial channel following dam removal

    NASA Astrophysics Data System (ADS)

    Curran, J. C.; Buckley, E.; Calos, S.

    2013-12-01

    The South River, located in the Piedmont region of Virginia, is a tributary to the South Fork of the Shenandoah River. A sequence of dams was built on the river flows in the town of Waynesboro, Virginia, while the oldest over 100 years. This series of four dams (one large and three small) were removed in November, 2011. Geomorphic data were collected before, during, and after the dam removals, including surface and subsurface sediment samples, reservoir sediment samples, suspended sediment concentrations, channel bathymetry, and cross section transects. These data document the changes in the channel as sediment stored both behind the dams and in the channel bed moved through the river. As the channel returned to a free flowing condition, the channel bed has changed from fully alluvial to a mixed bedrock-alluvial state. A HEC-RAS model of the South River was developed to assess the accuracy of model predictions against the measured data. The channel did not migrate upon dam removal and the bank locations remained stable, providing a reasonable test case for the HEC-RAS model. Numerous dams built along Piedmont channels are now 100 or more years old. As dam removal becomes more common, having a means for predicting changes to the river system upon removal will make removal more possible in terms of public relations and watershed management. We assess the ability of HEC-RAS to predict changes through this case study of a dam removal common to many in the eastern US.

  6. Application of Watershed Ecological Risk Assessment Methods to Watershed Management

    EPA Science Inventory

    Watersheds are frequently used to study and manage environmental resources because hydrologic boundaries define the flow of contaminants and other stressors. Ecological assessments of watersheds are complex because watersheds typically overlap multiple jurisdictional boundaries,...

  7. Examination of physical and regulatory variables leading to small dam removal in Wisconsin.

    PubMed

    Orr, Cailin H; Roth, Brian M; Forshay, Kenneth J; Gonzales, James D; Papenfus, Michael M; Wassell, Rebecca D G

    2004-01-01

    The decision to remove or repair a dam depends on multiple variables, many of which encompass both physical and social factors. In Wisconsin, the Department of Natural Resources is mandated to inspect small dams every ten years. A safety inspection often acts as a trigger event to a dam removal or repair decision. Although the issues surrounding a dam removal decision are often couched as ecological, these decisions are influenced by their social and regulatory context. In this work, we examine descriptive variables of Wisconsin dams that were inspected and consequently removed or maintained between 1985 and 1990. We hypothesize that geographic location, height of dam, size of impoundment, age of dam, and type of ownership determine the likelihood of a safety inspection, and the subsequent likelihood of removal. Using a logistic model, we find that publicly owned dams had the greatest probability of inspection after 1985. Of these dams, older dams and those with smaller impoundments were most likely to be removed. We were unable to build a strong predictive model for dam removal with our suite of variables, suggesting that a community's decision to remove or maintain a dam is complex and heterogeneous.

  8. CG-DAMS: Concrete gravity dam stability analysis software

    SciTech Connect

    Not Available

    1993-01-01

    CG-DAMS is a finite element based program written specifically for the stability analysis of concrete gravity dams. The code automates the prediction and evaluation of cracking in the dam, along the dam-rock interface, and in the foundation using incremental nonlinear analysis techniques based on the smeared crack'' approach. Its primary application is in the computation of dam-rock interface sliding stability factors of safety. The automated procedure for crack propagation analysis replaces the trial-and-error cracked-base analysis method commonly used in gravity dam safety analyses. This Application manual of CG-DAMS illustrates, through sample problems, the many features of the software. Example problems illustrate the capabilities of both CG-DAMS-PC and CG-DAMS-ABAQUS. CG-DAMS-PC is a menu driven program that runs on 386/486 PCs under the DOS operating system (4 Megabytes RAM, 25 Megabytes of hard disk space). CG-DAMS-ABAQUS is a pre- and post-processor along with a concrete constitutive model and distributed load module that interfaces with the ABAQUS general purpose finite element program. The PC program contains thermal analysis capabilities, a rough crack constitutive model, and an interface to the CRFLOOD software not available with the ABAQUS version. The CG-DAMS-ABAQUS program contains time marching dynamic analysis capabilities not available with the PC program. Example analyses presented include static, pseudo dynamic, and time marching dynamic analyses. The manual also presents sensitivity evaluations on mesh size and foundation material strength. Comparisons are presented between CG-DAMS and gravity method calculations. Comparisons with other finite element software are included for the dynamic time history analyses.

  9. Integrated Resource Management at a Watershed Scale

    NASA Astrophysics Data System (ADS)

    Byrne, J. M.; MacDonald, R. J.; Cairns, D.; Barnes, C. C.; Mirmasoudi, S. S.; Lewis, D.

    2014-12-01

    Watershed hydrologists, managers and planners have a long list of resources to "manage." Our group has worked for over a decade to develop and apply the GENESYS (Generate Earth Systems Science) high-resolution spatial hydrometeorological model. GENESYS was intended for modelling of alpine snowpack, and that work has been the subject of a series of hydrometeorology papers that applied the model to evaluate how climate change may impact water resources for a series of climate warming scenarios through 2100. GENESYS has research modules that have been used to assess alpine glacier mass balance, soil water and drought, forest fire risk under climate change, and a series of papers linking GENESYS to a water temperature model for small headwater streams. Through a major commercialization grant, we are refining, building, adopting, and adapting routines for flood hydrology and hydraulics, surface and groundwater storage and runoff, crop and ecosystem soil water budgets, and biomass yields. The model will be available for research collaborations in the near future. The central goal of this development program is to provide a series of research and development tools for non-profit integrated resource management in the developed and developing world. A broader question that arises is what are the bounds of watershed management, if any? How long should our list of "managed" resources be? Parallel work is evaluating the relative values of watershed specialists managing many more resources with the watershed. Hydroelectric power is often a key resource complimentary to wind, solar and biomass renewable energy developments; and biomass energy is linked to water supply and agriculture. The August 2014 massive tailings dam failure in British Columbia threatens extensive portions of the Fraser River sockeye salmon run, millions of fish, and there are concerns about long-term contamination of water supplies for many British Columbians. This disaster, and many others that may occur

  10. Watersheds: where we live

    USGS Publications Warehouse

    Vandas, Stephen; Farrar, Frank

    1996-01-01

    We all live in a watershed. Animals and plants all live there with us. Everyone affects what happens in a watershed by how we treat the natural resources. So what is a watershed? It is the land area that drains water to a stream, river, lake, or ocean. Water travels over the Earth's surface across forest land, farm fields, pastures, suburban lawns, and city streets, or it seeps into the soil and makes its way to a stream as local ground water. Watersheds come in many different shapes and sizes. Some contain mountains and hills, and others are nearly flat. A watershed can be affected by many different activities and events. Construction of cities and towns, farming, logging, and the application and disposal of many garden and household chemicals can affect the quantity and quality of water flowing from a watershed.

  11. Geomorphic responses to large check-dam removal on a mountain river in Taiwan

    NASA Astrophysics Data System (ADS)

    Wang, H.; Stark, C. P.; Cook, K. L.; Kuo, W.

    2011-12-01

    Dam removal has become an important aspect of river restoration in recent years, but studies documenting the physical and ecological response to dam removal are still lacking - particularly in mountain rivers and following major floods. This presentation documents the recent removal of a large dam on a coarse-grained, steep (an order of magnitude greater than on the Marmot) mountain channel in Taiwan. The Chijiawan river, a tributary of the Tachia River draining a 1236 km2 watershed, is the only habitat in Taiwan of the endangered Formosan landlocked salmon. The habitat of this fish has been cut significantly since the 1960s following construction of check dams designed to prevent reservoir sedimentation downstream. The largest and lowermost barrier on Chijiawan creek is the 15m high, "No. 1 Check Dam" built in 1971. Forty years later, in early 2011, the sediment wedge behind the dam had reached an estimated 0.2 million m3 and the dam toe had been scoured about 4m below its foundation, posing a serious risk of dam failure. For these reasons, the Shei-Pa National Park removed the dam in late May 2011. To monitor the response of the river to dam removal, we installed video cameras, time-lapse cameras, stage recorders, and turbidity sensors, conducted surveys of grain size distributions and longitudinal profiles, and carried out repeat photography. Channel changes were greatest immediately following removal as a result of the high stream power, steep energy slope, and unconsolidated alluvial fill behind the dam. Headcut propagation caused immediate removal of the sand-grade sediment and progressive channel widening. One month after dam removal, a minor flood event excavated a big wedge of sediment from the impoundment. Most of the subsequent downstream deposition occurred within 500m of the dam, with alluviation reaching up to 0.5m in places. Two months after dam removal, erosion had propagated 300m upstream into the impounded sediment along a bed profile of gradient

  12. 1000 dams down and counting

    USGS Publications Warehouse

    O'Connor, James E.; Duda, Jeff J.; Grant, Gordon E.

    2015-01-01

    Forty years ago, the demolition of large dams was mostly fiction, notably plotted in Edward Abbey's novel The Monkey Wrench Gang. Its 1975 publication roughly coincided with the end of large-dam construction in the United States. Since then, dams have been taken down in increasing numbers as they have filled with sediment, become unsafe or inefficient, or otherwise outlived their usefulness (1) (see the figure, panel A). Last year's removals of the 64-m-high Glines Canyon Dam and the 32-m-high Elwha Dam in northwestern Washington State were among the largest yet, releasing over 10 million cubic meters of stored sediment. Published studies conducted in conjunction with about 100 U.S. dam removals and at least 26 removals outside the United States are now providing detailed insights into how rivers respond (2, 3).

  13. Master Watershed Stewards.

    ERIC Educational Resources Information Center

    Comer, Gary L.

    The Master Watershed Stewards (MWS) Program is a pilot project (developed through the cooperation of the Ohio State University Extension Logan and Hardin County Offices and the Indian Lake Watershed Project) offering the opportunity for communities to get involved at the local level to protect their water quality. The program grew out of the…

  14. Developing a Watershed Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2010-01-01

    This article presents a watershed challenge that gives students an opportunity to investigate the challenge of using a watershed area as a site for development, examining the many aspects of this multifaceted problem. This design challenge could work well in a team-based format, with students taking on specific aspects of the challenges and…

  15. Site and Watershed Mapping.

    ERIC Educational Resources Information Center

    Institute for Environmental Education, Cleveland, OH.

    Presented as part of a larger unit on watershed investigations are a slideshow script and a map and compass unit intended to help high school students better visualize the relationship between a water sampling site, the entire stream, community, and watershed. The script discusses features of a topographical map, shows how to read one, and…

  16. Health impacts of large dams

    SciTech Connect

    Lerer, L.B.; Scudder, T.

    1999-03-01

    Large dams have been criticized because of their negative environmental and social impacts. Public health interest largely has focused on vector-borne diseases, such as schistosomiasis, associated with reservoirs and irrigation projects. Large dams also influence health through changes in water and food security, increases in communicable diseases, and the social disruption caused by construction and involuntary resettlement. Communities living in close proximity to large dams often do not benefit from water transfer and electricity generation revenues. A comprehensive health component is required in environmental and social impact assessments for large dam projects.

  17. Soils of Walker Branch Watershed

    SciTech Connect

    Lietzke, D.A.

    1994-01-01

    indicates that most of this silty material is the result of slope wash processed during the Holocene Age. Residual soils of the watershed were related to the underlying geologic formations by their morphology and types of chert. Colluvial soils were identified and mapped whenever the colluvium thickness exceeded 20 in. (50 cm). Except for the ancient colluvial soils (colluvium without a present-day source area), colluvial soils were not separated according to their geologic age, but stacked colluvial deposits are located in low footslope landforms. Colluvial soils in the watershed were identified and mapped according to their morphologic properties that would influence the perching and subsurface movement of water. Alluvial soils were restricted to present floodplains, low fan terraces, and low fan deltas. Nearly all alluvial soils contained very young surficial sediments derived from slopewash resulting from land clearing and subsequent agricultural activities.

  18. Discover a Watershed: The Watershed Manager Educators Guide

    ERIC Educational Resources Information Center

    Project WET Foundation, 2002

    2002-01-01

    This guide contains 19 science-based, multidisciplinary activities that teach what a watershed is, how it works and why we must all consider ourselves watershed managers. An extensive background section introduces readers to fundamental watershed concepts. Each activity adapts to local watersheds, contains e-links for further Internet research and…

  19. Estimation of pollutant loads considering dam operation in Han River Basin by BASINS/Hydrological Simulation Program-FORTRAN.

    PubMed

    Jung, Kwang-Wook; Yoon, Choon-G; Jang, Jae-Ho; Kong, Dong-Soo

    2008-01-01

    Effective watershed management often demands qualitative and quantitative predictions of the effect of future management activities as arguments for policy makers and administration. The BASINS geographic information system was developed to compute total maximum daily loads, which are helpful to establish hydrological process and water quality modeling system. In this paper the BASINS toolkit HSPF model is applied in 20,271 km(2) large watershed of the Han River Basin is used for applicability of HSPF and BMPs scenarios. For proper evaluation of watershed and stream water quality, comprehensive estimation methods are necessary to assess large amounts of point source and nonpoint-source (NPS) pollution based on the total watershed area. In this study, The Hydrological Simulation Program-FORTRAN (HSPF) was estimated to simulate watershed pollutant loads containing dam operation and applied BMPs scenarios for control NPS pollution. The 8-day monitoring data (about three years) were used in the calibration and verification processes. Model performance was in the range of "very good" and "good" based on percent difference. The water-quality simulation results were encouraging for this large sizable watershed with dam operation practice and mixed land uses; HSPF proved adequate, and its application is recommended to simulate watershed processes and BMPs evaluation.

  20. An investigation on water quality of Darlik Dam drinking water using satellite images.

    PubMed

    Alparslan, Erhan; Coşkun, H Gonca; Alganci, Ugur

    2010-07-06

    Darlik Dam supplies 15% of the water demand of Istanbul Metropolitan City of Turkey. Water quality (WQ) in the Darlik Dam was investigated from Landsat 5 TM satellite images of the years 2004, 2005, and 2006 in order to determine land use/land cover changes in the watershed of the dam that may deteriorate its WQ. The images were geometrically and atmospherically corrected for WQ analysis. Next, an investigation was made by multiple regression analysis between the unitless planetary reflectance values of the first four bands of the June 2005 Landsat TM image of the dam and WQ parameters, such as chlorophyll-a, total dissolved matter, turbidity, total phosphorous, and total nitrogen, measured at satellite image acquisition time at seven stations in the dam. Finally, WQ in the dam was studied from satellite images of the years 2004, 2005, and 2006 by pattern recognition techniques in order to determine possible water pollution in the dam. This study was compared to a previous study done by the authors in the Küçükçekmece water reservoir, also in Istanbul City.

  1. A sediment budget for a small semiarid watershed in southeastern Arizona, USA

    NASA Astrophysics Data System (ADS)

    Nichols, M. H.; Nearing, M. A.; Polyakov, V. O.; Stone, J. J.

    2013-01-01

    A sediment budget was developed for a 43.7 ha and a nested 3.7 ha semiarid, shrub dominated watershed based on hydrologic, geomorphic, erosion, and sediment data collected from 1963 through 2006 on the USDA-ARS Walnut Gulch Experimental Watershed in the southwestern US. Sediment budgets based on such extensive and intensive field campaigns over several decades are rare. The sediment budget was balanced with a high degree of confidence because the study watershed is controlled by an earth dam at the outlet. Although the channel network is well developed and incising in the steeper reaches of the watershed, hillslopes are the dominant source of sediment, contributing 85% of the overall total sediment yield. Erosion and sediment redistribution were driven by highly variable rainfall and runoff during July, August, and September. Sediment transfers are influenced by channel abstractions and the presence of the outlet dam, which created conditions for deposition in the pond approach reach. Although earth dams are ubiquitous throughout the southwestern US, and they can provide a measure of outlet sediment yield, these outlet measurements may be insufficient to interpret temporal and spatial variability in watershed sediment dynamics. Identification of dominant processes and sediment sources is critical for determining management actions that will improve rangeland conditions.

  2. Elucidating the effects of dam restoration on hydrologic patterns in streams and tributaries

    NASA Astrophysics Data System (ADS)

    Cain, M. R.; Russo, T. A.; Sullivan, P. L.; Neal, A. L.

    2014-12-01

    Dam restoration or removal can result in a hydrogeological regime change, as the draining and refilling of reservoirs influences the regional water table position We evaluate how the refilling of Lake Perez, central Pennsylvania, influences surface water-groundwater interactions in the lakebed, within a stream that runs through the lakebed, and in a tributary upstream of the lake. Lake Perez was drained in 2008 to address structural stability problems at the dam. Following restoration in the spring of 2014, the reservoir was partially refilled and drained. To quantify the controls of dam restoration on hydrologic patterns in the watershed, stream discharge and temperature were continuously monitored above and below the lake since September 2013. Groundwater levels and temperature were also monitored at two sites (total of 19 wells) within the lakebed and one site upstream of the reservoir (total of 8 wells). Results from streambed tracer tests are also available to help quantify lakebed exchange characteristics. Data collected prior to and during these filling and drainage events provide insight into shallow surface flow and short-term drainage dynamics of a small watershed influenced by damming. Pre-dam restoration groundwater level data from Shavers Creek suggest the potential for groundwater discharge to the stream, while geochemical evidence indicates that low permeability legacy sediments impeded groundwater-stream water interactions. We demonstrate how the initial stages of refilling the lake have altered groundwater-surface water interactions within the lakebed and in local upstream tributaries.

  3. Watersheds in disordered media

    NASA Astrophysics Data System (ADS)

    Andrade, Joséi, Jr.; Araújo, Nuno; Herrmann, Hans; Schrenk, Julian

    2015-02-01

    What is the best way to divide a rugged landscape? Since ancient times, watersheds separating adjacent water systems that flow, for example, toward different seas, have been used to delimit boundaries. Interestingly, serious and even tense border disputes between countries have relied on the subtle geometrical properties of these tortuous lines. For instance, slight and even anthropogenic modifications of landscapes can produce large changes in a watershed, and the effects can be highly nonlocal. Although the watershed concept arises naturally in geomorphology, where it plays a fundamental role in water management, landslide, and flood prevention, it also has important applications in seemingly unrelated fields such as image processing and medicine. Despite the far-reaching consequences of the scaling properties on watershed-related hydrological and political issues, it was only recently that a more profound and revealing connection has been disclosed between the concept of watershed and statistical physics of disordered systems. This review initially surveys the origin and definition of a watershed line in a geomorphological framework to subsequently introduce its basic geometrical and physical properties. Results on statistical properties of watersheds obtained from artificial model landscapes generated with long-range correlations are presented and shown to be in good qualitative and quantitative agreement with real landscapes.

  4. River response to dam removal: the Souhegan River and the Merrimack Village Dam, Merrimack, New Hampshire

    NASA Astrophysics Data System (ADS)

    Pearson, A. J.; Snyder, N. P.; Collins, M. J.; Santaniello, D. J.

    2009-12-01

    The Souhegan River is a tributary of the Merrimack River that drains a 443 km2 watershed in southern New Hampshire. The lowermost barrier on the Souhegan River was the ~4-m high Merrimack Village Dam (MVD, ~500 m upstream of the confluence with the Merrimack River), which was breached and removed starting on August 6, 2008. The MVD was built in 1906 at a location where various dams have existed since the 18th century. Based on a pre-removal sediment-thickness survey, the MVD impounded at least 62,000 m3 of sediment, mostly sand. We use a May 2008 ground penetrating radar survey of the impoundment to better constrain this sediment volume and stratigraphy. We also use historical maps and aerial photographs to estimate the possible extent of dam-influenced deposition at the site. We use 12 monumented cross sections, longitudinal profiles, repeat photography, and sediment samples to document the response of the Souhegan River to the removal of the MVD. Our study is part of the first full application of a recently published guide for stream barrier removal monitoring. Prior to dam removal, in August 2007 and June 2008, we surveyed the cross sections and longitudinal profile. We conducted re-surveys after removal in August and October 2008, and again in July and August 2009. Comparison between pre- and post-removal surveys shows that, in a 495-m reach upstream of the former location of the MVD, the Souhegan River eroded a net 38,100 m3 (47,900 metric tons) of sediment. This response began with rapid (hours to days) incision of a narrow channel, exhuming in some places bedrock and boulders that likely formed the pre-dam riverbed. Over the year since dam removal, the channel has widened by bank erosion but this process is limited by root strength and recruitment of large woody debris in the riparian zone of the former impoundment. Downstream of the former dam location, during the first days after removal, a sand deposit up to 1.0 to 3.5 m thick, or approximately 18,500 m3

  5. Engaging Pennsylvania Teachers in Watershed Education

    ERIC Educational Resources Information Center

    Gruver, Joshua; Luloff, A. E.

    2008-01-01

    Water-resource scientists have become increasingly concerned about global water quality and quantity issues. Water and watershed education are now mandated topics for school-aged youth. Pennsylvania teachers lack consistent and accessible curricula to teach students about water quality and quantity. A mail survey administered in 2004 determined…

  6. War damages and reconstruction of Peruca dam

    SciTech Connect

    Nonveiller, E.; Rupcic, J. |; Sever, Z.

    1999-04-01

    The paper describes the heavy damages caused by blasting in the Peruca rockfill dam in Croatia in January 1993. Complete collapse of the dam by overtopping was prevented through quick action of the dam owner by dumping clayey gravel on the lowest sections of the dam crest and opening the bottom outlet of the reservoir, thus efficiently lowering the water level. After the damages were sufficiently established and alternatives for restoration of the dam were evaluated, it was decided to construct a diaphragm wall through the damaged core in the central dam part as the impermeable dam element and to rebuild the central clay core at the dam abutments. Reconstruction works are described.

  7. PROFILE: Management of Sedimentation in Tropical Watersheds.

    PubMed

    NAGLE; FAHEY; LASSOIE

    1999-05-01

    / The sedimentation of reservoirs is a serious problem throughout the tropics, yet most attempts to control sedimentation in large river basins have not been very successful. Reliable information on erosion rates and sources of sediments has been lacking. In regions where geologically unstable terrain combines with high rainfall, natural erosion rates might be so high that the effects of human activity are limited. Estimates of natural erosion in these situations often have been poor because of the episodic nature of most erosion during large storms and because mass-wasting may supply much of the sediment. The predominance of mass-wasting in some watersheds can result in an unexpectedly high ratio of bedload to suspended load, shifting sedimentation to "live" rather than "dead" storage within reservoirs. Furthermore, the inappropriate use of the Universal Soil Loss Equation to assess the effectiveness of erosion control measures has led to inaccurate estimates of the sediment reduction benefits that could accrue to watershed treatment efforts. Although reducing erosion from cultivated areas is desirable for other reasons, efforts aimed at reducing reservoir sedimentation by controlling agricultural sources of erosion may have limited benefits if the principal sources are of natural origin or are associated with construction of the dams and reservoirs and with rural roads and trails. Finally, the most appropriate locations for watershed rehabilitation depend on the magnitude of temporary storage of colluvium and alluvium within the river basin: Where storage volume is large and residence time of sediment very long, reducing agricultural erosion may have limited impacts on sedimentation within the expected life of a reservoir. Systematic development and analysis of sediment budgets for representative watersheds is needed to address these limitations and thereby improve both the planning of river basin development schemes and the allocation of resources towards

  8. Fish Passage Assessment: Big Canyon Creek Watershed, Technical Report 2004.

    SciTech Connect

    Christian, Richard

    2004-02-01

    This report presents the results of the fish passage assessment as outlined as part of the Protect and Restore the Big Canyon Creek Watershed project as detailed in the CY2003 Statement of Work (SOW). As part of the Northwest Power Planning Council's Columbia Basin Fish and Wildlife Program (FWP), this project is one of Bonneville Power Administration's (BPA) many efforts at off-site mitigation for damage to salmon and steelhead runs, their migration, and wildlife habitat caused by the construction and operation of federal hydroelectric dams on the Columbia River and its tributaries. The proposed restoration activities within the Big Canyon Creek watershed follow the watershed restoration approach mandated by the Fisheries and Watershed Program. Nez Perce Tribal Fisheries/Watershed Program vision focuses on protecting, restoring, and enhancing watersheds and treaty resources within the ceded territory of the Nez Perce Tribe under the Treaty of 1855 with the United States Federal Government. The program uses a holistic approach, which encompasses entire watersheds, ridge top to ridge top, emphasizing all cultural aspects. We strive toward maximizing historic ecosystem productive health, for the restoration of anadromous and resident fish populations. The Nez Perce Tribal Fisheries/Watershed Program (NPTFWP) sponsors the Protect and Restore the Big Canyon Creek Watershed project. The NPTFWP has the authority to allocate funds under the provisions set forth in their contract with BPA. In the state of Idaho vast numbers of relatively small obstructions, such as road culverts, block thousands of miles of habitat suitable for a variety of fish species. To date, most agencies and land managers have not had sufficient, quantifiable data to adequately address these barrier sites. The ultimate objective of this comprehensive inventory and assessment was to identify all barrier crossings within the watershed. The barriers were then prioritized according to the amount of

  9. 6. GENE WASH DAM, LOOKING NORTHWEST. SURVEY REFLECTOR IN FOREGROUND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. GENE WASH DAM, LOOKING NORTHWEST. SURVEY REFLECTOR IN FOREGROUND FOR MONITORING MOVEMENT OF DAM AND EARTH. - Gene Wash Reservoir & Dam, 2 miles west of Parker Dam, Parker Dam, San Bernardino County, CA

  10. An adaptive watershed management assessment based on watershed investigation data.

    PubMed

    Kang, Min Goo; Park, Seung Woo

    2015-05-01

    The aim of this study was to assess the states of watersheds in South Korea and to formulate new measures to improve identified inadequacies. The study focused on the watersheds of the Han River basin and adopted an adaptive watershed management framework. Using data collected during watershed investigation projects, we analyzed the management context of the study basin and identified weaknesses in water use management, flood management, and environmental and ecosystems management in the watersheds. In addition, we conducted an interview survey to obtain experts' opinions on the possible management of watersheds in the future. The results of the assessment show that effective management of the Han River basin requires adaptive watershed management, which includes stakeholders' participation and social learning. Urbanization was the key variable in watershed management of the study basin. The results provide strong guidance for future watershed management and suggest that nonstructural measures are preferred to improve the states of the watersheds and that consistent implementation of the measures can lead to successful watershed management. The results also reveal that governance is essential for adaptive watershed management in the study basin. A special ordinance is necessary to establish governance and aid social learning. Based on the findings, a management process is proposed to support new watershed management practices. The results will be of use to policy makers and practitioners who can implement the measures recommended here in the early stages of adaptive watershed management in the Han River basin. The measures can also be applied to other river basins.

  11. Watershed Restoration Project

    SciTech Connect

    Julie Thompson; Betsy Macfarlan

    2007-09-27

    In 2003, the U.S. Department of Energy issued the Eastern Nevada Landscape Coalition (ENLC) funding to implement ecological restoration in Gleason Creek and Smith Valley Watersheds. This project was made possible by congressionally directed funding that was provided through the US Department of Energy, Energy Efficiency and Renewable Energy, Office of the Biomass Program. The Ely District Bureau of Land Management (Ely BLM) manages these watersheds and considers them priority areas within the Ely BLM district. These three entities collaborated to address the issues and concerns of Gleason Creek and Smith Valley and prepared a restoration plan to improve the watersheds’ ecological health and resiliency. The restoration process began with watershed-scale vegetation assessments and state and transition models to focus on restoration sites. Design and implementation of restoration treatments ensued and were completed in January 2007. This report describes the restoration process ENLC undertook from planning to implementation of two watersheds in semi-arid Eastern Nevada.

  12. Is it worth a dam?

    PubMed Central

    Joyce, S

    1997-01-01

    Once a sign of modernization and growth, dams are often seen today as symbols of environmental and social devastation. Over 800,000 dams have been built worldwide to provide drinking water, flood control, hydropower, irrigation, navigation, and water storage. Dams do indeed provide these things,but at the cost of several adverse, unexpected effects: disruption of ecosystems, decline of fish stocks, forced human and animal resettlements, and diseases such as malaria, which are borne by vectors that thrive in quiet waters. PMID:9349830

  13. Geochemical discrimination of five pleistocene Lava-Dam outburst-flood deposits, western Grand Canyon, Arizona

    USGS Publications Warehouse

    Fenton, C.R.; Poreda, R.J.; Nash, B.P.; Webb, R.H.; Cerling, T.E.

    2004-01-01

    Pleistocene basaltic lava dams and outburst-flood deposits in the western Grand Canyon, Arizona, have been correlated by means of cosmogenic 3He (3Hec) ages and concentrations of SiO2, Na2O, K2O, and rare earth elements. These data indicate that basalt clasts and vitroclasts in a given outburst-flood deposit came from a common source, a lava dam. With these data, it is possible to distinguish individual dam-flood events and improve our understanding of the interrelations of volcanism and river processes. At least five lava dams on the Colorado River failed catastrophically between 100 and 525 ka; subsequent outburst floods emplaced basalt-rich deposits preserved on benches as high as 200 m above the current river and up to 53 km downstream of dam sites. Chemical data also distinguishes individual lava flows that were collectively mapped in the past as large long-lasting dam complexes. These chemical data, in combination with age constraints, increase our ability to correlate lava dams and outburst-flood deposits and increase our understanding of the longevity of lava dams. Bases of correlated lava dams and flood deposits approximate the elevation of the ancestral river during each flood event. Water surface profiles are reconstructed and can be used in future hydraulic models to estimate the magnitude of these large-scale floods.

  14. Gene Wash and Copper Basin Dams are surviving alkali-aggregate reaction

    SciTech Connect

    Hill, C.J.

    1995-12-31

    Gene Wash and Copper Basin Dams were constructed in 1937 and 1938, and are owned and operated by the Metropolitan Water District of Southern California (MWD). The dams are located in San Bernardino County, California, close to the Colorado River, and very close to the easternmost point of California. They form two intermediate storage facilities on the Colorado River Aqueduct system which conveys water from Lake Havasu to the Los Angeles and San Diego areas. The locations of the dams are shown. Gene Wash Dam is a concrete arch structure, with a maximum height of arch of 131 feet. There is a gravity thrust block on the right abutment and the total crest length is 430 feet. Copper Basin Dam is a concrete arch dam with a maximum height of arch of 187 feet and a crest length of 253 feet. Plans, elevations and sections for both dams. The dams are in the Whipple Mountains at the eastern edge of the Mojave Desert. Between June and October, maximum temperatures usually exceed 100 degrees Farenheit, while daily low temperatures in this period are generally in the 60`s and 70`s. Winter temperatures are mild, with daytime highs in the 70`s and 80`s, and lows only occasionally below freezing. The area is arid, with total annual rainfall generally between two and ten inches. Both dams were built in desert washes with no permanent flow. The foundation for both structures is a strong, erosion-resistant, red-brown, non-marine sandstone and conglomerate of Tertiary age known as the Copper Basin Formation (Buwalda, 1937). Spillways for both dams are ungated ogee crests, which are separate from the dams. Gene Wash Dam and Copper Basin Dam are geographically close together, are of similar design, and were constructed at the same time, using the same materials. Their performance since construction, not surprisingly, has been similar.

  15. Deer Creek Dam, Dam, 1,204 feet/238 degrees from intersection of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Deer Creek Dam, Dam, 1,204 feet/238 degrees from intersection of dam complex access road and U.S. Highway 189 to center of dam, 874 feet/352 degrees from Hydroelectric Powerplant (HAER UT-93-B) to center of dam, Charleston, Wasatch County, UT

  16. Beyond hydrology in the sustainability assessment of dams: A planners perspective - The Sarawak experience

    NASA Astrophysics Data System (ADS)

    Andre, Edward

    2012-01-01

    SummaryThere is increasing concern about the availability of water supplies in developing countries to provide clean drinking water and sanitation as well as providing for irrigation for food security. This has led to hydrologically led investigation to establish the feasibility and storage capacity of potentially new dam sites. This task has become more difficult for hydrologists and others with the uncertainties created by climate change and the measurement of the hydrological, geographical and ecological footprint of new dams. The questions asked by hydrologists are increasingly likely to be required to be cast in terms of the four pillars of sustainability; environmental, economic, social and institutional. Similarly, regional planners have to be more cognisant of the social outcomes of dam development while understanding the wider hydrological context at a watershed and basin level. The paper defines the concept of sustainability assessment in the context of resettlement and analyses its implications for the Bakun Hydro-electric project in Sarawak, Malaysia. Specifically it attempts to address the question of what social sustainability would really mean in the context of communities affected by dam projects, and their catchments using hermeneutics, tradeoffs and offsets. The findings of this question were presented at a hydrological conference held in Santiago in October 2010, based on the outcome of specific questionnaire responses received from indigenous peoples affected by the Bakun Dam hydroelectric project. The paper also offers some insights pertaining to the social sustainability assessment aspects of dams and their catchments.

  17. FORMATION AND FAILURE OF NATURAL DAMS.

    USGS Publications Warehouse

    Costa, John E.; Schuster, Robert L.

    1988-01-01

    Of the numerous kinds of dams that form by natural processes, dams formed from landslides, glacial ice, and late-neoglacial moraines present the greatest threat to people and property. Landslide dams form a wide range of physiographic settings. The most common types of mass movements that form landslide dams are rock and debris avalanches; rock and soil slumps and slides; and mud, debris, and earth flows. The most common initiation mechanisms for dam-forming landslides are excessive rainfall and snowmelt and earthquakes. Natural dams may cause upstream flooding as the lake rises and downstream flooding as a result of failure of the dam. Although data are few, for the same potential energy at the dam site, downstream flood peaks from the failure of glacier-ice dams are smaller than those from landslide, moraine, and constructed earth-fill and rock-fill dam failures.

  18. Impacts of Post-Dam Land-use/Land-cover Changes on Modification of Extreme precipitation in Contrasting Hydro-climate and Terrain Features

    NASA Astrophysics Data System (ADS)

    Woldemichael, A. T.; Hossain, F.

    2013-12-01

    Understanding the impact of post-dam climate feedbacks, due to land-use/land-cover (LULC) variability, on modification of extreme precipitation (EP) remains a challenge for a 21st century approach to dam design and operation. In this study, we used the Regional Atmospheric Modeling System (RAMS, version 6.0), involving a number of pre-defined LULC scenarios to address the important question regarding dams and their impoundments: How sensitive are the hydroclimatology and terrain features of a region in modulating the post-dam response of climate feedbacks to EP? The study region covered the Owyhee dam/reservoir on Owyhee River Watershed (ORW) -located in eastern Oregon. A systematic perturbation of the relative humidity in the initial and boundary condition of the model was carried out to simulate EP. Among the different LULC scenarios used in the simulation over the ORW, irrigation expansion in the post-dam era resulted in an increase in EP up to 6% in the 72-hr precipitation total. The contribution of the reservoir on EP added 8% to the 72-hr total when compared to the pre-dam LULC conditions. In order to address the science question, a previously completed investigation on the Folsom dam (American River Watershed, ARW) in California, was compared with the ORW findings on the basis of contrasting differences in hydroclimatology and terrain features. Our results indicate that the post-dam LULC change scenarios impact EP of ORW (Owyhee Dam) is much greater than the EP of the ARW (Folsom Dam) due to its semi-arid climate (leeward side) and flat terrain. LULC changes are found to be less sensitive to EP modification in the windward side of the mountainous terrain of ARW.

  19. Panama Canal Watershed Experiment- Agua Salud Project

    USGS Publications Warehouse

    Stallard, Robert F.; Ogden, Fred L.; Elsenbeer, Helmut; Hall, Jefferson S.

    2010-01-01

    The Agua Salud Project utilizes the Panama Canal’s (Canal) central role in world commerce to focus global attention on the ecosystem services provided by tropical forests. The Canal was one of the great engineering projects in the world. Completed in 1914, after almost a decade of concerted effort, its 80 km length greatly shortened the voyage between the Atlantic and Pacific Oceans. An entire class of ships, the Panamax, has been constructed to maximize the amount of cargo that can be carried in a Canal passage. In today’s parlance, the Canal is a “green” operation, powered largely by water (Table 1). The locks, three pairs on each end with a net lift of 27 meters, are gravity fed. For each ton of cargo that is transferred from ocean to ocean, about 13 tons of water (m3) are used. Lake Gatún forms much of the waterway in the Canal transect. Hydroelectricity is generated at the Gatún dam, whenever there is surplus water, and at Madden Dam (completed in 1936) when water is transferred from Lake Alhajuela to Lake Gatún. The Canal watershed is the source of drinking water for Panama City and Colon City, at either end of the Canal, and numerous towns in between.

  20. A method to evaluate the overall performances of watershed conservation practices conducted after severe landslides-related hazards

    NASA Astrophysics Data System (ADS)

    Huang, Wen-Shun; Jan, Chyan-Deng; Zeng, Yi-Chao; Wang, Ji-Shang; Lin, Shiao-Syuan

    2014-05-01

    The Tseng-Wen Reservoir watershed is the largest and the most important reservoir in southern Taiwan. The watershed of the Tseng-Wen Reservoir suffered severe landslide-related hazards and deposits caused by Typhoon Morakot in August 2009. After the severe hazards, the government conducted many conservation practices, such as check dams, slit dams, ground sills, revetments, vegetation treatments and regulation work on torrents, in the Tseng-Wen Reservoir watershed. Since 2009 Typhoon Morakot, the government has carried on the program of conservation for three years. It is necessary to review and adjust the current situations of the conservation practices and restoration in order to plan the following conservative project. To evaluate the overall performances of conservation practices, we propose a method including five factors to reflect the performances of conservation practices. The five factors are (1) reduction of watershed sediment yield, (2) river-course recovery, (3) reduction of watershed landslide area, (4) reduction of peak discharge, and (5) amount of sediment directly stabilized by conservation practices. To compare the performances, we normalize the factors and present the five normalized factors in a radar-diagram. The results showed that the evaluated basins are restored well and close to the characteristics of watershed before Typhoon Morakot. The assessments from field investigation are corresponding to the evaluated results. The five factors can adequately normalize the differences of the characteristics before and after severe landslide-related hazards in the watershed, and furthermore they can enhance the inferior factors for the future conservation works.

  1. Watershed Central: A New Gateway to Watershed Information

    EPA Science Inventory

    Many communities across the country struggle to find the right approaches, tools and data to in their watershed plans. EPA recently posted a new Web site called "Watershed Central, a “onestop" tool, to help watershed organizations and others find key resources to protect their ...

  2. Watershed Central: Dynamic Collaboration for Improving Watershed Management (Philadelphia)

    EPA Science Inventory

    The Watershed Central web and wiki pages will be presented and demonstrated real-time as part of the overview of Web 2.0 collaboration tools for watershed management. The presentation portion will discuss how EPA worked with watershed practitioners and within the Agency to deter...

  3. Dam Removal Information Portal (DRIP)—A map-based resource linking scientific studies and associated geospatial information about dam removals

    USGS Publications Warehouse

    Duda, Jeffrey J.; Wieferich, Daniel J.; Bristol, R. Sky; Bellmore, J. Ryan; Hutchison, Vivian B.; Vittum, Katherine M.; Craig, Laura; Warrick, Jonathan A.

    2016-08-18

    The removal of dams has recently increased over historical levels due to aging infrastructure, changing societal needs, and modern safety standards rendering some dams obsolete. Where possibilities for river restoration, or improved safety, exceed the benefits of retaining a dam, removal is more often being considered as a viable option. Yet, as this is a relatively new development in the history of river management, science is just beginning to guide our understanding of the physical and ecological implications of dam removal. Ultimately, the “lessons learned” from previous scientific studies on the outcomes dam removal could inform future scientific understanding of ecosystem outcomes, as well as aid in decision-making by stakeholders. We created a database visualization tool, the Dam Removal Information Portal (DRIP), to display map-based, interactive information about the scientific studies associated with dam removals. Serving both as a bibliographic source as well as a link to other existing databases like the National Hydrography Dataset, the derived National Dam Removal Science Database serves as the foundation for a Web-based application that synthesizes the existing scientific studies associated with dam removals. Thus, using the DRIP application, users can explore information about completed dam removal projects (for example, their location, height, and date removed), as well as discover sources and details of associated of scientific studies. As such, DRIP is intended to be a dynamic collection of scientific information related to dams that have been removed in the United States and elsewhere. This report describes the architecture and concepts of this “metaknowledge” database and the DRIP visualization tool.

  4. Dam Removal Information Portal (DRIP)—A map-based resource linking scientific studies and associated geospatial information about dam removals

    USGS Publications Warehouse

    Duda, Jeffrey J.; Wieferich, Daniel J.; Bristol, R. Sky; Bellmore, J. Ryan; Hutchison, Vivian B.; Vittum, Katherine M.; Craig, Laura; Warrick, Jonathan A.

    2016-01-01

    The removal of dams has recently increased over historical levels due to aging infrastructure, changing societal needs, and modern safety standards rendering some dams obsolete. Where possibilities for river restoration, or improved safety, exceed the benefits of retaining a dam, removal is more often being considered as a viable option. Yet, as this is a relatively new development in the history of river management, science is just beginning to guide our understanding of the physical and ecological implications of dam removal. Ultimately, the “lessons learned” from previous scientific studies on the outcomes dam removal could inform future scientific understanding of ecosystem outcomes, as well as aid in decision-making by stakeholders. We created a database visualization tool, the Dam Removal Information Portal (DRIP), to display map-based, interactive information about the scientific studies associated with dam removals. Serving both as a bibliographic source as well as a link to other existing databases like the National Hydrography Dataset, the derived National Dam Removal Science Database serves as the foundation for a Web-based application that synthesizes the existing scientific studies associated with dam removals. Thus, using the DRIP application, users can explore information about completed dam removal projects (for example, their location, height, and date removed), as well as discover sources and details of associated of scientific studies. As such, DRIP is intended to be a dynamic collection of scientific information related to dams that have been removed in the United States and elsewhere. This report describes the architecture and concepts of this “metaknowledge” database and the DRIP visualization tool.

  5. Impact of debris dams on hyporheic interaction along a semi-arid stream

    NASA Astrophysics Data System (ADS)

    Lautz, Laura K.; Siegel, Donald I.; Bauer, Robert L.

