Forecasting the remaining reservoir capacity in the Laurentian Great Lakes watershed

NASA Astrophysics Data System (ADS)

Alighalehbabakhani, Fatemeh; Miller, Carol J.; Baskaran, Mark; Selegean, James P.; Barkach, John H.; Dahl, Travis; Abkenar, Seyed Mohsen Sadatiyan

2017-12-01

Sediment accumulation behind a dam is a significant factor in reservoir operation and watershed management. There are many dams located within the Laurentian Great Lakes watershed whose operations have been adversely affected by excessive reservoir sedimentation. Reservoir sedimentation effects include reduction of flood control capability and limitations to both water supply withdrawals and power generation due to reduced reservoir storage. In this research, the sediment accumulation rates of twelve reservoirs within the Great Lakes watershed were evaluated using the Soil and Water Assessment Tool (SWAT). The estimated sediment accumulation rates by SWAT were compared to estimates relying on radionuclide dating of sediment cores and bathymetric survey methods. Based on the sediment accumulation rate, the remaining reservoir capacity for each study site was estimated. Evaluation of the anthropogenic impacts including land use change and dam construction on the sediment yield were assessed in this research. The regression analysis was done on the current and pre-European settlement sediment yield for the modeled watersheds to predict the current and natural sediment yield in un-modeled watersheds. These eleven watersheds are in the state of Indiana, Michigan, Ohio, New York, and Wisconsin.

Dam removal: Listening in

NASA Astrophysics Data System (ADS)

Foley, M. M.; Bellmore, J. R.; O'Connor, J. E.; Duda, J. J.; East, A. E.; Grant, G. E.; Anderson, C. W.; Bountry, J. A.; Collins, M. J.; Connolly, P. J.; Craig, L. S.; Evans, J. E.; Greene, S. L.; Magilligan, F. J.; Magirl, C. S.; Major, J. J.; Pess, G. R.; Randle, T. J.; Shafroth, P. B.; Torgersen, C. E.; Tullos, D.; Wilcox, A. C.

2017-07-01

Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (< 5 years) and do not adequately represent the diversity of dam types, watershed conditions, and dam-removal methods in the U.S.

Dam removal: Listening in

USGS Publications Warehouse

Foley, Melissa M.; Bellmore, James; O'Connor, James E.; Duda, Jeff; East, Amy E.; Grant, Gordon G.; Anderson, Chauncey; Bountry, Jennifer A.; Collins, Mathias J.; Connolly, Patrick J.; Craig, Laura S.; Evans, James E.; Greene, Samantha; Magilligan, Francis J.; Magirl, Christopher S.; Major, Jon J.; Pess, George R.; Randle, Timothy J.; Shafroth, Patrick B.; Torgersen, Christian E.; Tullos, Desiree D.; Wilcox, Andrew C.

2017-01-01

Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (< 5 years) and do not adequately represent the diversity of dam types, watershed conditions, and dam-removal methods in the U.S.

Geophysical methods for the assessment of earthen dams

USDA-ARS?s Scientific Manuscript database

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...

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.

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

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.

Informing watershed connectivity barrier prioritization decisions: A synthesis

USGS Publications Warehouse

McKay, S. K.; Cooper, A. R.; Diebel, M.W.; Elkins, D.; Oldford, G.; Roghair, C.; Wieferich, Daniel J.

2017-01-01

Water resources and transportation infrastructure such as dams and culverts provide countless socio-economic benefits; however, this infrastructure can also disconnect the movement of organisms, sediment, and water through river ecosystems. Trade-offs associated with these competing costs and benefits occur globally, with applications in barrier addition (e.g. dam and road construction), reengineering (e.g. culvert repair), and removal (e.g. dam removal and aging infrastructure). Barrier prioritization provides a unique opportunity to: (i) restore and reconnect potentially large habitat patches quickly and effectively and (ii) avoid impacts prior to occurrence in line with the mitigation hierarchy (i.e. avoid then minimize then mitigate). This paper synthesizes 46 watershed-scale barrier planning studies and presents a procedure to guide barrier prioritization associated with connectivity for aquatic organisms. We focus on practical issues informing prioritization studies such as available data sets, methods, techniques, and tools. We conclude with a discussion of emerging trends and issues in barrier prioritization and key opportunities for enhancing the body of knowledge.