    2006-01-01

    Hyporheic exchange increases the potential for solute retention in streams by slowing downstream transport and increasing solute contact with the substrate. Hyporheic exchange may be a major mechanism to remove nutrients in semi-arid watersheds, where livestock have damaged stream riparian zones and contributed nutrients to stream channels. Debris dams, such as beaver dams and anthropogenic log dams, may increase hyporheic interactions by slowing stream water velocity, increasing flow complexity and diverting water to the subsurface.Here, we report the results of chloride tracer injection experiments done to evaluate hyporheic interaction along a 320 m reach of Red Canyon Creek, a second order stream in the semi-arid Wind River Range of Wyoming. The study site is part of a rangeland watershed managed by The Nature Conservancy of Wyoming, and used as a hydrologic field site by the University of Missouri Branson Geologic Field Station. The creek reach we investigated has debris dams and tight meanders that hypothetically should enhance hyporheic interaction. Breakthrough curves of chloride measured during the field experiment were modelled with OTIS-P, a one-dimensional, surface-water, solute-transport model from which we extracted the storage exchange rate and cross-sectional area of the storage zone As for hyporheic exchange. Along gaining reaches of the stream reach, short-term hyporheic interactions associated with debris dams were comparable to those associated with severe meanders. In contrast, along the non-gaining reach, stream water was diverted to the subsurface by debris dams and captured by large-scale near-stream flow paths. Overall, hyporheic exchange rates along Red Canyon Creek during snowmelt recession equal or exceed exchange rates observed during baseflow at other streams.

  6. Entering the watershed

    SciTech Connect

    Doppelt, B.; Scurlock, M.; Frissell, C.; Karr, J.

    1993-01-01

    The ecological integrity of a river is a direct function of the health of its watershed. Riverine pollution, habitat degradation, and extinction of aquatic biodiversity are all issues that must be addressed at the ecosystem level. The product of a two-year project established by The Pacific Rivers Council to develop new federal riverine protection and restoration policy alternatives, this book recommends a comprehensive new approach to river protection: a nationwide, strategic community- and ecosystem-based watershed restoration initiative founded upon principles of watershed dynamics, ecosystem function, and conservation biology. The book describes in detail the existing level of damage of rivers and species. A new, intensified national emphasis on rivers is presented. The flaws and gaps in existing policy are analyzed. The scientific underpinnings and management strategies needed in new policy are outlined. Specific policy proposals are made.

  7. Anthropogenic Effects on Total Water Storage from GRACE on Large South American Watersheds

    NASA Astrophysics Data System (ADS)

    Xavier, L.; Becker, M.; Cazenave, A. A.; Güntner, A.; Rotunno, O.

    2009-12-01

    Over continents, GRACE total water storage (TWS) solutions are expected to represent main surface, soil and groundwater stocks variability. Recent studies have showed that intensive groundwater resources withdrawal in India can be “captured” by GRACE. Another important anthropogenic impact on the natural water cycle is the building and operation of large dams. Even though they impact primarily the local water stock variations, one can expect subsequent changes on the water cycle and some evidence of this from GRACE. This would be particularly evident where the volume of stored water behind dams represents a significant proportion of the total TWS. In this study, we analyzed the effect on the water cycle of large dams over South American large watersheds. Most of Brazilians large dams are located in the Upper Paraná watershed, upstream the Itaipu dam. By performing a correlation analysis between the upstream integrated rainfall and the GRACE TWS series, we found a noticeable phase difference between the two quantities. The phase difference is larger over the utmost upstream region of Upper Parana watershed. We assumed that this pattern could be due to an effect of man-made reservoirs. We took into account the reservoirs storage and found that they induce an additional phase-lag of about 1 month in the TWS response to precipitation forcing. We also investigated dams’ impact on the simulations of the Water Gap Hydrological Model. The results also show a similar time delay similar, suggesting that the model correctly accounts for the dam effect. Finally we see similar lags, though smaller, over other South American river basins.

  8. Influence of check dams on debris-flow run-out intensity

    NASA Astrophysics Data System (ADS)

    Remaã®Tre, A.; van Asch, Th. W. J.; Malet, J.-P.; Maquaire, O.

    2008-12-01

    Debris flows are very dangerous phenomena claiming thousands of lives and millions of Euros each year over the world. Disaster mitigation includes non-structural (hazard mapping, insurance policies), active structural (drainage systems) and passive structural (check dams, stilling basins) countermeasures. Since over twenty years, many efforts are devoted by the scientific and engineering communities to the design of proper devices able to capture the debris-flow volume and/or break down the energy. If considerable theoretical and numerical work has been performed on the size, the shape and structure of check dams, allowing the definition of general design criteria, it is worth noting that less research has focused on the optimal location of these dams along the debris-flow pathway. In this paper, a methodological framework is proposed to evaluate the influence of the number and the location of the check dams on the reduction of the debris-flow intensity (in term of flow thickness, flow velocity and volume). A debris-flow model is used to simulate the run-out of the debris flow. The model uses the Janbu force diagram to resolve the force equilibrium equations; a bingham fluid rheology is introduced and represents the resistance term. The model has been calibrated on two muddy debris-flow events that occurred in 1996 and 2003 at the Faucon watershed (South French Alps). Influence of the check dams on the debris-flow intensity is quantified taking into account several check dams configurations (number and location) as input geometrical parameters. Results indicate that debris-flow intensity is decreasing with the distance between the source area and the first check dams. The study demonstrates that a small number of check dams located near the source area may decrease substantially the debris-flow intensity on the alluvial fans.

  9. Understanding the impact of dam-triggered land use/land cover change on the modification of extreme precipitation

    NASA Astrophysics Data System (ADS)

    Woldemichael, Abel T.; Hossain, Faisal; Pielke, Roger, Sr.; Beltrán-Przekurat, Adriana

    2012-09-01

    Two specific questions are addressed in this study regarding dams (artificial reservoirs). (1) Can a dam (artificial reservoir) and the land use/land cover (LULC) changes triggered by it physically alter extreme precipitation? The term extreme precipitation (EP) is used as a way of representing the model-derived upper bound of precipitation that pertains to the engineering definition of the standard probable maximum precipitation (PMP) used in design of dams. (2) Among the commonly experienced LULC changes due to dams, which type of change leads to the most detectable alteration of extreme precipitation? The American River Basin (ARW) and the Folsom dam were selected as a study region. Four scenarios of LULC change (comprising also various reservoir surface areas) were analyzed in a step by step fashion to elucidate the scenario leading to most significant impact on EP. The Regional Atmospheric Modeling System (RAMS, version 6.0) was used to analyze the impact of these LULC scenarios in two modes. In the first mode (called normal), the probable precipitation pattern due to each LULC scenario was identified. The second mode (called moisture-maximized), the PMP pattern represented from a 100% relative humidity profile was generated as an indicator of extreme precipitation (EP). For the particular case of ARW and Folsom dam, irrigation was found as having the most detectable impact on EP (a 5% increase in 72 h total for the normal mode and a 3% increase for the moisture-maximized mode) in and around the ARW watershed. Doubling the reservoir size, on the other hand, brought only a small change in EP. Our RAMS-simulated results demonstrate that LULC changes driven by surrounding landscape alteration resulting from the dams can, in fact, alter the local to regional hydrometeorology as well as extreme precipitation. There is a strong possibility of a positive feedback mechanism initiated by irrigated landscapes located upwind of orographic rain producing watersheds that

  10. Watershed nitrogen and mercury geochemical fluxes integrate landscape factors in long-term research watersheds at Acadia National Park, Maine, USA.

    PubMed

    Kahl, J S; Nelson, S J; Fernandez, I; Haines, T; Norton, S; Wiersma, G B; Jacobson, G; Amirbahman, A; Johnson, K; Schauffler, M; Rustad, L; Tonnessen, K; Lent, R; Bank, M; Elvir, J; Eckhoff, J; Caron, H; Ruck, P; Parker, J; Campbell, J; Manski, D; Breen, R; Sheehan, K; Grygo, A

    2007-03-01

    This paper is an overview of this special issue devoted to watershed research in Acadia National Park (Acadia NP). The papers address components of an integrated research program on two upland watersheds at Acadia NP, USA (44 degrees 20' N latitude; 68 degrees 15' E longitude). These watersheds were instrumented in 1998 to provide a long-term foundation for regional ecological and watershed research. The research was initiated as part of EPA/NPS PRIMENet (Park Research and Intensive Monitoring of Ecosystems Network), a system of UV-monitoring stations and long-term watershed research sites located in US national parks. The initial goals at Acadia NP were to address research questions about mercury, acid rain, and nitrogen saturation developed from prior research. The project design was based on natural differences in forests and soils induced by an intense wildfire in one watershed in 1947. There is no evidence of fire in the reference watershed for several hundred years. We are testing hypotheses about controls on surface water chemistry, and bioavailability of contaminants in the contrasting watersheds. The unburned 47-ha Hadlock Brook watershed is 70% spruce-fir mature conifer forest. In contrast, burned 32-ha Cadillac Brook watershed, 4 km northeast of the Hadlock watershed, is 20% regenerating mixed northern hardwoods and 60% shrub/rocky balds. Differences in atmospheric deposition are controlled primarily by forest stand composition and age. The watersheds are gauged and have water chemistry stations at 122 m (Cadillac) and 137 m (Hadlock); watershed maximum elevations are 468 and 380 m, respectively. The stream water chemistry patterns reflect, in part, the legacy of the intense fire, which, in turn, controls differences in forest vegetation and soil characteristics. These factors result in higher nitrogen and mercury flux from the unburned watershed, reflecting differences in atmospheric deposition, contrasting ecosystem pools of nitrogen and mercury, and

  11. Check dams effects on sediment transport in steep slope flume

    NASA Astrophysics Data System (ADS)

    Piton, Guillaume; Recking, Alain

    2014-05-01

    Depending on many influences (geology, relief, hydrology, land use, etc.) some mountainous watershed are prone to cause casualties and facilities damages. Large amounts of sediments episodically released by torrents are often the biggest problem in torrent related hazard mitigation. Series of transversal structures as check dams and ground sills are often used in the panel of risk mitigation technics. A large literature exits on check dams and it mainly concerns engineering design, e.g. toe scouring, stability stress diagram, changes in upper and lower reaches equilibrium slopes. Check dams in steep slope rivers constitute fixed points in the bed profile and prevent general bed incision. However their influence on sediment transport once they are filled is not yet clear. Two flume test campaigns, synthetize in Table 1, were performed to investigate this question: Table 1 : experiment plan Run (duration) Ref1 (50h)CD1a (30h)CD1b (30h)Ref2 (92h)CD2 (18h) Solid feeding discharge (g.s^-1) 44 44 44 60 60 Number of check dams none 1 3 none 2 A nearly 5-m-long, 10-cm-wide and 12%-steep flume was used. The water discharge was set to 0,55 l/s in all runs. A mixture of poorly sorted natural sediments with diameters between 0.8 and 40 mm was used. An open solid-discharge-feeding circuit kept the inlet sediment flux constant during all experiments. As both feeding rates did not present variation, changes in outlet solid discharge were assumed to be due to bed variations in the bed storage. We observed strong fluctuations of solid flux and slope in each reaches of all runs between: (i) steep aggradating armoured bed and (ii) less steep and finer bed releasing bedload sheets during erosion events and inducing bedload pulses. All experiments showed consistent results: transported volume associated with erosion event decreased with the length between two subsequent check dams. Solid transversal structures shorten the upstream erosion-propagation and avoid downstream change in the

  12. Floods from tailings dam failures.

    PubMed

    Rico, M; Benito, G; Díez-Herrero, A

    2008-06-15

    This paper compiles the available information on historic tailings dam failures with the purpose to establish simple correlations between tailings ponds geometric parameters (e.g., dam height, tailings volume) and the hydraulic characteristics of floods resulting from released tailings. Following the collapse of a mining waste dam, only a part of tailings and polluted water stored at the dam is released, and this outflow volume is difficult to estimate prior the incident. In this study, tailings' volume stored at the time of failure was shown to have a good correlation (r2=0.86) with the tailings outflow volume, and the volume of spilled tailings was correlated with its run-out distance (r2=0.57). An envelope curve was drawn encompassing the majority of data points indicating the potential maximum downstream distance affected by a tailings' spill. The application of the described regression equations for prediction purposes needs to be treated with caution and with support of on-site measurement and observations. However, they may provide a universal baseline approximation on tailing outflow characteristics (even if detailed dam information is unavailable), which is of a great importance for risk analysis purposes.

  13. Dam-Breach hydrology of the Johnstown flood of 1889-challenging the findings of the 1891 investigation report.

    PubMed

    Coleman, Neil M; Kaktins, Uldis; Wojno, Stephanie

    2016-06-01

    In 1891 a report was published by an ASCE committee to investigate the cause of the Johnstown flood of 1889. They concluded that changes made to the dam by the South Fork Fishing and Hunting Club did not cause the disaster because the embankment would have been overflowed and breached if the changes were not made. We dispute that conclusion based on hydraulic analyses of the dam as originally built, estimates of the time of concentration and time to peak for the South Fork drainage basin, and reported conditions at the dam and in the watershed. We present a LiDAR-based volume of Lake Conemaugh at the time of dam failure (1.455 × 10(7) m(3)) and hydrographs of flood discharge and lake stage decline. Our analytical approach incorporates the complex shape of this dam breach. More than 65 min would have been needed to drain most of the lake, not the 45 min cited by most sources. Peak flood discharges were likely in the range 7200 to 8970 m(3) s(-1). The original dam design, with a crest ∼0.9 m higher and the added capacity of an auxiliary spillway and five discharge pipes, had a discharge capacity at overtopping more than twice that of the reconstructed dam. A properly rebuilt dam would not have overtopped and would likely have survived the runoff event, thereby saving thousands of lives. We believe the ASCE report represented state-of-the-art for 1891. However, the report contains discrepancies and lapses in key observations, and relied on excessive reservoir inflow estimates. The confidence they expressed that dam failure was inevitable was inconsistent with information available to the committee. Hydrodynamic erosion was a likely culprit in the 1862 dam failure that seriously damaged the embankment. The Club's substandard repair of this earlier breach sowed the seeds of its eventual destruction.

  14. Fluvial wood function downstream of beaver versus man-made dams in headwater streams in Massachusetts, USA

    NASA Astrophysics Data System (ADS)

    David, G. C.; DeVito, L. F.; Munz, K. T.; Lisius, G.

    2014-12-01

    Fluvial wood is an essential component of stream ecosystems by providing habitat, increasing accumulation of organic matter, and increasing the processing of nutrients and other materials. However, years of channel alterations in Massachusetts have resulted in low wood loads despite the afforestation that has occurred since the early 1900s. Streams have also been impacted by a large density of dams, built during industrialization, and reduction of the beaver population. Beavers were reintroduced to Massachusetts in the 1940s and they have since migrated throughout the state. Beaver dams impound water, which traps sediment and results in the development of complex channel patterns and more ecologically productive and diverse habitats than those found adjacent to man-made dams. To develop better management practices for dam removal it is essential that we understand the geomorphic and ecologic function of wood in these channels and the interconnections with floodplain dynamics and stream water chemistry. We investigate the connections among fluvial wood, channel morphology, floodplain soil moisture dynamics, and stream water chemistry in six watersheds in Massachusetts that have been impacted by either beaver or man-made dams. We hypothesize that wood load will be significantly higher below beaver dams, subsequently altering channel morphology, water chemistry, and floodplain soil moisture. Reaches are surveyed up- and downstream of each type of dam to better understand the impact dams have on the fluvial system. Surveys include a longitudinal profile, paired with dissolved oxygen and ammonium measurements, cross-section and fluvial wood surveys, hydraulic measurements, and floodplain soil moisture mapping. We found that dissolved oxygen mirrored the channel morphology, but did not vary significantly between reaches. Wood loads were significantly larger downstream of beaver dams, which resulted in significant changes to the ammonium levels. Floodplain soil moisture

  15. Dam-Breach hydrology of the Johnstown flood of 1889-challenging the findings of the 1891 investigation report.

    PubMed

    Coleman, Neil M; Kaktins, Uldis; Wojno, Stephanie

    2016-06-01

    In 1891 a report was published by an ASCE committee to investigate the cause of the Johnstown flood of 1889. They concluded that changes made to the dam by the South Fork Fishing and Hunting Club did not cause the disaster because the embankment would have been overflowed and breached if the changes were not made. We dispute that conclusion based on hydraulic analyses of the dam as originally built, estimates of the time of concentration and time to peak for the South Fork drainage basin, and reported conditions at the dam and in the watershed. We present a LiDAR-based volume of Lake Conemaugh at the time of dam failure (1.455 × 10(7) m(3)) and hydrographs of flood discharge and lake stage decline. Our analytical approach incorporates the complex shape of this dam breach. More than 65 min would have been needed to drain most of the lake, not the 45 min cited by most sources. Peak flood discharges were likely in the range 7200 to 8970 m(3) s(-1). The original dam design, with a crest ∼0.9 m higher and the added capacity of an auxiliary spillway and five discharge pipes, had a discharge capacity at overtopping more than twice that of the reconstructed dam. A properly rebuilt dam would not have overtopped and would likely have survived the runoff event, thereby saving thousands of lives. We believe the ASCE report represented state-of-the-art for 1891. However, the report contains discrepancies and lapses in key observations, and relied on excessive reservoir inflow estimates. The confidence they expressed that dam failure was inevitable was inconsistent with information available to the committee. Hydrodynamic erosion was a likely culprit in the 1862 dam failure that seriously damaged the embankment. The Club's substandard repair of this earlier breach sowed the seeds of its eventual destruction. PMID:27441292

  16. Designing for Watershed Inquiry

    ERIC Educational Resources Information Center

    Bodzin, Alec; Shive, Louise

    2004-01-01

    In this article, we describe a collaborative design initiative with three secondary school teachers to promote the use of Web-based inquiry in the context of a watershed investigation. Design interviews that focus on instructional goals and pedagogical beliefs of classroom teachers were conducted. The interview protocol used a curricular framework…

  17. Sourcebook for Watershed Education.

    ERIC Educational Resources Information Center

    Cole-Misch, Sally; And Others

    The Global Rivers Environmental Education Network (GREEN) watershed education program is unique from other water monitoring programs because it emphasizes action-oriented and problem-solving approaches based on an interdisciplinary education and extensive networking with others traveling down a similar path. This sourcebook offers guidance based…

  18. WATERSHED BASED SURVEY DESIGNS

    EPA Science Inventory

    The development of watershed-based design and assessment tools will help to serve the multiple goals for water quality monitoring required under the Clean Water Act, including assessment of regional condition to meet Section 305(b), identification of impaired water bodies or wate...

  19. USEPA WATERSHED APPROACH

    EPA Science Inventory

    The U.S. Environmental Protection Agency's Office of Research and Development has developed a well defined research plan to evaluate pollutants within watersheds. This plan is defined by long term goals and annual performance measures. The first goal is to provide the approache...

  20. Retrofitting for watershed drainage

    SciTech Connect

    Bennett, D.B. ); Heaney, J.P. )

    1991-09-01

    Over the past 8 years, degradation in Florida's Indian River Lagoon has taken the form of fish kills, reduced viable recreational and commercial fisheries, and loss of seagrass beds. Stormwater drainage practices in the watershed have been identified as the primary culprit in the slow demise of the lagoon. Specific drainage problems include an increased volume of freshwater runoff to the estuarine receiving water and deposition of organic sediments, reduced water clarity because of increased discharge of suspended solids and tea colored' groundwater - a result of drainage-canal-induced land dewatering, and eutrophication caused by nutrient loadings. In addition, poor flushing in lagoon segments makes runoff impacts even more damaging to the ecosystem. Recently, the lagoon has received national, regional, state, and local attention over its degradation and citizens' action and multi-agency efforts to restore it. To mitigate damage to the Indian River lagoon, agencies are considering alternatives such as retrofitting to reduce pollutant loads and implementing a more comprehensive watershed approach to stormwater management instead of individual controls on new development currently widely practiced. A comprehensive, long-term watershed control approach avoids unnecessary construction expenses, encourages cost-effective tradeoffs based on specific objectives, facilities performance monitoring, and accounts for cumulative impacts of continued growth in the watershed.

  1. Three Gorges Dam, China

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This ASTER image shows a 60 km stretch of the Yangtze River in China, including the Xiling Gorge, the eastern of the three gorges. In the left part of the image is the construction site of the Three Gorges Dam, the world's largest.

    This image was acquired on July 20, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is part of NASA's Earth Science Enterprise, a long-term research and technology program designed to examine Earth's land, oceans, atmosphere, ice and life as a total integrated system.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    Size: 60 x 24 km (36 x 15 miles) Location: 30.6 deg. North lat., 111.2 deg. East long. Orientation: North at top Image Data: ASTER

  2. 17. VIEW OF MAIN AND DIVERSION DAMS FROM WATERGATE AFTER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. VIEW OF MAIN AND DIVERSION DAMS FROM WATER-GATE AFTER REMOVAL OF DRIFTWOOD. DIVERSION DAM IN LEFT FOREGROUND, MAIN DAM TO THE RIGHT. Photographed July 18, 1938. - Forge Creek Dam-John Cable Mill, Townsend, Blount County, TN

  3. Synthesizing Fluvial Sedimentary and Geomorphic Response to Dam Removal—A Two-Decade Perspective

    NASA Astrophysics Data System (ADS)

    East, A. E.; Major, J. J.; Bountry, J.; Randle, T. J.; O'Connor, J. E.; Grant, G.; Wilcox, A. C.; Magirl, C. S.; Magilligan, F. J.; Collins, M. J.; Pess, G. R.; Tullos, D. D.

    2015-12-01

    Over the last several decades there has been a marked increase in the number of dams removed in the United States, including the recent removal of large dams impounding millions of cubic meters of sediment. From these removals, common findings have begun to emerge: (1) Rivers are resilient, showing rapid geomorphic and sedimentary response to dam removals, especially when removals are sudden rather than prolonged, and where rivers have adequate stream power. Rivers can rapidly evacuate large percentages of stored reservoir sediment (≥40% within one year)—particularly where sediment is coarse-grained (sand and gravel), and can move evacuated sediment long distances (>20 km downstream) within a year, given sufficient transport capacity. The channel downstream typically takes months to years—not decades—to achieve a degree of stability within its natural range of variability. (2) Modest flows can erode large amounts of reservoir sediment and move it downstream. Large floods are not required to move substantial sediment volumes, especially from non-cohesive reservoir deltas. Once the most easily accessed sediment is eroded, however, larger floods can continue to access the remnant reservoir sediment and redistribute it downstream. Portions of the redistributed sediment remain (up- and downstream of the dam site), shaping a new landscape. (3) Dam height, sediment volume, and sediment grain size and cohesion strongly influence response to dam removal. Although removals of small dams with little stored sediment are more common, removals of large dams (≥10 m) with major sediment releases have had longer-lasting and more widespread downstream effects. (4) Downstream valley morphology and hydrology strongly influence the distribution of released sediment. Bedrock confinement versus wide alluvial reaches, downstream channel gradient, locations and depths of channel pools, locations and geometries of existing channel bars, position of the dam within a watershed, and

  4. Influence of groundwater pumping on streamflow restoration following upstream dam removal

    USGS Publications Warehouse

    Constantz, J.; Essaid, H.

    2007-01-01

    We compared streamflow in basins under the combined impacts of an upland dam and groundwater pumping withdrawals, by examining streamflow in the presence and absence of each impact. As a qualitative analysis, inter-watersbed streamflow comparisons were performed for several rivers flowing into the east side of the Central Valley, CA. Results suggest that, in the absence of upland dams supporting large reservoirs, some reaches of these rivers might develop ephemeral streamflow in late summer. As a quantitative analysis, we conducted a series of streamflow/ groundwater simulations (using MODFLOW-2000 plus the streamflow routing package, SFR1) for a representative hypothetical watershed, with an upland dam and groundwater pumping in the downstream basin, under humid, semi-arid, and and conditions. As a result of including the impact of groundwater pumping, post-dam removal simulated streamflow was significantly less than natural streamflow. The model predicts extensive ephemeral conditions in the basin during September for both the arid and semi-arid cases. The model predicts continued perennial conditions in the humid case, but spatially weighted, average streamflow of only 71% of natural September streamflow, as a result of continued pumping after dam removal.

  5. Aging Water Infrastructure

    EPA Science Inventory

    The Aging Water Infrastructure (AWI) research program is part of EPA’s larger effort called the Sustainable Water Infrastructure (SI) initiative. The SI initiative brings together drinking water and wastewater utility managers; trade associations; local watershed protection organ...

  6. The Dramatic Methods of Hans van Dam.

    ERIC Educational Resources Information Center

    van de Water, Manon

    1994-01-01

    Interprets for the American reader the untranslated dramatic methods of Hans van Dam, a leading drama theorist in the Netherlands. Discusses the functions of drama as a method, closed dramatic methods, open dramatic methods, and applying van Dam's methods. (SR)

  7. Simulation of Breach Outflow for Earthfill Dam

    NASA Astrophysics Data System (ADS)

    Razad, Azwin Zailti Abdul; Sabri Muda, Rahsidi; Mohd Sidek, Lariyah; Azia, Intan Shafilah Abdul; Hanum Mansor, Faezah; Yalit, Ruzaimei

    2013-06-01

    Dams have been built for many reasons such as irrigation, hydropower, flood mitigation, and water supply to support development for the benefit of human. However, the huge amount of water stored behind the dam can seriously pose adverse impacts to the downstream community should it be released due to unwanted dam break event. To minimise the potential loss of lives and property damages, a workable Emergency Response Plan is required to be developed. As part of a responsible dam owner and operator, TNB initiated a study on dam breach modelling for Cameron Highlands Hydroelectric Scheme to simulate the potential dam breach for Jor Dam. Prediction of dam breach parameters using the empirical equations of Froehlich and Macdonal-Langridge-Monopolis formed the basis of the modelling, coupled with MIKE 11 software to obtain the breach outflow due to Probable Maximum Flood (PMF). This paper will therefore discuss the model setup, simulation procedure and comparison of the prediction with existing equations.

  8. Have Large Dams Altered Extreme Precipitation Patterns?

    NASA Astrophysics Data System (ADS)

    Hossain, Faisal; Jeyachandran, Indumathi; Pielke, Roger

    2009-12-01

    Dams and their impounded waters are among the most common civil infrastructures, with a long heritage of modern design and operations experience. In particular, large dams, defined by the International Commission on Large Dams (ICOLD) as having a height greater than 15 meters from the foundation and holding a reservoir volume of more than 3 million cubic meters, have the potential to vastly transform local climate, landscapes, regional economics, and urbanization patterns. In the United States alone, about 75,000 dams are capable of storing a volume of water equaling almost 1 year's mean runoff of the nation [Graf, 1999]. The World Commission on Dams (WCD) reports that at least 45,000 large dams have been built worldwide since the 1930s. These sheer numbers raise the question of the extent to which large dams and their impounded waters alter patterns that would have been pervasive had the dams not been built.

  9. 78 FR 53494 - Dam Safety Modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... Dam Safety Modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams AGENCY: Tennessee... preferred alternative in its final environmental impact statement (EIS) for the dam safety modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams. The notice of availability (NOA) of the...

  10. Changes in Fish Habitat And Demography Following Dam Removal in a Headwater Catchment: Linking Geomorphic, Hydrologic, and Ecological Controls

    NASA Astrophysics Data System (ADS)

    Magilligan, F. J.; Nislow, K. H.; Kynard, B.; Hackman, A. M.

    2013-12-01

    Dam removal is a major component of river restoration efforts in New England. More than 115 dams have been removed in the past few decades with the goal to restore historical runs of diadromous fish. Taking advantage of the Fall 2012 removal of the 5 m high Pelham Dam in central Massachusetts, we sampled pre- and post-removal geomorphic parameters (18 cross-sections along a 800 m reach, Wolman pebble counts, embeddedness surveys, and detailed long profiles) in Amethyst Brook (23 km2) an upstream tributary of the Fort River drainage. These geomorphic assessments were combined with detailed quantitative electrofishing surveys of stream fish richness and abundance above and below the dam site and throughout the watershed; genetic assignments and stable isotope analysis to determine population connectivity; and visual surveys of native anadromous Sea lamprey (Petromyzon marinus) nest sites. Post-removal assessments were complicated by two events: (1) upstream knickpoint migration exhumed an older (ca. early 19th century) intact wooden crib dam ~ 120 m upstream of the former stone dam, and (2) the occurrence of a 10-20 yr RI flood 6 months after removal which caused further upstream incision and downstream aggradation. Geomorphic results document that all 11 cross-sections downstream of the former dam fined significantly with typical reductions of 30-60% in mean particle size. This has major implications for Sea lamprey that require gravel for spawning which was largely absent downstream of the former sediment-trapping dam. This fining was associated with downstream bed aggradation, reflecting the new, post-removal flux of material. Similarly, post-removal, but pre-flood, bed surveys indicate ~ 2 m of incision had migrated 25 m upstream of the former reservoir before encountering the exhumed dam, which now acts as the new grade control, limiting progressive headcutting. The combination of changes in channel bed sedimentology, the occurrence of a large magnitude flood

  11. Watershed analysis of the Salmon River watershed, Washington : hydrology

    USGS Publications Warehouse

    Bidlake, William R.

    2003-01-01

    The U.S. Geological Survey analyzed selected hydrologic conditions as part of a watershed analysis of the Salmon River watershed, Washington, conducted by the Quinault Indian Nation. The selected hydrologic conditions were analyzed according to a framework of hydrologic key questions that were identified for the watershed. The key questions were posed to better understand the natural, physical, and biological features of the watershed that control hydrologic responses; to better understand current streamflow characteristics, including peak and low flows; to describe any evidence that forest harvesting and road construction have altered frequency and magnitude of peak and low flows within the watershed; to describe what is currently known about the distribution and extent of wetlands and any impacts of land management activities on wetlands; and to describe how hydrologic monitoring within the watershed might help to detect future hydrologic change, to preserve critical ecosystem functions, and to protect public and private property.

  12. WinDAM C earthen embankment internal erosion analysis software

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two primary causes of dam failure are overtopping and internal erosion. For the purpose of evaluating dam safety for existing earthen embankment dams and proposed earthen embankment dams, Windows Dam Analysis Modules C (WinDAM C) software will simulate either internal erosion or erosion resulting f...

  13. Chloride effects on nitrogen dynamics in forested and suburban stream debris dams.

    PubMed

    Hale, Rebecca L; Groffman, Peter M

    2006-01-01

    Organic debris dams (accumulations of organic material) can function as "hotspots" of nitrogen (N) processing in streams. Suburban streams are often characterized by high flows that prevent the accumulation of organic debris and by elevated concentrations of solutes, especially nitrate (NO(3)(-)) and chloride (Cl(-)). In this study we (1) studied the effects of urbanization on the extent and characteristics of debris dams in large and small streams and (2) evaluated the effects of NO(3)(-) and Cl(-) on rates of N cycle processes in these debris dams. In some suburban streams debris dams were small and rare, but in others factors that reduce the effects of high stream flows fostered the maintenance of debris dams. Ambient denitrification enzyme activity (DEA) in these suburban and forested streams was positively correlated with stream NO(3)(-) concentrations. In laboratory microcosms, DEA in debris dam material from a forested reference stream was increased by NO(3)(-) additions. Chloride additions constrained the response of DEA to NO(3)(-) additions in material from the forested stream, but had no effect on DEA in material from streams with a history of high Cl(-) levels. Chloride additions changed the sign of net N mineralization from negative (consumption of inorganic N) to positive in debris dam material from the forested reference stream, but had no effect on net mineralization in material from streams with a history of exposure to Cl(-). Understanding the factors regulating the maintenance and N cycling activity of organic debris, and incorporating them into urban stream management plans could have important effects on N dynamics in suburban watersheds. PMID:17071914

  14. Chloride effects on nitrogen dynamics in forested and suburban stream debris dams.

    PubMed

    Hale, Rebecca L; Groffman, Peter M

    2006-01-01

    Organic debris dams (accumulations of organic material) can function as "hotspots" of nitrogen (N) processing in streams. Suburban streams are often characterized by high flows that prevent the accumulation of organic debris and by elevated concentrations of solutes, especially nitrate (NO(3)(-)) and chloride (Cl(-)). In this study we (1) studied the effects of urbanization on the extent and characteristics of debris dams in large and small streams and (2) evaluated the effects of NO(3)(-) and Cl(-) on rates of N cycle processes in these debris dams. In some suburban streams debris dams were small and rare, but in others factors that reduce the effects of high stream flows fostered the maintenance of debris dams. Ambient denitrification enzyme activity (DEA) in these suburban and forested streams was positively correlated with stream NO(3)(-) concentrations. In laboratory microcosms, DEA in debris dam material from a forested reference stream was increased by NO(3)(-) additions. Chloride additions constrained the response of DEA to NO(3)(-) additions in material from the forested stream, but had no effect on DEA in material from streams with a history of high Cl(-) levels. Chloride additions changed the sign of net N mineralization from negative (consumption of inorganic N) to positive in debris dam material from the forested reference stream, but had no effect on net mineralization in material from streams with a history of exposure to Cl(-). Understanding the factors regulating the maintenance and N cycling activity of organic debris, and incorporating them into urban stream management plans could have important effects on N dynamics in suburban watersheds.

  15. Rubber dam isolation in a difficult situation.

    PubMed

    Re, G J; Porter, K H; Marshall, T D

    1986-09-01

    Rubber dam retainers can be modified easily in the dental office to enable the dentist to isolate teeth with difficult restorative problems with the rubber dam. Isolation with the rubber dam enhances visibility and access and gives the dentist the opportunity to render safe, restorative care of high quality to the patient.

  16. Rubber dam--the easy way.

    PubMed

    Small, B W

    1999-01-01

    Rubber dam use can only enhance a dental procedure by allowing better access, visibility, and dry field isolation. The reasons offered by many dentists for not using the dam can be overcome by additional training and clinical use. Suggestions are given that have made rubber dam use routine for the author and have facilitated much improved dentistry.

  17. Webinar: Stepped chute design for embankment dams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changing demographics in the vicinity of dams have led to hazard creep in a number of dams worldwide. Many of these dams now have insufficient spillway capacity as a result of these changes in hazard classification from low to significant or high hazard. Stepped chutes applied to the embankment da...

  18. 30 CFR 56.20010 - Retaining dams.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Retaining dams. 56.20010 Section 56.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of...

  19. 30 CFR 57.20010 - Retaining dams.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Retaining dams. 57.20010 Section 57.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20010 Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be...

  20. 30 CFR 57.20010 - Retaining dams.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Retaining dams. 57.20010 Section 57.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20010 Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be...

  1. 30 CFR 56.20010 - Retaining dams.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Retaining dams. 56.20010 Section 56.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of...

  2. Evolution of a Dammed River: Trajectories of Geomorphic Change on the Trinity River, CA

    NASA Astrophysics Data System (ADS)

    Curtis, J. A.; Guerrero, T. M.

    2012-12-01

    Historic landuse, dam construction (ca. 1964), water storage and flow diversion within the Trinity River watershed resulted in simplification of the river planform and dramatic losses in riparian habitat. The pre-dam Trinity River included a series of deep pools, active bar sequences, minor amounts of riparian vegetation, and an extensive floodplain. Dam construction and the export of ~ 75 to 90% of the average annual inflow at the top of the study reach lead to riparian encroachment, channel narrowing, stabilization of alluvial features, and a decline in coarse bed material. Following dam closure channel complexity decreased as bars were stabilized and coalesced into a system-wide post-dam topographic bench with an extensive riparian berm. Flow diversions further resulted in the abandonment of the pre-dam geomorphic floodplain and aggradation of tributary confluences due to dramatic reductions in flow competency and capacity. Beginning in 2001, the Trinity River Restoration Program (TRRP) implemented a combination of flow releases, gravel augmentation, bank rehabilitation, and watershed restoration to promote dynamic channel processes. The TRRP functions under an adaptive management framework which includes external peer review. In this regard the TRRP requested a geomorphic assessment of a 65-km restoration reach during pre- and post-restoration time periods which will be used to inform future restoration work. Building upon previous work at the site and reach scale we digitized a series of geomorphic maps and quantified the nature, extent and rates of geomorphic change during five post-dam time periods. Terrestrial and aquatic features were mapped using rectified orthophotography (1980, 1997, 2001, 2006, 2009, 2011) and the resultant data were used to determine trajectories of geomorphic change related to natural river processes and restoration actions. The series of geomorphic maps illustrate a system-wide perspective of evolving geomorphic features and

  3. The formation and failure of natural dams

    USGS Publications Warehouse

    Costa, J.E.; Schuster, R.L.

    1987-01-01

    Of the numerous kinds of dams that form by natural processes, dams formed from landslides, glacial ice, and neoglacial moraines present the greatest threat to people and property. The most common types of mass movements that form landslide dams are rock and debris avalanches, rock and soil slumps and slides, and mud, debris, and earth flows. The most common initiation mechanisms for dam-forming landslides are excessive rainfall and snowmelt and earthquakes. Landslide dams can be classified into six categories based on their relation with the valley floor. Type I dams (11%) of the 81 landslide dams around the world that were classifed do not reach from one valley side to the other. Type II dams (44%) span the entire valley flood, occasionally depositing material high up on opposite valley sides. Type III dams (41%) move considerable distances both upstream and downstream from the landslide failure. Type IV dams (1%) are rare and involve the contemporaneous failure of material from both sides of a valley. Type V dams (1%) are also rare, and are created when a single landslide sends multiple tongues of debris into a valley forming two or more landslide dams in the same surfaces, that extend under the stream or valley and emerge on the opposite valley side. Many landslide dams fail shortly after formation. Overtopping is by far the most common cause of failure. Glacial ice dams can produce at least nine kinds of ice-dammed lakes. The most dangerous are lakes formed in main valleys dammed by tributary glaciers. Failure can occur by erosion of a drainage tunnel under or through the ice dam or by a channel over the ice dam. Cold polar ice dams generally drain supraglacially or marginally by downmelting of an outlet channel. Warmer temperate-ice dams tend to fail by sudden englacial or subglacial breaching and drainage. Late neoglacial moraine-dammed lakes are located in steep mountain areas affected by the advances and retreats of valley glaciers in the last several

  4. Fort Cobb Reservoir Watershed, Oklahoma and Thika River Watershed, Kenya Twinning Pilot Project

    NASA Astrophysics Data System (ADS)

    Moriasi, D.; Steiner, J.; Arnold, J.; Allen, P.; Dunbar, J.; Shisanya, C.; Gathenya, J.; Nyaoro, J.; Sang, J.

    2007-12-01

    Nairobi. A dam was constructed in 1994 with a water reservoir of 70 million m3. Thika River also supplies water to Masinga Reservoir to supply the seven forks dams, which together supply 75% of the nation's electricity. The quantity of water in rivers and reservoirs is decreased due to sedimentation while water quality is degraded by sediments, and sediment-borne nutrients and pesticides. The focus of this pilot twinning project is watershed erosion and reservoir sedimentation assessment. This will be accomplished by (1) a rapid watershed/catchment erosion assessment using ground based measurements and remote sensing/GIS techniques, 2) use of Acoustic Profiling Systems (APS) for reservoir sedimentation measurement studies, and 3) advanced water quality modeling using the soil and water assessment tool (SWAT) model. Data acquired will be used for sediment transport modeling to1) determine sediment "hot spots" and management practices that will minimize sediments into reservoirs in order to 2) maintain the reservoirs on which many farmers depend for their livelihood and a cleaner environment. This project will provide an opportunity for 1) sharing knowledge and experience among the stakeholders, 2) building capacity through formal and informal education opportunities through reciprocal hosting of decision makers and water experts, and 3) technology transfer of pilot results with recommended management practices to reduce reservoir sedimentation rates.

  5. Ancient landslide-dam events in the Jishi Gorge, upper Yellow River valley, China

    NASA Astrophysics Data System (ADS)

    Dong, Guanghui; Zhang, Fanyu; Ma, Minmin; Fan, Yuxin; Zhang, Jiawu; Wang, Zongli; Chen, Fahu

    2014-05-01

    Some scholars have argued that the formation and outburst of an ancient dammed lake in the Jishi Gorge at ca. 3700 cal yr BP resulted in the destruction of Lajia, the site of a famous prehistoric disaster in the Guanting Basin, upper Yellow River valley, China. However, the cause of the dammed lake and the exact age of the dam breaching are still debated. We investigated ancient landslides and evidence for the dammed lake in the Jishi Gorge, including dating of soil from the shear zone of an ancient landslide, sediments of the ancient dammed lake, and loess above lacustrine sediments using radiocarbon and optically stimulated luminescence (OSL) dating methods. Six radiocarbon dates and two OSL dates suggested that the ancient landslides and dammed lake events in the Jishi Gorge probably occurred around 8100 cal yr BP, and the ancient dammed lake was breached between 6780 cal yr BP and 5750 cal yr BP. Hence, the outburst of the ancient dammed lake in the Jishi Gorge was unrelated to the ruin of the Lajia site, but likely resulted in flood disasters in the Guanting Basin around 6500 cal yr BP.

  6. Vulnerability of Karangkates dams area by means of zero crossing analysis of data magnetic

    SciTech Connect

    Sunaryo, E-mail: sunaryo.geofis.ub@gmail.com; Susilo, Adi

    2015-04-24

    Study with entitled Vulnerability Karangkates Dam Area By Means of Zero Crossing Analysis of Data Magnetic has been done. The study was aimed to obtain information on the vulnerability of two parts area of Karangkates dams, i.e. Lahor dam which was inaugurated in 1977 and Sutami dam inaugurated in 1981. Three important things reasons for this study are: 1). The dam age was 36 years old for Lahor dam and 32 years old for Sutami dam, 2). Geologically, the location of the dams are closed together to the Pohgajih local shear fault, Selorejo local fault, and Selorejo limestone-andesite rocks contact plane, and 3). Karangkates dams is one of the important Hydro Power Plant PLTA with the generating power of about 400 million KWH per year from a total of about 29.373MW installed in Indonesia. Geographically, the magnetic data acquisition was conducted at coordinates (112.4149oE;-8.2028oS) to (112.4839oE;-8.0989oS) by using Proton Precession Magnetometer G-856. Magnetic Data acquisition was conducted in the radial direction from the dams with diameter of about 10 km and the distance between the measurements about 500m. The magnetic data acquisition obtained the distribution of total magnetic field value in the range of 45800 nT to 44450 nT. Residual anomalies obtained by doing some corrections, including diurnal correction, International Geomagnetic Reference Field (IGRF) correction, and reductions so carried out the distribution of the total magnetic field value in the range of -650 nT to 700 nT. Based on the residual anomalies, indicate the presence of 2 zones of closed closures dipole pairs at located in the west of the Sutami dam and the northwest of the Lahor dam from 5 total zones. Overlapping on the local geological map indicated the lineament of zero crossing patterns in the contour of residual anomaly contour with the Pohgajih shear fault where located at about 4 km to the west of the Sutami dam approximately and andesite-limestone rocks contact where located

  7. Vulnerability of Karangkates dams area by means of zero crossing analysis of data magnetic

    NASA Astrophysics Data System (ADS)

    Sunaryo, Susilo, Adi

    2015-04-01

    Study with entitled Vulnerability Karangkates Dam Area By Means of Zero Crossing Analysis of Data Magnetic has been done. The study was aimed to obtain information on the vulnerability of two parts area of Karangkates dams, i.e. Lahor dam which was inaugurated in 1977 and Sutami dam inaugurated in 1981. Three important things reasons for this study are: 1). The dam age was 36 years old for Lahor dam and 32 years old for Sutami dam, 2). Geologically, the location of the dams are closed together to the Pohgajih local shear fault, Selorejo local fault, and Selorejo limestone-andesite rocks contact plane, and 3). Karangkates dams is one of the important Hydro Power Plant PLTA with the generating power of about 400 million KWH per year from a total of about 29.373MW installed in Indonesia. Geographically, the magnetic data acquisition was conducted at coordinates (112.4149oE;-8.2028oS) to (112.4839oE;-8.0989oS) by using Proton Precession Magnetometer G-856. Magnetic Data acquisition was conducted in the radial direction from the dams with diameter of about 10 km and the distance between the measurements about 500m. The magnetic data acquisition obtained the distribution of total magnetic field value in the range of 45800 nT to 44450 nT. Residual anomalies obtained by doing some corrections, including diurnal correction, International Geomagnetic Reference Field (IGRF) correction, and reductions so carried out the distribution of the total magnetic field value in the range of -650 nT to 700 nT. Based on the residual anomalies, indicate the presence of 2 zones of closed closures dipole pairs at located in the west of the Sutami dam and the northwest of the Lahor dam from 5 total zones. Overlapping on the local geological map indicated the lineament of zero crossing patterns in the contour of residual anomaly contour with the Pohgajih shear fault where located at about 4 km to the west of the Sutami dam approximately and andesite-limestone rocks contact where located at

  8. Ghana Watershed Prototype Products

    USGS Publications Warehouse

    ,

    2007-01-01

    Introduction/Background A number of satellite data sets are available through the U.S. Geological Survey (USGS) for monitoring land surface features. Representative data sets include Landsat, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and Shuttle Radar Topography Mission (SRTM). The Ghana Watershed Prototype Products cover an area within southern Ghana, Africa, and include examples of the aforementioned data sets along with sample SRTM derivative data sets.

  9. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China.

    PubMed

    Liu, Renzhi; Liu, Jing; Zhang, Zhijiao; Borthwick, Alistair; Zhang, Ke

    2015-12-01

    Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA), designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the "source-pathway-target" in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing) in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River). Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method. PMID:26633450

  10. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China

    PubMed Central

    Liu, Renzhi; Liu, Jing; Zhang, Zhijiao; Borthwick, Alistair; Zhang, Ke

    2015-01-01

    Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA), designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the “source-pathway-target” in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing) in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River). Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method. PMID:26633450

  11. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China.

    PubMed

    Liu, Renzhi; Liu, Jing; Zhang, Zhijiao; Borthwick, Alistair; Zhang, Ke

    2015-12-02

    Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA), designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the "source-pathway-target" in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing) in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River). Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method.

  12. Predicting recolonization patterns and interactions between potamodromous and anadromous salmonids in response to dam removal in the Elwha River, Washington State, USA

    USGS Publications Warehouse

    Brenkman, S.J.; Pess, G.R.; Torgersen, C.E.; Kloehn, K.K.; Duda, J.J.; Corbett, S.C.

    2008-01-01

    The restoration of salmonids in the Elwha River following dam removal will cause interactions between anadromous and potamodromous forms as recolonization occurs in upstream and downstream directions. Anadromous salmonids are expected to recolonize historic habitats, and rainbow trout (Oncorhynchus mykiss) and bull trout (Salvelinus confluentus) isolated above the dams for 90 years are expected to reestablish anadromy. We summarized the distribution and abundance of potamodromous salmonids, determined locations of spawning areas, and mapped natural barriers to fish migration at the watershed scale based on data collected from 1993 to 2006. Rainbow trout were far more abundant than bull trout throughout the watershed and both species were distributed up to river km 71. Spawning locations for bull trout and rainbow trout occurred in areas where we anticipate returning anadromous fish to spawn. Nonnative brook trout were confined to areas between and below the dams, and seasonal velocity barriers are expected to prevent their upstream movements. We hypothesize that the extent of interaction between potamodromous and anadromous salmonids will vary spatially due to natural barriers that will limit upstream-directed recolonization for some species of salmonids. Consequently, most competitive interactions will occur in the main stem and floodplain downstream of river km 25 and in larger tributaries. Understanding future responses of Pacific salmonids after dam removal in the Elwha River depends upon an understanding of existing conditions of the salmonid community upstream of the dams prior to dam removal.

  13. Space and habitat use by black bears in the Elwha valley prior to dam removal

    USGS Publications Warehouse

    Sager-Fradkin, K.A.; Jenkins, K.J.; Happe, P.J.; Beecham, J.J.; Wright, R.G.; Hoffman, R.A.

    2008-01-01

    Dam removal and subsequent restoration of salmon to the Elwha River is expected to cause a shift in nutrient dynamics within the watershed. To document how this influx of nutrients and energy may affect black bear (Ursus americanus) ecology, we used radio-telemetry to record movements of 11 male and two female black bears in the Elwha Valley from 2002-06. Our objective was to collect baseline data on bear movements prior to dam removal. We calculated annual home ranges, described seasonal timing of den entry and emergence, and described seasonal patterns of distribution and habitat use. Adaptive kernel home ranges were larger formales (mean = 151.1 km2, SE = 21.4) than females (mean = 38.8 km2, SE = 13.0). Males ranged widely and frequently left the watershed during late summer. Further, they exhibited predictable and synchronous patterns of elevation change throughout each year. Bears entered their winter dens between 8 October and 15 December and emerged from dens between 10 March and 9 May. Male bears used low-elevation conifer and hardwood forests along the Elwha floodplain during spring, mid- to high-elevation forests and meadows during early summer, high-elevation forests, meadows and shrubs during late summer, and mid-elevation forests, shrubs and meadows during fall. Data acquired during this study provide important baseline information for comparison after dam removal, when bears may alter their late summer and fall movement and denning patterns to take advantage of energy-rich spawning salmon.

  14. Synthesis of common management concerns associated with dam removal

    USGS Publications Warehouse

    Tullos, Desiree D.; Collins, Mathias J.; Bellmore, J. Ryan; Bountry, Jennifer A.; Connolly, Patrick J.; Shafroth, Patrick B.; Wilcox, Andrew C.

    2016-01-01

    Managers make decisions regarding if and how to remove dams in spite of uncertainty surrounding physical and ecological responses, and stakeholders often raise concerns about certain negative effects, regardless of whether or not these concerns are warranted at a particular site. We used a dam-removal science database supplemented with other information sources to explore seven frequently-raised concerns, herein Common Management Concerns (CMCs). We investigate the occurrence of these concerns and the contributing biophysical controls. The CMCs addressed are: degree and rate of reservoir sediment erosion, excessive channel incision upstream of reservoirs, downstream sediment aggradation, elevated downstream turbidity, drawdown impacts on local water infrastructure, colonization of reservoir sediments by non-native plants, and expansion of invasive fish. Biophysical controls emerged for some of the concerns, providing managers with information to assess whether a given concern is likely to occur at a site. To fully assess CMC risk, managers should concurrently evaluate site conditions and identify the ecosystem or human uses that will be negatively affected if the biophysical phenomenon producing the CMC occurs. We show how many CMCs have one or more controls in common, facilitating the identification of multiple risks at a site, and demonstrate why CMC risks should be considered in the context of other factors like natural watershed variability and disturbance history.

  15. EPA'S WATERSHED MANAGEMENT AND MODELING RESEARCH PROGRAM

    EPA Science Inventory

    Watershed management presumes that community groups can best solve many water quality and ecosystem problems at the watershed level rather than at the individual site, receiving waterbody, or discharger level. After assessing and ranking watershed problems, and setting environ...

  16. RESEARCH NEEDS FOR EFFECTIVE WATERSHED PLANNING

    EPA Science Inventory

    Watershed research has historically focused on physical and biological processes, stressor-response, and effects research, providing valuable understanding of the effects of human activity and natural disturbances on watershed ecosystems. Continued research to support watershed ...

  17. Nonlinear Seismic Analysis of Morrow Point Dam

    SciTech Connect

    Noble, C R; Nuss, L K

    2004-02-20

    This research and development project was sponsored by the United States Bureau of Reclamation (USBR), who are best known for the dams, power plants, and canals it constructed in the 17 western states. The mission statement of the USBR's Dam Safety Office, located in Denver, Colorado, is ''to ensure Reclamation dams do not present unacceptable risk to people, property, and the environment.'' The Dam Safety Office does this by quickly identifying the dams which pose an increased threat to the public, and quickly completing the related analyses in order to make decisions that will safeguard the public and associated resources. The research study described in this report constitutes one element of USBR's research and development work to advance their computational and analysis capabilities for studying the response of dams to strong earthquake motions. This project focused on the seismic response of Morrow Point Dam, which is located 263 km southwest of Denver, Colorado.

  18. Seismic safety of high concrete dams

    NASA Astrophysics Data System (ADS)

    Chen, Houqun

    2014-08-01

    China is a country of high seismicity with many hydropower resources. Recently, a series of high arch dams have either been completed or are being constructed in seismic regions, of which most are concrete dams. The evaluation of seismic safety often becomes a critical problem in dam design. In this paper, a brief introduction to major progress in the research on seismic aspects of large concrete dams, conducted mainly at the Institute of Water Resources and Hydropower Research (IWHR) during the past 60 years, is presented. The dam site-specific ground motion input, improved response analysis, dynamic model test verification, field experiment investigations, dynamic behavior of dam concrete, and seismic monitoring and observation are described. Methods to prevent collapse of high concrete dams under maximum credible earthquakes are discussed.

  19. Challenges to natural process restoration: common dam removal management concerns

    NASA Astrophysics Data System (ADS)

    Collins, M. J.; Tullos, D. D.; Bellmore, J. R.; Bountry, J.; Connolly, P. J.; Shafroth, P. B.; Wilcox, A. C.

    2015-12-01

    Practitioners must make dam removal decisions in spite of uncertainty about physical and ecological responses. This can result in implementing structural controls or other interventions at a site to avoid anticipated negative effects, sometimes even if a given concern is not warranted. We used a newly available dam removal science database and other information sources to explore seven frequently raised issues we call "Common Management Concerns" (CMCs), investigating their occurrence and the contributing biophysical controls. We describe these controls to enable managers to better assess if further analyses are warranted at their sites before interventions are planned and implemented. The CMCs addressed are: rate and degree of reservoir sediment erosion; drawdown impacts on local water infrastructure; excessive channel incision; downstream sediment aggradation; elevated turbidity; colonization of reservoir sediments by non-native plants; and expansion of invasive fish. The relative dearth of case studies available for many CMCs limited the generalizable conclusions we could draw about prevalence, but the available data and established understanding of relevant processes revealed important biophysical phenomena controlling the likelihood of CMC occurrence. To assess CMC risk, we recommend managers concurrently evaluate if site conditions suggest the ecosystem, infrastructure, or other human uses will be negatively affected if the biophysical phenomenon producing the CMC occurs. We show how many CMCs have one or more controls in common, facilitating the identification of multiple risks at a site, and demonstrate why CMC risks should be considered in the context of other important factors like watershed disturbance history, natural variability, and dam removal tradeoffs. Better understanding CMCs and how to evaluate them will enable practitioners to avoid unnecessary interventions and thus maximize opportunities for working with natural processes to restore river

  20. The effects of ageing on the immune response to Schistosoma haematobium and hookworm by measuring circulating immune complexes, C3, IgG, IgA and IgM levels in residents of Omi dam area of Kogi State, Nigeria.

    PubMed

    Oyeyinka, G O; Awogun, I A; Akande, T M; Awarun, J A; Arinola, O G; Salimonu, L S

    2003-09-01

    In this study, the effects of infestation (with Schistosoma haematobium or hookworm) during host ageing on the serum levels of circulating immune complexes (CIC), C3, IgG, IgA and IgM were examined in residents of Omi dam area of Kogi state, Nigeria. S. haematobium-infested and hookworm-infested individuals showed no significant alteration in the levels of CIC, C3, IgG, IgA and IgM in comparison with controls. These levels were the same in infested subjects and controls even when the patients were pooled. Infested old people had the same concentrations of serum CIC, C3 IgG and IgM in comparison with infested young people but IgA levels were higher in the aged group (t=2.100; P<0.05); and were significantly correlated with age (r=0.301; P<0.05). No significant increase in CIC levels with rising age (r=0.123; P>0.20) was observed in the overall population of infested subjects; and infestation in old age did not alter CIC, C3, IgG, IgA and IgM levels in comparison with uninfested young people. For the uninfested, IgG, IgA and IgM values were similar in the aged and the young but the levels of CIC were higher (t=2.156; P<0.05; r=0.280; P<0.05) and C3 lower (t=3.313; P<0.01; r=-0.236; P>0.10) in the aged. The results of this study suggest that the elevated CIC levels found in old people is age-related; and that the contribution of parasitic infestation to these raised levels is uncertain.

  1. Supplement Analysis for the Watershed Management Program EIS (DOE/EIS-0265/SA-75) - Gourlay Creek Fish Ladder Project

    SciTech Connect

    Stewart, Shannon C.

    2002-02-20

    BPA proposes to fund the construction of a fish passage facility at the Gourlay Creek Dam/water reservoir in Columbia County, Oregon. The City of Scappoose owns and manages close to half of the Gourlay Creek Watershed including high quality habitat above and below the Gourlay Creek Dam. Gourlay Creek Dam has been identified as a key limiting factor in the re-generation of salmon and trout in the Gourlay Creek Watershed. Currently it provides a complete barrier to fish passage for Endangered Species Act (ESA) listed salmonids, as well as to salmonids that are under status review for ESA listing. Historically, Gourlay Creek has provided important salmonid habitat within the Scappoose Bay Watershed. Salmonids still utilize the lower reaches of Gourlay Creek. The goal of the project is to provide unimpeded access for juvenile and adult salmonids to historic habitat upstream of the dam. The project would open up over two miles of habitat for coho and cutthroat trout and nearly four miles of habitat for steelhead.

  2. Two-dimensional simulations of extreme floods on a large watershed

    NASA Astrophysics Data System (ADS)

    England, John F.; Velleux, Mark L.; Julien, Pierre Y.

    2007-12-01

    SummaryWe investigate the applicability of the Two-dimensional, Runoff, Erosion and Export (TREX) model to simulate extreme floods on large watersheds in semi-arid regions in the western United States. Spatially-distributed extreme storm and channel components are implemented so that the TREX model can be applied to this problem. TREX is demonstrated via calibration, validation and simulation of extreme storms and floods on the 12,000 km 2 Arkansas River watershed above Pueblo, Colorado. The model accurately simulates peak, volume and time to peak for the record June 1921 extreme flood calibration and a May 1894 flood validation. A Probable Maximum Precipitation design storm is used to apply the calibrated model. The distributed model TREX captures the effects of spatial and temporal variability of extreme storms for dam safety purposes on large watersheds, and is an alternative to unit-hydrograph rainfall-runoff models.

  3. Flathead River Focus Watershed Coordinator, 2002 Annual Report.

    SciTech Connect

    DuCharme, Lynn

    2003-04-01

    The Bonneville Power Administration (BPA) has long been involved with funding of the Cooperative Habitat Protection and Improvement with Private Landowners program in accordance with the Northwest Power Planning Council's (NPPC) Fish & Wildlife Program (Section 7.7). Section 7.7B.1 requires the establishment of ''at least one model watershed coordinator selected by each representative state''. This project was initiated in 1997 with the purpose of fulfilling the NPPC's watershed program within the Flathead River basin in western Montana. Currently, the Flathead watershed has been radically altered by hydropower and other land uses. With the construction of Hungry Horse, Bigfork and Kerr dams, the Flathead River system has been divided into isolated populations. Bull trout have been listed as threatened by the US Fish and Wildlife Service and westslope cutthroat trout have been petitioned for listing. Many streams in the drainage have been destabilized during recent decades. Past legal and illegal species introductions are also causing problems. This project fosters in-kind, out-of-place mitigation to offset the impacts of hydroelectric power to 72 miles of the South Fork of the Flathead River and its tributaries upstream of Hungry Horse Dam. Key subbasins within the Flathead drainage, which are critical to native species restoration, are experiencing rapid changes in land ownership and management direction. Subdivision and residential development of agricultural and timber lands adjacent to waterways in the drainage pose one of the greatest threats to weak but recoverable stocks of trout species. Plum Creek Timber Company, a major landholder in the Flathead drainage is currently divesting itself of large tracks of its lakeshore and streamside holdings. Growth of small tract development throughout the area and its tributaries is occurring at a record rate. Immediate to short-term action is required to protect stream corridors through many of these areas if cost

  4. Flathead River Focus Watershed Coordinator, 2005-2006 Annual Report.

    SciTech Connect

    DuCharme, Lynn

    2006-05-01

    The Bonneville Power Administration (BPA) has long been involved with funding of the Cooperative Habitat Protection and Improvement with Private Landowners program in accordance with the Northwest Power Planning Council's (NPPC) Fish & Wildlife Program (Section 7.7). Section 7.7B.1 requires the establishment of ''at least one model watershed coordinator selected by each representative state''. This project was initiated in 1997 with the purpose of fulfilling the NWPCC's watershed program within the Flathead River basin in western Montana. Currently, the Flathead watershed has been radically altered by hydropower and other land uses. With the construction of Hungry Horse, Bigfork and Kerr dams, the Flathead River system has been divided into isolated populations. Bull trout have been listed as threatened by the US Fish and Wildlife Service and westslope cutthroat trout have been petitioned for listing. Many streams in the drainage have been destabilized during recent decades. Past legal and illegal species introductions are also causing problems. This project fosters in-kind, out-of-place mitigation to offset the impacts of hydroelectric power to 72 miles of the South Fork of the Flathead River and its tributaries upstream of Hungry Horse Dam. Key subbasins within the Flathead drainage, which are critical to native species restoration, are experiencing rapid changes in land ownership and management direction. Subdivision and residential development of agricultural and timber lands adjacent to waterways in the drainage pose one of the greatest threats to weak but recoverable stocks of trout species. Plum Creek Timber Company, a major landholder in the Flathead drainage is currently divesting itself of large tracks of its lakeshore and streamside holdings. Growth of small tract development throughout the area and its tributaries is occurring at a record rate. Immediate to short-term action is required to protect stream corridors through many of these areas if cost

  5. Flathead River Focus Watershed Coordinator, 2003-2004 Annual Report.

    SciTech Connect

    DuCharme, Lynn

    2004-06-01

    The Bonneville Power Administration (BPA) has long been involved with funding of the Cooperative Habitat Protection and Improvement with Private Landowners program in accordance with the Northwest Power Planning Council's (NPPC) Fish & Wildlife Program (Section 7.7). Section 7.7B.1 requires the establishment of ''at least one model watershed coordinator selected by each representative state''. This project was initiated in 1997 with the purpose of fulfilling the NWPCC's watershed program within the Flathead River basin in western Montana. Currently, the Flathead watershed has been radically altered by hydropower and other land uses. With the construction of Hungry Horse, Bigfork and Kerr dams, the Flathead River system has been divided into isolated populations. Bull trout have been listed as threatened by the US Fish and Wildlife Service and westslope cutthroat trout have been petitioned for listing. Many streams in the drainage have been destabilized during recent decades. Past legal and illegal species introductions are also causing problems. This project fosters in-kind, out-of-place mitigation to offset the impacts of hydroelectric power to 72 miles of the South Fork of the Flathead River and its tributaries upstream of Hungry Horse Dam. Key subbasins within the Flathead drainage, which are critical to native species restoration, are experiencing rapid changes in land ownership and management direction. Subdivision and residential development of agricultural and timber lands adjacent to waterways in the drainage pose one of the greatest threats to weak but recoverable stocks of trout species. Plum Creek Timber Company, a major landholder in the Flathead drainage is currently divesting itself of large tracks of its lakeshore and streamside holdings. Growth of small tract development throughout the area and its tributaries is occurring at a record rate. Immediate to short-term action is required to protect stream corridors through many of these areas if cost

  6. Flathead River Focus Watershed Coordinator, 2004-2005 Annual Report.

    SciTech Connect

    DuCharme, Lynn

    2006-06-26

    The Bonneville Power Administration (BPA) has long been involved with funding of the Cooperative Habitat Protection and Improvement with Private Landowners program in accordance with the Northwest Power Planning Council's (NPPC) Fish & Wildlife Program (Section 7.7). Section 7.7B.1 requires the establishment of ''at least one model watershed coordinator selected by each representative state''. This project was initiated in 1997 with the purpose of fulfilling the NWPCC's watershed program within the Flathead River basin in western Montana. Currently, the Flathead watershed has been radically altered by hydropower and other land uses. With the construction of Hungry Horse, Bigfork and Kerr dams, the Flathead River system has been divided into isolated populations. Bull trout have been listed as threatened by the US Fish and Wildlife Service and westslope cutthroat trout have been petitioned for listing. Many streams in the drainage have been destabilized during recent decades. Past legal and illegal species introductions are also causing problems. This project fosters in-kind, out-of-place mitigation to offset the impacts of hydroelectric power to 72 miles of the South Fork of the Flathead River and its tributaries upstream of Hungry Horse Dam. Key subbasins within the Flathead drainage, which are critical to native species restoration, are experiencing rapid changes in land ownership and management direction. Subdivision and residential development of agricultural and timber lands adjacent to waterways in the drainage pose one of the greatest threats to weak but recoverable stocks of trout species. Plum Creek Timber Company, a major landholder in the Flathead drainage is currently divesting itself of large tracks of its lakeshore and streamside holdings. Growth of small tract development throughout the area and its tributaries is occurring at a record rate. Immediate to short-term action is required to protect stream corridors through many of these areas if cost

  7. Asotin Creek Model Watershed Plan: Asotin County, Washington, 1995.

    SciTech Connect

    Browne, Dave

    1995-04-01

    The Northwest Power Planning Council completed its ``Strategy for Salmon'' in 1992. This is a plan, composed of four specific elements,designed to double the present production of 2.5 million salmon in the Columbia River watershed. These elements have been called the ``four H's'': (1) improve harvest management; (2) improve hatcheries and their production practices; (3) improve survival at hydroelectric dams; and (4) improve and protect fish habitat. The Asotin Creek Model Watershed Plan is the first to be developed in Washington State which is specifically concerned with habitat protection and restoration for salmon and trout. The plan is consistent with the habitat element of the ``Strategy for Salmon''. Asotin Creek is similar in many ways to other salmon-bearing streams in the Snake River system. Its watershed has been significantly impacted by human activities and catastrophic natural events, such as floods and droughts. It supports only remnant salmon and trout populations compared to earlier years. It will require protection and restoration of its fish habitat and riparian corridor in order to increase its salmonid productivity.

  8. Ecosystem experiment reveals benefits of natural and simulated beaver dams to a threatened population of steelhead (Oncorhynchus mykiss)

    PubMed Central

    Bouwes, Nicolaas; Weber, Nicholas; Jordan, Chris E.; Saunders, W. Carl; Tattam, Ian A.; Volk, Carol; Wheaton, Joseph M.; Pollock, Michael M.

    2016-01-01

    Beaver have been referred to as ecosystem engineers because of the large impacts their dam building activities have on the landscape; however, the benefits they may provide to fluvial fish species has been debated. We conducted a watershed-scale experiment to test how increasing beaver dam and colony persistence in a highly degraded incised stream affects the freshwater production of steelhead (Oncorhynchus mykiss). Following the installation of beaver dam analogs (BDAs), we observed significant increases in the density, survival, and production of juvenile steelhead without impacting upstream and downstream migrations. The steelhead response occurred as the quantity and complexity of their habitat increased. This study is the first large-scale experiment to quantify the benefits of beavers and BDAs to a fish population and its habitat. Beaver mediated restoration may be a viable and efficient strategy to recover ecosystem function of previously incised streams and to increase the production of imperiled fish populations. PMID:27373190

  9. The Impact of the Dachaoshan Dam on Seasonal Hydrological Dynamics in the Main Stream of the Mekong River

    NASA Astrophysics Data System (ADS)

    Kameyama, S.; Shimazaki, H.; Nohara, S.; Fukushima, M.; Kudo, K.; Sato, T.

    2008-12-01

    In the Mekong River watershed, traditional social and industrial systems have long existed in harmony with water and biological resources. Since the 1950s, many dam-construction projects have been started to develop power and water resources to meet increasing demand for energy and food production. Since the 1970s, there have been temporary interruptions to these projects because of civil war or regional volatility of international relations. Many of these projects have been restarted in the last 15 years. This raises international interest, as there are transboundary issues cross-border issues related to both development assistance and environmental conservation. By 2008, two Chinese dams had already been completed (the Manwan dam in 1996 and the Dachaoshan dam in 2003) on the Mekong River in Yunnan province. Dam construction has some positive impacts, such as electricity production, management of water resources, and flood control. However, upstream control of water discharge can have negative impacts on traditional agricultural systems and fisheries downstream from the dams, such as drastic changes in flow volume and sediment load. We used hydrological simulation of the watershed to quantify the impact of the construction of the Dachaoshan dam by comparing annual water discharge and sediment transport before and after the dam was completed. Our main objectives were to use watershed hydrologic modeling to simulate changes to annual hydrological parameters and sediment transport, and to map spatio-temporal changes of these data before and after dam construction. Our study area covered the part of the Mekong River main channel that extends about 100 km downstream from the junction of the borders of Myanmar, Thailand, and the Lao People's Democratic Republic. We used five data validation points at 25-km intervals along this section of the river and calculated model parameters every 1 km. The years we modeled were 1990 (began dam construction) and 2006 (after dam

  10. Ecosystem experiment reveals benefits of natural and simulated beaver dams to a threatened population of steelhead (Oncorhynchus mykiss).

    PubMed

    Bouwes, Nicolaas; Weber, Nicholas; Jordan, Chris E; Saunders, W Carl; Tattam, Ian A; Volk, Carol; Wheaton, Joseph M; Pollock, Michael M

    2016-01-01

    Beaver have been referred to as ecosystem engineers because of the large impacts their dam building activities have on the landscape; however, the benefits they may provide to fluvial fish species has been debated. We conducted a watershed-scale experiment to test how increasing beaver dam and colony persistence in a highly degraded incised stream affects the freshwater production of steelhead (Oncorhynchus mykiss). Following the installation of beaver dam analogs (BDAs), we observed significant increases in the density, survival, and production of juvenile steelhead without impacting upstream and downstream migrations. The steelhead response occurred as the quantity and complexity of their habitat increased. This study is the first large-scale experiment to quantify the benefits of beavers and BDAs to a fish population and its habitat. Beaver mediated restoration may be a viable and efficient strategy to recover ecosystem function of previously incised streams and to increase the production of imperiled fish populations. PMID:27373190

  11. EPRI dam safety workshop summary: Proceedings

    SciTech Connect

    Corso, R.

    1998-10-01

    The Electric Power Research Institute (EPRI) has an extensive history of working with utilities, federal and state agencies, consultants, and other interests to conduct a number of workshops and studies to improve the safety of dams. Through these efforts, EPRI has developed a number of tools to assist dam owners, particularly EPRI members, in the evaluation and modification of dams. Although a considerable amount of progress has been made toward improving dam safety, there remain among the over 75,000 dams in the US a significant number of structures that require in-depth evaluation and possible modifications. At the same time, there are pressures from several directions to prioritize dam safety issues and find cost-effective solutions to problems because there seems to be an ever-decreasing amount of funds to address dam safety. In that regard, EPRI is sensitive to those cost considerations in a changing utility environment. Therefore, EPRI recently entered into discussions with utilities, regulatory agencies, federal agencies (dam owners), and others interested in dam safety issues. From those discussions, a number of research ideas were developed, which were distilled into three primary topics and several secondary topics of importance. The three primary areas of concern included: penstocks, tunnels, and gates; instrumentation and monitoring; and post-tensioned anchors. This report will provide a review of the workshop and insight on ideas for future dam safety R and D.

  12. INTEGRATIVE CONSIDERATIONS IN WATERSHED PLANNING

    EPA Science Inventory

    Understanding the filters through which society views the values produced by watersheds is key to developing effective and adaptable watershed plans, and ultimately a measure of how well policy makers are likely to meet a sustainability, or any other, intent. Many natural resour...

  13. Egypt: after the Aswan Dam

    SciTech Connect

    Walton, S.

    1981-05-01

    Ten years after its completion, the controversial Aswan High Dam's hydrologic and human consequences are clearer because of a joint US-Egyptian interdisciplinary study. Water supply and distribution is emerging as a major world resource problem with the recognition that unsafe drinking water and inadequate sanitation contribute to health problems. Dams provide water supplies, but they also create conditions favorable to the spread of water-borne diseases. The Aswan Dam solved problems of flooding and drought by opening 2.5 million acres to year-round irrigation, although some of the reclaimed land has been lost to urban expansion and shoreline erosion, and provides hydroelectric power. The negative effects include increasing soil salinity, changes in the water table, excessive downstream water plant growth, and diseases such as schistosomiasis and other intestinal parasites, and the social impact on the Nubians, whose homeland was flooded. Planners must use the information gathered in this study to see that the benefits outweigh the human costs. 22 references, 7 figures.

  14. Temporary Restoration of Bull Trout Passage at Albeni Falls Dam, 2008 Progress Report.

    SciTech Connect

    Bellgraph, Brian J.

    2009-03-31

    The goal of this project is to provide temporary upstream passage of bull trout around Albeni Falls Dam on the Pend Oreille River, Idaho. Our specific objectives are to capture fish downstream of Albeni Falls Dam, tag them with combination acoustic and radio transmitters, release them upstream of Albeni Falls Dam, and determine if genetic information on tagged fish can be used to accurately establish where fish are located during the spawning season. In 2007, radio receiving stations were installed at several locations throughout the Pend Oreille River watershed to detect movements of adult bull trout; however, no bull trout were tagged during that year. In 2008, four bull trout were captured downstream of Albeni Falls Dam, implanted with transmitters, and released upstream of the dam at Priest River, Idaho. The most-likely natal tributaries of bull trout assigned using genetic analyses were Grouse Creek (N = 2); a tributary of the Pack River, Lightning Creek (N = 1); and Rattle Creek (N = 1), a tributary of Lightning Creek. All four bull trout migrated upstream from the release site in Priest River, Idaho, were detected at monitoring stations near Dover, Idaho, and were presumed to reside in Lake Pend Oreille from spring until fall 2008. The transmitter of one bull trout with a genetic assignment to Grouse Creek was found in Grouse Creek in October 2008; however, the fish was not found. The bull trout assigned to Rattle Creek was detected in the Clark Fork River downstream from Cabinet Gorge Dam (approximately 13 km from the mouth of Lightning Creek) in September but was not detected entering Lightning Creek. The remaining two bull trout were not detected in 2008 after detection at the Dover receiving stations. This report details the progress by work element in the 2008 statement of work, including data analyses of fish movements, and expands on the information reported in the quarterly Pisces status reports.

  15. Downstream effects of dams on channel geometry and bottomland vegetation: Regional patterns in the Great Plains

    USGS Publications Warehouse

    Friedman, J.M.; Osterkamp, W.R.; Scott, M.L.; Auble, G.T.

    1998-01-01

    The response of rivers and riparian forests to upstream dams shows a regional pattern related to physiographic and climatic factors that influence channel geometry. We carried out a spatial analysis of the response of channel geometry to 35 dams in the Great Plains and Central Lowlands, USA. The principal response of a braided channel to an upstream dam is channel-narrowing, and the principal response of a meandering channel is a reduction in channel migration rate. Prior to water management, braided channels were most common in the southwestern Plains where sand is abundant, whereas meandering channels were most common in the northern and eastern Plains. The dominant response to upstream dams has been channel-narrowing in the southwestern Plains (e.g., six of nine cases in the High Plains) and reduction in migration rate in the north and east (e.g., all of twelve cases in the Missouri Plateau and Western Lake Regions). Channel-narrowing is associated with a burst of establishment of native and exotic woody riparian pioneer species on the former channel bed. In contrast, reduction in channel migration rate is associated with a decrease in reproduction of woody riparian pioneers. Thus, riparian pioneer forests along large rivers in the southwestern Plains have temporarily increased following dam construction while such forests in the north and east have decreased. These patterns explain apparent contradictions in conclusions of studies that focused on single rivers or small regions and provide a framework for predicting effects of dams on large rivers in the Great Plains and elsewhere. These conclusions are valid only for large rivers. A spatial analysis of channel width along 286 streams ranging in mean annual discharge from 0.004 to 1370 cubic meters per second did not produce the same clear regional pattern, in part because the channel geometries of small and large streams are affected differently by a sandy watershed.

  16. Predicting Ecosystem Response to the Removal of the Elwha River Dams, Washington State, U.S.A.

    NASA Astrophysics Data System (ADS)

    Pess, G. R.; McHenry, M.; Beechie, T. J.

    2005-12-01

    The Elwha River dams have disconnected the upper and lower Elwha watershed for over 90 years. This has resulted in a disruption to upstream salmonid migration and a 'loss' of 90% of the salmonid habitat. The dams have also interrupted the downstream movement of both sediment and wood, leading to such inputs being dominated by local sources (e.g., bank erosion and avulsions). The current salmon habitat, as well as salmonid abundance and distribution, reflects these changes. Current salmonid populations (several of which are hatchery-dominated) are either dramatically smaller than estimated historical population or extirpated. Nevertheless, salmonid populations do persist below the dams in part because channel incision has not been significant, and floodplain habitats remain an important component of the Elwha River ecosystem. Impending removal of these dams presents an opportunity to explore linkages among changes in salmonid populations, sediment supply, in-channel wood abundance, and habitat and ecosystem attributes. Sampling of ecosystem attributes before and after dam removal, as well as in nearby reference rivers will elucidate functional relationships among salmonid populations, sediment and wood supply, formation and persistence of river and floodplain habitats, and resultant ecosystem dynamics. Dam removal will (1) reconnect upstream habitats increasing salmonid carrying capacity, and (2) allow the downstream movement of sediment and wood leading to long-term aquatic habitat improvements. Both large-scale changes will allow salmonid populations to rebuild on a watershed-scale. We hypothesize that the salmonid recolonization will be concentrated in several large alluvial valleys in the Middle and Upper Elwha.

  17. Impact of Artificial Reservoir Size on Probable Maximum Flood (PMF): The case of Folsom Dam on American River

    NASA Astrophysics Data System (ADS)

    Yigzaw, W. Y.; Hossain, F.

    2011-12-01

    Artificial reservoirs are created with the construction of dams on a given river. The design of these dams usually considers available historical data. However, the impact of future flood extremes that may change due to the local feedback from reservoir is not considered in conventional dam design approach. Recent study using a regional atmospheric model has shown that the size (surface area) of reservoir can physically increase the probable maximum precipitation (PMP). Probable Maximum Flood (PMF), which is the key design parameter for hydraulic features of a dam, is estimated from PMP and the hydrology of the basin. Hence, it is important to understand the impact of reservoir size on PMF. Given the non-linearity of the rainfall-runoff process, a key question that needs to be asked by water managers now is, "what is the dependency of PMF on the size of an artificial reservoir given the strong local atmospheric feedbacks?" Using the American River Watershed (ARW) as a representative example of an impounded watershed with a large artificial reservoir (Folsom Dam), this study sets up the distributed Variable Infiltration Capacity (VIC) model to simulate the PMF from the atmospheric feedbacks for various reservoir sizes. The atmospheric feedbacks were simulated in the form of PMP in a previous study using the Regional Atmospheric Modeling System (RAMS). The RAMS-generated PMP scenarios were propagated through VIC model to simulate the PMFs. The study overcomes several logistic and conceptual hurdles to generating the basin's natural response to PMF given the extensive nature of upstream impoundment on various tributaries and incomplete stream flow record for adequate calibration. The results obtained from this study will be used to show how large artificial reservoirs should be managed and operated for flood control in a changing climate with strong local feedbacks triggered by the dam itself.

  18. Developing a geomorphic approach for ranking watersheds for rehabilitation, Zuni Indian Reservation, New Mexico

    USGS Publications Warehouse

    Gellis, A.C.; Cheama, A.; Lalio, S.M.

    2001-01-01

    As a result of past erosion problems on the Zuni Indian Reservation in western New Mexico, the US Congress in 1990 authorized the Zuni Tribe to begin a program for watershed rehabilitation. This paper describes an approach to rank the most appropriate watersheds for rehabilitation for the Zuni Reservation. The approach was based on data collected during a 3-year study on geomorphic and anthropogenic characteristics of the Rio Nutria Watershed, including data on (i) arroyo cross-sectional changes, (ii) erosion-control structures, and (iii) sheetwash erosion. Results of this 3-year study indicated that 61 of 85 channel cross-sections aggraded and channels with lower width-to-depth ratios eroded. Results on assessment of erosion-control structures, some dating back to the 1930's, indicated that 60% of earthen dams and 22% of rock-and-brush structures were breached or flanked in the Rio Nutria Watershed. Sheetwash erosion measured on five land-cover sites (sagebrush, pasture, chained pin??on and juniper, unchained pin??on and juniper, and ponderosa pine) indicated chained pin??on and juniper sites and pasture sites had the highest volume-weighted sediment concentrations of 13,000 and 9970 ppm, respectively. Based on interpretations of the 3-year study in the Rio Nutria Watershed, a two-stage approach was developed to rank the most appropriate watersheds for rehabilitation on the Zuni Reservation. In the first stage, the reservation was divided into eight major watersheds, which were ranked according to the most potential for erosion. In the second stage, the watershed with the most potential for erosion was divided into sub-basins, which were ranked according to the most potential for erosion. Quantitative and qualitative information on physical and anthropogenic factors were used at each stage to rank the watersheds. Quantitative physical data included headcut density, percentage of bare ground, percentage of chained area, channel width-to-depth ratio, change in

  19. Impact of Watershed Development on Sediment Transport and Seasonal Flooding in the Main Stream of the Mekong River

    NASA Astrophysics Data System (ADS)

    Kameyama, S.; Nohara, S.; Sato, T.; Fujii, Y.; Kudo, K.

    2009-12-01

    The Mekong River watershed is undergoing rapid economic progress and population growth, raising conflicts between watershed development and environmental conservation. A typical conflict is between the benefits of dam construction versus the benefits of watershed ecological services. In developed countries, this conflict is changing to a coordinated search for outcomes that are mutually acceptable to all stakeholders. In the Mekong River, however, government policy gives priority to watershed development for ensuring steady energy supplies. Since the 1990s, a series of dams called “the Mekong Cascade” have been under construction. Dam construction has multiple economic values as electric power supply, irrigation water, flood control, etc. On the other hand, the artificial flow discharge controls of dam moderate seasonal hydrologic patterns of the Asian monsoon region. Dam operations can change the sediment transport regime and river structure. Furthermore, their impacts on watershed ecosystems and traditional economic activities of fisheries and agriculture in downstream areas may be severe. We focus on dam impacts on spatio-temporal patterns of sediment transport and seasonal flood in riparian areas downstream from Mekong River dams. Our study river section is located on 100 km down stream from the Golden Triangle region of Myanmar, Laos, and Thailand. We selected a 10-km section in this main channel to simulate seasonal flooding. We modeled the river hydrology in the years 1991 and 2002, before and after the Manwan dam construction (1986-1993). For this simulation, we adapted three models (distributed runoff model, 1-D hydrological model, and 2-D flood simulation with sediment movement algorithm.) Input data on river structure, water velocity, and flow volume were acquired from field survey data in November 2007 and 2008. In the step of parameter decision, we adopted the shuffled complex evolution method. To validate hydrologic parameters, we used annual

  20. Sediment and 137Cs transport and accumulation in the Ogaki Dam of eastern Fukushima

    NASA Astrophysics Data System (ADS)

    Yamada, Susumu; Kitamura, Akihiro; Kurikami, Hiroshi; Yamaguchi, Masaaki; Malins, Alex; Machida, Masahiko

    2015-01-01

    The Ogaki Dam Reservoir is one of the principal irrigation dam reservoirs in the Fukushima Prefecture and its upstream river basin was heavily contaminated by radioactivity from the Fukushima Daiichi Nuclear Power Plant accident. For the purpose of environmental assessment, it is important to determine the present condition of the water in the reservoir and to understand the behavior of sediment-sorbed radioactive cesium under different modes of operation of the dam, as these factors affect further contamination of arable farmlands downstream of the reservoir through sediment migration. This paper addresses this issue with numerical simulations of fluvial processes in the reservoir using the two-dimensional Nays2D code. We distinguish three grades of sediment (clay, silt, and sand), as cesium adherence depends on sediment grain size and surface area. Boundary conditions for the simulations were informed by monitoring data of the upstream catchment and by the results from a separate watershed simulation for sediment transport into the reservoir. The performance of the simulation method was checked by comparing the results for a typhoon flood in September 2013 against field monitoring data. We present results for sediment deposition on the reservoir bed and the discharge via the dam under typical yearly flood conditions, for which the bulk of annual sediment migration from the reservoir occurs. The simulations show that almost all the sand and silt that enter into the reservoir deposit onto the reservoir bed. However, the locations where they tend to deposit differ, with sand tending to deposit close to the entrance of the reservoir, whereas silt deposits throughout the reservoir. Both sand and silt settle within a few hours of entering the reservoir. In contrast, clay remains suspended in the reservoir water for a period as long as several days, thus increasing the amount that is discharged downstream from the reservoir. Under the current operating mode of the dam

  1. Sources, Transport, and Storage of Sediment at Selected Sites in the Chesapeake Bay Watershed

    USGS Publications Warehouse

    Gellis, Allen C.; Hupp, Cliff R.; Pavich, Milan J.; Landwehr, Jurate M.; Banks, William S.L.; Hubbard, Bernard E.; Langland, Michael J.; Ritchie, Jerry C.; Reuter, Joanna M.