National Dam Safety Program. Onondaga Dam (Inventory Number NY 794), Oswego River Basin, Onondaga County, New York. Phase I Inspection Report.

DTIC Science & Technology

1981-06-30

Onondag Darn IC^Tjr 50 DO.GWAO1%Q I /W0 (Inventory Numiber NY 794), Oswego River , Basin , Onondage County, New York.Phs IS.DISR)UTI!4 TAY- I Inspection...Dam: Onondaga Dam ID. No. NY 794 State Located: New York County: Onondaga Watershed: Oswego River Basin Stream: Onondaga Creek Date of Inspection...CL E E C4)S0. 0. w CD 2. > C CD C C I 0 0 PHASE I INSPECTION REPORT ONONDAGA DAM I.D. NO NY 794 OSWEGO RIVER BASIN ONONDAGA COUNTY, NEW YORK SECTION 1

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

Physical and biological responses to an alternative removal strategy of a moderate-sized dam in Washington, USA.

Treesearch

Shannon Claeson; B. Coffin

2015-01-01

Dam removal is an increasingly practised river restoration technique, and ecological responses vary with watershed, dam and reservoir properties, and removal strategies. Moderate-sized dams, like Hemlock Dam (7.9m tall and 56m wide), are large enough that removal effects could be significant, but small enough that mitigation may be possible through a modified dam...

The changing hydrology of a dammed Amazon

PubMed Central

Timpe, Kelsie; Kaplan, David

2017-01-01

Developing countries around the world are expanding hydropower to meet growing energy demand. In the Brazilian Amazon, >200 dams are planned over the next 30 years, and questions about the impacts of current and future hydropower in this globally important watershed remain unanswered. In this context, we applied a hydrologic indicator method to quantify how existing Amazon dams have altered the natural flow regime and to identify predictors of alteration. The type and magnitude of hydrologic alteration varied widely by dam, but the largest changes were to critical characteristics of the flood pulse. Impacts were largest for low-elevation, large-reservoir dams; however, small dams had enormous impacts relative to electricity production. Finally, the “cumulative” effect of multiple dams was significant but only for some aspects of the flow regime. This analysis is a first step toward the development of environmental flows plans and policies relevant to the Amazon and other megadiverse river basins. PMID:29109972

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…

The Effects of Dams on Downstream Channel Characteristics in Pennsylvania and Maryland: Assessing the Potential Consequences of Dam Removal

NASA Astrophysics Data System (ADS)

Skalak, K. J.; Pizzuto, J. E.; Jenkins, P.

2003-12-01

The potential downstream effects of dam removal were assessed on fifteen sites of varying dam size and characteristics in Pennsylvania and Maryland. The dams ranged in size from a 30 cm high fish weir to a water supply dam 57 m high. Stream order ranged from 1 to 4. The dams are located in watersheds with varying degrees of human disturbance and urbanization. The dams are also operated differently, with significant consequences for hydraulic residence time and downstream flow variability. Most streams were alluvial, but 6 of the reaches were clearly bedrock channels. We hypothesize that the channel upstream, which is unaffected by the dam, will provide an accurate model for the channel downstream of the dam long after dam removal. Therefore, reaches upstream and downstream of the dam were compared to determine the effects of the dam as well as the condition of the stream that will ultimately develop decades after dam removal. Surprisingly, the dams had no consistent influence on channel morphology. However, the percentage of sand is significantly lower downstream than upstream: the mean % sand downstream is 11.47%, while the mean % sand upstream is 21.39%. The coarser fractions of the bed, as represented by the 84th percentile grain diameter, are unaffected by the presence of the dam. These results imply that decades after dam removal, the percentage of sand on the bed will increase, but the coarse fraction of the bed will remain relatively unchanged.