    2009-01-01

    The Chesapeake Bay Watershed covers 165,800 square kilometers and is supplied with water and sediment from five major physiographic provinces: Appalachian Plateau, Blue Ridge, Coastal Plain, Piedmont, and the Valley and Ridge. Suspended-sediment loads measured in the Chesapeake Bay Watershed showed that the Piedmont Physiographic Province has the highest rates of modern (20th Century) sediment yields, measured at U.S. Geological Survey streamflow-gaging stations, and the lowest rates of background or geologic rates of erosion (~10,000 years) measured with in situ beryllium-10. In the agricultural and urbanizing Little Conestoga Creek Watershed, a Piedmont watershed, sources of sediment using the 'sediment-fingerprinting' approach showed that streambanks were the most important source (63 percent), followed by cropland (37 percent). Cesium-137 inventories, which quantify erosion rates over a 40-year period, showed average cropland erosion of 19.39 megagrams per hectare per year in the Little Conestoga Creek Watershed. If this erosion rate is extrapolated to the 13 percent of the watershed that is in cropland, then cropland could contribute almost four times the measured suspended-sediment load transported out of the watershed (27,600 megagrams per hectare per year), indicating that much of the eroded sediment is being deposited in channel and upland storage. The Piedmont has had centuries of land-use change, from forest to agriculture, to suburban and urban areas, and in some areas, back to forest. These land-use changes mobilized a large percentage of sediment that was deposited in upland and channel storage, and behind thousands of mill dams. The effects of these land-use changes on erosion and sediment transport are still being observed today as stored sediment in streambanks is a source of sediment. Cropland is also an important source of sediment. The Coastal Plain Physiographic Province has had the lowest sediment yields in the 20th Century and with sandy

  2. Optimizing multiple dam removals under multiple objectives: Linking tributary habitat and the Lake Erie ecosystem

    NASA Astrophysics Data System (ADS)

    Zheng, Pearl Q.; Hobbs, Benjamin F.; Koonce, Joseph F.

    2009-12-01

    A model is proposed for optimizing the net benefits of removing multiple dams in U.S. watersheds of Lake Erie by quantifying impacts upon social, ecological, and economic objectives of importance to managers and stakeholders. Explicit consideration is given to the linkages between newly accessible tributary habitat and the lake's ecosystem. The model is a mixed integer linear program (MILP) that selects a portfolio of potential dam removals that could achieve the best possible value of a weighted sum of the objective(s), while still satisfying the constraints. Using response functions extracted from the Lake Erie Ecological Model and an empirical cost model, the MILP accounts for ecological and economic effects of habitat changes for both desirable native walleye and undesirable sea lamprey. The solutions show the effect on removal decisions of alternative prioritizations among cost and environmental objectives and the resulting trade-offs among those objectives. The MILP can be used as a screening model to identify portfolios of dam removals that are potentially cost-effective enhancements of habitat and the Lake Erie ecosystem; subsequent site-specific studies would be needed prior to actually removing dams.

  3. Elevated streamflows increase dam passage by juvenile coho salmon during winter: Implications of climate change in the Pacific Northwest

    USGS Publications Warehouse

    Kock, Tobias J.; Liedtke, Theresa L.; Rondorf, Dennis W.; Serl, John D.; Kohn, Mike; Bumbaco, Karin A.

    2012-01-01

    A 4-year evaluation was conducted to determine the proportion of juvenile coho salmon Oncorhynchus kisutch passing Cowlitz Falls Dam, on the Cowlitz River, Washington, during winter. River and reservoir populations of coho salmon parr were monitored using radiotelemetry to determine if streamflow increases resulted in increased downstream movement and dam passage. This was of interest because fish that pass downstream of Cowlitz Falls Dam become landlocked in Riffe Lake and are lost to the anadromous population. Higher proportions of reservoir-released fish (0.391-0.480) passed Cowlitz Falls Dam than did river-released fish (0.037-0.119). Event-time analyses demonstrated that streamflow increases were important predictors of dam passage rates during the study. The estimated effect of increasing streamflows on the risk of dam passage varied annually and ranged from 9% to 75% for every 28.3 m3/s increase in streamflow. These results have current management implications because they demonstrate the significance of dam passage by juvenile coho salmon during winter months when juvenile fish collection facilities are typically not operating. The results also have future management implications because climate change predictions suggest that peak streamflow timing for many watersheds in the Pacific Northwest will shift from late spring and early summer to winter. Increased occurrence of intense winter flood events is also expected. Our results demonstrate that juvenile coho salmon respond readily to streamflow increases and initiate downstream movements during winter months, which could result in increased passage at dams during these periods if climate change predictions are realized in the coming decades.

  4. Exporting dams: China's hydropower industry goes global.

    PubMed

    McDonald, Kristen; Bosshard, Peter; Brewer, Nicole

    2009-07-01

    In line with China's "going out" strategy, China's dam industry has in recent years significantly expanded its involvement in overseas markets. The Chinese Export-Import Bank and other Chinese financial institutions, state-owned enterprises, and private firms are now involved in at least 93 major dam projects overseas. The Chinese government sees the new global role played by China's dam industry as a "win-win" situation for China and host countries involved. But evidence from project sites such as the Merowe Dam in Sudan demonstrates that these dams have unrecognized social and environmental costs for host communities. Chinese dam builders have yet to adopt internationally accepted social and environmental standards for large infrastructure development that can assure these costs are adequately taken into account. But the Chinese government is becoming increasingly aware of the challenge and the necessity of promoting environmentally and socially sound investments overseas.

  5. Measurement of Dam Deformations: Case Study of Obruk Dam (Turkey)

    NASA Astrophysics Data System (ADS)

    Gulal, V. Engin; Alkan, R. Metin; Alkan, M. Nurullah; İlci, Veli; Ozulu, I. Murat; Tombus, F. Engin; Kose, Zafer; Aladogan, Kayhan; Sahin, Murat; Yavasoglu, Hakan; Oku, Guldane

    2016-04-01

    In the literature, there is information regarding the first deformation and displacement measurements in dams that were conducted in 1920s Switzerland. Todays, deformation measurements in the dams have gained very different functions with improvements in both measurement equipment and evaluation of measurements. Deformation measurements and analysis are among the main topics studied by scientists who take interest in the engineering measurement sciences. The Working group of Deformation Measurements and Analysis, which was established under the International Federation of Surveyors (FIG), carries out its studies and activities with regard to this subject. At the end of the 1970s, the subject of the determination of fixed points in the deformation monitoring network was one of the main subjects extensively studied. Many theories arose from this inquiry, as different institutes came to differing conclusions. In 1978, a special commission with representatives of universities has been established within the FIG 6.1 working group; this commission worked on the issue of determining a general approach to geometric deformation analysis. The results gleaned from the commission were discussed at symposiums organized by the FIG. In accordance with these studies, scientists interested in the subject have begun to work on models that investigate cause and effect relations between the effects that cause deformation and deformation. As of the scientist who interest with the issue focused on different deformation methods, another special commission was established within the FIG engineering measurements commission in order to classify deformation models and study terminology. After studying this material for a long time, the official commission report was published in 2001. In this prepared report, studies have been carried out by considering the FIG Engineering Surveying Commission's report entitled, 'MODELS AND TERMINOLOGY FOR THE ANALYSIS OF GEODETIC MONITORING OBSERVATIONS

  6. 18. DETAIL AT JUNCTION OF MAIN DAM AT LEFT AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. DETAIL AT JUNCTION OF MAIN DAM AT LEFT AND DIVERSION DAM AT RIGHT SHOWING LOG CRIBBING. SPACES INSIDE CRIBBING WERE FILLED WITH STONE TO ANCHOR DAM; DETERIORATION OF DAM HAS ALLOWED STONE BALLAST TO WASH AWAY. Photographed July 18, 1938. - Forge Creek Dam-John Cable Mill, Townsend, Blount County, TN

  7. View of upstream face of the forebay dam of Grand ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of upstream face of the forebay dam of Grand Coulee Dam, looking west. Construction of the forebay dam, which replaced the eastern end of the original Grand Coulee Dam, was completed in 1974. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  8. Dam breaching and Chinook salmon recovery

    USGS Publications Warehouse

    Dambacher, Jeffrey M.; Rossignol, Philippe A.; Li, Hiram W.; Emlen, John M.; Kareiva, Peter; Marvier, Michelle; Michelle M. McClure,

    2001-01-01

    The Report by Kareiva et al. on recovery and management options for spring/summer chinook salmon (1) has the potential to have a major impact in deciding whether to breach dams on the Snake River. Based on interpretation of their model results, they argue that dam breaching would be insufficient to reverse the decline of salmon. An examination of the specifics of their model, however, suggests that, despire their argument, dam breaching remains a viable recovery option for chinook salmon.

  9. Watershed-based survey designs.

    PubMed

    Detenbeck, Naomi E; Cincotta, Dan; Denver, Judith M; Greenlee, Susan K; Olsen, Anthony R; Pitchford, Ann M

    2005-04-01

    Watershed-based sampling design and assessment tools help serve the multiple goals for water quality monitoring required under the Clean Water Act, including assessment of regional conditions to meet Section 305(b), identification of impaired water bodies or watersheds to meet Section 303(d), and development of empirical relationships between causes or sources of impairment and biological responses. Creation of GIS databases for hydrography, hydrologically corrected digital elevation models, and hydrologic derivatives such as watershed boundaries and upstream-downstream topology of subcatchments would provide a consistent seamless nationwide framework for these designs. The elements of a watershed-based sample framework can be represented either as a continuous infinite set defined by points along a linear stream network, or as a discrete set of watershed polygons. Watershed-based designs can be developed with existing probabilistic survey methods, including the use of unequal probability weighting, stratification, and two-stage frames for sampling. Case studies for monitoring of Atlantic Coastal Plain streams, West Virginia wadeable streams, and coastal Oregon streams illustrate three different approaches for selecting sites for watershed-based survey designs. PMID:15861987

  10. Watershed-based survey designs

    USGS Publications Warehouse

    Detenbeck, N.E.; Cincotta, D.; Denver, J.M.; Greenlee, S.K.; Olsen, A.R.; Pitchford, A.M.

    2005-01-01

    Watershed-based sampling design and assessment tools help serve the multiple goals for water quality monitoring required under the Clean Water Act, including assessment of regional conditions to meet Section 305(b), identification of impaired water bodies or watersheds to meet Section 303(d), and development of empirical relationships between causes or sources of impairment and biological responses. Creation of GIS databases for hydrography, hydrologically corrected digital elevation models, and hydrologic derivatives such as watershed boundaries and upstream-downstream topology of subcatchments would provide a consistent seamless nationwide framework for these designs. The elements of a watershed-based sample framework can be represented either as a continuous infinite set defined by points along a linear stream network, or as a discrete set of watershed polygons. Watershed-based designs can be developed with existing probabilistic survey methods, including the use of unequal probability weighting, stratification, and two-stage frames for sampling. Case studies for monitoring of Atlantic Coastal Plain streams, West Virginia wadeable streams, and coastal Oregon streams illustrate three different approaches for selecting sites for watershed-based survey designs. ?? Springer Science + Business Media, Inc. 2005.

  11. 78 FR 60271 - Hollow Dam Power Company; Ampersand Hollow Dam Hydro, LLC; Notice of Application for Transfer of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-01

    ... Federal Energy Regulatory Commission Hollow Dam Power Company; Ampersand Hollow Dam Hydro, LLC; Notice of..., Hollow Dam Power Company (transferor) and Ampersand Hollow Dam Hydro, LLC (transferee) filed an application for transfer of license for the Hollow Dam Project, FERC No. 6972, located on the West Branch...

  12. Mercury in Indiana watersheds: retrospective for 2001-2006

    USGS Publications Warehouse

    Risch, Martin R.; Baker, Nancy T.; Fowler, Kathleen K.; Egler, Amanda L.; Lampe, David C.

    2010-01-01

    Information about total mercury and methylmercury concentrations in water samples and mercury concentrations in fish-tissue samples was summarized for 26 watersheds in Indiana that drain most of the land area of the State. Mercury levels were interpreted with information on streamflow, atmospheric mercury deposition, mercury emissions to the atmosphere, mercury in wastewater, and landscape characteristics. Unfiltered total mercury concentrations in 411 water samples from streams in the 26 watersheds had a median of 2.32 nanograms per liter (ng/L) and a maximum of 28.2 ng/L. When these concentrations were compared to Indiana water-quality criteria for mercury, 5.4 percent exceeded the 12-ng/L chronic-aquatic criterion, 59 percent exceeded the 1.8-ng/L Great Lakes human-health criterion, and 72.5 percent exceeded the 1.3-ng/L Great Lakes wildlife criterion. Mercury concentrations in water were related to streamflow, and the highest mercury concentrations were associated with the highest streamflows. On average, 67 percent of total mercury in streams was in a particulate form, and particulate mercury concentrations were significantly lower downstream from dams than at monitoring stations not affected by dams. Methylmercury is the organic fraction of total mercury and is the form of mercury that accumulates and magnifies in food chains. It is made from inorganic mercury by natural processes under specific conditions. Unfiltered methylmercury concentrations in 411 water samples had a median of 0.10 ng/L and a maximum of 0.66 ng/L. Methylmercury was a median 3.7 percent and maximum 64.8 percent of the total mercury in 252 samples for which methylmercury was reported. The percentages of methylmercury in water samples were significantly higher downstream from dams than at other monitoring stations. Nearly all of the total mercury detected in fish tissue was assumed to be methylmercury. Fish-tissue samples from the 26 watersheds had wet-weight mercury concentrations that

  13. Watersheds and Explosive percolation

    NASA Astrophysics Data System (ADS)

    Herrmann, Hans J.; Araujo, Nuno A. M.

    The recent work by Achlioptas, D'Souza, and Spencer opened up the possibility of obtaining a discontinuous (explosive) percolation transition by changing the stochastic rule of bond occupation. Despite the active research on this subject, several questions still remain open about the leading mechanism and the properties of the system. We review the largest cluster and the Gaussian models recently introduced. We show that, to obtain a discontinuous transition it is solely necessary to control the size of the largest cluster, suppressing the growth of a cluster di_ering significantly, in size, from the average one. As expected for a discontinuous transition, a Gaussian cluster-size distribution and compact clusters are obtained. The surface of the clusters is fractal, with the same fractal dimension of the watershed line.

  14. 1. General view of dam looking west, showing both the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. General view of dam looking west, showing both the downstream buttresses and the upstream arch-rings. The spillway is on the far end of the dam. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  15. 7. DETAIL VIEW OF DAM, SHOWING ROLLER GATES, GATE PIERS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. DETAIL VIEW OF DAM, SHOWING ROLLER GATES, GATE PIERS, HEADHOUSES AND DAM BRIDGE, LOOKING NORTHWEST, UPSTREAM - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 9, Lynxville, Crawford County, WI

  16. 5. DETAIL VIEW OF DAM, SHOWING ROLLER AND TAINTER GATES, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. DETAIL VIEW OF DAM, SHOWING ROLLER AND TAINTER GATES, GATE PIERS, HEADHOUSES AND DAM BRIDGE, LOOKING NORTHWEST, UPSTREAM - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 9, Lynxville, Crawford County, WI

  17. 56. LOCK AND DAM NO. 26 (REPLACEMENT). AUXILIARY LOCK AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. LOCK AND DAM NO. 26 (REPLACEMENT). AUXILIARY LOCK AND REMAINDER OF DAM -- CONCRETE MONOLITH PLAN AND WALL ELEVATIONS (WITH LOCK APPURTENANCES). Drawing V-601 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

  18. GENERAL VIEW OF THE WILSON DAM, LOOKING SOUTHEAST, GENERATING PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GENERAL VIEW OF THE WILSON DAM, LOOKING SOUTHEAST, GENERATING PLANT IN THE BACKGROUND. - Wilson Dam & Hydroelectric Plant, Spanning Tennessee River at Wilson Dam Road (Route 133), Muscle Shoals, Colbert County, AL

  19. 5. VIEW SHOWING DOWNSTREAM FACE AND TOE OF DAM, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW SHOWING DOWNSTREAM FACE AND TOE OF DAM, LOOKING SOUTHWEST - High Mountain Dams in Upalco Unit, Kidney Lake Dam, Ashley National Forest, 4.7 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  20. 3. OVERALL VIEW OF DAM, SHOWING UPSTREAM FACE, LOOKING EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. OVERALL VIEW OF DAM, SHOWING UPSTREAM FACE, LOOKING EAST - High Mountain Dams in Upalco Unit, Kidney Lake Dam, Ashley National Forest, 4.7 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  1. 6. VIEW SHOWING DOWNSTREAM FACE AND TOE OF DAM, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW SHOWING DOWNSTREAM FACE AND TOE OF DAM, LOOKING SOUTHWEST - High Mountain Dams in Upalco Unit, Kidney Lake Dam, Ashley National Forest, 4.7 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  2. 4. VIEW SHOWING UPSTREAM FACE OF DAM, LOOKING NORTHEAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW SHOWING UPSTREAM FACE OF DAM, LOOKING NORTHEAST - High Mountain Dams in Upalco Unit, Kidney Lake Dam, Ashley National Forest, 4.7 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  3. 4. VIEW, LOOKING SOUTHWEST, SHOWING A LARGE FIELDSTONE DAM (KNOWN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW, LOOKING SOUTHWEST, SHOWING A LARGE FIELD-STONE DAM (KNOWN LOCALLY AS DAM NO. 1), BUILT BY THE CCC - J. Clark Salyer National Wildlife Refuge Dams, Along Lower Souris River, Kramer, Bottineau County, ND

  4. 8. VIEW OF DAM 83, SHOWING OLD SOURIS RIVER CHANNEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF DAM 83, SHOWING OLD SOURIS RIVER CHANNEL FROM THE DOWNSTREAM FACE OF THE DAM WITH POND A IN THE BACKGROUND, LOOKING SOUTH - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  5. 3. VIEW, LOOKING NORTHEAST, SHOWING A SMALL FIELDSTONE DAM (KNOWN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW, LOOKING NORTHEAST, SHOWING A SMALL FIELD-STONE DAM (KNOWN LOCALLY AS DAM NO. 2), BUILT BY THE CCC - J. Clark Salyer National Wildlife Refuge Dams, Along Lower Souris River, Kramer, Bottineau County, ND

  6. Dam located to east of powerhouse, view from south. This ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Dam located to east of powerhouse, view from south. This dam holds back the waters of the Chattahoochee River to form the mill pond north of Riverdale Cotton Mill - Riverdale Cotton Mill, Powerhouse & Dam, Valley, Chambers County, AL

  7. 2. OVERALL VIEW OF DAM, SHOWING CREST AND DOWNSTREAM FACE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. OVERALL VIEW OF DAM, SHOWING CREST AND DOWNSTREAM FACE, WITH CONCRETE EXTENSION IN FOREGROUND, LOOKING NORTH - High Mountain Dams in Bonneville Unit, Fire Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

  8. 10. BRIDGE IN CONTEXT OF DAM, THIRD POWER HOUSE IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. BRIDGE IN CONTEXT OF DAM, THIRD POWER HOUSE IN FOREGROUND, LOOKING NORTH BY 360 DEGREES - Columbia River Bridge at Grand Coulee Dam, Spanning Columbia River at State Route 155, Coulee Dam, Okanogan County, WA

  9. 3. DETAIL VIEW OF DAM, SHOWING ROLLER AND TAINTER GATES, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. DETAIL VIEW OF DAM, SHOWING ROLLER AND TAINTER GATES, GATE PIERS, HEADHOUSES AND DAM BRIDGES, LOOKING SOUTH, DOWNSTREAM - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 4, Alma, Buffalo County, WI

  10. 2. East side of lower dam shown with water flowing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. East side of lower dam shown with water flowing over dam. VIEW WEST - Loleta Recreation Area, Lower Dam, 6 miles Southeast of interesection of State Route 24041 & State Route 66, Loleta, Elk County, PA

  11. 9. VIEW OF LATERAL GATE ON CANAL NEAR DAM, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF LATERAL GATE ON CANAL NEAR DAM, LOOKING SOUTHEAST - High Mountain Dams in Upalco Unit, Twin Pots Dam, Ashley National Forest, 10.1 miles North of Mountain Home, Mountain Home, Duchesne County, UT

  12. 14. VIEW OF DAM SITE, LOOKING SOUTH (DOWNSTREAM). MIXING PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. VIEW OF DAM SITE, LOOKING SOUTH (DOWNSTREAM). MIXING PLANT IS VISIBLE AT RIGHT, COFFER DAM IS UPSTREAM OF PLACING TOWER. EAST DOME IS VISIBLE AT LEFT OF TOWER, c. 1927 - Coolidge Dam, Gila River, Peridot, Gila County, AZ

  13. A new watershed assessment framework for Nova Scotia: A high-level, integrated approach for regions without a dense network of monitoring stations

    NASA Astrophysics Data System (ADS)

    Sterling, Shannon M.; Garroway, Kevin; Guan, Yue; Ambrose, Sarah M.; Horne, Peter; Kennedy, Gavin W.

    2014-11-01

    High-level, integrated watershed assessments are a basic requirement for freshwater planning, as they create regional summaries of multiple environmental stressors for the prioritization of watershed conservation, restoration, monitoring, and mitigation. There is a heightened need for a high-level, integrated watershed assessment in Nova Scotia as it faces pressing watershed issues relating to acidification, soil erosion, acid rock drainage, eutrophication, and water withdrawals related to potential shale gas development. But because of the relative sparseness of the on-the-ground effects-based data, for example on water quality or fish assemblages, previously created approaches for integrated watershed assessment cannot be used. In a government/university collaboration, we developed a new approach that relies solely on easier-to-collect and more available exposure-based variables to perform the first high-level watershed assessment in Nova Scotia. In this assessment, a total of 295 watershed units were studied. We used Geographic Information Systems (GIS) to map and analyze 13 stressor variables that represent risks to aquatic environment (e.g., road/stream crossing density, acid rock drainage risk, surface water withdrawals, human land use, and dam density). We developed a model to link stressors with impacts to aquatic systems to serve as a basis for a watershed threat ranking system. Resource management activities performed by government and other stakeholders were also included in this analysis. Our assessment identifies the most threatened watersheds, enables informed comparisons among watersheds, and indicates where to focus resource management and monitoring efforts. Stakeholder communication tools produced by the NSWAP include a watershed atlas to communicate the assessment results to a broader audience, including policy makers and public stakeholders. This new framework for high-level watershed assessments provides a resource for other regions that also

  14. COMPARATIVE ASSESSMENT OF TWO DISTRIBUTED WATERSHED MODELS WITH APPLICATION TO A SMALL WATERSHED

    EPA Science Inventory

    Distributed watershed models are beneficial tools for assessment of management practices on runoff and water-induced erosion. This paper evaluates, by application to an experimental watershed, two promising distributed watershed-scale sediment models in detail: The Kinematic Runo...

  15. Putting watershed restoration in context: alternative future scenarios influence management outcomes.

    PubMed

    Fullerton, A H; Steel, E A; Caras, Y; Sheer, M; Olson, P; Kaje, J

    2009-01-01

    Predicting effects of habitat restoration is an important step for recovery of imperiled anadromous salmonid populations. Habitat above three major hydropower dams in the Lewis River watershed, southwestern Washington, USA, will soon become accessible to anadromous fish. We used multiple models to estimate habitat conditions above dams and fish population responses. Additionally, we used scenario planning to predict how habitat and fish will respond to potential future trends in land use due to human population growth and riparian conservation policies. Finally, we developed a hypothetical management strategy (i.e., a set of prioritized restoration projects in specific locations within the watershed) as an example of how a fixed amount of restoration funds might be spent to enhance the success of reintroducing fish above dams. We then compared predicted outcomes from this new strategy to those of six previously modeled strategies. We estimated how the choice of the best management strategy might differ among alternative future scenarios. Results suggest that dam passage will provide access to large amounts of high-quality habitat that will benefit fish populations. Moreover, conservation of existing riparian areas, if implemented, has the potential to improve conditions to a much greater extent than restoration strategies examined, despite expected urban growth. We found that the relative performance of management strategies shifted when fish were allowed to migrate above dams, but less so among alternative futures examined. We discuss how predicted outcomes from these seven hypothetical management strategies could be used for developing an on-the-ground strategy to address a real management situation. PMID:19323185

  16. Putting watershed restoration in context: alternative future scenarios influence management outcomes.

    PubMed

    Fullerton, A H; Steel, E A; Caras, Y; Sheer, M; Olson, P; Kaje, J

    2009-01-01

    Predicting effects of habitat restoration is an important step for recovery of imperiled anadromous salmonid populations. Habitat above three major hydropower dams in the Lewis River watershed, southwestern Washington, USA, will soon become accessible to anadromous fish. We used multiple models to estimate habitat conditions above dams and fish population responses. Additionally, we used scenario planning to predict how habitat and fish will respond to potential future trends in land use due to human population growth and riparian conservation policies. Finally, we developed a hypothetical management strategy (i.e., a set of prioritized restoration projects in specific locations within the watershed) as an example of how a fixed amount of restoration funds might be spent to enhance the success of reintroducing fish above dams. We then compared predicted outcomes from this new strategy to those of six previously modeled strategies. We estimated how the choice of the best management strategy might differ among alternative future scenarios. Results suggest that dam passage will provide access to large amounts of high-quality habitat that will benefit fish populations. Moreover, conservation of existing riparian areas, if implemented, has the potential to improve conditions to a much greater extent than restoration strategies examined, despite expected urban growth. We found that the relative performance of management strategies shifted when fish were allowed to migrate above dams, but less so among alternative futures examined. We discuss how predicted outcomes from these seven hypothetical management strategies could be used for developing an on-the-ground strategy to address a real management situation.

  17. McNary Dam, Ice Harbor Dam, and Lower Monumental Dam Smolt Monitoring Program; 1996 Annual Report.

    SciTech Connect

    Hillson, Todd; Lind, Sharon; Price, William

    1997-07-01

    The Washington Department of Fish & Wildlife (WDFW) assumed responsibility for the Smolt Monitoring Program at McNary Dam on the Columbia River in 1990 and at the new juvenile collection facility at Lower Monumental Dam on the Snake River in 1993. In 1996, Smolt Monitoring Program activities also began at the new juvenile collection facility located at Ice Harbor Dam. This report summarizes the 1996 Smolt Monitoring work at all three sites. The work at Ice Harbor consisted of Gas Bubble Trauma (GBT) monitoring only. In general, the 1996 passage season at both the McNary and Lower Monumental sites can be characterized by reduced passage of juveniles through the collection systems due to elevated river flows and spill, and low (<1%) overall facility mortality rates most likely resulting from cooler water temperatures. In accordance with the National Marine Fisheries Service recommendations (NMFS, 1995) all spring migrants were bypassed at McNary Dam in 1996. Mechanical problems within the McNary collection system resulted in collection and sampling activities being delayed until April 18 at this site, while sampling and collection began on the scheduled starting date of April 1 at Lower Monumental Dam. Monitoring operations were conducted through December 14 at McNary Dam and through October 28 at Lower Monumental Dam. An ongoing transportation evaluation summer migrant marking program was conducted at McNary Dam in 1996 by the NMFS. This necessitated the sampling of 394,211 additional fish beyond the recommended sampling guidelines. All total, 509,237 and 31,219 juvenile salmonids were anesthetized and individually counted, examined for scale loss, injuries, and brands by WDFW Smolt Monitoring personnel in 1996 at McNary Dam and Lower Monumental Dam, respectively.

  18. COMPLEMENTARY APPROACHES TO WATERSHED ASSESSMENT

    EPA Science Inventory

    Anthropogenic activities in watersheds affect aquatic organisms, riparian vegetation, and their ability to support avian populations. Our objective was to compare indicators of stream and riparian condition with the composition of breeding bird populations in six Rhode Island s...

  19. Asotin Creek Model Watershed Plan

    SciTech Connect

    Browne, D.; Holzmiller, J.; Koch, F.; Polumsky, S.; Schlee, D.; Thiessen, G.; Johnson, C.

    1995-04-01

    The Asotin Creek Model Watershed Plan is the first to be developed in Washington State which is specifically concerned with habitat protection and restoration for salmon and trout. The plan is consistent with the habitat element of the ``Strategy for Salmon``. Asotin Creek is similar in many ways to other salmon-bearing streams in the Snake River system. Its watershed has been significantly impacted by human activities and catastrophic natural events, such as floods and droughts. It supports only remnant salmon and trout populations compared to earlier years. It will require protection and restoration of its fish habitat and riparian corridor in order to increase its salmonid productivity. The watershed coordinator for the Asotin County Conservation District led a locally based process that combined local concerns and knowledge with technology from several agencies to produce the Asotin Creek Model Watershed Plan.

  20. Watershed Simulation of Nutrient Processes

    EPA Science Inventory

    In this presentation, nitrogen processes simulated in watershed models were reviewed and compared. Furthermore, current researches on nitrogen losses from agricultural fields were also reviewed. Finally, applications with those models were reviewed and selected successful and u...

  1. STEWARDS: A watershed data system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Comprehensive, long-term data from watersheds across diverse environments are needed for hydrologic and ecosystem analysis and for model development, calibration and validation. To support the Agricultural Research Service's Conservation Effects Assessment Project (CEAP) in assessing impacts of USDA...

  2. Supplement Analysis for the Watershed Management Program EIS - John Day Watershed Restoration Program

    SciTech Connect

    N /A

    2004-08-04

    The Bonneville Power Administration (BPA) is proposing to fund the John Day Watershed Restoration Program, which includes projects to improve watershed conditions, resulting in improved fish and wildlife habitat. The project was planned and coordinated by the Confederated Tribes of the Warm Springs through the John Day Basin Office in Prairie City, Oregon. A variety of activities will be implemented, described below. The project will involve the installation of four permanent lay flat diversions (structures) to replace temporary diversions. Two structures would be constructed in Beech Creek, one in Little Beech Creek and one in the John Day River. The structures will replace temporary pushup dams, which were constructed annually of various materials. Installation of the permanent diversion structures eliminates the stream-disturbing activities associated with annual installation of temporary structures. They also will enable fish passage in all flow conditions, an improvement over the temporary structures which can obstruct fish passage under some conditions. Five scour chains will be installed in six sites within the John Day River. The chains will be 3 feet long and consist of 1/4 inch chain. They will be buried within the streambed to monitor the movement of material in the streambed. Other activities that will be implemented include: Installation of off-site water systems in areas where fencing and revegetation projects are implemented, in order to restrict livestock access to waterways; construction of facilities to return irrigation flows to the Johns Day River, including the installation of pipe to replace failing drains or return ditches; installation of pumps to replace temporary diversions; and removal of junipers from approximately 500 acres per year by hand felling.

  3. 75 FR 62024 - Metal and Nonmetal Dams

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-07

    ... an Advance Notice of Proposed Rulemaking (75 FR 49429) asking interested parties to comment on... Safety and Health Administration 30 CFR Parts 56 and 57 RIN 1219-AB70 Metal and Nonmetal Dams AGENCY..., operation, and maintenance of safe dams which can assure miners are protected from the hazards of...

  4. Potential for seepage erosion of landslide dam

    USGS Publications Warehouse

    Meyer, W.; Schuster, R.L.; Sabol, M.A.

    1994-01-01

    The failure potential of the debris-avalanche dam at Castle Lake near Mount St. Helens, Washington, by three processes of seepage erosion (1) Heave; (2) piping; and (3) internal erosion, is examined. Results indicated that the dam is stable against piping but potentially locally unstable against heave. -from Authors

  5. 75 FR 49429 - Metal and Nonmetal Dams

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ..., processing minerals, treating or supplying water, and controlling run- off and sediment. Although many of... 100-foot high dam at a limestone mine in Puerto Rico released over 10 million gallons of water and... slope failure in 1987, the mine operator installed instruments in the dam to monitor internal...

  6. Watershed Boundary Dataset for Mississippi

    USGS Publications Warehouse

    Wilson, K. Van; Clair, Michael G.; Turnipseed, D. Phil; Rebich, Richard A.

    2009-01-01

    The U.S. Geological Survey, in cooperation with the Mississippi Department of Environmental Quality, U.S. Department of Agriculture-Natural Resources Conservation Service, Mississippi Department of Transportation, U.S. Department of Agriculture-Forest Service, and the Mississippi Automated Resource Information System developed a 1:24,000-scale Watershed Boundary Dataset for Mississippi including watershed and subwatershed boundaries, codes, names, and areas. The Watershed Boundary Dataset for Mississippi provides a standard geographical framework for water-resources and selected land-resources planning. The original 8-digit subbasins (Hydrologic Unit Codes) were further subdivided into 10-digit watersheds (62.5 to 391 square miles (mi2)) and 12-digit subwatersheds (15.6 to 62.5 mi2) - the exceptions being the Delta part of Mississippi and the Mississippi River inside levees, which were subdivided into 10-digit watersheds only. Also, large water bodies in the Mississippi Sound along the coast were not delineated as small as a typical 12-digit subwatershed. All of the data - including watershed and subwatershed boundaries, subdivision codes and names, and drainage-area data - are stored in a Geographic Information System database, which are available at: http://ms.water.usgs.gov/. This map shows information on drainage and hydrography in the form of U.S. Geological Survey hydrologic unit boundaries for water-resource 2-digit regions, 4-digit subregions, 6-digit basins (formerly called accounting units), 8-digit subbasins (formerly called cataloging units), 10-digit watershed, and 12-digit subwatersheds in Mississippi. A description of the project study area, methods used in the development of watershed and subwatershed boundaries for Mississippi, and results are presented in Wilson and others (2008). The data presented in this map and by Wilson and others (2008) supersede the data presented for Mississippi by Seaber and others (1987) and U.S. Geological Survey (1977).

  7. The Impact of Dam-Reservoir-Foundation Interaction on Nonlinear Response of Concrete Gravity Dams

    SciTech Connect

    Amini, Ali Reza; Motamedi, Mohammad Hossein; Ghaemian, Mohsen

    2008-07-08

    To study the impact of dam-reservoir-foundation interaction on nonlinear response of concrete gravity dams, a two-dimensional finite element model of a concrete gravity dam including the dam body, a part of its foundation and a part of the reservoir was made. In addition, the proper boundary conditions were used in both reservoir and foundation in order to absorb the energy of outgoing waves at the far end boundaries. Using the finite element method and smeared crack approach, some different seismic nonlinear analyses were done and finally, we came to a conclusion that the consideration of dam-reservoir-foundation interaction in nonlinear analysis of concrete dams is of great importance, because from the performance point of view, this interaction significantly improves the nonlinear response of concrete dams.

  8. Age estimations of wild pallid sturgeon (Scaphirhynchus albus, Forbes & Richardson 1905) based on pectoral fin spines, otoliths and bomb radiocarbon: inferences on recruitment in the dam-fragmented Missouri River

    USGS Publications Warehouse

    Braaten, P. J.; Campana, S. E.; Fuller, D. B.; Lott, R. D.; Bruch, R. M.; Jordan, G. R.

    2015-01-01

    An extant stock of wild pallid sturgeon Scaphirhynchus albus persists in the fragmented upper Missouri River basin of Montana and North Dakota. Although successful spawning and hatch of embryos has been verified, long-term catch records suggest that recruitment has not occurred for several decades as the extant stock lacks juvenile size classes and is comprised exclusively of large, presumably old individuals. Ages of 11 deceased (death years 1997–2007) wild S. albus (136–166 cm fork length) were estimated based on pectoral fin spines, sagittal otoliths and bomb radiocarbon (14C) assays of otoliths to test the hypothesis that members of this stock are old and to provide inferences on recruitment years that produced the extant stock. Age estimations based on counts of presumed annuli were about 2 years greater for otoliths (mean = 51 years, range = 43–57 years) than spines (mean = 49 years, range = 37–59 years). Based on 14C assays, confirmed birth years for all individuals occurred prior to 1957, thus establishing known longevity of at least 50 years. Estimated age based on presumed otolith annuli for one S. albus was validated to at least age 49. Although 14C assays confirmed pre-1957 birth years for all S. albus, only 56% of estimated ages from spines and 91% of estimated ages from otoliths depicted pre-1957 birth years. Both ageing structures were subject to under-ageing error (up to 15 years). Lack of or severe curtailment of S. albus recruitment in the upper Missouri River basin since the mid-1950s closely parallels the 1953–1957 timeframe when a mainstem reservoir was constructed and started to fill. This reservoir may function as a system-wide stressor to diminish recruitment success of S. albus in the upper Missouri River basin.

  9. Walker Branch Watershed Ecosystems Data

    DOE Data Explorer

    Walker Branch Watershed is located on the U. S. Department of Energy's Oak Ridge Reservation near Oak Ridge, in Anderson County, Tennessee. The Walker Branch Watershed Project began in 1967 under sponsorship of the U. S. Atomic Energy Commission (now the U. S. Department of Energy). Initially, the project centered primarily on the geologic and hydrologic processes that control the amounts and chemistry of water moving through the watershed. Past projects have included: • U. S. Department of Energy funded studies of watershed hydrology and forest nutrient dynamics • National Oceanic and Atmospheric Administration funded studies of forest micrometeorology • Studies of atmospheric deposition under the National Atmospheric Deposition Program • The International Biological Program Eastern Deciduous Forest Biome Project • National Science Foundation sponsored studies of trace element cycling and stream nutrient spiraling • Electric Power Research Institute funded studies of the effects of acidic deposition on canopy processes and soil chemistry. These projects have all contributed to a more complete understanding of how forest watersheds function and have provided insights into the solution of energy-related problems associated with air pollution, contaminant transport, and forest nutrient dynamics. This is one of a few sites in the world characterized by long-term, intensive environmental studies. The Walker Branch Watershed website at http://walkerbranch.ornl.gov/ provides maps, photographs, and data on climate, precipitation, atmospheric deposition, stream discharge and runoff, stream chemistry, and vegetation. [Taken from http://walkerbranch.ornl.gov/ABOUTAAA.HTM

  10. Immediate changes in stream channel geomorphology, aquatic habitat, and fish assemblages following dam removal in a small upland catchment

    NASA Astrophysics Data System (ADS)

    Magilligan, F. J.; Nislow, K. H.; Kynard, B. E.; Hackman, A. M.

    2016-01-01

    Dam removal is becoming an increasingly important component of river restoration, with > 1100 dams having been removed nationwide over the past three decades. Despite this recent progression of removals, the lack of pre- to post-removal monitoring and assessment limits our understanding of the magnitude, rate, and sequence of geomorphic and/or ecological recovery to dam removal. Taking advantage of the November 2012 removal of an old (~ 190 year-old) 6-m high, run-of-river industrial dam on Amethyst Brook (26 km2) in central Massachusetts, we identify the immediate eco-geomorphic responses to removal. To capture the geomorphic responses to dam removal, we collected baseline data at multiple scales, both upstream (~ 300 m) and downstream (> 750 m) of the dam, including monumented cross sections, detailed channel-bed longitudinal profiles, embeddedness surveys, and channel-bed grain size measurements, which were repeated during the summer of 2013. These geomorphic assessments were combined with detailed quantitative electrofishing surveys of stream fish richness and abundance above and below the dam site and throughout the watershed and visual surveys of native anadromous sea lamprey (Petromyzon marinus) nest sites. Post-removal assessments were complicated by two events: (1) upstream knickpoint migration exhumed an older (ca. late eighteenth century) intact wooden crib dam ~ 120 m upstream of the former stone dam, and (2) the occurrence of a 10-20 year RI flood 6 months after removal that caused further upstream incision and downstream aggradation. Now that the downstream reach has been reconnected to upstream sediment supply, the predominant geomorphic response was bed aggradation and associated fining (30-60% reduction). At dam proximal locations, aggradation ranged from 0.3 to > 1 m where a large woody debris jam enhanced aggradation. Although less pronounced, distal locations still showed aggradation with a mean depth of deposition of ~ 0.20 m over the 750-m

  11. Emergent stability in a large, free-flowing watershed.

    PubMed

    Moore, Jonathan W; Beakes, Michael P; Nesbitt, Holly K; Yeakel, Justin D; Patterson, David A; Thompson, Lisa A; Phillis, Corey C; Braun, Douglas C; Favaro, Corinna; Scott, David; Carr-Harris, Charmaine; Atlas, William I

    2015-02-01

    While it is widely recognized that financial stock portfolios can be stabilized through diverse investments, it is also possible that certain habitats can function as natural portfolios that stabilize ecosystem processes. Here we propose and examine the hypothesis that free-flowing river networks act as such portfolios and confer stability through their integration of upstream geological, hydrological, and biological diversity. We compiled a spatially (142 sites) and temporally (1980-present) extensive data set on fisheries, water flows, and temperatures, from sites within one of the largest watersheds in the world that remains without dams on its mainstem, the Fraser River, British Columbia, Canada. We found that larger catchments had more stable fisheries catches, water flows, and water temperatures than smaller catchments. These data provide evidence that free-flowing river networks function as hierarchically nested portfolios with stability as an emergent property. Thus, free-flowing river networks can represent a natural system for buffering variation and extreme events.

  12. Hydrologic data for the Obed River watershed, Tennessee

    USGS Publications Warehouse

    Knight, Rodney R.; Wolfe, William J.; Law, George S.

    2014-01-01

    The Obed River watershed drains a 520-square-mile area of the Cumberland Plateau physiographic region in the Tennessee River basin. The watershed is underlain by conglomerate, sandstone, and shale of Pennsylvanian age, which overlie Mississippian-age limestone. The larger creeks and rivers of the Obed River system have eroded gorges through the conglomerate and sandstone into the deeper shale. The largest gorges are up to 400 feet deep and are protected by the Wild and Scenic Rivers Act as part of the Obed Wild and Scenic River, which is managed by the National Park Service. The growing communities of Crossville and Crab Orchard, Tennessee, are located upstream of the gorge areas of the Obed River watershed. The cities used about 5.8 million gallons of water per day for drinking water in 2010 from Lake Holiday and Stone Lake in the Obed River watershed and Meadow Park Lake in the Caney Fork River watershed. The city of Crossville operates a wastewater treatment plant that releases an annual average of about 2.2 million gallons per day of treated effluent to the Obed River, representing as much as 10 to 40 percent of the monthly average streamflow of the Obed River near Lancing about 35 miles downstream, during summer and fall. During the past 50 years (1960–2010), several dozen tributary impoundments and more than 2,000 small farm ponds have been constructed in the Obed River watershed. Synoptic streamflow measurements indicate a tendency towards dampened high flows and slightly increased low flows as the percentage of basin area controlled by impoundments increases.

  13. Do we need construct more dams?

    NASA Astrophysics Data System (ADS)

    Chen, J.; Shi, H.

    2013-12-01

    This paper reviews global dam development in association with the growths of global population, economy, and energy consumption in the past several decades, and also evaluates contributions of dam development to future world sustainable development. Eventually, this paper answers whether we need more dams in the future or not. The world population has rapidly increased from 1.6 billion in 1900, 2.5 billion in 1950, 6.1 billion in 2000, to 7.0 billion in 2011, and is projected to reach 9.5 billion in 2050; similarly, the world economy has dramatically expanded. To maintain socioeconomic development, the consumption of water, food and energy has increased rapidly as well. However, the total volume of available water resource over the world is limited, the food production largely depends on water supply, and the main energy sources are still oil, coal and gas at present, which are regarded as non-renewable resources. Accordingly, it is expected that we will face serious problems to deal with the challenges of water crisis, food security and energy shortage in the near future. In order to enhance the capability of regulating water resource, a great number of global dams (and related reservoirs) have been constructed in the last one hundred years; currently, almost all large rivers over the world have been regulated by dams. The reservoirs can supply sufficient water for irrigated land to ensure food production, and the associated hydropower stations can generate electricity. This article collects the dam data from the ICOLD (International Commission on Large Dams) and GRanD (Global Reservoir and Dam) databases, and some socioeconomic data, including population, economy, and consumptions of water, food and energy over the world. Analysis of these data reveals that global dam development has a great impact on the world sustainable development. Further, it is concluded that we need further dam development to maintain our future development.

  14. Development and application of a comprehensive simulation model to evaluate impacts of watershed structures and irrigation water use on streamflow and groundwater: The case of Wet Walnut Creek Watershed, Kansas, USA

    USGS Publications Warehouse

    Ramireddygari, S.R.; Sophocleous, M.A.; Koelliker, J.K.; Perkins, S.P.; Govindaraju, R.S.

    2000-01-01

    -central Kansas. The main objective of this study was to assess the impacts of watershed structures and irrigation water use on streamflow and groundwater levels, which in turn affect availability of water for the Cheyenne Bottoms Wildlife Refuge Management area. The surface-water flow model, POTYLDR, and the groundwater flow model, MODFLOW, were combined into an integrated, watershed-scale, continuous simulation model. Major revisions and enhancements were made to the POTYLDR and MODFLOW models for simulating the detailed hydrologic budget for the Wet Walnut Creek Watershed. The computer simulation model was calibrated and verified using historical streamflow records (at Albert and Nekoma gaging stations), reported irrigation water use, observed water-level elevations in watershed structure pools, and groundwater levels in the alluvial aquifer system. To assess the impact of watershed structures and irrigation water use on streamflow and groundwater levels, a number of hypothetical management scenarios were simulated under various operational criteria for watershed structures and different annual limits on water use for irrigation. A standard `base case' was defined to allow comparative analysis of the results of different scenarios. The simulated streamflows showed that watershed structures decrease both streamflows and groundwater levels in the watershed. The amount of water used for irrigation has a substantial effect on the total simulated streamflow and groundwater levels, indicating that irrigation is a major budget item for managing water resources in the watershed.A comprehensive simulation model that combines the surface water flow model POTYLDR and the groundwater flow model MODFLOW was used to study the impacts of watershed structures (e.g., dams) and irrigation water use (including stream-aquifer interactions) on streamflow and groundwater. The model was revised, enhanced, calibrated, and verified, then applied to evaluate the hydrologic budget for Wet Wal

  15. Quantifying floodplain and mainstem channel response to the removal of the Elwha River dams using "old school" techniques

    NASA Astrophysics Data System (ADS)

    Pess, G. R.; McHenry, M.; Peters, R.; Beechie, T. J.; Duda, J. J.; Liermann, M. C.; Bakke, P. D.; Morley, S. A.; McMillan, J. R.; Denton, K.

    2012-12-01

    In 2011 a multi-year deconstruction of two long-standing, high-head dams began on the Elwha River, Washington State. Over the past decade, we have been monitoring a variety of ecosystem attributes in the Elwha River basin to establish baseline conditions prior to one of the largest watershed restoration projects in the US. Our study design is tailored to the Elwha's geomorphic template, as different channel types are expected to respond differently to the large amount of sediment that will be released. A primary focus of this effort has been on the 28 km of floodplain channels below the dams (for every 1km of main stem habitat there is 1.35km of floodplain channel). Another focus has been on main stem channel features such as pool and riffle habitat, which are critical habitats for salmonids and other biota. How will these floodplain channels and mainstem channel features react to the large amount of sediment that is being released? We have used simple field techniques such as longitudinal profiles of floodplain channels, pebble counts, turbidity measurements, and the amount of sediment accumulation in pools and riffles to document baseline as well as "during dam removal" conditions. Early results indicate increased turbidity downstream of dams throughout deconstruction, suggesting there will be dramatic increases in fine sediment accumulations once dam removal is completed. We plan to continue using inexpensive methods to quantify the geomorphic and ecological change following dam removal in the Elwha River basin. These findings have direct implications for other dam removal projects.

  16. Benthic invertebrates and periphyton in the Elwha river basin: Current conditions and predicted response to dam removal

    USGS Publications Warehouse

    Morley, S.A.; Duda, J.J.; Coe, H.J.; Kloehn, K.K.; McHenry, M.L.

    2008-01-01

    The impending removal of two dams on the Elwha River in Washington State offers a unique opportunity to study ecosystem restoration at a watershed scale. We examine how periphyton and benthic invertebrate assemblages vary across regulated and unregulated sections of the Elwha River and across different habitat types, and establish baseline data for tracking future changes following dam removal. We collected multiple years of data on physical habitat, water chemistry, periphyton, and benthic invertebrates from 52 sites on the Elwha River and a reference section on the Quinault River, a neighboring basin. We found that substrate in regulated river sections was coarser and less heterogeneous in size than in unregulated sections, and summer water temperature and specific conductivity higher. Periphyton biomass was also consistently higher in regulated than unregulated sections. Benthic invertebrate assemblage structure at sites above both dams was distinct from sites between and below the dams, due in large part to dominance of mayfly taxa compared to higher relative abundance of midges and non-insect taxa at downstream sites. Following dam removal, we anticipate that both periphyton and benthic invertebrate abundance and diversity will temporarily decrease between and below dams as a result of sediment released from behind the reservoirs. Over the long-term, increased floodplain heterogeneity and recolonization by anadromous fish will alter benthic invertebrate and periphyton assemblages via increases in niche diversity and inputs of marine-derived nutrients. The extended timeline predicted for Elwha River recovery and the complexities of forecasting ecological response highlights the need for more long-term assessments of dam removal and river restoration practices.

  17. Performance of crosses among Hereford, Angus and Simmental cattle with different levels of Simmental breeding: V. Calf production, milk production and reproduction of three- to eight-year-old dams.

    PubMed

    Kress, D D; Doornbos, D E; Anderson, D C

    1990-07-01

    Measures of maternal productivity and reproduction of Hereford (HH), Angus-Hereford (AH), 25% Simmental-75% Hereford (1S3H), 50% Simmental-50% Hereford (1S1H) and 75% Simmental-25% Hereford (3S1H) dams were studied. Half of each dam breed group was bred to Tartentaise and half to Charolais sires to produce 706 calves at weaning from 930 exposures to breeding in a Montana range environment. Data were analyzed according to a model that included the fixed effects of year, dam breed group, dam age, calf sex, calf sire breed, plus appropriate two-way interactions, linear partial regression on calf birth date and random effects of sire within dam breed group (maternal grandsire of the calf) and sire within calf sire breed. Calf sex interacted with calf sire breed for several traits, but interactions were due to changes of magnitude of differences between sexes. There were no significant interactions of dam breed group with other main effects for calf growth traits, except for the interaction with calf sire breed for some calf growth traits. This interaction was due to a change in magnitude; it suggested that larger sire breeds should be matched to larger dam breeds with greater potential for milk production. The only significant interaction for traits that included reproduction of the dam was dam breed group X age of dam. Ranking of dam breed groups depended on age at measurement. Differences among dam breed groups were significant for most traits. Calf weaning weights for HH, AH, 1S3H, 1S1H and 3S1H dams were 211, 223, 227, 237 and 243 kg, respectively; calf weaning weights per cow exposed were 157, 163, 179, 189 and 169 kg; calf weaning weights per unit of dam weight were .40, .41, .43, .44 and .42, respectively. Thus, dam breed groups that weaned the largest calves were not necessarily the most productive under Montana range conditions.

  18. Growth traits and composition of two- and three-way-cross intact male progeny of Bos taurus and Bos indicus X Bos taurus dams.

    PubMed

    Van Ornum, K M; Bailey, C M; Ringkob, T P; Koh, Y O

    1987-07-01

    Feedlot traits, carcass traits and distribution of commercial cuts of crossbred intact male progeny (n = 556) from young and mature Hereford, Red Poll, Hereford X Red Poll, Red Poll X Hereford, Angus X Hereford, Angus X Charolais, Brahman X Hereford and Brahman X Angus dams were evaluated. First-calf heifers were bred to Red Angus bulls; Santa Gertrudis sires were used for each cow's second and third breeding seasons. Calves from these young dams were slaughtered at 13 mo. Calves of mature dams were all sired by Limousin bulls and slaughtered at 12 mo. Dam breed was a major source of variation in most bull traits. Progeny of Brahman-cross dams were inferior (P less than .01) in daily gain, final weight, carcass weight and in edible cuts/day of age compared with progeny from Bos taurus dams. Intact male progeny of Angus X Charolais dams ranked highest in longissimus area, cutability, and edible cuts/day of age. The range of dam breed means in percentage of steak, roast, bone-in cuts (chuck short ribs and back ribs), short plate and thin cuts, and lean trim was just over 1%. Greater variation among dam breeds existed in fat measurements. Analyses in which Hereford-Red Poll diallel data for young dams and mature dams were combined showed positive maternal heterosis for dressing percentage (P less than .05), carcass weight (P less than .05), carcass weight/day of age (P less than .05), estimated carcass fat (P less than .05), fat thickness (P less than .01) and marbling score (P less than .01). Reciprocal effects were inconsequential. Results illustrate the importance of dam breed-type effects in formulating breeding strategies for commercial beef herds. PMID:3610866

  19. Growth traits and composition of two- and three-way-cross intact male progeny of Bos taurus and Bos indicus X Bos taurus dams.

    PubMed

    Van Ornum, K M; Bailey, C M; Ringkob, T P; Koh, Y O

    1987-07-01

    Feedlot traits, carcass traits and distribution of commercial cuts of crossbred intact male progeny (n = 556) from young and mature Hereford, Red Poll, Hereford X Red Poll, Red Poll X Hereford, Angus X Hereford, Angus X Charolais, Brahman X Hereford and Brahman X Angus dams were evaluated. First-calf heifers were bred to Red Angus bulls; Santa Gertrudis sires were used for each cow's second and third breeding seasons. Calves from these young dams were slaughtered at 13 mo. Calves of mature dams were all sired by Limousin bulls and slaughtered at 12 mo. Dam breed was a major source of variation in most bull traits. Progeny of Brahman-cross dams were inferior (P less than .01) in daily gain, final weight, carcass weight and in edible cuts/day of age compared with progeny from Bos taurus dams. Intact male progeny of Angus X Charolais dams ranked highest in longissimus area, cutability, and edible cuts/day of age. The range of dam breed means in percentage of steak, roast, bone-in cuts (chuck short ribs and back ribs), short plate and thin cuts, and lean trim was just over 1%. Greater variation among dam breeds existed in fat measurements. Analyses in which Hereford-Red Poll diallel data for young dams and mature dams were combined showed positive maternal heterosis for dressing percentage (P less than .05), carcass weight (P less than .05), carcass weight/day of age (P less than .05), estimated carcass fat (P less than .05), fat thickness (P less than .01) and marbling score (P less than .01). Reciprocal effects were inconsequential. Results illustrate the importance of dam breed-type effects in formulating breeding strategies for commercial beef herds.

  20. Deformation Monitoring and Bathymetry Analyses in Rock-Fill Dams, a Case Study at Ataturk Dam

    NASA Astrophysics Data System (ADS)

    Kalkan, Y.; Bilgi, S.

    2014-12-01

    Turkey has 595 dams constructed between 1936 and 2013 for the purposes of irrigation, flood control, hydroelectric energy and drinking water. A major portion of the dam basins in Turkey are deprived of vegetation and have slope topography on near surrounding area. However, landscaping covered with forest around the dam basin is desirable for erosion control. In fact; the dams, have basins deprived of vegetation, fill up quickly due to sediment transport. Erosion control and forestation are important factors, reducing the sediment, to protect the water basins of the dams and increase the functioning life of the dams. The functioning life of dams is as important as the investment and construction. Nevertheless, in order to provide safety of human life living around, well planned monitoring is essential for dams. Dams are very large and critical structures and they demand the use or application of precise measuring systems. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. Monitoring is an essential component of the dam after construction and during operation and must en­able the timely detection of any behavior that could deteriorate the dam, potentially result in its shutdown or failure. Considering the time and labor consumed by long-term measurements, processing and analysis of measured data, importance of the small structural motions at regular intervals could be comprehended. This study provides some information, safety and the techniques about the deformation monitoring of the dams, dam safety and related analysis. The case study is the deformation measurements of Atatürk Dam in Turkey which is the 6th largest dam of world considering the filling volume of embankment. Brief information is given about the

  1. Dam Failure Inundation Map Project

    NASA Technical Reports Server (NTRS)

    Johnson, Carl; Iokepa, Judy; Dahlman, Jill; Michaud, Jene; Paylor, Earnest (Technical Monitor)

    2000-01-01

    At the end of the first year, we remain on schedule. Property owners were identified and contacted for land access purposes. A prototype software package has been completed and was demonstrated to the Division of Land and Natural Resources (DLNR), National Weather Service (NWS) and Pacific Disaster Center (PDC). A field crew gathered data and surveyed the areas surrounding two dams in Waimea. (A field report is included in the annual report.) Data sensitivity analysis was initiated and completed. A user's manual has been completed. Beta testing of the software was initiated, but not completed. The initial TNK and property owner data collection for the additional test sites on Oahu and Kauai have been initiated.

  2. CG-DAMS: Concrete gravity dam stability analysis software. Application manual, final report

    SciTech Connect

    Not Available

    1993-01-01

    CG-DAMS is a finite element based program written specifically for the stability analysis of concrete gravity dams. The code automates the prediction and evaluation of cracking in the dam, along the dam-rock interface, and in the foundation using incremental nonlinear analysis techniques based on the ``smeared crack`` approach. Its primary application is in the computation of dam-rock interface sliding stability factors of safety. The automated procedure for crack propagation analysis replaces the trial-and-error cracked-base analysis method commonly used in gravity dam safety analyses. This Application manual of CG-DAMS illustrates, through sample problems, the many features of the software. Example problems illustrate the capabilities of both CG-DAMS-PC and CG-DAMS-ABAQUS. CG-DAMS-PC is a menu driven program that runs on 386/486 PCs under the DOS operating system (4 Megabytes RAM, 25 Megabytes of hard disk space). CG-DAMS-ABAQUS is a pre- and post-processor along with a concrete constitutive model and distributed load module that interfaces with the ABAQUS general purpose finite element program. The PC program contains thermal analysis capabilities, a rough crack constitutive model, and an interface to the CRFLOOD software not available with the ABAQUS version. The CG-DAMS-ABAQUS program contains time marching dynamic analysis capabilities not available with the PC program. Example analyses presented include static, pseudo dynamic, and time marching dynamic analyses. The manual also presents sensitivity evaluations on mesh size and foundation material strength. Comparisons are presented between CG-DAMS and gravity method calculations. Comparisons with other finite element software are included for the dynamic time history analyses.

  3. Dams on the Mekong: Cumulative sediment starvation

    NASA Astrophysics Data System (ADS)

    Kondolf, G. M.; Rubin, Z. K.; Minear, J. T.

    2014-06-01

    The Mekong River, largely undeveloped prior to 1990, is undergoing rapid dam construction. Seven dams are under construction on the mainstem in China and 133 proposed for the Lower Mekong River and tributaries. We delineated nine distinct geomorphic regions, for which we estimated sediment yields based on geomorphic characteristics, tectonic history, and the limited sediment transport data available. We then applied the 3W model to calculate cumulative sediment trapping by these dams, accounting for changing trap efficiency over time and multiple dams on a single river system. Under a "definite future" scenario of 38 dams (built or under construction), cumulative sediment reduction to the Delta would be 51%. Under full build-out of all planned dams, cumulative sediment trapping will be 96%. That is, once in-channel stored sediment is exhausted, only 4% of the predam sediment load would be expected to reach the Delta. This scenario would have profound consequences on productivity of the river and persistence of the Delta landform itself, and suggests that strategies to pass sediment through/around dams should be explored to prevent the consequences of downstream sediment starvation.

  4. What Is a Watershed? Implications of Student Conceptions for Environmental Science Education and the National Science Education Standards

    ERIC Educational Resources Information Center

    Shepardson, Daniel P.; Wee, Bryan; Priddy, Michelle; Schellenberger, Lauren; Harbor, Jon

    2007-01-01

    The purpose of this study was to investigate students' conceptions about watersheds. Specifically: (1) What are students' conceptions of a watershed? and (2) In what ways might students' conceptions vary by grade level and community setting? This study was descriptive in nature and reflected a cross-age design involving the collection of…

  5. Importance of Field Data for Numerical Modeling to Dam Removal on a Mountain Channel

    NASA Astrophysics Data System (ADS)

    Kuo, W. C.; Wang, H. W.

    2015-12-01

    In 2011, a 13-m high Chijiawan Dam on Chijiawan Creek was removed due to the safety concern due to aging structure and scoured dam foundation as well as habitat restoration of the endangered Formosan landlocked salmon. Similar to Chijiawan Dam, many dams in Taiwan are located in steep mountainous area with coarser sediment and high sediment yield, and may be removed in the near future. Since the capability of current sediment transport model is insufficient, a systematic planning of field survey and monitoring work can effectively help to decrease data uncertainty in simulation. In this study, we aimed to understand the minimum requirements of data for numerical model to predict channel responses after dam removal, according to the data of pre-project and long term post-project monitoring works from removal of Chijiawan dam. We collected the hourly discharge data of Taipower gaging station located 6.8 km from the dam from 2010 to 2012 and conducted surveys of grain size distributions, cross-sectional and longitudinal profiles. We applied Sedimentation and River Hydraulics (SRH) one-dimensional model to simulate bed elevation changes by different setting of data input, including bed sediment, roughness coefficient, cross-section spacing, and flow discharge. Then, we performed a sensitivity analysis by using Root Mean Square Error (RMSE) to evaluate the minimum requirements of data for predicting to dam removal. The RMSE variability of varied setting of bed sediment, roughness coefficient, cross-section spacing, and flow discharge ranged from 0.02 m, 0.17 m, 0.14 m and 0.09 m, respectively. The results highlight that the simulation is sensitive to roughness coefficient, cross-section spacing, and flow discharge, and less sensitive to bed sediment. We anticipate the results will help decision maker to understand the importance of field data in future removals.

  6. Estimating accumulation rates and physical properties of sediment behind a dam: Englebright Lake, Yuba River, northern California

    USGS Publications Warehouse

    Snyder, N.P.; Rubin, D.M.; Alpers, C.N.; Childs, J. R.; Curtis, J.A.; Flint, L.E.; Wright, S.A.

    2004-01-01

    Studies of reservoir sedimentation are vital to understanding scientific and management issues related to watershed sediment budgets, depositional processes, reservoir operations, and dam decommissioning. Here we quantify the mass, organic content, and grain-size distribution of a reservoir deposit in northern California by two methods of extrapolating measurements of sediment physical properties from cores to the entire volume of impounded material. Englebright Dam, completed in 1940, is located on the Yuba River in the Sierra Nevada foothills. A research program is underway to assess the feasibility of introducing wild anadromous fish species to the river upstream of the dam. Possible management scenarios include removing or lowering the dam, which could cause downstream transport of stored sediment. In 2001 the volume of sediments deposited behind Englebright Dam occupied 25.5% of the original reservoir capacity. The physical properties of this deposit were calculated using data from a coring campaign that sampled the entire reservoir sediment thickness (6–32 m) at six locations in the downstream ∼3/4 of the reservoir. As a result, the sediment in the downstream part of the reservoir is well characterized, but in the coarse, upstream part of the reservoir, only surficial sediments were sampled, so calculations there are more uncertain. Extrapolation from one-dimensional vertical sections of sediment sampled in cores to entire three-dimensional volumes of the reservoir deposit is accomplished via two methods, using assumptions of variable and constant layer thickness. Overall, the two extrapolation methods yield nearly identical estimates of the mass of the reservoir deposit of ∼26 × 106 metric tons (t) of material, of which 64.7–68.5% is sand and gravel. Over the 61 year reservoir history this corresponds to a maximum basin-wide sediment yield of ∼340 t/km2/yr, assuming no contribution from upstream parts of the watershed impounded by other dams. The

  7. Karstification at Beskonak dam site and reservoir area, southern Turkey

    SciTech Connect

    Degirmenci, M.

    1993-10-01

    Beskonak dam and hydroelectric power plant are planned to be constructed on the Koepruecay river, 40 km east of the Antalya city. In the dam site and reservoir area, Koepruecay Conglomerates of Miocene age and the Beskonak Formation (sandstone-claystone) alternating with each other crop out vertically. Koepruecay conglomerates, with the components of limestone fragments and carbonate texture, are karstic and permeable, whereas the Beskonak Formation is impermeable. At the northern edge of the reservoir area, the Olukkoeprue karst springs discharge at a minimum of 30 m{sup 3}/s. These springs discharge mainly through vertical and subvertical joint systems. Intensive superficial karstification developed along the joint systems and the terrane reveals columns of rocks, called {open_quotes}fairy chimneys.{close_quotes} Olukkoeprue springs represent the discharge point for a large and continuous system of underground solution cavities. In the Koepruecay basin, there are numerous karstic features within the conglomerates. Within the reservoir area, Kurukoeprue cave, with a length of 530 m, is an example of these caves developed within the conglomerates. In some parts of the reservoir area, where the groundwater level is lower than the surface-river elevation, a highly developed karstification zone is present within the fluctuation range of groundwater between depths of 40 and 50 m. The above-mentioned Kurukoeprue cave is an active cave developed in the dam site and its vicinity. The solution conduits developed along the system of mostly vertical fractures and joints are interconnected, thus giving rise to a three-dimensional conduit network. On the other hand, a majority of these conduits have clay and calcite filling materials. Karstification in the dam site varies with depths exponentially. Data suggest that karstification has a vertical extention as deep as -220 m. 4 refs., 9 figs.

  8. Discussion of "Aeration, flow instabilities, and residual energy on pooled stepped spillways of embankment dams" by Stephen Felder and Hubert Chanson

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stepped spillways applied to embankment dams provide overtopping protection and address a common deficiency in aging dams by providing increased spillway capacity. Pooled-stepped spillways offer a design alternative to the traditional flat-stepped spillways. Researchers from the University of Quee...

  9. The role of dams in development.

    PubMed

    Altinbilek, Doğan

    2002-01-01

    Dams are a major issue in sustainable management of finite water resources; they have also become the subject of vigorous public debate. This article considers them in the light of the report of the World Commission on Dams and using the example of Turkey. It is argued that economic development and population growth, particularly in arid and semi-arid regions, make plain the need for dams for hydropower and irrigation. Environmental impact assessment is essential, as are effective programmes for resettlement to avoid the impoverishment of displaced people.

  10. Geology, hydrology, and geochemistry of the Black Creek watershed near Mocanaqua, Luzerne County, Pennsylvania

    USGS Publications Warehouse

    Newport, Thomas Gwyn; Koester, Harry E.; Bergin, Marion Joseph

    1968-01-01

    Bedrock in the watershed, from oldest to youngest, consists of the Mauch Chunk Formation of Mississippian and, in part, of Pennsylvanian age; the Pottsville Formation of Pennsylvanian age; and the Llewellyn Formation of Pennsylvanian age. The anthracite beds are in the Llewellyn Formation.

  11. Comparison of Natural Dams from Lava Flows and Landslides on the Owyhee River, Oregon

    NASA Astrophysics Data System (ADS)

    Ely, L. L.; Brossy, C. C.; Othus, S. M.; Orem, C.; Fenton, C.; House, P. K.; O'Connor, J. E.; Safran, E. B.

    2008-12-01

    Numerous large lava flows and mass movements have temporarily dammed the Owyhee River in southeastern Oregon at various temporal and spatial scales. These channel-encroaching events potentially play a significant role in creating and maintaining the geomorphic features of river canyons in uplifted volcanic terranes that compose a significant part of the western U.S. Abundant landslides and lava flows have the capacity to inhibit incision by altering channel slope, width, and bed character, and burying valley- bottom bedrock under exogenous material; or promote incision by generating cataclysmic floods through natural dam failures. The natural dams vary in their source, morphology, longevity and process of removal, which in turn affects the extent and duration of their impact on the river. The 3 most recent lava flows filled the channel 10-75 m deep and flowed up to 26 kilometers downvalley, creating long, low dams that were subject to gradual, rather than catastrophic, removal. In the last 125 ka, the Saddle Butte and West Crater lava dams created reservoirs into which 10-30 meters of silt and sand were deposited. The river overtopped the dams and in most reaches eventually cut a new channel through the adjacent, less resistant bedrock buttresses. Terraces at several elevations downstream and upstream of the West Crater dam indicate periods of episodic incision ranging from 0.28 to 1.7 mm/yr., based on 3He exposure ages on strath surfaces and boulder-rich fluvial deposits. In contrast to the lava dams, outburst flood deposits associated with landslide dams are common along the river. The mechanisms of failure are related to the geologic setting, and include rotational slump complexes, cantilevered blocks and block slides, and massive earthflows. Most large-scale mass movements occur in reaches where the Owyhee canyon incises through stacks of interbedded fluviolacustrine sediments capped with lava flows. The frequently observed association of landslides and flood

  12. Monitoring dam structural health from space: Insights from novel InSAR techniques and multi-parametric modeling applied to the Pertusillo dam Basilicata, Italy

    NASA Astrophysics Data System (ADS)

    Milillo, Pietro; Perissin, Daniele; Salzer, Jacqueline T.; Lundgren, Paul; Lacava, Giusy; Milillo, Giovanni; Serio, Carmine

    2016-10-01

    The availability of new constellations of synthetic aperture radar (SAR) sensors is leading to important advances in infrastructure monitoring. These constellations offer the advantage of reduced revisit times, providing low-latency data that enable analysis that can identify infrastructure instability and dynamic deformation processes. In this paper we use COSMO-SkyMed (CSK) and TerraSAR-X (TSX) data to monitor seasonal induced deformation at the Pertusillo dam (Basilicata, Italy) using multi-temporal SAR data analysis. We analyzed 198 images spanning 2010-2015 using a coherent and incoherent PS approach to merge COSMO-SkyMed adjacent tracks and TerraSAR-X acquisitions, respectively. We used hydrostatic-seasonal-temporal (HST) and hydrostatic-temperature-temporal (HTT) models to interpret the non-linear deformation at the dam wall using ground measurements together with SAR time-series analysis. Different look geometries allowed us to characterize the horizontal deformation field typically observed at dams. Within the limits of our models and the SAR acquisition sampling we found that most of the deformation at the Pertusillo dam can be explained by taking into account only thermal seasonal dilation and hydrostatic pressure. The different models show slightly different results when interpreting the aging term at the dam wall. The results highlight how short-revisit SAR satellites in combination with models widely used in the literature for interpreting pendulum and GPS data can be used for supporting structural health monitoring and provide valuable information to ground users directly involved in field measurements.

  13. 46. Photocopy of photograph, c. 1933. VIEW OF DAM AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. Photocopy of photograph, c. 1933. VIEW OF DAM AND FOREBAY. NOTE ALL WATER FLOWING THROUGH FOREBAY AND OUT EITHER TAILRACE OR SLUICE GATE (INSTEAD OF OVER DAM) BECAUSE OF LOW WATER FLOW. (Courtesy of the Potomac Edison Company Library (Hagerstown, MD), Historical Data Files, Dam No. 5 listing - Dam No. 5 Hydroelectric Plant, On Potomac River, Hedgesville, Berkeley County, WV

  14. 6. DAM AFTERBAY, WITH OWYEE RIVER IN FOREGROUND, SHOWING OUTLET ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. DAM AFTERBAY, WITH OWYEE RIVER IN FOREGROUND, SHOWING OUTLET TUNNEL PORTAL (LEFT) AND POWERHOUSE AND ENTRANCE PORTAL TO DAM INTERIOR (RIGHT). NOTE RELEASE OF WATER FROM NEEDLE VALVE NUMBER 2 IN VALVEHOUSE ON DAM. VIEW TO SOUTHEAST. - Owyhee Dam, Across Owyhee River, Nyssa, Malheur County, OR

  15. 7. SOUTHEAST VIEW OF BIG DALTON DAM SHOWING THE MULTIPLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. SOUTHEAST VIEW OF BIG DALTON DAM SHOWING THE MULTIPLE ARCHES, AN UPSTREAM VIEW OF THE PARAPET WALL ALONG THE CREST OF THE DAM, AND THE SHELTER HOUSE AT THE EAST END OF THE DAM. - Big Dalton Dam, 2600 Big Dalton Canyon Road, Glendora, Los Angeles County, CA

  16. Sediment storage dam: A structural gully erosion control and sediment trapping measure, northern Ethiopia

    NASA Astrophysics Data System (ADS)

    Mekonnen, Mulatie; Keesstra, Saskia; Baartman, Jantiene; Ritsema, Coen

    2014-05-01

    Gully erosion is a prime problem in Ethiopia. This study assessed the severity of gully erosion and the role of sediment storage dams (SSD) in restoring gullies and preventing further gully development, its sediment trapping efficacy (STE) and its capacity in converting degraded gully lands to productive land. On average 2.5 m deep, 6.6 m wide and 28.3 m long gullies were formed in Minizr watershed, northwest Ethiopia, in 2013. Concentrated surface runoff, traditional ditches, graded terraces without suitable water ways and road construction are the main causes of such serious gully erosion. Over grazing, tunnel flow and lack of proper immediate gully treatment actions after gully initiation are found to be additional causes of the problem. Gully erosion was also found as the major source of sediment for downstream rivers and water reservoirs. The annual volume of soil eroded from only four gullies was 1941.3 m3. To control gully erosion, SSDs were found to be important physical structures, which can trap significant amount of sediment within gullies and they can convert unproductive gully land to productive agricultural land for fruit and crop production. Eight SSDs trapped about 44*103 m3 of sediment within 2 to 8 years. Two representative SSDs constructed using gabion and stone were tested for their STE. Results showed that their efficacy was 74.1% and 66.4% for the gabion and stone SSDs, respectively. Six of the older SSDs were already full of sediment and created 0.75 ha of productive land within 2 to 8 years. SSDs best fits to treat large size and deep gullies where other gully control measures, check dams, could not function well. To prevent gully formation, controlling its causes that is avoiding traditional ditches, practicing grassed water ways to safely remove runoff water from graded terraces, integrated watershed and road side management practices are important solutions. KEY WORDS: Sediment storage dam, gully erosion, sediment trapping efficacy

  17. Dam Breach Release of Non-Cohesive Sediments: Channel Response and Recovery Rates

    NASA Astrophysics Data System (ADS)

    Collins, M. J.; Boardman, G.; Banks, W.; Andrews, M.; Conlon, M.; Dillow, J. J. A.; Gellis, A.; Lowe, S.; McClain, S.; Miller, A. J.; Snyder, N. P.; Wilcock, P. R.

    2014-12-01

    Dam removals featuring unchecked releases of non-cohesive sediments are excellent opportunities to learn more about stream channel response to abrupt increases in bed material supply that can occur deliberately or by natural processes like landslides and volcanic eruptions. Understanding channel response to sediment pulses, including response rates, is essential because human uses of river channels and floodplains are impacted by these events as are aquatic habitats. We had the opportunity to study a dam removal site at the Simkins Dam in Maryland, USA, that shares many important geophysical attributes of another well-studied dam removal in the humid northeast United States [Merrimack Village Dam, New Hampshire; Pearson et al., 2011]. The watershed sizes are the same order of magnitude (102 km2), and at both sites relatively low head dams were removed (~ 3-4 m) and ~60,000 m3 of dominantly sand-sized sediments discharged to low-gradient reaches immediately downstream. Analyzing four years of repeat morphometry and bed sediment grain size surveys at the Simkins site on the Patapsco River, as well as continuous discharge and suspended sediment gaging data, we clearly document a two-phase response in the upstream reach as described by Pearson et al. [2011] for their New Hampshire site and noted at other dam removals [e.g., Major et al., 2012]. In the early phase, approximately 50% of the impounded sediment mass was eroded rapidly over a period of about three months when flows were very modest (Figure 1). After incision to base level and channel widening in the former impoundment, a second phase began when further erosion depended on floods large enough to access impounded sediments more distant from the newly-formed channel. We also found important differences in the upstream responses at the Maryland and New Hampshire sites that appear to be related to valley type (non-glaciated versus glaciated, respectively). Response variances immediately downstream between the

  18. GROUND WATER AND WATERSHEDS AND ENVIRONMENTAL PROTECTION

    EPA Science Inventory

    Effective watershed management has the potential to achieve both drinking water and ecological protection goals. However, it is important that the watershed perspective be three- dimensional and include the hidden subsurface. The subsurface catchment, or groundwatershed, is geohy...

  19. Watershed Management in the United States

    EPA Science Inventory

    A watershed approach provides an effective framework for dealing with water resources challenges. Watersheds provide drinking water, recreation, and ecological habitat, as well as a place for waste disposal, a source of industrial cooling water, and navigable inland water transpo...

  20. ASSESSMENT AND MANAGEMENT OF WATERSHED MICROBIAL CONTAMINANTS

    EPA Science Inventory

    Numerous sources of infectious disease causing microorganisms exist in watersheds and can impact recreational and drinking water quality. Organisms of concern include bacteria, viruses, and parasites. The watershed manager is challenged to limit human contact with pathogens, limi...

  1. A multiobjective optimization model for dam removal: an example trading off salmon passage with hydropower and water storage in the Willamette basin

    NASA Astrophysics Data System (ADS)

    Kuby, Michael J.; Fagan, William F.; ReVelle, Charles S.; Graf, William L.

    2005-08-01

    We introduce the use of systematic, combinatorial, multiobjective optimization models to analyse ecological-economic tradeoffs and to support complex decision-making associated with dam removal in a river system. The model's ecological objective enhances salmonid migration and spawning by maximizing drainage area reconnected to the sea. The economic objective minimizes loss of hydropower and storage capacity. We present a proof-of-concept demonstration for the Willamette River watershed (Oregon, USA). The case study shows a dramatic tradeoff in which removing twelve dams reconnects 52% of the basin while sacrificing only 1.6% of hydropower and water-storage capacity. Additional ecological gains, however, come with increasingly steeper economic costs. A second model incorporates existing fish-passage systems. Because of data limitations and model simplifications, these results are intended solely for the purpose of illustrating a novel application of multiobjective programming to dam-removal issues. Far more work would be needed to make policy-relevant recommendations. Nevertheless, this research suggests that the current practice of analysing dam-removal decisions on a dam-by-dam basis be supplemented by evaluation on a river-system basis, trading off economic and ecological goals.

  2. Hydrologic calibration of paired watersheds using a MOSUM approach

    DOE PAGES

    Ssegane, H.; Amatya, D. M.; Muwamba, A.; Chescheir, G. M.; Appelboom, T.; Tollner, E. W.; Nettles, J. E.; Youssef, M. A.; Birgand, F.; Skaggs, R. W.

    2015-01-09

    Paired watershed studies have historically been used to quantify hydrologic effects of land use and management practices by concurrently monitoring two neighboring watersheds (a control and a treatment) during the calibration (pre-treatment) and post-treatment periods. This study characterizes seasonal water table and flow response to rainfall during the calibration period and tests a change detection technique of moving sums of recursive residuals (MOSUM) to select calibration periods for each control-treatment watershed pair when the regression coefficients for daily water table elevation (WTE) were most stable to reduce regression model uncertainty. The control and treatment watersheds included 1–3 year intensively managedmore » loblolly pine (Pinus taeda L.) with natural understory, same age loblolly pine intercropped with switchgrass (Panicum virgatum), 14–15 year thinned loblolly pine with natural understory (control), and switchgrass only. Although monitoring during the calibration period spanned 2009 to 2012, silvicultural operational practices that occurred during this period such as harvesting of existing stand and site preparation for pine and switchgrass establishment may have acted as external factors, potentially shifting hydrologic calibration relationships between control and treatment watersheds. Results indicated that MOSUM was able to detect significant changes in regression parameters for WTE due to silvicultural operations. This approach also minimized uncertainty of calibration relationships which could otherwise mask marginal treatment effects. All calibration relationships developed using this MOSUM method were quantifiable, strong, and consistent with Nash–Sutcliffe Efficiency (NSE) greater than 0.97 for WTE and NSE greater than 0.92 for daily flow, indicating its applicability for choosing calibration periods of paired watershed studies.« less

  3. Hydrologic calibration of paired watersheds using a MOSUM approach

    SciTech Connect

    Ssegane, H.; Amatya, D. M.; Muwamba, A.; Chescheir, G. M.; Appelboom, T.; Tollner, E. W.; Nettles, J. E.; Youssef, M. A.; Birgand, F.; Skaggs, R. W.

    2015-01-09

    Paired watershed studies have historically been used to quantify hydrologic effects of land use and management practices by concurrently monitoring two neighboring watersheds (a control and a treatment) during the calibration (pre-treatment) and post-treatment periods. This study characterizes seasonal water table and flow response to rainfall during the calibration period and tests a change detection technique of moving sums of recursive residuals (MOSUM) to select calibration periods for each control-treatment watershed pair when the regression coefficients for daily water table elevation (WTE) were most stable to reduce regression model uncertainty. The control and treatment watersheds included 1–3 year intensively managed loblolly pine (Pinus taeda L.) with natural understory, same age loblolly pine intercropped with switchgrass (Panicum virgatum), 14–15 year thinned loblolly pine with natural understory (control), and switchgrass only. Although monitoring during the calibration period spanned 2009 to 2012, silvicultural operational practices that occurred during this period such as harvesting of existing stand and site preparation for pine and switchgrass establishment may have acted as external factors, potentially shifting hydrologic calibration relationships between control and treatment watersheds. Results indicated that MOSUM was able to detect significant changes in regression parameters for WTE due to silvicultural operations. This approach also minimized uncertainty of calibration relationships which could otherwise mask marginal treatment effects. All calibration relationships developed using this MOSUM method were quantifiable, strong, and consistent with Nash–Sutcliffe Efficiency (NSE) greater than 0.97 for WTE and NSE greater than 0.92 for daily flow, indicating its applicability for choosing calibration periods of paired watershed studies.

  4. Grays River Watershed Geomorphic Analysis

    SciTech Connect

    Geist, David R

    2005-04-30

    This investigation, completed for the Pacific Northwest National Laboratory (PNNL), is part of the Grays River Watershed and Biological Assessment commissioned by Bonneville Power Administration under project number 2003-013-00 to assess impacts on salmon habitat in the upper Grays River watershed and present recommendations for habitat improvement. This report presents the findings of the geomorphic assessment and is intended to support the overall PNNL project by evaluating the following: The effects of historical and current land use practices on erosion and sedimentation within the channel network The ways in which these effects have influenced the sediment budget of the upper watershed The resulting responses in the main stem Grays River upstream of State Highway 4 The past and future implications for salmon habitat.

  5. Analysis of seismic disaster failure mechanism and dam-break simulation of high arch dam

    NASA Astrophysics Data System (ADS)

    Zhang, Jingkui; Zhang, Liaojun

    2014-06-01

    Based on a Chinese national high arch dam located in a meizoseismal region, a nonlinear numerical analysis model of the damage and failure process of a dam-foundation system is established by employing a 3-D deformable distinct element code (3DEC) and its re-development functions. The proposed analysis model considers the dam-foundation-reservoir coupling effect, influence of nonlinear contact in the opening and closing of the dam seam surface and abutment rock joints during strong earthquakes, and radiation damping of far field energy dissipation according to the actual workability state of an arch dam. A safety assessment method and safety evaluation criteria is developed to better understand the arch dam system disaster process from local damage to ultimate failure. The dynamic characteristics, disaster mechanism, limit bearing capacity and the entire failure process of a high arch dam under a strong earthquake are then analyzed. Further, the seismic safety of the arch dam is evaluated according to the proposed evaluation criteria and safety assessment method. As a result, some useful conclusions are obtained for some aspects of the disaster mechanism and failure process of an arch dam. The analysis method and conclusions may be useful in engineering practice.

  6. Allergic reaction after rubber dam placement.

    PubMed

    de Andrade, E D; Ranali, J; Volpato, M C; de Oliveira, M M

    2000-03-01

    In the last few years allergic reactions to natural rubber latex (NRL) have increased in dental practice affecting both the dental team and patients. Some case reports discuss the potential risks of hypersensitivity to NRL products. An adverse patient reaction after dental rubber dam placement is reported. About 1 min after the isolation of the tooth with a rubber dam the patient presented signs and symptoms of hypersensitivity. Oxygen and intravenous hydrocortisone were administered and the patient kept under observation. After 2 h she had stable vital signs and no more allergics symptoms. It is unclear whether components of the NRL dam or the cornstarch powder incorporated with the rubber dam was responsible for the allergic reaction. Dentists must be aware of the health problem and be prepared for an adequate management in dental practice.

  7. ESTIMATION OF NAVIGATION - DAM DISCHARGE IN ILLINOIS.

    USGS Publications Warehouse

    Weiss, Linda S.

    1987-01-01

    Techniques were used to estimate discharge for the Brandon Road Dam on the Des Plaines River and the Dresden Island, Marseilles, and Starved Rock Dams on the Illinois River in northern Illinois. Tainter gates are operated to regulate streamflow at all dams. Additionally, headgates are used for regulation of the Brandon Road Dam. Stage-discharge, gate-opening relations were developed from a total of 91 discharge measurements that range from 198 to 86,400 cubic feet per second (5. 6 to 2,450 cubic meters per second). Values for discharge coefficients, in equations that express discharge as a function of tailwater depth, headwater depth, and vertical height of gate opening, were determined for conditions of free-orifice, submerged-orifice, free-weir, and submerged-weir flow past a tainter gate.

  8. White Sturgeon Passage at The Dalles Dam

    USGS Publications Warehouse

    ,

    2008-01-01

    Researchers at the USGS Western Fisheries Research Center's Columbia River Research Laboratory, working with the U.S. Army Corps of Engineers, sought to better understand upstream and downstream passage of white sturgeon at dams. A study at The Dalles Dam provided the opportunity to compare two fish ladders; one that passes sturgeon upstream to one that does not, to determine if subtle differences in construction result in better passage of white sturgeon. Researchers conducted a study using a combination of acoustic and radio telemetry technologies to obtain information on juvenile and adult white sturgeon near The Dalles Dam, with the objectives of characterizing the distribution and movements of white sturgeon in the immediate vicinity of the dam and to determine timing and routes of upstream and downstream passage.

  9. 76 FR 25310 - Intent To Prepare an Environmental Impact Statement for the Zoar Levee and Diversion Dam, Dam...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ... Levee and Diversion Dam, Dam Safety Modification Study, Tuscarawas County, OH AGENCY: Department of the... with Zoar Levee and Diversion Dam. These high hazard structures do not meet current performance... . SUPPLEMENTARY INFORMATION: 1. Authority: Investigation and justification of modifications for dam...

  10. 76 FR 34799 - Permanent Dam Safety Modification at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams, TN

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... Alternatives: permanent modifications to dam structures and removal of the temporary HESCO baskets before the... Permanent Dam Safety Modification at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams, TN AGENCY... various alternatives for permanent modifications to the existing dam facilities at Cherokee, Fort...

  11. 33 CFR 208.19 - Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Texas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Marshall Ford Dam and Reservoir... Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Texas. In the interest of flood control, the Lower Colorado River Authority (LCRA) shall operate the Marshall Ford Dam...

  12. Influence of dams on river-floodplain dynamics in the Elwha River, Washington

    USGS Publications Warehouse

    Kloehn, K.K.; Beechie, T.J.; Morley, S.A.; Coe, H.J.; Duda, J.J.

    2008-01-01

    The Elwha dam removal project presents an ideal opportunity to study how historic reduction and subsequent restoration of sediment supply alter river-floodplain dynamics in a large, forested river floodplain. We used remote sensing and onsite data collection to establish a historical record of floodplain dynamics and a baseline of current conditions. Analysis was based on four river reaches, three from the Elwha River and the fourth from the East Fork of the Quinault River. We found that the percentage of floodplain surfaces between 25 and 75 years old decreased and the percentage of surfaces >75 years increased in reaches below the Elwha dams. We also found that particle size decreased as downstream distance from dams increased. This trend was evident in both mainstem and side channels. Previous studies have found that removal of the two Elwha dams will initially release fine sediment stored in the reservoirs, then in subsequent decades gravel bed load supply will increase and gradually return to natural levels, aggrading river beds up to 1 m in some areas. We predict the release of fine sediments will initially create bi-modal grain size distributions in reaches downstream of the dams, and eventual recovery of natural sediment supply will significantly increase lateral channel migration and erosion of floodplain surfaces, gradually shifting floodplain age distributions towards younger age classes.

  13. 36 CFR 251.35 - Petersburg watershed.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Section 251.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Miscellaneous Land Uses Petersburg Watershed § 251.35 Petersburg watershed. (a) Except as authorized in paragraphs (b) and (c), access to lands within the Petersburg watershed, Tongass National Forest,...

  14. 36 CFR 251.35 - Petersburg watershed.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Section 251.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Miscellaneous Land Uses Petersburg Watershed § 251.35 Petersburg watershed. (a) Except as authorized in paragraphs (b) and (c), access to lands within the Petersburg watershed, Tongass National Forest,...

  15. 36 CFR 251.35 - Petersburg watershed.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Section 251.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Miscellaneous Land Uses Petersburg Watershed § 251.35 Petersburg watershed. (a) Except as authorized in paragraphs (b) and (c), access to lands within the Petersburg watershed, Tongass National Forest,...

  16. 36 CFR 251.35 - Petersburg watershed.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Section 251.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Miscellaneous Land Uses Petersburg Watershed § 251.35 Petersburg watershed. (a) Except as authorized in paragraphs (b) and (c), access to lands within the Petersburg watershed, Tongass National Forest,...

  17. 36 CFR 251.35 - Petersburg watershed.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Section 251.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Miscellaneous Land Uses Petersburg Watershed § 251.35 Petersburg watershed. (a) Except as authorized in paragraphs (b) and (c), access to lands within the Petersburg watershed, Tongass National Forest,...

  18. Annual peak streamflow and ancillary data for small watersheds in central and western Texas

    USGS Publications Warehouse

    Harwell, Glenn R.; Asquith, William H.

    2011-01-01

    Estimates of annual peak-streamflow frequency are needed for flood-plain management, assessment of flood risk, and design of structures, such as roads, bridges, culverts, dams, and levees. Regional regression equations have been developed and are used extensively to estimate annual peak-streamflow frequency for ungaged sites in natural (unregulated and rural or nonurbanized) watersheds in Texas (Asquith and Slade, 1997; Asquith and Thompson, 2008; Asquith and Roussel, 2009). The most recent regional regression equations were developed by using data from 638 Texas streamflow-gaging stations throughout the State with eight or more years of data by using drainage area, channel slope, and mean annual precipitation as predictor variables (Asquith and Roussel, 2009). However, because of a lack of sufficient historical streamflow data from small, rural watersheds in certain parts of the State (central and western), substantial uncertainity exists when using the regional regression equations for the purpose of estimating annual peak-streamflow frequency.

  19. Watershed Education for Broadcast Meteorologists

    NASA Astrophysics Data System (ADS)

    Lamos, J. P.; Sliter, D.; Espinoza, S.; Spangler, T. C.

    2006-12-01

    The National Environmental Education and Training Organization (NEETF) published a report in 2005 that summarized the findings of ten years of NEETF and Roper Research. The report stated, "Our years of data from Roper surveys show a persistent pattern of environmental ignorance even among the most educated and influential members of society." Market research has also shown that 80% of television viewers list the weather as the primary reason for watching the local news. Broadcast meteorologists, with a broader understanding of environmental and related sciences have an opportunity to use their weathercasts to inform the public about the environment and the factors that influence environmental health. As "station scientists," broadcast meteorologists can use the weather, and people's connection to it, to broaden their understanding of the environment they live in. Weather and watershed conditions associated with flooding and drought have major human and environmental impacts. Increasing the awareness of the general public about basic aspects of the hydrologic landscape can be an important part of mitigating the adverse effects of too much or too little precipitation, and of protecting the environment as well. The concept of a watershed as a person's natural neighborhood is a very important one for understanding hydrologic and environmental issues. Everyone lives in a watershed, and the health of a watershed is the result of the interplay between weather and human activity. This paper describes an online course to give broadcast meteorologists a basic understanding of watersheds and how watersheds are impacted by weather. It discusses how to convey watershed science to a media- savvy audience as well as how to model the communication of watershed and hydrologic concepts to the public. The course uses a narrative, story-like style to present its content. It is organized into six short units of instruction, each approximately 20 minutes in duration. Each unit is

  20. Handling protocol of posterior composites Rubber Dam.

    PubMed

    Strydom, C

    2005-08-01

    Although it can never provide perfect isolation, rubber dam greatly facilitates adhesive procedures by keeping the operating field dry throughout operative procedures. Research has shown time and again that the modern dentin bonding agents cannot cope with blood- or saliva contamination. In spite of this very few dentists use rubber dam routinely. Once experienced in its use, it should not take up much more clinical time than 2 minutes.

  1. Economics of erosion control in a subtropical watershed: a Dominican case

    SciTech Connect

    Veloz, A.; Southgate, D.; Hitzhusen, F.; Macgregor, R.

    1985-05-01

    The authors analyze a soil conservation project for the watershed of Caldesia hydroelectric dam in the Dominican Republic in order to explain the human realities that underlie environmental problems in the less developed countries (LDCs) and to help identify elements of successful strategies for coping with those problems. They chose this particular case study because many LDCs are counting on water resource development to increase domestic power generation and to expand agriculture by reducing sedimentation from erosion. The policy implications of their study focus on two issues: the lack of widespread adoption of soil-conserving practices and the policy tools which government can use to encourage change. 24 references, 5 tables.

  2. Wind River Watershed Restoration Project; Underwood Conservation District, Annual Report 2002-2003.

    SciTech Connect

    White, Jim

    2004-02-01

    The goal of the Wind River project is to preserve, protect and restore Wind River steelhead. In March, 1998, the National Marine Fisheries Service listed the steelhead of the lower Columbia as 'threatened' under the Endangered Species Act. In 1997, the Washington Department of Fish and Wildlife rated the status of the Wind River summer run steelhead as critical. Due to the status of this stock, the Wind River summer steelhead have the highest priority for recovery and restoration in the state of Washington's Lower Columbia Steelhead Conservation Initiative. The Wind River Project includes four cooperating agencies. Those are the Underwood Conservation District (UCD), United States Geological Service (USGS), US Forest Service (USFS), and Washington State Department of Fish & Wildlife (WDFW). Tasks include monitoring steelhead populations (USGS and WDFW), Coordinating a Watershed Committee and Technical Advisory Group (UCD), evaluating physical habitat conditions (USFS and UCD), assessing watershed health (all), reducing road sediments sources (USFS), rehabilitating riparian corridors, floodplains, and channel geometry (UCD, USFS), evaluate removal of Hemlock Dam (USFS), and promote local watershed stewardship (UCD, USFS). UCD's major efforts have included coordination of the Wind River Watershed Committee and Technical Advisory Committee (TAC), water temperature and water chemistry monitoring, riparian habitat improvement projects, and educational activities. Our coordination work enables the local Watershed Committee and TAC to function and provide essential input to Agencies, and our habitat improvement work focuses on riparian revegetation. Water chemistry and temperature data collection provide information for monitoring watershed conditions and fish habitat, and are comparable with data gathered in previous years. Water chemistry information collected on Trout Creek should, with 2 years data, determine whether pH levels make conditions favorable for a fish

  3. Morphometry and land cover based multi-criteria analysis for assessing the soil erosion susceptibility of the western Himalayan watershed.

    PubMed

    Altaf, Sadaff; Meraj, Gowhar; Romshoo, Shakil Ahmad

    2014-12-01

    Complex mountainous environments such as Himalayas are highly susceptibility to natural hazards particular those that are triggered by the action of water such as floods, soil erosion, mass movements and siltation of the hydro-electric power dams. Among all the natural hazards, soil erosion is the most implicit and the devastating hazard affecting the life and property of the millions of people living in these regions. Hence to review and devise strategies to reduce the adverse impacts of soil erosion is of utmost importance to the planners of watershed management programs in these regions. This paper demonstrates the use of satellite based remote sensing data coupled with the observational field data in a multi-criteria analytical (MCA) framework to estimate the soil erosion susceptibility of the sub-watersheds of the Rembiara basin falling in the western Himalaya, using geographical information system (GIS). In this paper, watershed morphometry and land cover are used as an inputs to the MCA framework to prioritize the sub-watersheds of this basin on the basis of their different susceptibilities to soil erosion. Methodology included the derivation of a set of drainage and land cover parameters that act as the indicators of erosion susceptibility. Further the output from the MCA resulted in the categorization of the sub-watersheds into low, medium, high and very high erosion susceptibility classes. A detailed prioritization map for the susceptible sub-watersheds based on the combined role of land cover and morphometry is finally presented. Besides, maps identifying the susceptible sub-watersheds based on morphometry and land cover only are also presented. The results of this study are part of the watershed management program in the study area and are directed to instigate appropriate measures to alleviate the soil erosion in the study area. PMID:25154685

  4. Morphometry and land cover based multi-criteria analysis for assessing the soil erosion susceptibility of the western Himalayan watershed.

    PubMed

    Altaf, Sadaff; Meraj, Gowhar; Romshoo, Shakil Ahmad

    2014-12-01

    Complex mountainous environments such as Himalayas are highly susceptibility to natural hazards particular those that are triggered by the action of water such as floods, soil erosion, mass movements and siltation of the hydro-electric power dams. Among all the natural hazards, soil erosion is the most implicit and the devastating hazard affecting the life and property of the millions of people living in these regions. Hence to review and devise strategies to reduce the adverse impacts of soil erosion is of utmost importance to the planners of watershed management programs in these regions. This paper demonstrates the use of satellite based remote sensing data coupled with the observational field data in a multi-criteria analytical (MCA) framework to estimate the soil erosion susceptibility of the sub-watersheds of the Rembiara basin falling in the western Himalaya, using geographical information system (GIS). In this paper, watershed morphometry and land cover are used as an inputs to the MCA framework to prioritize the sub-watersheds of this basin on the basis of their different susceptibilities to soil erosion. Methodology included the derivation of a set of drainage and land cover parameters that act as the indicators of erosion susceptibility. Further the output from the MCA resulted in the categorization of the sub-watersheds into low, medium, high and very high erosion susceptibility classes. A detailed prioritization map for the susceptible sub-watersheds based on the combined role of land cover and morphometry is finally presented. Besides, maps identifying the susceptible sub-watersheds based on morphometry and land cover only are also presented. The results of this study are part of the watershed management program in the study area and are directed to instigate appropriate measures to alleviate the soil erosion in the study area.

  5. How to update design floods after the construction of small reservoirs and check dams: A case study from the Daqinghe river basin, China

    NASA Astrophysics Data System (ADS)

    Li, Jianzhu; Sun, Huafeng; Feng, Ping

    2016-06-01

    Several small reservoirs and a large number of check dams had been constructed in the Wangkuai reservoir watershed after 1970s, and flood time series lacked stationarity, which affected the original design flood hydrographs for the Wangkuai reservoir. Since the location, storage capacity and drainage area of the large number of check dams were unknown, we present a method to estimate their total storage capacities (TSC) and total drainage areas (TDA) by using the recorded rainstorm and flood data. On the basis of TSC and TDA, the flood events which occurred in an undisturbed period were reconstructed under current conditions to obtain a stationary flood series. A frequency analysis was subsequently performed to assess the design flood peak and volume for both small and medium design floods with a 10-200 year return period. For large and catastrophic floods, it was assumed that the upstream check dams and small reservoirs would be destroyed, and water stored in these hydraulic structures were re-routed to the Wangkuai reservoir by unit hydrograph. The modified flood peak and volume decreased for floods with a 10-200 year return period when compared to the current design flood. But for large design floods with a return period exceeding 500 years, peak discharge increased. This study provides a new method for design flood calculation or modification of the original design flood in watersheds with a large number of check dams.

  6. Distributional Impacts of Large Dams in China

    NASA Astrophysics Data System (ADS)

    Bao, X.

    2010-12-01

    Dams on a river are believed to have heterogeneous impacts to the upstream, local and downstream areas. Generally, irrigation dams will bring benefits to the downstream by facilitating more irrigation, while it will bring negative impacts to upstream due to inundation or no impact to local area as a combination result of population dislocation and economic benefits. This paper checked the impacts of large dams (above 100 meters) on the upstream, downstream and local area, using 2000-2008 county level data in China. Robust heterogeneous impacts of different categories of dams (mainly dams serving for irrigation, hydropower, or other purposes) were found on different areas, using IV regression approaches. Dams higher than 100 meters are significantly and heterogeneously impacting agricultural production, urban employment and rural per capita income. Its beneficial impact on agriculture production is significant for downstream especially in continuous drought years. But its impacts on social welfare indicators, such as primary school enrollment and hospital beds, are not heterogeneously different across regions.

  7. Evaluation of surface properties and atmospheric disturbances caused by post-dam alterations of land use/land cover

    NASA Astrophysics Data System (ADS)

    Woldemichael, A. T.; Hossain, F.; Pielke, R., Sr.

    2014-09-01

    This study adopted a differential land-use/land-cover (LULC) analysis to evaluate dam-triggered land-atmosphere interactions for a number of LULC scenarios. Two specific questions were addressed: (1) can dam-triggered LULC heterogeneities modify surface and energy budget, which, in turn, change regional convergence and precipitation patterns? (2) How extensive is the modification in surface moisture and energy budget altered by dam-triggered LULC changes occurring in different climate and terrain features? The Regional Atmospheric Modeling System (RAMS, version 6.0) was set up for two climatologically and topographically contrasting regions: the American River watershed (ARW), located in California, and the Owyhee River watershed (ORW), located in eastern Oregon. For the selected atmospheric river precipitation event of 29 December 1996 to 3 January 1997, simulations of three pre-defined LULC scenarios are performed. The definition of the scenarios are (1) the "control" scenario, representing the contemporary land use, (2) the "pre-dam" scenario, representing the natural landscape before the construction of the dams and (3) the "non-irrigation" scenario, representing the condition where previously irrigated landscape in the control is transformed to the nearby land-use type. Results indicated that the ARW energy and moisture fluxes were more extensively affected by dam-induced changes in LULC than the ORW. Both regions, however, displayed commonalities in the modification of land-atmosphere processes due to LULC changes, with the control-non-irrigation scenario creating more change than the control-pre-dam scenarios. These commonalities were: (1) the combination of a decrease in temperature (up to 0.15 °C) and an increase at dew point (up to 0.25 °C) was observed; (2) there was a larger fraction of energy partitioned to latent heat flux (up to 10 W m-2) that increased the amount of water vapor in the atmosphere and resulted in a larger convective available

  8. Evaluation of surface properties and atmospheric disturbances caused by post-dam alterations of land-use/land-cover

    NASA Astrophysics Data System (ADS)

    Woldemichael, A. T.; Hossain, F.; Pielke, R., Sr.

    2014-05-01

    This study adopted a differential land-use/land-cover (LULC) analysis to evaluate dam-triggered land-atmosphere interactions for a number of LULC scenarios. Two specific questions were addressed: (1) can dam-triggered LULC heterogeneities modify surface and energy budget which, in turn, change regional convergence and precipitation patterns? and (2) how extensive is the modification in surface moisture and energy budget altered by dam-triggered LULC changes occurring in different climate and terrain features? The Regional Atmospheric Modeling System (RAMS, version 6.0) was set up for two climatologically and topographically contrasting regions: the American River Watershed (ARW) located in California and the Owyhee River Watershed (ORW) located in eastern Oregon. For the selected atmospheric river precipitation event of 29 December 1996 to 3 January 1997, simulations of three pre-defined LULC scenarios are performed. The definition of the scenarios are: (1) the control scenario representing the contemporary land-use, (2) the pre-dam scenario representing the natural landscape before the construction of the dams and (3) the non-irrigation scenario representing the condition where previously irrigated landscape in the control is transformed to the nearby land-use type. Results indicated that the ARW energy and moisture fluxes were more extensively affected by dam-induced changes in LULC than the ORW. Both regions, however, displayed commonalities in the modification of land-atmosphere processes due to LULC changes, with the control-non-irrigation scenario creating more change than the control-pre-dam scenarios. These commonalities were: (1) the combination of a decrease in temperature (up to 0.15 °C) and an increase in dewpoint (up to 0.25 °C) was observed, (2) there was a larger fraction of energy partitioned to latent heat flux (up to 10 W m-2) that increased the amount of water vapor to the atmosphere and resulted in a larger convective available potential

  9. Using 137Cs to quantify the sediment delivery ratio in a small watershed.

    PubMed

    Li, Mian; Yao, Wenyi; Li, Zhanbin; Liu, Puling; Yang, Er; Shen, Zhenzhou

    2012-01-01

    Understanding the sediment delivery ratio (SDR) is important in controlling sediments for the sustainable development of natural resources and in the design of the construction such as dams and reservoirs. The purpose of this investigation is to determine the SDR by the (137)Cs tracing method in a small watershed in the Sichuan Hilly Basin of China. In the study watershed, different land plots are divided according to the land use type, and 97 sampling sites were selected from these plots. The results show that the average net soil loss rates from the forest land and sloping cultivated land are 1759 and 4468t/km(2)a, respectively. No (137)Cs was detectable on the bare rock surfaces and previous work showed that the erosion rate from the bare rock area was 14,260t/km(2)a. In the depositional zone, the sedimentation rates in the Caoto (a kind of cultivated land located at the foot of hills) and paddy field are 3113 and 3562t/km(2)a, respectively. Combining the area of each land use in the small watershed, the SDR of 0.40 is obtained in the past four decades. The (137)Cs technique was shown to provide an effective and rapid means of estimating the SDR within the small watershed.

  10. Beaver Ponds: Resurgent Nitrogen Sinks for Rural Watersheds in the Northeastern United States.

    PubMed

    Lazar, Julia G; Addy, Kelly; Gold, Arthur J; Groffman, Peter M; McKinney, Richard A; Kellogg, Dorothy Q

    2015-09-01

    Beaver-created ponds and dams, on the rise in the northeastern United States, reshape headwater stream networks from extensive, free-flowing reaches to complexes of ponds, wetlands, and connecting streams. We examined seasonal and annual rates of nitrate transformations in three beaver ponds in Rhode Island under enriched nitrate-nitrogen (N) conditions through the use of N mass balance techniques on soil core mesocosm incubations. We recovered approximately 93% of the nitrate N from our mesocosm incubations. Of the added nitrate N, 22 to 39% was transformed during the course of the incubation. Denitrification had the highest rates of transformation (97-236 mg N m d), followed by assimilation into the organic soil N pool (41-93 mg N m d) and ammonium generation (11-14 mg N m d). Our denitrification rates exceeded those in several studies of freshwater ponds and wetlands; however, rates in those ecosystems may have been limited by low concentrations of nitrate. Assuming a density of 0.7 beaver ponds km of catchment area, we estimated that in nitrate-enriched watersheds, beaver pond denitrification can remove approximately 50 to 450 kg nitrate N km catchment area. In rural watersheds of southern New England with high N loading (i.e., 1000 kg km), denitrification from beaver ponds may remove 5 to 45% of watershed nitrate N loading. Beaver ponds represent a relatively new and substantial sink for watershed N if current beaver populations persist. PMID:26436285

  11. Analysis of the spatial discretization modeling watershed using the hydrology distributed model CEQUEAU

    NASA Astrophysics Data System (ADS)

    Guerra-Cobián, V. H.; Ba, K. M.; Díaz-Delgado, C.; Quentin, E.; Carsteanu, A. A.; Salas-Limón, D.

    2009-04-01

    Today, the use of hydrological models is essential, since they can be used to analyze various aspects such as runoff, flooding, the operation of dams and supply systems, water use, and use and protection of groundwater. In this research, we examined the effect on the spatial variation of the discretization in sixteen watersheds on distributed hydrological model simulations CEQUEAU. The overall objective was to propose criteria for determining the optimum size of mesh for the watershed discretization. The main methodological steps that were undertaken focused on the selection of hydrometric stations, the creation of hydrometeorlogical databases through the acquisition and adaptation of geodata. Furthermore, within the framework of research, we developed a new hydrogeomatic module that works in GIS Idrisi, which was part of the information used in hydrological modeling. The model CEQUEAU was performed in watershed study, using the Nash criterion for evaluating the results of simulations. Finally, statistical analysis was performed of the results, to propose criteria to determine the optimal size of mesh. The results of the analysis of spatial discretization were broadly satisfactory, because, in the simulations were obtained on average Nash coefficient between 0.6538 and 0.9823. The application of statistical techniques to the results of the analysis of spatial discretization, there were two multiple linear regression models with R2 values for each of 0.780 and 0.817. These equations obtained can be used as a criterion for determining the optimum size of spatial discretization watershed.

  12. Multiagent distributed watershed management

    NASA Astrophysics Data System (ADS)

    Giuliani, M.; Castelletti, A.; Amigoni, F.; Cai, X.

    2012-04-01

    Deregulation and democratization of water along with increasing environmental awareness are challenging integrated water resources planning and management worldwide. The traditional centralized approach to water management, as described in much of water resources literature, is often unfeasible in most of the modern social and institutional contexts. Thus it should be reconsidered from a more realistic and distributed perspective, in order to account for the presence of multiple and often independent Decision Makers (DMs) and many conflicting stakeholders. Game theory based approaches are often used to study these situations of conflict (Madani, 2010), but they are limited to a descriptive perspective. Multiagent systems (see Wooldridge, 2009), instead, seem to be a more suitable paradigm because they naturally allow to represent a set of self-interested agents (DMs and/or stakeholders) acting in a distributed decision process at the agent level, resulting in a promising compromise alternative between the ideal centralized solution and the actual uncoordinated practices. Casting a water management problem in a multiagent framework allows to exploit the techniques and methods that are already available in this field for solving distributed optimization problems. In particular, in Distributed Constraint Satisfaction Problems (DCSP, see Yokoo et al., 2000), each agent controls some variables according to his own utility function but has to satisfy inter-agent constraints; while in Distributed Constraint Optimization Problems (DCOP, see Modi et al., 2005), the problem is generalized by introducing a global objective function to be optimized that requires a coordination mechanism between the agents. In this work, we apply a DCSP-DCOP based approach to model a steady state hypothetical watershed management problem (Yang et al., 2009), involving several active human agents (i.e. agents who make decisions) and reactive ecological agents (i.e. agents representing

  13. Dam failure analysis for the Lago de Matrullas Dam, Orocovis, Puerto Rico

    USGS Publications Warehouse

    Torres-Sierra, Heriberto; Gómez-Fragoso, Julieta

    2015-01-01

    Results from the simulated dam failure of the Lago de Matrullas Dam using the HEC–RAS model for the 6- and 24-hour PMP events showed peak discharges at the dam of 3,149.33 and 3,604.70 m3/s, respectively. Dam failure during the 100-year-recurrence, 24-hour rainfall event resulted in a peak discharge of 2,103.12 m3/s directly downstream from the dam. Dam failure under sunny day conditions produced a peak discharge of 1,695.91 m3/s at the dam assuming the antecedent lake level was at the morning-glory spillway invert elevation. Flood-inundation maps prepared as part of the study depict the flood extent and provide valuable information for preparing an Emergency Action Plan. Results of the failure analysis indicate that a failure of the Lago de Matrullas Dam could cause flooding to many of the inhabited areas along stream banks from the Lago de Matrullas Dam to the mouth of the Río Grande de Manatí. Among the areas most affected are the low-lying regions in the vicinity of the towns of Ciales, Manatí, and Barceloneta. The delineation of the flood boundaries near the town of Barceloneta considered the effects of a levee constructed during 2000 at Barceloneta in the flood plain of the Río Grande de Manatí to provide protection against flooding to the near-by low-lying populated areas. The results showed overtopping can be expected in the aforementioned levee during 6- and 24-hour probable-maximum-precipitation dam failure scenarios. No overtopping of the levee was simulated, however, during dam failure scenarios under the 100-year recurrence, 24-hour rainfall event or sunny day conditions.

  14. Understanding the Impact of Dam-triggered Land-Use/Land-Cover Change on the Modification of Extreme Precipitation

    NASA Astrophysics Data System (ADS)

    Woldemichael, A. T.; Hossain, F.

    2012-12-01

    Two specific questions are addressed in this study regarding dams (artificial reservoirs). The first one is 'can a dam (artificial reservoir) and the land-use/land-cover (LULC) changes triggered by it physically alter extreme precipitation (EP)?' The second question is 'among the commonly experienced LULC changes due to dams, which type of change leads to the most detectable alteration of extreme precipitation?' The American River Basin (ARW) and the Folsom dam were selected as a study region. Four scenarios of LULC change (comprising also various reservoir surface areas) were analyzed in a step by step fashion to elucidate the scenario leading to most significant impact on EP. The Regional Atmospheric Modeling System (RAMS, version 6.2) was used to analyze the impact of these LULC scenarios in two modes. In the first mode (called normal), the probable precipitation pattern due to each LULC scenario was identified. The second mode, called moisture-maximized, the extreme pattern represented from a 100% relative humidity profile, was generated as an indicator of EP. For the particular case of ARW and Folsom dam, irrigation was found as having the most detectable impact on EP (a 5% increase in 72 hour total for the normal mode and 3% increase for the moisture maximized mode) in and around the ARW watershed. Doubling the reservoir size, on the other hand, brought only a small change in EP. Our RAMS-simulated results demonstrate that LULC changes driven by dams can in fact alter the local to regional hydrometeorology as well as extreme precipitation.

  15. WATERSHED-BASED SURVEY DESIGNS

    EPA Science Inventory

    Water-based sampling design and assessment tools help serve the multiple goals for water quality monitoring required under the Clean Water Act, including assessment of regional conditions to meet Section 305(b), identification if impaired water bodies or watersheds to meet Sectio...

  16. MARYLAND AGRICULTURE AND YOUR WATERSHED

    EPA Science Inventory



    Using primarily 1995 State of Maryland agricultural statistics data, a new methodology was demonstrated with which State natural resource managers can analyze the areal extent of agricultural lands and production data on a watershed basis. The report organized major crop ...

  17. Little River Experimental Watershed Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term, watershed-scale hydrologic and climatic data are invaluable for natural resource and environmental planning and management. Historically, long-term hydrologic records have proved critical for flood forecasting, water conservation and management, agricultural and drought planning, and for...

  18. Soils of Walker Branch Watershed

    SciTech Connect

    Lietzke, D.A.

    1994-03-01

    The soil survey of Walker Branch Watershed (WBW) utilized the most up-to-date knowledge of soils, geology, and geohydrology in building the soils data base needed to reinterpret past research and to begin new research in the watershed. The soils of WBW were also compared with soils mapped elsewhere along Chestnut Ridge on the Oak Ridge Reservation to (1) establish whether knowledge obtained elsewhere could be used within the watershed, (2) determine whether there were any soils restricted to the watershed, and (3) evaluate geologic formation lateral variability. Soils, surficial geology, and geomorphology were mapped at a scale of 1:1,200 using a paper base map having 2-ft contour intervals. Most of the contours seemed to reasonably represent actual landform configurations, except for dense wooded areas. For example, the very large dolines or sinkholes were shown on the contour base map, but numerous smaller ones were not. In addition, small drainageways and gullies were often not shown. These often small but important features were located approximately as soil mapping progressed.

  19. Discover a Watershed: The Everglades.

    ERIC Educational Resources Information Center

    Robinson, George B.; And Others

    This publication is designed for both classroom teachers and nonformal educators of young people in grades 6 through 12. It can provide a 6- to 8-week course of study on the watershed with students participating in activities as they are ordered in the guide, or activities may be used in any order with educators selecting those appropriate for the…

  20. MANAGING URBAN WATERSHED PATHOGEN CONTAMINATION

    EPA Science Inventory

    This presentation is a summary of the EPA National Risk Management Research Laboratory (NRMRL) publication entitled Managing Urban Watershed Pathogen Contamination, EPA/600/R-03/111 (September 2003). It is available on the internet at http://www.epa.gov/ednnrmrl/repository/water...

  1. A spatial assessment of hydrologic alteration caused by dams in the Northeastern United States using a Neural Network based daily reservoir operation scheme

    NASA Astrophysics Data System (ADS)

    Ehsani, N.; Vorosmarty, C. J.; Fekete, B. M.; Rosenzweig, B.; Tessler, Z. D.

    2014-12-01

    Considering the impacts of dams on natural hydrology and ecosystems, it is important to be able to simulate their behavior and effects in hydrological and ecological models. Overlooking human engineering of river systems may significantly affect modelling results and impact decisions addressing water management issues. Simulating reservoir operation at the regional and global scale remains a challenge in water resource and environmental science. There are numerous studies that model the operating rules of a single or small cluster of dams based on available observed data or that try to find an optimized set of rules for their operation based on their characteristics and intended purpose. On the other hand, there are few works that consider the operation of dams for regional and global hydrological models. One major problem in modeling dams operation in such large-scale systems is the lack of efficient algorithms for modelling reservoir operation. Depending on site-specific characteristics of the dam, its watershed and its intended purpose, each dam has a specific and optimum operating rule; as a result, effective simulation of their operation is not a trivial task when hundreds and thousands of dams exist in the area of study. As part of the development of the Northeast Regional Earth System Model (NE-RESM), we are developing an integrated hydrological modeling framework that incorporates various aspects of the coupled human-hydrologic system, from supply to demand, into a single framework. We use an Artificial Neural Network to develop an accurate yet generalized daily operating rule with minimal input requirements that is suitable for use in large scale hydrological models. We implement this reservoir operating scheme into WBMplus and study how dams alter natural hydrology of the Northeastern United States. We also show how climate change impacts the operation of reservoirs and hence availability of water in the region by the end of the 21st century.

  2. A riverscape perspective of Pacific salmonids and aquatic habitats prior to large-scale dam removal in the Elwha River, Washington, USA

    USGS Publications Warehouse

    Brenkman, S.J.; Duda, J.J.; Torgersen, C.E.; Welty, E.; Pess, G.R.; Peters, R.; McHenry, M.L.

    2012-01-01

     Dam removal has been increasingly proposed as a river restoration technique. In 2011, two large hydroelectric dams will be removed from Washington State’s Elwha River. Ten anadromous fish populations are expected to recolonise historical habitats after dam removal. A key to understanding watershed recolonisation is the collection of spatially continuous information on fish and aquatic habitats. A riverscape approach with an emphasis on biological data has rarely been applied in mid-sized, wilderness rivers, particularly in consecutive years prior to dam removal. Concurrent snorkel and habitat surveys were conducted from the headwaters to the mouth (rkm 65–0) of the Elwha River in 2007 and 2008. This riverscape approach characterised the spatial extent, assemblage structure and patterns of relative density of Pacific salmonids. The presence of dams influenced the longitudinal patterns of fish assemblages, and species richness was the highest downstream of the dams, where anadromous salmonids still have access. The percent composition of salmonids was similar in both years for rainbow trout, Oncorhynchus mykiss (Walbaum), coastal cutthroat trout, Oncorhynchus clarkii clarkii (Richardson) (89%; 88%), Chinook salmon, Oncorhynchus tshawytscha (Walbaum) (8%; 9%), and bull trout, Salvelinus confluentus (Suckley) (3% in both years). Spatial patterns of abundance for rainbow and cutthroat trout (r = 0.76) and bull trout (r = 0.70) were also consistent between years. Multivariate and univariate methods detected differences in habitat structure along the river profile caused by natural and anthropogenic factors. The riverscape view highlighted species-specific biological hotspots and revealed that 60–69% of federally threatened bull trout occurred near or below the dams. Spatially continuous surveys will be vital in evaluating the effectiveness of upcoming dam removal projects at restoring anadromous salmonids.

  3. Project Planning for Cougar Dam during 2010

    USGS Publications Warehouse

    Haskell, Craig A.; Tiffan, Kenneth F.

    2011-01-01

    Cougar Dam is a 158 m-tall, rock fill dam located about 63 km east of Springfield, Oregon. Completed in 1963, the dam is owned and operated by the U.S. Army Corps of Engineers (USACE). It impounds Cougar Reservoir, which is 9.7 km long, has a surface area of 518 ha, and is predominately used for flood control. The pool elevation typically ranges from a maximum conservation pool of 515 m (1,690 ft) National Geodetic Vertical Datum (NGVD) in summer to a minimum flood control elevation of 467 m (1,532 ft NGVD) in winter. The reservoir thermally stratifies in the summer, has an average depth of 37 m, and holds 153,500 acre-feet when full. Cougar Dam is located on the South Fork of the McKenzie River 7 km upstream from the mainstem McKenzie River, a tributary of the Willamette River. The McKenzie River Basin basin supports the largest remaining population of wild spawning spring Chinook salmon in the Willamette River Basin (National Oceanic and Atmospheric Administration; NOAA, 2008). Cougar Dam and others were collectively deemed to cause jeopardy to the sustainability of anadromous fish stocks in the Willamette River Basin (NOAA, 2008). Prior to dam construction, as many as 805 redds were observed in the South Fork of the McKenzie River (Willis and others, 1960) and it is estimated that 40 km of spawning habitat were lost when access was blocked after dam construction. The 2008 Willamette Biological Opinion (BIOP) requires improvements to operations and structures to reduce impacts on Upper Willamette River (UWR) Chinook salmon (Oncorhynchus tshawytscha) and UWR steelhead (O. mykiss; NOAA, 2008). In 2010, an adult fish collection facility was completed below Cougar Dam to collect returning adult salmon for transport to spawning habitats above the dam. Before that time, returning adult spring Chinook salmon were transported to upstream spawning areas as part of a trap-and-haul program with adults passed ranging annually from 0 to 1,038 (Taylor, 2000). The progeny of

  4. Runoff responses to afforestation in a watershed of the Loess Plateau, China

    NASA Astrophysics Data System (ADS)

    Huang, Mingbin; Zhang, Lu; Gallichand, Jacques

    2003-09-01

    Afforestation has been suggested as a means of improving soil and water conservation in north-western China, especially on the Loess Plateau. Understanding of the hydrological responses to afforestation will help us develop sustainable watershed management strategies. A study was conducted during the period of 1956 to 1980 to evaluate runoff responses to afforestation in a watershed on the Loess Plateau with an area of 1·15 km2, using a paired watershed approach. Deciduous trees, including locust (locusta L.), apricot (praecox L.) and elm (ulmus L.), were planted on about 80% of a treated watershed, while a natural grassland watershed remained unchanged. It was estimated that cumulative runoff yield in the treated watershed was reduced by 32% as a result of afforestation. A significant trend was also observed that shows annual runoff reduction increases with the age of the trees planted. Reduction in monthly runoff occurred mainly from June to September, which was ascribed to greater rainfall and utilization by trees during this period. Afforestation also resulted in reduction in the volume and peak flow of storm runoff events in the treated watershed with greater reduction in peak flow. Copyright

  5. Runoff responses to afforestation in a watershed of the Loess Plateau, China

    NASA Astrophysics Data System (ADS)

    Huang, M.; Zhang, L.; Gallichand, J.

    2003-04-01

    Afforestation has been suggested as a means of imroving soil and water conservation in Northwestern China, especially in the Loess Plateau. Understanding of the hydrological responses to afforestation will help us develop sustainable watershed management strategies. A study was conducted during the period of 1956 to 1995 to evaluated runoff responses to afforestation in a watershed in the Loess Plateau, using a paired watershed approach. Deciduoud tress, including locust, apricot and elm, were planted on about 80% of a treated watershed, while a natural grassland watershed remained unchanged. It was estimated that cumulative runoff yield in the treated watershed was reduced by 32% as a result of afforestation. Asignificant trend was also observed that shows annual runoff reduction increases with the age of the trees planted. Reduction in monthly runoff occurred mainly from June to September, which was ascribed to greater rainfall and utilization by trees during this period. Afforeststion also resulted in reduction in the volume and peak flow of storm runoff events in treated watershed with greater reduction in peak flow.

  6. Evaluation of Fall Chinook and Chum Salmon Spawning below Bonneville Dam; 2002-2003 Annual Report.

    SciTech Connect

    van der Naald, Wayne; Clark, Roy; Brooks, Robert

    2004-01-01

    In 2002 a total of 364 adult fall chinook and 472 chum were sampled for biological data in the Ives and Pierce islands area below Bonneville Dam. Vital statistics were developed from 290 fall chinook and 403 chum samples. The peak redd count for fall chinook was 214. The peak redd count for chum was 776. Peak spawning time for fall chinook was set at approximately 15 November. Peak spawning time for chum occurred approximately 6 December. There were estimated to be a total of 1,881 fall chinook spawning below Bonneville Dam in 2002. The study area's 2002 chum population was estimated to be 4,232 spawning fish. Temperature unit data suggests that below Bonneville Dam 2002 brood bright stock, fall chinook emergence began on February 3 2003 and ended 7 May 2003, with peak emergence occurring 20 April. 2002 brood juvenile chum emergence below Bonneville Dam began 27 January and continued through 6 April 2003. Peak chum emergence took place 1 March. A total of 10,925 juvenile chinook and 1,577 juvenile chum were sampled between the dates of 24 January and 21 July 2003 below Bonneville Dam. Juvenile chum migrated from the study area in the 40-55 mm fork length range. Migration of chum occurred during the months of March, April and May. Sampling results suggest fall chinook migration from rearing areas took place during the month of June 2003 when juvenile fall chinook were in the 65 to 80 mm fork length size range. Adult and juvenile sampling below Bonneville Dam provided information to assist in determining the stock of fall chinook and chum spawning and rearing below Bonneville Dam. Based on observed spawning times, adult age and sex composition, juvenile emergence timing, juvenile migration timing and juvenile size at the time of migration, it appears that in 2002 and 2003 the majority of fall chinook using the area below Bonneville Dam were of a late-spawning, bright stock of fall chinook. Observed spawning times, adult age and sex composition, GSI and DNA analysis

  7. Evaluation of Fall Chinook and Chum Salmon Spawning below Bonneville Dam; 2003-2004 Annual Report.

    SciTech Connect

    van der Naald, Wayne; Duff, Cameron; Brooks, Robert

    2005-01-01

    In 2003 a total of 253 adult fall chinook and 113 chum were sampled for biological data in the Ives and Pierce islands area below Bonneville Dam. Vital statistics were developed from 221 fall chinook and 109 chum samples. The peak redd count for fall chinook was 190. The peak redd count for chum was 262. Peak spawning time for fall chinook was set at approximately 24 November. Peak spawning time for chum occurred approximately 24 November. There were estimated to be a total of 1,533 fall chinook spawning below Bonneville Dam in 2003. The study area's 2003 chum population was estimated to be 688 spawning fish. Temperature unit data suggests that below Bonneville Dam 2003 brood bright stock, fall chinook emergence began on January 6, 2004 and ended 28 April 2004, with peak emergence occurring 13 April. 2003 brood juvenile chum emergence below Bonneville Dam began 22 February and continued through 15 April 2004. Peak chum emergence took place 25 March. A total of 25,433 juvenile chinook and 4,864 juvenile chum were sampled between the dates of 20 January and 28 June 2004 below Bonneville Dam. Juvenile chum migrated from the study area in the 40-55 mm fork length range. Migration of chum occurred during the months of March, April and May. Sampling results suggest fall chinook migration from rearing areas took place during the month of June 2004 when juvenile fall chinook were in the 65 to 80 mm fork length size range. Adult and juvenile sampling below Bonneville Dam provided information to assist in determining the stock of fall chinook and chum spawning and rearing below Bonneville Dam. Based on observed spawning times, adult age and sex composition, juvenile emergence timing, juvenile migration timing and juvenile size at the time of migration, it appears that in 2003 all of the fall chinook using the area below Bonneville Dam were of a late-spawning, bright stock. Observed spawning times, adult age and sex composition, GSI and DNA analysis, juvenile emergence timing

  8. Spatial variability of soil properties and soil erodibility in the Alqueva dam watershed, Portugal

    NASA Astrophysics Data System (ADS)

    Ferreira, V.; Panagopoulos, T.; Andrade, R.; Guerrero, C.; Loures, L.

    2015-01-01

    The aim of this work is to investigate how the spatial variability of soil properties and soil erodibility (K factor) were affected by the changes in land use allowed by irrigation with water from a reservoir in a semiarid area. To this, three areas representative of different land uses (agroforestry grassland, Lucerne crop and olive orchard) were studied within a 900 ha farm. The interrelationships between variables were analyzed by multivariate techniques and extrapolated using geostatistics. The results confirmed differences between land uses for all properties analyzed, which was explained mainly by the existence of diverse management practices (tillage, fertilization and irrigation), vegetation cover and local soil characteristics. Soil organic matter, clay and nitrogen content decreased significantly, while K factor increased with intensive cultivation. The HJ-biplot methodology was used to represent the variation of soil erodibility properties grouped in land uses. Native grassland was the least correlated with the other land uses. K factor demonstrated high correlation mainly with very fine sand and silt. The maps produced with geostatistics were crucial to understand the current spatial variability in the Alqueva region. Facing the intensification of land-use conversion, a sustainable management is needed to introduce protective measures to control soil erosion.

  9. Bed load transport formulas in dam break flows

    NASA Astrophysics Data System (ADS)

    Nicolás Cantero-Chinchilla, Francisco; Castro-Orgaz, Oscar; Ayuso-Muñoz, Jose Luis

    2015-04-01

    be investigated in them. Finally, recommendations for using the best bed load transport formulas are given. REFERENCES [1] Fraccarollo, L., & Capart, H. (2002). Riemann wave description of erosional dam-break flows. Journal of Fluid Mechanics, 461, 183-228. [2] Wu, W., & Wang, S. S. (2007). One-dimensional modeling of dam-break flow over movable beds. Journal of hydraulic engineering, 133(1), 48-58. [3] Van Rijn, L. C. (1984). Sediment transport, part I: bed load transport. Journal of hydraulic engineering, 110(10), 1431-1456. [4] García, M. H. (Ed.). (2008). Sedimentation engineering: processes, measurements, modeling, and practice (No. 110). ASCE Publications. [5] Alonso, C. V., Neibling, W. H., & Foster, G. R. (1981). Estimating sediment transport capacity in watershed modeling. Transactions of the ASAE, 24(5).

  10. Adjustment of the San Francisco estuary and watershed to decreasing sediment supply in the 20th century

    USGS Publications Warehouse

    Schoellhamer, David H.; Wright, Scott A.; Drexler, Judith Z.

    2013-01-01

    The general progression of human land use is an initial disturbance (e.g., deforestation, mining, agricultural expansion, overgrazing, and urbanization) that creates a sediment pulse to an estuary followed by dams that reduce sediment supply. We present a conceptual model of the effects of increasing followed by decreasing sediment supply that includes four sequential regimes, which propagate downstream: a stationary natural regime, transient increasing sediment supply, transient decreasing sediment supply, and a stationary altered regime. The model features characteristic lines that separate the four regimes. Previous studies of the San Francisco Estuary and watershed are synthesized in the context of this conceptual model. Hydraulic mining for gold in the watershed increased sediment supply to the estuary in the late 1800s. Adjustment to decreasing sediment supply began in the watershed and upper estuary around 1900 and in the lower estuary in the 1950s. Large freshwater flow in the late 1990s caused a step adjustment throughout the estuary and watershed. It is likely that the estuary and watershed are still capable of adjusting but further adjustment will be as steps that occur only during greater floods than previously experienced during the adjustment period. Humans are actively managing the system to try to prevent greater floods. If this hypothesis of step changes occurring for larger flows is true, then the return interval of step changes will increase or, if humans successfully control floods in perpetuity, there will be no more step changes.

  11. Repeatability and genotypic correlations of reproductive and productive traits of crossbred beef cattle dams.

    PubMed

    Silva, L N; Gasparino, E; Torres Júnior, R A A; Euclides Filho, K; Silva, L O C; Alencar, M M; Souza Júnior, M D; Battistelli, J V F; Silva, S C C

    2015-01-01

    Beef cattle production requires reproductive efficiency. However, measures of reproductive traits are not usually collected; consequently, correlated traits that could be used as indicators would be useful. We examined associations between measures of reproductive and productive efficiency that could be used as selection indicators. Data from 194 dams of the genetic groups Angus x Nelore, Caracu x Nelore, and Valdostana x Nelore collected over 4 years were used. The reproductive traits analyzed were days to heat (DH), calving interval (CI), days to calving (DC), and pregnancy rate (PR). The productive traits were dam weight (DW), body condition score (BCS), calf weight (CW), and weaning rate (WR). The effects on the model were: year, genetic group, reproductive status (RS), age, reproductive rest, and breed of bull (CW and WR). Multivariate analyses were performed, using the Bayesian approach via Gibbs sampling. We conclude that the reproductive measures are ineffective as selection indicators, whereas using dam weight may be a good alternative.

  12. Dental dam patch: an effective intraoral repair technique using cyanoacrylate.

    PubMed

    Liebenberg, W H

    1998-10-01

    Secondary dental dam retention is a critical component of successful dental dam isolation and relates to the provision of an effective seal at the dam/tooth junction. Restorative success can be compromised if this seal is inadvertently interrupted during the operative effort. One such periodic mishap is entanglement of the bur and the interdental dam strip during caries or restorative removal. This invariably results in a gaping interproximal defect in the dam. This article discusses the importance of optimum isolation as it relates to current "wet bonding" adhesive procedures, and introduces a repair technique using a patch of dental dam and cyanoacrylate.

  13. Marmot Dam Removal: Predictions and Observations

    NASA Astrophysics Data System (ADS)

    Cui, Y.; Orr, B. K.; Wilcox, A.; Vick, J.; Podolak, C.; Wilcox, P.

    2008-12-01

    The 14-m tall Marmot Dam on the Sandy River, Oregon was removed in the summer of 2007, allowing the approximately 730,000 cubic meters of sand and gravel to remain in the river for natural erosion by the flow. Pre-dam removal studies included sediment transport modeling that simulated several dam removal alternatives and provided key pieces of information that allowed a diverse stakeholder group to unanimously agree on the "blow-and-go" alternative, allowing a large amount of sediment to be released to a major salmonid-bearing river in the Columbia River basin. Although it is still too early to provide a comprehensive evaluation of the model performance because morphological responses in the downstream reaches, if any, are likely years away, observations to date (one year after dam removal) indicate that model predictions are generally accurate. Here we present some of the key findings of pre-dam-removal sediment transport modeling predictions and compare them with post-removal observations.

  14. Holocene beaver damming, fluvial geomorphology, and climate in Yellowstone National Park, Wyoming

    NASA Astrophysics Data System (ADS)

    Persico, Lyman; Meyer, Grant

    2009-05-01

    We use beaver-pond deposits and geomorphic characteristics of small streams to assess long-term effects of beavers and climate change on Holocene fluvial activity in northern Yellowstone National Park. Although beaver damming has been considered a viable mechanism for major aggradation of mountain stream valleys, this has not been previously tested with stratigraphic and geochronologic data. Thirty-nine radiocarbon ages on beaver-pond deposits fall primarily within the last 4000 yr, but gaps in dated beaver occupation from ~ 2200-1800 and 950-750 cal yr BP correspond with severe droughts that likely caused low to ephemeral discharges in smaller streams, as in modern severe drought. Maximum channel gradient for reaches with Holocene beaver-pond deposits decreases with increasing basin area, implying that stream power limits beaver damming and pond sediment preservation. In northern Yellowstone, the patchy distribution and cumulative thickness of mostly < 2 m of beaver-pond deposits indicate that net aggradation forced by beaver damming is small, but beaver-enhanced aggradation in some glacial scour depressions is greater. Although 20th-century beaver loss and dam abandonment caused significant local channel incision, most downcutting along alluvial reaches of the study streams is unrelated to beaver dam abandonment or predates historic beaver extirpation.

  15. Dams and the fish fauna of the Neotropical region: impacts and management related to diversity and fisheries.

    PubMed

    Agostinho, A A; Pelicice, F M; Gomes, L C

    2008-11-01

    Reservoirs have been built in almost all of the hydrographic basins of Brazil. Their purposes include water supply for cities, irrigation and mainly, generation of electricity. There are more than 700 large dams and associated reservoirs in the large rivers of the country. These reservoirs favor local and regional economic development, but they also bring serious and irreversible alterations in the natural hydrologic regime of rivers, affecting habitat quality and the dynamics of the biota. In the impounded area, the main impact is the change from lotic to lentic water, which influences aquatic fauna, including fishes. Impacts of reservoirs present relevant spatiotemporal variations. Immediately after reservoir formation, fish species richness usually increases due to incorporation of surrounding habitats, but richness decreases as reservoirs age. However, impacts downstream of dams appear to be similar or stronger than those that occur within the reservoir. Dams promote discharge control, altering the seasonal cycles of floods. These effects are augmented when dams are constructed in cascades. Therefore, dams profoundly influence composition and structure of fish assemblages. Most affected species are the rheophilics and long distance migratory that require distinct habitats to fulfill their life cycles. Populations of migratory species may collapse or even disappear in intensely regulated stretches. Management actions taken to minimize impacts of dams in Brazil historically considered construction of fish passages, fishery control and stocking. The results of these actions are questionable and/or with clear failures. In this paper, we give emphasis to the Paraná River basin, the most affected by dams in Brazil. We describe some patterns in the alteration and decline in fish diversity in areas influenced by dams. We also discuss negative consequences in the fishery and ecosystems functioning. Finally, we argue the relevance and the success of the management

  16. Dams and the fish fauna of the Neotropical region: impacts and management related to diversity and fisheries.

    PubMed

    Agostinho, A A; Pelicice, F M; Gomes, L C

    2008-11-01

    Reservoirs have been built in almost all of the hydrographic basins of Brazil. Their purposes include water supply for cities, irrigation and mainly, generation of electricity. There are more than 700 large dams and associated reservoirs in the large rivers of the country. These reservoirs favor local and regional economic development, but they also bring serious and irreversible alterations in the natural hydrologic regime of rivers, affecting habitat quality and the dynamics of the biota. In the impounded area, the main impact is the change from lotic to lentic water, which influences aquatic fauna, including fishes. Impacts of reservoirs present relevant spatiotemporal variations. Immediately after reservoir formation, fish species richness usually increases due to incorporation of surrounding habitats, but richness decreases as reservoirs age. However, impacts downstream of dams appear to be similar or stronger than those that occur within the reservoir. Dams promote discharge control, altering the seasonal cycles of floods. These effects are augmented when dams are constructed in cascades. Therefore, dams profoundly influence composition and structure of fish assemblages. Most affected species are the rheophilics and long distance migratory that require distinct habitats to fulfill their life cycles. Populations of migratory species may collapse or even disappear in intensely regulated stretches. Management actions taken to minimize impacts of dams in Brazil historically considered construction of fish passages, fishery control and stocking. The results of these actions are questionable and/or with clear failures. In this paper, we give emphasis to the Paraná River basin, the most affected by dams in Brazil. We describe some patterns in the alteration and decline in fish diversity in areas influenced by dams. We also discuss negative consequences in the fishery and ecosystems functioning. Finally, we argue the relevance and the success of the management

  17. Anthropocene streams and base-level controls from historic dams in the unglaciated mid-Atlantic region, USA.

    PubMed

    Merritts, Dorothy; Walter, Robert; Rahnis, Michael; Hartranft, Jeff; Cox, Scott; Gellis, Allen; Potter, Noel; Hilgartner, William; Langland, Michael; Manion, Lauren; Lippincott, Caitlin; Siddiqui, Sauleh; Rehman, Zain; Scheid, Chris; Kratz, Laura; Shilling, Andrea; Jenschke, Matthew; Datin, Katherine; Cranmer, Elizabeth; Reed, Austin; Matuszewski, Derek; Voli, Mark; Ohlson, Erik; Neugebauer, Ali; Ahamed, Aakash; Neal, Conor; Winter, Allison; Becker, Steven

    2011-03-13

    Recently, widespread valley-bottom damming for water power was identified as a primary control on valley sedimentation in the mid-Atlantic US during the late seventeenth to early twentieth century. The timing of damming coincided with that of accelerated upland erosion during post-European settlement land-use change. In this paper, we examine the impact of local drops in base level on incision into historic reservoir sediment as thousands of ageing dams breach. Analysis of lidar and field data indicates that historic milldam building led to local base-level rises of 2-5 m (typical milldam height) and reduced valley slopes by half. Subsequent base-level fall with dam breaching led to an approximate doubling in slope, a significant base-level forcing. Case studies in forested, rural as well as agricultural and urban areas demonstrate that a breached dam can lead to stream incision, bank erosion and increased loads of suspended sediment, even with no change in land use. After dam breaching, key predictors of stream bank erosion include number of years since dam breach, proximity to a dam and dam height. One implication of this work is that conceptual models linking channel condition and sediment yield exclusively with modern upland land use are incomplete for valleys impacted by milldams. With no equivalent in the Holocene or late Pleistocene sedimentary record, modern incised stream-channel forms in the mid-Atlantic region represent a transient response to both base-level forcing and major changes in land use beginning centuries ago. Similar channel forms might also exist in other locales where historic milling was prevalent.

  18. Anthropocene streams and base-level controls from historic dams in the unglaciated mid-Atlantic region, USA

    USGS Publications Warehouse

    Merritts, Dorothy; Walter, Robert; Rahnis, Michael; Hartranft, Jeff; Cox, Scott; Gellis, Allen; Potter, Noel; Hilgartner, William; Langland, Michael; Manion, Lauren; Lippincott, Caitlin; Siddiqui, Sauleh; Rehman, Zain; Scheid, Chris; Kratz, Laura; Shilling, Andrea; Jenschke, Matthew; Datin, Katherine; Cranmer, Elizabeth; Reed, Austin; Matuszewski, Derek; Voli, Mark; Ohlson, Erik; Neugebauer, Ali; Ahamed, Aakash; Neal, Conor; Winter, Allison; Becker, Steven

    2011-01-01

    Recently, widespread valley-bottom damming for water power was identified as a primary control on valley sedimentation in the mid-Atlantic US during the late seventeenth to early twentieth century. The timing of damming coincided with that of accelerated upland erosion during post-European settlement land-use change. In this paper, we examine the impact of local drops in base level on incision into historic reservoir sediment as thousands of ageing dams breach. Analysis of lidar and field data indicates that historic milldam building led to local base-level rises of 2-5 m (typical milldam height) and reduced valley slopes by half. Subsequent base-level fall with dam breaching led to an approximate doubling in slope, a significant base-level forcing. Case studies in forested, rural as well as agricultural and urban areas demonstrate that a breached dam can lead to stream incision, bank erosion and increased loads of suspended sediment, even with no change in land use. After dam breaching, key predictors of stream bank erosion include number of years since dam breach, proximity to a dam and dam height. One implication of this work is that conceptual models linking channel condition and sediment yield exclusively with modern upland land use are incomplete for valleys impacted by milldams. With no equivalent in the Holocene or late Pleistocene sedimentary record, modern incised stream-channel forms in the mid-Atlantic region represent a transient response to both base-level forcing and major changes in land use beginning centuries ago. Similar channel forms might also exist in other locales where historic milling was prevalent.

  19. Anthropocene streams and base-level controls from historic dams in the unglaciated mid-Atlantic region, USA.

    PubMed

    Merritts, Dorothy; Walter, Robert; Rahnis, Michael; Hartranft, Jeff; Cox, Scott; Gellis, Allen; Potter, Noel; Hilgartner, William; Langland, Michael; Manion, Lauren; Lippincott, Caitlin; Siddiqui, Sauleh; Rehman, Zain; Scheid, Chris; Kratz, Laura; Shilling, Andrea; Jenschke, Matthew; Datin, Katherine; Cranmer, Elizabeth; Reed, Austin; Matuszewski, Derek; Voli, Mark; Ohlson, Erik; Neugebauer, Ali; Ahamed, Aakash; Neal, Conor; Winter, Allison; Becker, Steven

    2011-03-13

    Recently, widespread valley-bottom damming for water power was identified as a primary control on valley sedimentation in the mid-Atlantic US during the late seventeenth to early twentieth century. The timing of damming coincided with that of accelerated upland erosion during post-European settlement land-use change. In this paper, we examine the impact of local drops in base level on incision into historic reservoir sediment as thousands of ageing dams breach. Analysis of lidar and field data indicates that historic milldam building led to local base-level rises of 2-5 m (typical milldam height) and reduced valley slopes by half. Subsequent base-level fall with dam breaching led to an approximate doubling in slope, a significant base-level forcing. Case studies in forested, rural as well as agricultural and urban areas demonstrate that a breached dam can lead to stream incision, bank erosion and increased loads of suspended sediment, even with no change in land use. After dam breaching, key predictors of stream bank erosion include number of years since dam breach, proximity to a dam and dam height. One implication of this work is that conceptual models linking channel condition and sediment yield exclusively with modern upland land use are incomplete for valleys impacted by milldams. With no equivalent in the Holocene or late Pleistocene sedimentary record, modern incised stream-channel forms in the mid-Atlantic region represent a transient response to both base-level forcing and major changes in land use beginning centuries ago. Similar channel forms might also exist in other locales where historic milling was prevalent. PMID:21282157

  20. The Remains of the Dam: What Have We Learned From 10 Years of Dam Removals?

    NASA Astrophysics Data System (ADS)

    Grant, G. E.; O'Connor, J. E.; Major, J. J.

    2012-12-01

    Over the past 10 years in the U.S., dam removal has evolved from an occasionally implemented, rarely studied, and poorly understood intervention to improve rivers, to a much more frequently accomplished and better studied and understood approach to river restoration. Over that same time period, the numbers and sizes of dams and volumes of sediment released have dramatically increased. By some estimates close to 1000 dams have been removed over the last 100 years, with most of those occurring within the last 10. While most of these are small (less than 15 m high) dams, removals of dams up to 70 m high are presently underway. Releases of sediment associated with these removals over the past 10 years have also increased by close to four orders of magnitude; for example removal of the Elwha River dams in Washington is estimated to release almost 107 m3 of sediment into the lower Elwha River. Given a decade's worth of dam removals and, in some cases, well-orchestrated case studies of the effects of removal on the geomorphology and (to a lesser extent) ecology of rivers, what have we learned? More specifically, where do we now stand with respect to being able to predict the consequences of future dam removals? Drawing on both field examples and numerical models of dam removals in the western U.S., several key lessons stand out. Although every dam removal and river are different, removals initiate very rapid upstream river response and reservoir erosion and evacuation of sediment by various mechanisms that are strongly controlled by grain size of the deposit, volumes of residual sediment relative to total reservoir volume, and style of dam removal (instantaneous versus staged). Erosion of sediment accumulations in fully and partially filled (by sediment) reservoirs proceeds by different trajectories and rates, with full reservoirs releasing sediment primarily by upstream knickpoint retreat while erosion and sediment release in partially-filled reservoirs proceeds by

  1. Sediment budget variation at watershed scale due to anthropogenic pressures, and its relationship to coastal erosion

    NASA Astrophysics Data System (ADS)

    Aiello, Antonello; Adamo, Maria; Canora, Filomena

    2014-05-01

    The transfer of sediments from hydrographic basins towards the coast is a significant pathway of material transfer on Earth. In sedimentary environment, the main portion of sediment that enters the coastal areas is derived originally from erosion in the coastal watersheds. Extensive anthropogenic pressures carried out within coastal basins have long shown negative impacts on littoral environments. In fluvial systems, sediments trapped behind dams and in-stream gravel mining cause the reduction in sediment supply to the coast. Along the Jonian littoral of the Basilicata Region (southern Italy), natural coastal processes have been severely disrupted since the second half of the 20th century as a result of riverbed sand and gravel mining and dam construction, when economic advantages were measured in terms of the development of infrastructure, water storage, and hydropower production for the agricultural, industrial and socio-economic development of the area. Particularly, the large numbers of dams and impoundments that have been built in the hydrographic basins have led a signi?cant reduction on river sediment loads. As a result, the Jonian littoral is experiencing a catalysed erosion phenomenon. In order to increase understanding of the morpho-dynamics of the Jonian littoral environment and more fully appreciate the amount of coastal erosion, an evaluation of the sediment budget change due to dam construction within the hydrographic basins of the Basilicata Region needs to be explored. Since quantitative data on decadal trends in river sediment supply before and after dam construction are lacking, as well as updated dam silting values, river basin assessment of the spatial patterns and estimated amount of sediment erosion and deposition are important in evaluating changes in the sediment budget. As coastal areas are being affected by an increasing number of population and socio-economic activities, the amount of sediment deficit at the littoral can permit to

  2. Impact of Artificial Reservoir Size and Land Use Land Cover on Probable Maximum Flood: The case of Folsom Dam on American River

    NASA Astrophysics Data System (ADS)

    Yigzaw, W. Y.; Hossain, F.

    2012-12-01

    The design of the dams usually considers available historical data for analysis of the flood frequency. The limitation of this approach is the potential shift in flood frequency due to physically plausible factors that cannot be foreseen during design. For example, future flood extremes may change, among other factors, due to strong local atmospheric feedbacks from the reservoir and surrounding land use and land cover (LULC). Probable Maximum Flood (PMF), which is the key design parameter for hydraulic features of a dam, is estimated from Probable Maximum Precipitation (PMP) and the hydrology of the watershed. Given the non-linearity of the rainfall-runoff process, a key question that needs to be answered is "How do reservoir size and/or LULC modify extreme flood patterns, specifically probable maximum flood?" Using the American River Watershed (ARW) as a representative example of an impounded watershed with a large artificial reservoir (i.e., Folsom Dam), this study applied the distributed Variable Infiltration Capacity (VIC) model to simulate the PMF from the atmospheric feedbacks simulated for various LULC scenarios. The atmospheric feedbacks were simulated numerically as PMP using the Regional Atmospheric Modeling System (RAMS). The RAMS-generated PMP scenarios were propagated through the VIC model to simulate the PMFs. Comparison of PMF results for Pre-dam and Current Scenario conditions showed that PMF peak flow can decrease by about 105 m3/s; while comparison of Current Scenario with Non-irrigation PMF results showed that irrigation development has increased the PMF by 125m3/s. On the other hand, the reservoir size had virtually no detectable impact on PMP and consequently on PMF results. Where downstream levee capacity is already under-designed to handle a dam's spillway capacity, such as for the case study, such increases indicate a likely impact on downstream flood risk that any flood management protocol must adapt to. The premise that modern dam design

  3. Effects of nutrient restriction of bovine dams during early gestation on postnatal growth, carcass and organ characteristics, and gene expression in adipose tissue and muscle.

    PubMed

    Long, N M; Prado-Cooper, M J; Krehbiel, C R; DeSilva, U; Wettemann, R P

    2010-10-01

    Angus x Hereford heifers (15 mo and artificially inseminated to a single sire) were used to evaluate the effect of prenatal nutritional restriction on postnatal growth and development. At d 32 of gestation, dams were stratified by BW and BCS and allotted to a low-nutrition [55% of NRC (1996) requirements, n = 10] or moderate-nutrition [100% of NRC (1996) requirements, n = 10] diet. After 83 d of feeding, dams were commingled and received a diet in excess of requirements. Dams were allowed to calve naturally, and birth weights and growth of calves were recorded. Bulls were castrated at birth. Steers (16 mo of age, 5 per treatment) received a high-concentrate diet ad libitum to a constant age (88 ± 1 wk). Steers were slaughtered and weights of the empty body and organs were recorded. Samples of organs, muscle (complexus), and perirenal and subcutaneous adipose tissue were stored at -80 degrees C, and then DNA and protein concentrations were quantified and expression of genes associated with fatty acid metabolism and glucose uptake were measured in adipose and muscle tissue. Dams had similar (P > 0.33) BW and BCS at the beginning of the experiment. At the end of restriction, dams on the low-nutrition diet weighed less (P ≤ 0.01) and had less BCS (P < 0.001) than those on the moderate-nutrition diet. Length of gestation was 274 ± 2 d for dams in the low-nutrition treatment and 278 ± 2 d (P = 0.05) for dams in the moderate-nutrition treatment. Nutrient restriction during gestation did not influence birth weight or postnatal growth of calves. Lungs and trachea of steers whose dams were fed the low-nutrition diet weighed less (P = 0.05) at slaughter than those of steers whose dams were fed the moderate-nutrition diet; weights of other organs were not influenced by treatment. Complexus muscle from steers whose dams were fed the low-nutrition diet had a greater (P = 0.04) concentration of DNA and larger muscle fiber area compared with steers whose dams were fed the

  4. Developing a geomorphic approach for ranking watersheds for rehabilitation, Zuni Indian Reservation, New Mexico

    NASA Astrophysics Data System (ADS)

    Gellis, Allen C.; Cheama, Andres; Lalio, Sheldon M.

    2001-03-01

    As a result of past erosion problems on the Zuni Indian Reservation in western New Mexico, the US Congress in 1990 authorized the Zuni Tribe to begin a program for watershed rehabilitation. This paper describes an approach to rank the most appropriate watersheds for rehabilitation for the Zuni Reservation. The approach was based on data collected during a 3-year study on geomorphic and anthropogenic characteristics of the Rio Nutria Watershed, including data on (i) arroyo cross-sectional changes, (ii) erosion-control structures, and (iii) sheetwash erosion. Results of this 3-year study indicated that 61 of 85 channel cross-sections aggraded and channels with lower width-to-depth ratios eroded. Results on assessment of erosion-control structures, some dating back to the 1930s, indicated that 60% of earthen dams and 22% of rock-and-brush structures were breached or flanked in the Rio Nutria Watershed. Sheetwash erosion measured on five land-cover sites (sagebrush, pasture, chained piñon and juniper, unchained piñon and juniper, and ponderosa pine) indicated chained piñon and juniper sites and pasture sites had the highest volume-weighted sediment concentrations of 13,000 and 9970 ppm, respectively. Based on interpretations of the 3-year study in the Rio Nutria Watershed, a two-stage approach was developed to rank the most appropriate watersheds for rehabilitation on the Zuni Reservation. In the first stage, the reservation was divided into eight major watersheds, which were ranked according to the most potential for erosion. In the second stage, the watershed with the most potential for erosion was divided into sub-basins, which were ranked according to the most potential for erosion. Quantitative and qualitative information on physical and anthropogenic factors were used at each stage to rank the watersheds. Quantitative physical data included headcut density, percentage of bare ground, percentage of chained area, channel width-to-depth ratio, change in channel

  5. Toward policies and decision-making for dam removal.

    PubMed

    Doyle, Martin W; Harbor, Jon M; Stanley, Emily H

    2003-04-01

    Dam removal has emerged as a critical issue in environmental management. Agencies responsible for dams face a drastic increase in the number of potential dam removals in the near future. Given limited resources, these agencies need to develop ways to decide which dams should be removed and in what order. The underlying science of dam removal is relatively undeveloped and most agencies faced with dam removal lack a coherent purpose for removing dams. These shortcomings can be overcome by the implementation of two policies by agencies faced with dam removal: (1) the development and adoption of a prioritization scheme for what constitutes an important dam removal, and (2) the establishment of minimum levels of analysis prior to decision-making about a dam removal. Federal and state agencies and the scientific community must encourage an initial experimental phase of dam removal during which only a few dams are removed, and these are studied intensively. This will allow for the development of the fundamental scientific understanding needed to support effective decision-making in the future and minimize the risk of disasters arising from poorly thought out dam removal decisions. PMID:12677292

  6. Toward policies and decision-making for dam removal.

    PubMed

    Doyle, Martin W; Harbor, Jon M; Stanley, Emily H

    2003-04-01

    Dam removal has emerged as a critical issue in environmental management. Agencies responsible for dams face a drastic increase in the number of potential dam removals in the near future. Given limited resources, these agencies need to develop ways to decide which dams should be removed and in what order. The underlying science of dam removal is relatively undeveloped and most agencies faced with dam removal lack a coherent purpose for removing dams. These shortcomings can be overcome by the implementation of two policies by agencies faced with dam removal: (1) the development and adoption of a prioritization scheme for what constitutes an important dam removal, and (2) the establishment of minimum levels of analysis prior to decision-making about a dam removal. Federal and state agencies and the scientific community must encourage an initial experimental phase of dam removal during which only a few dams are removed, and these are studied intensively. This will allow for the development of the fundamental scientific understanding needed to support effective decision-making in the future and minimize the risk of disasters arising from poorly thought out dam removal decisions.

  7. Water-quality study of proposed reregulation dam downstream of Wolf Creek Dam, Cumberland River, Kentucky. Final report

    SciTech Connect

    Martin, J.L.

    1986-03-01

    This report describes the application of an unsteady, one-dimensional water-quality model to the Cumberland River below Wolf Creek Dam, Kentucky. A hydropower upgrade of Wolf Creek Dam and construction of a reregulation dam, located approximately 10 miles below Wolf Creek Dam, are under consideration. Simulations were conducted under unreregulated conditions and projected conditions following impoundment to provide information concerning the effect of the reregulation dam on water quality in the Cumberland River. Under the conditions simulated, the reregulation dam was predicted to have little impact on temporally averaged water temperatures or dissolved-oxygen concentrations. Temporal variations in water temperatures were retarded under reregulation conditions.

  8. Channel changes downstream from a dam

    USGS Publications Warehouse

    Hadley, R.F.; Emmett, W.W.

    1998-01-01

    A flood-control dam was completed during 1979 on Bear Creek, a small tributary stream to the South Platte River in the Denver, Colorado, area. Before and after dam closure, repetitive surveys between 1977 and 1992 at five cross sections downstream of the dam documented changes in channel morphology. During this 15-year period, channel width increased slightly, but channel depth increased by more than 40 percent. Within the study reach, stream gradient decreased and median bed material sizes coarsened from sand in the pools and fine gravel on the riffle to a median coarse gravel throughout the reach. The most striking visual change was from a sparse growth of streamside grasses to a dense growth of riparian woody vegetation.

  9. International small dam safety assurance policy benchmarks to avoid dam failure flood disasters in developing countries

    NASA Astrophysics Data System (ADS)

    Pisaniello, John D.; Dam, Tuyet Thi; Tingey-Holyoak, Joanne L.

    2015-12-01

    In developing countries small dam failure disasters are common yet research on their dam safety management is lacking. This paper reviews available small dam safety assurance policy benchmarks from international literature, synthesises them for applicability in developing countries, and provides example application through a case study of Vietnam. Generic models from 'minimum' to 'best' practice (Pisaniello, 1997) are synthesised with the World Bank's 'essential' and 'desirable' elements (Bradlow et al., 2002) leading to novel policy analysis and design criteria for developing countries. The case study involved 22 on-site dam surveys finding micro level physical and management inadequacies that indicates macro dam safety management policy performs far below the minimum benchmark in Vietnam. Moving assurance policy towards 'best practice' is necessary to improve the safety of Vietnam's considerable number of hazardous dams to acceptable community standards, but firstly achieving 'minimum practice' per the developed guidance is essential. The policy analysis/design process provides an exemplar for other developing countries to follow for avoiding dam failure flood disasters.

  10. Adapting Dam and Reservoir Design and Operations to Climate Change

    NASA Astrophysics Data System (ADS)

    Roy, René; Braun, Marco; Chaumont, Diane

    2013-04-01

    In order to identify the potential initiatives that the dam, reservoir and water resources systems owners and operators may undertake to cope with climate change issues, it is essential to determine the current state of knowledge of their impacts on hydrological variables at regional and local scales. Future climate scenarios derived from climate model simulations can be combined with operational hydrological modeling tools and historical observations to evaluate realistic pathways of future hydrological conditions for specific drainage basins. In the case of hydropower production those changes in hydrological conditions may have significant economic impacts. For over a decade the state owned hydropower producer Hydro Québec has been exploring the physical impacts on their watersheds by relying on climate services in collaboration with Ouranos, a consortium on regional climatology and adaptation to climate change. Previous climate change impact analysis had been including different sources of climate simulation data, explored different post-processing approaches and used hydrological impact models. At a new stage of this collaboration the operational management of Hydro Quebec aspired to carry out a cost-benefit analysis of considering climate change in the refactoring of hydro-power installations. In the process of the project not only a set of scenarios of future runoff regimes had to be defined to support long term planning decisions of a dam and reservoir operator, but also the significance of uncertainties needed to be communicated and made understood. We provide insight into a case study that took some unexpected turns and leaps by bringing together climate scientists, hydrologists and hydro-power operation managers. The study includes the selection of appropriate climate scenarios, the correction of biases, the application of hydrological models and the assessment of uncertainties. However, it turned out that communicating the science properly and

  11. Accounting for unknown foster dams in the genetic evaluation of embryo transfer progeny.

    PubMed

    Suárez, M J; Munilla, S; Cantet, R J C

    2015-02-01

    Animals born by embryo transfer (ET) are usually not included in the genetic evaluation of beef cattle for preweaning growth if the recipient dam is unknown. This is primarily to avoid potential bias in the estimation of the unknown age of dam. We present a method that allows including records of calves with unknown age of dam. Assumptions are as follows: (i) foster cows belong to the same breed being evaluated, (ii) there is no correlation between the breeding value (BV) of the calf and the maternal BV of the recipient cow, and (iii) cows of all ages are used as recipients. We examine the issue of bias for the fixed level of unknown age of dam (AOD) and propose an estimator of the effect based on classical measurement error theory (MEM) and a Bayesian approach. Using stochastic simulation under random mating or selection, the MEM estimating equations were compared with BLUP in two situations as follows: (i) full information (FI); (ii) missing AOD information on some dams. Predictions of breeding value (PBV) from the FI situation had the smallest empirical average bias followed by PBV obtained without taking measurement error into account. In turn, MEM displayed the highest bias, although the differences were small. On the other hand, MEM showed the smallest MSEP, for either random mating or selection, followed by FI, whereas ignoring measurement error produced the largest MSEP. As a consequence from the smallest MSEP with a relatively small bias, empirical accuracies of PBV were larger for MEM than those for full information, which in turn showed larger accuracies than the situation ignoring measurement error. It is concluded that MEM equations are a useful alternative for analysing weaning weight data when recipient cows are unknown, as it mitigates the effects of bias in AOD by decreasing MSEP.

  12. Accounting for unknown foster dams in the genetic evaluation of embryo transfer progeny.

    PubMed

    Suárez, M J; Munilla, S; Cantet, R J C

    2015-02-01

    Animals born by embryo transfer (ET) are usually not included in the genetic evaluation of beef cattle for preweaning growth if the recipient dam is unknown. This is primarily to avoid potential bias in the estimation of the unknown age of dam. We present a method that allows including records of calves with unknown age of dam. Assumptions are as follows: (i) foster cows belong to the same breed being evaluated, (ii) there is no correlation between the breeding value (BV) of the calf and the maternal BV of the recipient cow, and (iii) cows of all ages are used as recipients. We examine the issue of bias for the fixed level of unknown age of dam (AOD) and propose an estimator of the effect based on classical measurement error theory (MEM) and a Bayesian approach. Using stochastic simulation under random mating or selection, the MEM estimating equations were compared with BLUP in two situations as follows: (i) full information (FI); (ii) missing AOD information on some dams. Predictions of breeding value (PBV) from the FI situation had the smallest empirical average bias followed by PBV obtained without taking measurement error into account. In turn, MEM displayed the highest bias, although the differences were small. On the other hand, MEM showed the smallest MSEP, for either random mating or selection, followed by FI, whereas ignoring measurement error produced the largest MSEP. As a consequence from the smallest MSEP with a relatively small bias, empirical accuracies of PBV were larger for MEM than those for full information, which in turn showed larger accuracies than the situation ignoring measurement error. It is concluded that MEM equations are a useful alternative for analysing weaning weight data when recipient cows are unknown, as it mitigates the effects of bias in AOD by decreasing MSEP. PMID:25316505

  13. Optimizing the dammed: water supply losses and fish habitat gains from dam removal in California.

    PubMed

    Null, Sarah E; Medellín-Azuara, Josué; Escriva-Bou, Alvar; Lent, Michelle; Lund, Jay R

    2014-04-01

    Dams provide water supply, flood protection, and hydropower generation benefits, but also harm native species by altering the natural flow regime and degrading aquatic and riparian habitat. Restoring some rivers reaches to free-flowing conditions may restore substantial environmental benefits, but at some economic cost. This study uses a systems analysis approach to preliminarily evaluate removing rim dams in California's Central Valley to highlight promising habitat and unpromising economic use tradeoffs for water supply and hydropower. CALVIN, an economic-engineering optimization model, is used to evaluate water storage and scarcity from removing dams. A warm and dry climate model for a 30-year period centered at 2085, and a population growth scenario for year 2050 water demands represent future conditions. Tradeoffs between hydropower generation and water scarcity to urban, agricultural, and instream flow requirements were compared with additional river kilometers of habitat accessible to anadromous fish species following dam removal. Results show that existing infrastructure is most beneficial if operated as a system (ignoring many current institutional constraints). Removing all rim dams is not beneficial for California, but a subset of existing dams are potentially promising candidates for removal from an optimized water supply and free-flowing river perspective. Removing individual dams decreases statewide delivered water by 0-2282 million cubic meters and provides access to 0 to 3200 km of salmonid habitat upstream of dams. The method described here can help prioritize dam removal, although more detailed, project-specific studies also are needed. Similarly, improving environmental protection can come at substantially lower economic cost, when evaluated and operated as a system.

  14. Dam failure analysis for the Lago de Matrullas Dam, Orocovis, Puerto Rico

    USGS Publications Warehouse

    Torres-Sierra, Heriberto; Gómez-Fragoso, Julieta

    2015-01-01

    Results from the simulated dam failure of the Lago de Matrullas Dam using the HEC–RAS model for the 6- and 24-hour PMP events showed peak discharges at the dam of 3,149.33 and 3,604.70 m3/s, respectively. Dam failure during the 100-year-recurrence, 24-hour rainfall event resulted in a peak discharge of 2,103.12 m3/s directly downstream from the dam. Dam failure under sunny day conditions produced a peak discharge of 1,695.91 m3/s at the dam assuming the antecedent lake level was at the morning-glory spillway invert elevation. Flood-inundation maps prepared as part of the study depict the flood extent and provide valuable information for preparing an Emergency Action Plan. Results of the failure analysis indicate that a failure of the Lago de Matrullas Dam could cause flooding to many of the inhabited areas along stream banks from the Lago de Matrullas Dam to the mouth of the Río Grande de Manatí. Among the areas most affected are the low-lying regions in the vicinity of the towns of Ciales, Manatí, and Barceloneta. The delineation of the flood boundaries near the town of Barceloneta considered the effects of a levee constructed during 2000 at Barceloneta in the flood plain of the Río Grande de Manatí to provide protection against flooding to the near-by low-lying populated areas. The results showed overtopping can be expected in the aforementioned levee during 6- and 2

  15. Optimizing the dammed: water supply losses and fish habitat gains from dam removal in California.

    PubMed

    Null, Sarah E; Medellín-Azuara, Josué; Escriva-Bou, Alvar; Lent, Michelle; Lund, Jay R

    2014-04-01

    Dams provide water supply, flood protection, and hydropower generation benefits, but also harm native species by altering the natural flow regime and degrading aquatic and riparian habitat. Restoring some rivers reaches to free-flowing conditions may restore substantial environmental benefits, but at some economic cost. This study uses a systems analysis approach to preliminarily evaluate removing rim dams in California's Central Valley to highlight promising habitat and unpromising economic use tradeoffs for water supply and hydropower. CALVIN, an economic-engineering optimization model, is used to evaluate water storage and scarcity from removing dams. A warm and dry climate model for a 30-year period centered at 2085, and a population growth scenario for year 2050 water demands represent future conditions. Tradeoffs between hydropower generation and water scarcity to urban, agricultural, and instream flow requirements were compared with additional river kilometers of habitat accessible to anadromous fish species following dam removal. Results show that existing infrastructure is most beneficial if operated as a system (ignoring many current institutional constraints). Removing all rim dams is not beneficial for California, but a subset of existing dams are potentially promising candidates for removal from an optimized water supply and free-flowing river perspective. Removing individual dams decreases statewide delivered water by 0-2282 million cubic meters and provides access to 0 to 3200 km of salmonid habitat upstream of dams. The method described here can help prioritize dam removal, although more detailed, project-specific studies also are needed. Similarly, improving environmental protection can come at substantially lower economic cost, when evaluated and operated as a system. PMID:24594701

  16. Wind River Watershed Restoration 2004-2005 Annual Report.

    SciTech Connect

    Connolly, Patrick J.; Jezorek, Ian G.

    2008-11-10

    ) tags to track growth and movement of individuals. We snorkeled nine stream sections during 2004. Juvenile steelhead populations have varied greatly between streams and between years. Numbers of age-0 steelhead have increased substantially since 2000 within the MINE reach (rkm 35.0-40.0) section of the upper Wind River. Because of potential negative interactions with steelhead, naturally spawned populations of introduced juvenile Chinook salmon are of concern in the mainstem of the Wind River. During 2004, we deployed over 3,000 PIT tags in the Wind River subbasin, primarily in juvenile steelhead, but also in juvenile Chinook. We are compiling a dataset of recapture information on these tagged fish as well as interrogation information from Bonneville Dam and other sites. The habitat and fish data collected have been used in Ecosystem Diagnosis and Treatment modeling efforts, the Wind River Subbasin Plan, and the Total Maximum Daily Load report from Washington Department of Ecology. Continued monitoring of changes in habitat, combined with data on fish populations, will help guide planning efforts of land and fish managers. As long-term active and passive restoration actions are implemented in the Wind River and its tributaries, these data will provide the ability to measure change. Because the Wind River subbasin has no steelhead hatchery or supplementation, these data will be useful to compare population trends in subbasins with hatchery or supplementation management.

  17. Lac Courte Oreilles Hydro Dam Assessment

    SciTech Connect

    Weaver, Jason; Meyers, Amy

    2014-12-31

    The main objective of this project was to investigate upgrading the existing hydro power generating system at the Winter Dam. The tribe would like to produce more energy and receive a fair market power purchase agreement so the dam is no longer a drain on our budget but a contributor to our economy. We contracted Kiser Hydro, LLC Engineering for this project and received an engineering report that includes options for producing more energy with cost effective upgrades to the existing turbines. Included in this project was a negotiation of energy price sales negotiations.

  18. Vegetation distribution pattern in the dam areas along middle-low reach of Lancang-Mekong River in Yunnan Province, China

    NASA Astrophysics Data System (ADS)

    Li, Jinpeng; Dong, Shikui; Peng, Mingchun; Li, Xiaoyan; Liu, Shiliang

    2012-09-01

    Lancang-Mekong River Basin is one of ecoregions with rich biodiversity and high ecological values in the world. The basin has been strongly affected by human activities, particularly by dam construction. This study was conducted to investigate the vegetation distribution patterns in the dam areas along middle-low reach of the Lancang-Mekong River in Yunnan Province of China, where eight cascade dams have been planned or are being constructed. To identify the vegetation composition and structure, we sampled 126 quadrats along the transects arrayed vertically to both side of river channel from the year of 2004 to 2010. We found that the forest, shrub and grass communities were widely spread along the riverside. In low reach watershed of the Lancang-Mekong River, the dominated vegetations were grasses and shrubs which were severely disturbed by human activity. In middle reach of the Lancang-Mekong River, the dry-hot valley vegetation was found in the low valley. At high altitude, the pine forest and semi-evergreen seasonal forest were found. As a result of dam construction and operation, the structure and compositions of riparian vegetation were strongly changed. Some plants declined or disappeared due to the alteration of their habitats. The protection or restoration interventions are urgently needed to mitigate the risk of vegetation damage associated with dam projects along middle and low reach of the Lancang-Mekong River.

  19. A Watershed Integrity Definition and Assessment Approach to Support Strategic Management of Watersheds

    EPA Science Inventory

    Although defined hydrologically as a drainage basin, watersheds are systems that physically link the individual social and ecological attributes that comprise them. Hence the structure, function, and feedback systems of watersheds are dependent on interactions between these soci...

  20. Restore McComas Watershed; Meadow Creek Watershed, 2002-2003 Annual Report.

    SciTech Connect

    McRoberts, Heidi

    2004-01-01

    The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Meadow Creek watershed are coordinated with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Meadow Creek watershed of the South Fork Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing. During years 2000-2003, trees were planted in riparian areas within the meadow and its tributaries. Culverts have been prioritized for replacement to accommodate fish passage throughout the watershed. Designs for replacement are being coordinated with the Nez Perce National Forest. Twenty miles of road were contracted for decommissioning. Tribal crews completed maintenance to the previously built fence.

  1. Comparison of mercury mass loading in streams to atmospheric deposition in watersheds of Western North America: Evidence for non-atmospheric mercury sources.

    PubMed

    Domagalski, Joseph; Majewski, Michael S; Alpers, Charles N; Eckley, Chris S; Eagles-Smith, Collin A; Schenk, Liam; Wherry, Susan

    2016-10-15

    Annual stream loads of mercury (Hg) and inputs of wet and dry atmospheric Hg deposition to the landscape were investigated in watersheds of the Western United States and the Canadian-Alaskan Arctic. Mercury concentration and discharge data from flow gauging stations were used to compute annual mass loads with regression models. Measured wet and modeled dry deposition were compared to annual stream loads to compute ratios of Hg stream load to total Hg atmospheric deposition. Watershed land uses or cover included mining, undeveloped, urbanized, and mixed. Of 27 watersheds that were investigated, 15 had some degree of mining, either of Hg or precious metals (gold or silver), where Hg was used in the amalgamation process. Stream loads in excess of annual Hg atmospheric deposition (ratio>1) were observed in watersheds containing Hg mines and in relatively small and medium-sized watersheds with gold or silver mines, however, larger watersheds containing gold or silver mines, some of which also contain large dams that trap sediment, were sometimes associated with lower load ratios (<0.2). In the non-Arctic regions, watersheds with natural vegetation tended to have low ratios of stream load to Hg deposition (<0.1), whereas urbanized areas had higher ratios (0.34-1.0) because of impervious surfaces. This indicated that, in ecosystems with natural vegetation, Hg is retained in the soil and may be transported subsequently to streams as a result of erosion or in association with dissolved organic carbon. Arctic watersheds (Mackenzie and Yukon Rivers) had a relatively elevated ratio of stream load to atmospheric deposition (0.27 and 0.74), possibly because of melting glaciers or permafrost releasing previously stored Hg to the streams. Overall, our research highlights the important role of watershed characteristics in determining whether a landscape is a net source of Hg or a net sink of atmospheric Hg. PMID:27015962

  2. Comparison of mercury mass loading in streams to atmospheric deposition in watersheds of Western North America: Evidence for non-atmospheric mercury sources.

    PubMed

    Domagalski, Joseph; Majewski, Michael S; Alpers, Charles N; Eckley, Chris S; Eagles-Smith, Collin A; Schenk, Liam; Wherry, Susan

    2016-10-15

    Annual stream loads of mercury (Hg) and inputs of wet and dry atmospheric Hg deposition to the landscape were investigated in watersheds of the Western United States and the Canadian-Alaskan Arctic. Mercury concentration and discharge data from flow gauging stations were used to compute annual mass loads with regression models. Measured wet and modeled dry deposition were compared to annual stream loads to compute ratios of Hg stream load to total Hg atmospheric deposition. Watershed land uses or cover included mining, undeveloped, urbanized, and mixed. Of 27 watersheds that were investigated, 15 had some degree of mining, either of Hg or precious metals (gold or silver), where Hg was used in the amalgamation process. Stream loads in excess of annual Hg atmospheric deposition (ratio>1) were observed in watersheds containing Hg mines and in relatively small and medium-sized watersheds with gold or silver mines, however, larger watersheds containing gold or silver mines, some of which also contain large dams that trap sediment, were sometimes associated with lower load ratios (<0.2). In the non-Arctic regions, watersheds with natural vegetation tended to have low ratios of stream load to Hg deposition (<0.1), whereas urbanized areas had higher ratios (0.34-1.0) because of impervious surfaces. This indicated that, in ecosystems with natural vegetation, Hg is retained in the soil and may be transported subsequently to streams as a result of erosion or in association with dissolved organic carbon. Arctic watersheds (Mackenzie and Yukon Rivers) had a relatively elevated ratio of stream load to atmospheric deposition (0.27 and 0.74), possibly because of melting glaciers or permafrost releasing previously stored Hg to the streams. Overall, our research highlights the important role of watershed characteristics in determining whether a landscape is a net source of Hg or a net sink of atmospheric Hg.

  3. 3. POOL, DAM, AND INTAKE TO PIPELINE LEADING TO FISH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. POOL, DAM, AND INTAKE TO PIPELINE LEADING TO FISH WHEEL, LOOKING WEST-NORTHWEST. - Santa Ana River Hydroelectric System, Bear Creek Diversion Dam & Confluence Pool, Redlands, San Bernardino County, CA

  4. 1. SNAKE RIVER VALLEY IRRIGATION DISTRICT DAM, VIEW OF NORTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SNAKE RIVER VALLEY IRRIGATION DISTRICT DAM, VIEW OF NORTH ELEVATION OF INTAKE ON EAST SIDE OF DAM - Snake River Valley Irrigation District, East Side of Snake River (River Mile 796), Shelley, Bingham County, ID

  5. 5. VIEW SHOWING THE DOWNSTREAM SIDE OF SWAN FALLS DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW SHOWING THE DOWNSTREAM SIDE OF SWAN FALLS DAM AND POWER HOUSE, LOOKING UPSTREAM TO SOUTH FROM THE A MOUND OF DEBRIS ABOUT THIRTY TO FORTY FEET ABOVE THE RIVER - Swan Falls Dam, Snake River, Kuna, Ada County, ID

  6. 21. THE WHITNEY CONSTRUCTION CAMP AT THE DIVERSION DAM, FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. THE WHITNEY CONSTRUCTION CAMP AT THE DIVERSION DAM, FACING SOUTH. WOOD BURNING PLANT AT RIGHT, INTAKE GATES AT CENTER LEFT. Photographer: Walter J. Lubken, June 13, 1906 - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  7. 44. Reinforcement construction to Pleasant Dam. Photographer unknown, 1935. Source: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Reinforcement construction to Pleasant Dam. Photographer unknown, 1935. Source: Huber Collection, University of California, Berkeley, Water Resources Library. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  8. View of upstream face of Grand Coulee Dam, looking northeast. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of upstream face of Grand Coulee Dam, looking northeast. This image features a cloudless sky.) - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  9. 7. Detail view of reinforced concrete archrings comprising dam's upstream ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Detail view of reinforced concrete arch-rings comprising dam's upstream face. Impressions of the wooden formwork used in construction are visible in the concrete. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  10. 78. PALMDALE WATER COMPANY, LITTLEROCK DAM, EASTWOOD MULTIPLEARCHED TYPE: DIMENSIONS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    78. PALMDALE WATER COMPANY, LITTLEROCK DAM, EASTWOOD MULTIPLE-ARCHED TYPE: DIMENSIONS, SECTION THROUGH ARCH RING, SHEET 5; OCTOBER 2, 1919. Littlerock Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  11. 81. PALMDALE WATER COMPANY, LITTLE ROCK DAM: REINFORCEMENT, SECTION THROUGH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    81. PALMDALE WATER COMPANY, LITTLE ROCK DAM: REINFORCEMENT, SECTION THROUGH ARCH RING, AMENDED SHEET 6; SEPTEMBER, 1922. Palmdale Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  12. PALMDALE WATER COMPANY, LITTLE ROCK DAM: REINFORCEMENT, SECTION THROUGH ARCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PALMDALE WATER COMPANY, LITTLE ROCK DAM: REINFORCEMENT, SECTION THROUGH ARCH RING, AMENDED SHEET 6; SEPTEMBER, 1922. Palmdale Water District files - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  13. 80. LITTLE ROCK DAM: DIMENSIONS, SECTION THROUGH ARCH RING, AMENDED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    80. LITTLE ROCK DAM: DIMENSIONS, SECTION THROUGH ARCH RING, AMENDED SHEET 5; SEPTEMBER, 1922. Palmdale Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  14. 2. VIEW EAST OF HEADGATES AT SPOOL DAM; DRAIN GATE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW EAST OF HEADGATES AT SPOOL DAM; DRAIN GATE MECHANISM AND DAM EDGE AT RIGHT - Willimantic Linen Company, Mill No. 1, Immediately West of South Main Street, North Bank of Willimantic River, Windham, Windham County, CT

  15. 1. VIEW NORTH, SOUTH FACE OF DAM AT RIGHT CENTER, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW NORTH, SOUTH FACE OF DAM AT RIGHT CENTER, HEADGATES AND CANAL AT LEFT - Dayville Mills Hydroelectric Facility, Dam, North side of Route 101, .5 mile west of Route 395, Killingly Center, Windham County, CT

  16. 3. VIEW SOUTHEAST, WEST END OF DAM AT LEFT CENTER, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW SOUTHEAST, WEST END OF DAM AT LEFT CENTER, HEADGATE STRUCTURE AT CENTER - Dayville Mills Hydroelectric Facility, Dam, North side of Route 101, .5 mile west of Route 395, Killingly Center, Windham County, CT

  17. 2. VIEW EAST, WEST END OF DAM AT CENTER, HEADGATE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW EAST, WEST END OF DAM AT CENTER, HEADGATE OPERATING MECHANISMS AT LEFT - Dayville Mills Hydroelectric Facility, Dam, North side of Route 101, .5 mile west of Route 395, Killingly Center, Windham County, CT

  18. 10. Downstream face of Mormon Flat Dam under construction. Cement ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Downstream face of Mormon Flat Dam under construction. Cement storage shed is at center right. Photographer unknown, September 1924. Source: Salt River Project. - Mormon Flat Dam, On Salt River, Eastern Maricopa County, east of Phoenix, Phoenix, Maricopa County, AZ

  19. 11. VIEW OF HOCK OUTCROPPING, CONCRETE GRAVITY DAM FACE AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. VIEW OF HOCK OUTCROPPING, CONCRETE GRAVITY DAM FACE AND LAKE WITH TUNNEL INLET STRUCTURE IN DISTANCE, SHOWN AT MINIMUM WATER FLOW, LOOKING SOUTHEAST (UPSTREAM) - Van Arsdale Dam, South Fork of Eel River, Ukiah, Mendocino County, CA

  20. 1. OVERALL VIEW SHOWING FACE OF CONCRETE GRAVITY DAM AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. OVERALL VIEW SHOWING FACE OF CONCRETE GRAVITY DAM AND FISH LADDER, LOOKING SOUTHWEST (UPSTREAM) FROM SNORE OPPOSITE FISH LADDER - Van Arsdale Dam, South Fork of Eel River, Ukiah, Mendocino County, CA

  1. 12. DETAIL VIEW OF STEPPED CONCRETE GRAVITY DAM FACE AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. DETAIL VIEW OF STEPPED CONCRETE GRAVITY DAM FACE AND ROCK OUTCROPPING, WITH LAKE IN BACKGROUND, SHOWN AT MINIMUM WATER FLOW, LOOKING SOUTHEAST (UPSTREAM) - Van Arsdale Dam, South Fork of Eel River, Ukiah, Mendocino County, CA

  2. 10. DETAIL OF NONOVERFLOW SECTION OF DAM SHOWING PENSTOCK OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. DETAIL OF NON-OVERFLOW SECTION OF DAM SHOWING PENSTOCK OF SUBMERSIBLE TURBINE-GENERATOR - Middle Creek Hydroelectric Dam, On Middle Creek, West of U.S. Route 15, 3 miles South of Selinsgrove, Selinsgrove, Snyder County, PA

  3. 2. EASTSIDE RESERVOIR UNDER CONSTRUCTION LOOKING WEST WITH EAST DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. EASTSIDE RESERVOIR UNDER CONSTRUCTION LOOKING WEST WITH EAST DAM IN MIDDLE GROUND, WEST DAM IN DISTANCE. - Eastside Reservoir, Diamond & Domenigoni Valleys, southwest of Hemet, Hemet, Riverside County, CA

  4. "No. 190. Grand Valley Diversion Dam. Diversion gates, water flowing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    "No. 190. Grand Valley Diversion Dam. Diversion gates, water flowing into high line. June, 1917. R.B.D." - Grand Valley Diversion Dam, Half a mile north of intersection of I-70 & Colorado State Route 65, Cameo, Mesa County, CO

  5. 32. Otter Lake Dam. View from downstream show how the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. Otter Lake Dam. View from downstream show how the dam blends into its environment. Looking east-northeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  6. 23. VIEW OF HORSE MESA DAM, SHOWING SPILLWAY DISCHARGE TUNNEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. VIEW OF HORSE MESA DAM, SHOWING SPILLWAY DISCHARGE TUNNEL AT LEFT, RIGHT (OR NORTH) SPILLWAY, HEFU POWER UNIT, AND ORIGINAL POWER PLANT - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  7. 24. CLOSEUP VIEW OF HORSE MESA DAM. HEFU PENSTOCK IS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. CLOSE-UP VIEW OF HORSE MESA DAM. HEFU PENSTOCK IS AT CENTER RIGHT, AND LEFT (OR SOUTH) SPILLWAY CHUTE IS AT UPPER RIGHT - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  8. 22. VIEW SHOWING THE COMPLETED HORSE MESA DAM, EXCEPT FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. VIEW SHOWING THE COMPLETED HORSE MESA DAM, EXCEPT FOR TRANSFORMER EQUIPMENT BEING INSTALLED ABOVE THE POWER PLANT 1927 - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  9. 36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER PLANT, LOOKING NORTH. ONLY TWO OF THE THREE UNITS ARE VISIBLE - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  10. 5. DETAIL VIEW OF TOE SPILLWAY SECTION OF LOWWATER DAM, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. DETAIL VIEW OF TOE SPILLWAY SECTION OF LOW-WATER DAM, LOOKING NORTHWEST (UPSTREAM). ST. LOUIS WATER DEPARTMENT INTAKE IN BACKGROUND - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 27, Granite City, Madison County, IL

  11. 2. OVERALL VIEW OF LOWWATER DAM, LOOKING UPSTREAM. CHAIN OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. OVERALL VIEW OF LOW-WATER DAM, LOOKING UPSTREAM. CHAIN OF ROCKS BRIDGE AND ST. LOUIS WATER DEPARTMENT INTAKE IN BACKGROUND, LOOKING NORTHWEST - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 27, Granite City, Madison County, IL

  12. 56. Upstream face of diversion dam looking east. Headgates are ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. Upstream face of diversion dam looking east. Headgates are partially visible at far left. Photographer Mark Durben, 1986. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  13. 40. Reservoir behind Pleasant Dam, looking downstream, spillway is at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. Reservoir behind Pleasant Dam, looking downstream, spillway is at right. Photographer unknown, c. late 1920s. Source: MWD. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  14. 54. Downstream face of Agua Fria project's diversion dam showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. Downstream face of Agua Fria project's diversion dam showing initial masonry construction and poured concrete capping. Photographer Mark Durben, 1986. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  15. 57. Downstream side of left section of diversion dam. Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    57. Downstream side of left section of diversion dam. Photographer Mark Durben, 1986. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  16. 55. Downstream face of diversion dam looking northwest. Photographer Mark ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    55. Downstream face of diversion dam looking northwest. Photographer Mark Durben, 1986. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  17. 60. Waddell Dam in relation and spillway tailrace. Photographer Mark ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. Waddell Dam in relation and spillway tailrace. Photographer Mark Durben, 1986. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  18. 70. Downstream view of Waddell Dam spillway and taintor gates. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    70. Downstream view of Waddell Dam spillway and taintor gates. Photographer Mark Durben. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  19. 39. Pleasant Dam from east abutment with spillway visible at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. Pleasant Dam from east abutment with spillway visible at center. Photographer unknown, 1927. Source: MWD. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  20. 49. Downstream face of Humbug Creek Diversion Dam with sluice ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. Downstream face of Humbug Creek Diversion Dam with sluice opening at center. Photographer James Eastwood, 1986. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  1. 50. Upstream face of Humbug Creek Diversion Dam showing sluice ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. Upstream face of Humbug Creek Diversion Dam showing sluice opening. Photographer James Eastwood, 1986. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  2. 27. Evening view of downstream face of Pleasant Dam under ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. Evening view of downstream face of Pleasant Dam under construction. Part of construction camp housing is visible in foreground. Photographer unknown, 1927. Source: MWD. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  3. 1. Distant view of lock and dam to northeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Distant view of lock and dam to northeast - Mississippi River 9-Foot Channel, Lock & Dam No. 1, In Mississippi River at Mississippi Boulevard, below Ford Parkway Bridge, Saint Paul, Ramsey County, MN

  4. 2. Distant view of lock and dam to northwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Distant view of lock and dam to northwest - Mississippi River 9-Foot Channel, Lock & Dam No. 1, In Mississippi River at Mississippi Boulevard, below Ford Parkway Bridge, Saint Paul, Ramsey County, MN

  5. 3. Down river view of lock and dam to southwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Down river view of lock and dam to southwest - Mississippi River 9-Foot Channel, Lock & Dam No. 1, In Mississippi River at Mississippi Boulevard, below Ford Parkway Bridge, Saint Paul, Ramsey County, MN

  6. 4. View of dam front and sluiceway outlets Mississippi ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. View of dam front and sluiceway outlets - Mississippi River 9-Foot Channel, Lock & Dam No. 1, In Mississippi River at Mississippi Boulevard, below Ford Parkway Bridge, Saint Paul, Ramsey County, MN

  7. 11. VIEW OF SPILLWAY AT DAM 83, SHOWING REFUGE HEADQUARTERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. VIEW OF SPILLWAY AT DAM 83, SHOWING REFUGE HEADQUARTERS ON THE HORIZON (LEFT, CENTER), LOOKING EAST - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  8. 1. VIEW OF DAM 83, LOOKING SOUTHWEST FROM THE LOOKOUT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF DAM 83, LOOKING SOUTHWEST FROM THE LOOKOUT TOWER AT THE REFUGE HEADQUARTERS (see HAER No. ND-3-A-13 for comparison) - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  9. 9. VIEW OF SPILLWAY AT DAM 83, SHOWING LOCATION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF SPILLWAY AT DAM 83, SHOWING LOCATION OF FORMER CONCRETE FLASHBOARD STRUCTURE ON RIGHT, LOOKING WEST - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  10. 10. DETAIL VIEW OF SPILLWAY AT DAM 83, SHOWING RIVER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. DETAIL VIEW OF SPILLWAY AT DAM 83, SHOWING RIVER COBBLE PAVING (FOREGROUND) AND WINGWALL, LOOKING EAST - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  11. 6. VIEW NORTHEAST, WEST END OF DAM DURING CONSTRUCTION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW NORTHEAST, WEST END OF DAM DURING CONSTRUCTION OF FISHWAY, DECEMBER 1995, SHOWING REMOVAL OF PLANKING - Norwich Water Power Company, Dam, West bank of Shetucket River opposite Fourteenth Street, Greenville section, Norwich, New London County, CT

  12. 19. View of low crib dam, headworks, and tramway above ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. View of low crib dam, headworks, and tramway above dam, looking southeast. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  13. 77. Plan of Proposed Concrete of Rubble Masonry Dam at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    77. Plan of Proposed Concrete of Rubble Masonry Dam at Frog Tanks on the Agua Fria River, Arizona. September 1903. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  14. View of powerhouse and dam from third floor of original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of powerhouse and dam from third floor of original section of Langdale Cotton Mill, looking northeast - Langdale Cotton Mill, Powerhouse & Dam, 5910 Nineteenth Avenue, Valley, Chambers County, AL

  15. 6. EASTERLY VIEW OF BIG DALTON DAM SHOWING THE SHELTER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. EASTERLY VIEW OF BIG DALTON DAM SHOWING THE SHELTER HOUSE IN THE BACKGROUND. PHOTO TAKEN FROM THE ACCESS ROAD LEADING TO THE CONTROL HOUSE. - Big Dalton Dam, 2600 Big Dalton Canyon Road, Glendora, Los Angeles County, CA

  16. View of Read Sawmill masonry dam, site of submerged sawmill ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Read Sawmill masonry dam, site of submerged sawmill remains and earthen dam, facing north - Silas C. Read Sawmill, Outlet of Maxwell Lake near North Range Road, Fort Gordon, Richmond County, GA

  17. 12. VIEW SHOWING CCC CREWS FREEING FLOOD GATES AT DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. VIEW SHOWING CCC CREWS FREEING FLOOD GATES AT DAM 326 OF ICE TO PREVENT DAMAGE TO STRUCTURE - J. Clark Salyer National Wildlife Refuge, Dam 326, Along Lower Souris River, Kramer, Bottineau County, ND

  18. 10. DETAIL VIEW OF SPILLWAY AT DAM 326, SHOWING ORIGINAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. DETAIL VIEW OF SPILLWAY AT DAM 326, SHOWING ORIGINAL FIELD-STONE WEIR WALL BENEATH CONCRETE BUTTRESSING, LOOKING SOUTHEAST - J. Clark Salyer National Wildlife Refuge, Dam 326, Along Lower Souris River, Kramer, Bottineau County, ND

  19. 1. Salmon Creek Diversion Dam, weir (to left), sand and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Salmon Creek Diversion Dam, weir (to left), sand and silt sluice gate (center), main canal headworks (to right), view to northwest - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  20. 2. Salmon Creek Diversion Dam, overview, diversion weir center foreground, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Salmon Creek Diversion Dam, overview, diversion weir center foreground, headworks overflow weir to center left, view to east - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  1. 9. VIEW OF DAM FROM LEFT SIDE. PUMPCRETE PIPE LINES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF DAM FROM LEFT SIDE. PUMPCRETE PIPE LINES ARE CARRIED ON WALKWAY. UPSTREAM PARTS OF BUTTRESSES ARE FOG-SPRAYED TO PERMIT PROMPT FILLING OF CONTRACTION JOINTS. July 30, 1938 - Bartlett Dam, Verde River, Phoenix, Maricopa County, AZ

  2. 5. GORGE HIGH DAM; LOOKING TOWARD INTAKE WITH WATER FLOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. GORGE HIGH DAM; LOOKING TOWARD INTAKE WITH WATER FLOWING OVER THE TOP OF THE SPILLGATE, 1989. - Skagit Power Development, Gorge High Dam, On Skagit River, 2.9 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  3. 45. Reinforcement work to buttresses at Pleasant Dam. Support work ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. Reinforcement work to buttresses at Pleasant Dam. Support work for roadway and roadway visible. Photographer unknown, 1935. Source: Huber Collection. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  4. 1. UPSTREAM VIEW OF THE SOUTH CHANNEL DAM, LOOKING EAST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. UPSTREAM VIEW OF THE SOUTH CHANNEL DAM, LOOKING EAST. - Washington Water Power Company Post Falls Power Plant, South Channel Dam, West of intersection of Spokane & Fourth Streets, Post Falls, Kootenai County, ID

  5. 2. DOWNSTREAM VIEW OF THE SOUTH CHANNEL DAM, LOOKING WEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. DOWNSTREAM VIEW OF THE SOUTH CHANNEL DAM, LOOKING WEST. - Washington Water Power Company Post Falls Power Plant, South Channel Dam, West of intersection of Spokane & Fourth Streets, Post Falls, Kootenai County, ID

  6. 42. Credit TR. Dam No. 4 after 1936 flood; break ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. Credit TR. Dam No. 4 after 1936 flood; break as seen from upstream. Note original timber cribbing to left. Photo c. 1936. - Dam No. 4 Hydroelectric Plant, Potomac River, Martinsburg, Berkeley County, WV

  7. 44. Credit TR. Dam No. 4 after 1936 flood from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Credit TR. Dam No. 4 after 1936 flood from downstream showing break closed and installation of new concrete cap piece under way. Photo c. 1936. - Dam No. 4 Hydroelectric Plant, Potomac River, Martinsburg, Berkeley County, WV

  8. 10. VIEW OF WEST END OF SPILLWAY AT DAM 96, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. VIEW OF WEST END OF SPILLWAY AT DAM 96, SHOWING SEGMENT OF THE WEIR WALL WHICH HAS BEEN REPLACED WITH CONCRETE, LOOKING NORTHWEST - Upper Souris National Wildlife Refuge, Dam 96, Souris River Basin, Foxholm, Surrey (England), ND

  9. 11. DETAIL VIEW OF DAM 87, SHOWING STOPLOG STRUCTURE (PARTIALLY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. DETAIL VIEW OF DAM 87, SHOWING STOPLOG STRUCTURE (PARTIALLY HIDDEN BY MARSH GRASSES IN LOWER PART OF PHOTO) AT RIGHT (WEST) END OF SPILLWAY - Upper Souris National Wildlife Refuge, Dam 87, Souris River Basin, Foxholm, Surrey (England), ND

  10. 5. DETAIL VIEW OF DAM, SHOWING TAINTER GATES, GATE PIERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. DETAIL VIEW OF DAM, SHOWING TAINTER GATES, GATE PIERS AND DAN BRIDGE, WITH ROLLER GATE HEADHOUSES AND LOCKS IN BACKGROUND, LOOKING NORTHEAST, UPSTREAM - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 4, Alma, Buffalo County, WI

  11. 68. LITTLE ROCK AND PALMDALE IRRIGATION DISTRICT, LITTLE ROCK DAM: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. LITTLE ROCK AND PALMDALE IRRIGATION DISTRICT, LITTLE ROCK DAM: STRESS SHEET, SHEET 4; MAY, 1918. Littlerock Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  12. 71. PALMDALE WATER COMPANY, EASTWOOD MULTIPLEARCHED DAM: STRESS SHEET, SHEET ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    71. PALMDALE WATER COMPANY, EASTWOOD MULTIPLE-ARCHED DAM: STRESS SHEET, SHEET 3; DECEMBER 20, 1918. Littlerock Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  13. 1. OVERALL VIEW OF UPSTREAM FACE OF DAM; SPILLWAY IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. OVERALL VIEW OF UPSTREAM FACE OF DAM; SPILLWAY IN FOREGROUND, LOCK IN BACKGROUND ON NORTH RIVER BANK. VIEW TO NORTH. - Starved Rock Locks & Dam, Illinois Waterway River mile 231, Peru, La Salle County, IL

  14. 7. CLOSEUP VIEW OF WASHED UP 12' x 12' DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. CLOSE-UP VIEW OF WASHED UP 12' x 12' DAM SUPPORT TIMBERS, THREE BEARS LAKE, LOOKING NORTHEAST FROM SOUTH SIDE OF LAKE - Three Bears Lake & Dams, North of Marias Pass, East Glacier Park, Glacier County, MT

  15. 1. MORRIS DAM TEST FACILITY (MDTF) AND VARIABLEANGLE LAUNCHER AS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. MORRIS DAM TEST FACILITY (MDTF) AND VARIABLE-ANGLE LAUNCHER AS SEEN FROM STATE HIGHWAY 39 NEAR MORRIS DAM LOOKING EAST. - Variable Angle Launcher Complex, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  16. Interior of dam, showing one of the ten bays, looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior of dam, showing one of the ten bays, looking west through arched openings along the center of the dam. - Robert B. Morse Water Filtration Plant, 10700 and 10701 Columbia Pike, Silver Spring, Montgomery County, MD

  17. 4. Aerial view of Whitsett intake (lower right), Parker Dam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Aerial view of Whitsett intake (lower right), Parker Dam and village (left), Gene Wash Reservoir, Gene Pump Plant and village (right). - Parker Dam, Spanning Colorado River between AZ & CA, Parker, La Paz County, AZ

  18. 4. Side of view of upper dam overspill, taken from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Side of view of upper dam overspill, taken from west bank of Millstone Creek, VIEW EAST - Loleta Recreation Area, Upper Dam, 6 miles Southeast of interesection of State Route 24041 & State Route 66, Loleta, Elk County, PA

  19. 5. View of upper dam side sluice taken from east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View of upper dam side sluice taken from east bank of Millstone Creek. VIEW WEST - Loleta Recreation Area, Upper Dam, 6 miles Southeast of interesection of State Route 24041 & State Route 66, Loleta, Elk County, PA

  20. 3. Side view of upper dam overspill, taken from east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Side view of upper dam overspill, taken from east bank of Millstone Creek. VIEW WEST - Loleta Recreation Area, Upper Dam, 6 miles Southeast of interesection of State Route 24041 & State Route 66, Loleta, Elk County, PA

  1. 1. East side of lower dam shown with water level ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. East side of lower dam shown with water level dropped. VIEW WEST - Loleta Recreation Area, Lower Dam, 6 miles Southeast of interesection of State Route 24041 & State Route 66, Loleta, Elk County, PA

  2. 11. AVALON DAM GATE KEEPER'S COMPLEX: PUMPHOUSE AND LIFT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. AVALON DAM - GATE KEEPER'S COMPLEX: PUMPHOUSE AND LIFT FOR HOUSE WATER SUPPLY. VIEW TO EAST - Carlsbad Irrigation District, Avalon Dam, On Pecos River, 4 miles North of Carlsbad, Carlsbad, Eddy County, NM

  3. 20. HORSESHOE DAM LOOKING EAST WITH UPPER END DEMOLISHED FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. HORSESHOE DAM LOOKING EAST WITH UPPER END DEMOLISHED FOR NEW SPILLWAY (negative reversed) - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

  4. 7. ISLAND PLANT AND HORSESHOE DAM FROM WEST BANK (negative ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. ISLAND PLANT AND HORSESHOE DAM FROM WEST BANK (negative reversed) - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

  5. 4. AERIAL VIEW OF DAM SITE SHOWING OUTLET WORKS AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. AERIAL VIEW OF DAM SITE SHOWING OUTLET WORKS AND DIVERSION CHANNEL IN FOREGROUND.... Volume XVIII, No. 9, March 5, 1940. - Prado Dam, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

  6. 6. GENERAL CONSTRUCTION VIEW ALONG AXIS OF DAM FROM THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. GENERAL CONSTRUCTION VIEW ALONG AXIS OF DAM FROM THE EAST ABUTMENT.... Volume XVII, No. 18, December 18, 1939. - Prado Dam, Embankment, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

  7. 15. AERIAL PHOTOGRAPH OF DAM SITE SHOWING SPILLWAY OGEE SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. AERIAL PHOTOGRAPH OF DAM SITE SHOWING SPILLWAY OGEE SECTION AND SPILLWAY APRON EXCAVATION IN FOREGROUND.... Volume XVIII, No. 10, January 18, 1940. - Prado Dam, Spillway, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

  8. 34. DOWNSTREAM VIEW OF COOLIDGE DAM COMPLETED. POWER HOUSE, INTAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. DOWNSTREAM VIEW OF COOLIDGE DAM COMPLETED. POWER HOUSE, INTAKE TOWERS, WEST SPILLWAY CHANNEL AND DECORATIVE EAGLES ALL CLEARLY VISIBLE, c. 1928 - Coolidge Dam, Gila River, Peridot, Gila County, AZ

  9. Sediment depositions upstream of open check dams: new elements from small scale models

    NASA Astrophysics Data System (ADS)

    Piton, Guillaume; Le Guern, Jules; Carbonari, Costanza; Recking, Alain

    2015-04-01

    Torrent hazard mitigation remains a big issue in mountainous regions. In steep slope streams and especially in their fan part, torrential floods mainly result from abrupt and massive sediment deposits. To curtail such phenomenon, soil conservation measures as well as torrent control works have been undertaken for decades. Since the 1950s, open check dams complete other structural and non-structural measures in watershed scale mitigation plans1. They are often built to trap sediments near the fan apexes. The development of earthmoving machinery after the WWII facilitated the dredging operations of open check dams. Hundreds of these structures have thus been built for 60 years. Their design evolved with the improving comprehension of torrential hydraulics and sediment transport; however this kind of structure has a general tendency to trap most of the sediments supplied by the headwaters. Secondary effects as channel incision downstream of the traps often followed an open check dam creation. This sediment starvation trend tends to propagate to the main valley rivers and to disrupt past geomorphic equilibriums. Taking it into account and to diminish useless dredging operation, a better selectivity of sediment trapping must be sought in open check dams, i.e. optimal open check dams would trap sediments during dangerous floods and flush them during normal small floods. An accurate description of the hydraulic and deposition processes that occur in sediment traps is needed to optimize existing structures and to design best-adjusted new structures. A literature review2 showed that if design criteria exist for the structure itself, little information is available on the dynamic of the sediment depositions upstream of open check dams, i.e. what are the geomorphic patterns that occur during the deposition?, what are the relevant friction laws and sediment transport formula that better describe massive depositions in sediment traps?, what are the range of Froude and Shields

  10. Large-scale dam removal on the Elwha River, Washington, USA: Erosion of reservoir sediment

    NASA Astrophysics Data System (ADS)

    Randle, Timothy J.; Bountry, Jennifer A.; Ritchie, Andrew; Wille, Kurt

    2015-10-01

    than half of that in the coarse, noncohesive delta sediments. Dam removal resulted in the erosion and downstream release of 23% of the sediment in Lake Aldwell (1.12 ± 0.07 million m3) and 37% of the sediment in Lake Mills (5.95 ± 0.12 million m3), representing nearly four decades of sediment supply from the upstream watershed within a two-year time frame. A significant portion of the reservoir sediment is expected to remain as sediment terraces within the reservoir landscape, but additional erosion is expected after the remainder of the Glines Canyon Dam is removed and during future floods until the river reaches quasi-equilibrium. After phased dam removal, the reservoir landscape consists of a series of sediment terraces of varying heights composed of prograded coarse sediment overlying fine lakebed deposits. The predam surface is exposed along the river corridor, and abundant 1- to 3-m stumps from pre-removal forests create unique morphology where the river interacts with the predam landscape.

  11. 2. View of the southern twothirds of the dam showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. View of the southern two-thirds of the dam showing the Glens Falls Bridge over the Hudson River on the left, the Niagara Mohawk Power Corporation penstocks and inktake structure at the southeast corner of the dam, and the dam itself. The Finch Pruyn & Company Forebay is the foreground. Facing south. - Glens Falls Dam, 100' to 450' West of U.S. Route 9 Bridge Spanning Hudson River, Glens Falls, Warren County, NY

  12. "No. 172. General view of the dam, looking downstream from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    "No. 172. General view of the dam, looking downstream from the east end. F.E.D. June, 1916." Compare this historic image, taken upon dam completion (1916), with current-condition photograph HAER CO-90-1. The dam retains a remarkable degree of integrity of design and setting - Grand Valley Diversion Dam, Half a mile north of intersection of I-70 & Colorado State Route 65, Cameo, Mesa County, CO

  13. Reconstructing Watershed History from Reservoir Stratigraphy: Englebright Lake, Yuba River, Northern California

    NASA Astrophysics Data System (ADS)

    Snyder, N. P.; Alpers, C. N.; Childs, J. R.; Curtis, J. A.; Flint, L. E.; Holmes, C. W.; Rubin, D. M.; Wright, S. A.

    2004-12-01

    Reservoirs provide the opportunity to study fluvial processes and rates in a controlled setting because they are effective traps of sediment and are often well monitored. An extensive sediment coring and sampling campaign was done in Englebright Lake on the Yuba River in northern California as part of a fish-habitat restoration study. The Yuba watershed (particularly the southern part) was the site of intensive hydraulic gold mining in the 19th and early 20th century, and Englebright Dam was built in 1940 to trap mining debris. Results of a bathymetric survey in 2001 indicate that the reservoir was 26% full (22x106 m3 of material). The physical properties of the entire deposit were extrapolated from ˜300 m of cores collected at 7 sites along the longitudinal axis of the reservoir in 2002. The mass of the deposit is 26x106 metric tons, of which 3.2% is organic. The sediment is ˜65% sand and gravel, and distinct layers of differing grain size (sand-gravel, silt-clay, organics) are well preserved in the cores. The depositional chronology of the reservoir was established using 137Cs analysis and the relations between the cored stratigraphy and the hydrologic and impoundment history of the watershed. Deposits from three major flood events (1955, 1964, 1997; each with discharge >3,400 m3/s) were identified in the stratigraphy of most of the coring sites. Observations of recent (post-1997) depositional patterns are guiding the development of a conceptual model of reservoir-sedimentation processes during floods, drawdowns, and intraflood periods. Enlargement of an upstream dam on the North Yuba River in 1970 caused a decrease in flood frequency in the Yuba River and changed management of Englebright Lake (ending annual drawdowns). A relict topset-foreset-bottomset sequence observed in the cored stratigraphy is interpreted to correlate with this change in watershed management; a second deltaic sequence was deposited on top of the first after 1970. Post-1970 average annual

  14. Nitrogen sources to watersheds and estuaries: role of land cover mosaics and losses within watersheds.

    PubMed

    Valiela, I; Bowen, J L

    2002-01-01

    Across most of the World's coastal zone there has been a geographic transition from naturally vegetated to human-altered land covers, both agricultural and urban. This transition has increased the nitrogen loads to coastal watersheds, and from watersheds to receiving estuaries. We modeled the nitrogen entering the watershed of Waquoit Bay, Massachusetts, and found that as the transition took place, nitrogen loads to watersheds increased from 1938 to 1990. The relative magnitude of the contribution by wastewater, fertilizers, and atmospheric deposition depends on the land cover mosaics of a watershed. Atmospheric deposition was the major input to the watershed surface during this period, but because of different rates of loss within the watershed. wastewater became the major source of nitrogen flowing from the watershed to the receiving estuaries. Atmospheric deposition prevails in watersheds dominated by natural vegetation such as forests, but wastewater may become a dominant source in watersheds where urbanization increases. Increased nitrogen loads resulting from conversion of natural to human-altered watershed surfaces create eutrophication of receiving waters, with attendant changes in water quality, and marked shifts in the flora and food webs of the affected estuaries. Management efforts for restoration of eutrophied estuaries require maintenance of forested land, and control of wastewater and fertilizer inputs, the major terms in most affected places subject to local management. Wastewater and fertilizer nitrogen derive from within the watershed, which means local measures may effectively be used to control eutrophication of receiving waters.

  15. Volunteer Watershed Health Monitoring by Local Stakeholders: New Mexico Watershed Watch

    ERIC Educational Resources Information Center

    Fleming, William

    2003-01-01

    Volunteers monitor watershed health in more than 700 programs in the US, involving over 400,000 local stakeholders. New Mexico Watershed Watch is a student-based watershed monitoring program sponsored by the state's Department of Game and Fish which provides high school teachers and students with instruction on methods for water quality…

  16. Engaging Watershed Stakeholders for Cost-Effective Environmental Management Planning with "Watershed Manager"

    ERIC Educational Resources Information Center

    Williams, Jeffery R.; Smith, Craig M.; Roe, Josh D.; Leatherman, John C.; Wilson, Robert M.

    2012-01-01

    "Watershed Manager" is a spreadsheet-based model that is used in extension education programs for learning about and selecting cost-effective watershed management practices to reduce soil, nitrogen, and phosphorus losses from cropland. It can facilitate Watershed Restoration and Protection Strategy (WRAPS) stakeholder groups' development of…

  17. Watershed Stewardship Education Program--A Multidisciplinary Extension Education Program for Oregon's Watershed Councils.

    ERIC Educational Resources Information Center

    Conway, Flaxen D. L.; Godwin, Derek; Cloughesy, Mike; Nierenberg, Tara

    2003-01-01

    The Watershed Stewardship Education Program (WSEP) is a multidisciplinary Oregon Extension designed to help watershed councils, landowners, and others work effectively together on water management. Components include practical, easy-to-use educational materials, training in effective collaboration, a Master Watershed Stewards program, and advanced…

  18. Introduction to the Watershed Central Web Site and Watershed Wiki Mini-Workshop

    EPA Science Inventory

    Many communities across the country struggle to find the right approaches, tools and data to include in their watershed plans. EPA recently posted a new web site called "Watershed Central,” a “one-stop" tool, to help watershed organizations and others find key resources to protec...

  19. "Hills of Friends": Cultural Watersheds in the Sixth Grade.

    ERIC Educational Resources Information Center

    Adamson-Towner, Sioux

    1999-01-01

    Describes a sixth grade activity that focuses on cultural watersheds, in which students represent their "personal landscapes." Explains that students list watershed and cultural attributes in lesson one. In lesson two students paint a representation of their cultural watershed. (CMK)

  20. AN INTEGRATED COASTAL-WATERSHED MONITORING FRAMEWORK FOR ASSESSMENT

    EPA Science Inventory

    An approach for watershed classification in support of assessments, disgnosis of biological impairment, and prioritization of watershed restorations has been tested in coastal watersheds surrounding the western arm of Lake Superior and is currently being assessed for a series of ...