Analysis of the typical small watershed of warping dams in the sand properties

NASA Astrophysics Data System (ADS)

Li, Li; Yang, Ji Shan; Sun, Wei Ying; Shen, Sha Sha

2018-06-01

Coarse sediment with a particle size greater than 0.05mm is the main deposit of riverbed in the lower Yellow River, the Loess Plateau is one of the concentrated source of coarse sediment, warping dam is one of the important engineering measures for gully control. Jiuyuangou basin is a typical small basin in the first sub region of hilly-gullied loess region, twenty warping dams in Jiuyuangou basin was selected as research object, samples of sediment along the main line of dam from upper, middle to lower reaches of dam fields and samples of undisturbed soil in slope of dam control basin were taken to carry out particle gradation analysis, in the hope of clearing reducing capacity on coarse sediment of different types of warping dam through the experimental data. The results show that the undisturbed soil in slope of dam control basin has characteristics of standard loess, the particle size are mainly distributed in 0.025 0.05mm, and the 0.05mm particle size of Jiuyuangou basinof loess is an obvious boundary; Particle size of sediment in 15 warping dam of Jiuyuangou basin are mainly distributed in 0.031 0.05mm with the dam tail is greater than dam front in general. The separation effect of horizontal pipe drainage is better than shaft drainage for which particle size greater than 0.05mm, notch dam is for particle size between 0.025 0.1 mm, and fill dam is for particle size between 0.016 0.1 mm, they all have a certain function in the sediment sorting.

Assessment of sediment yield in a sloping Mediterranean watershed in Cyprus

NASA Astrophysics Data System (ADS)

Djuma, Hakan; Bruggeman, Adriana; Camera, Corrado

2014-05-01

In the Mediterranean region, water catchment sediment yield as a result of erosion is higher than in many other regions in Europe due to the climatic conditions, topography, lithology and land-use. Modelling sediment transport is difficult due to intermittent stream flow and highly irregular rainfall conditions in this region. The objective of this study is to quantify sediment yield of a highly sloping Mediterranean environment. This study is conducted in the Peristerona Watershed in Cyprus, which has ephemeral water flow. In the downstream area a series of check dams have been placed across the stream to slow the flow and increase groundwater recharge. The surface area of the watershed, upstream of the check dams, is 103 km2 with elevation changing between 1540 m and 280 m and a mean local slope higher than 40% for the mountainous part and lower than 8% for the plain. The long-term average annual precipitation ranges from 755 mm in the upstream area to 276 mm in the plain. The surface extent of the sediment that was deposited at the most upstream check dam during two seasons was measured with a Differential Global Positioning System. The depth of the sediment was measured with utility poles and bulk density samples from the sediment profile were collected. The sediment had a surface area of 12600 m2 and an average depth of 0.23 m. The mean of the sediment dry bulk density samples was 1.05 t m-3 with a standard deviation of 0.11. Based on these values, area specific sediment yield was computed as 1 t ha-1 per year for the entire catchment area upstream of the check dam, assuming a check dam sediment trap efficiency of 15%. Erosion in the watershed is currently modeled with PESERA using detailed watershed data.

Dam nation: A geographic census of American dams and their large-scale hydrologic impacts

NASA Astrophysics Data System (ADS)

Graf, William L.

1999-04-01

Newly available data indicate that dams fragment the fluvial system of the continental United States and that their impact on river discharge is several times greater than impacts deemed likely as a result of global climate change. The 75,000 dams in the continental United States are capable of storing a volume of water almost equaling one year's mean runoff, but there is considerable geographic variation in potential surface water impacts. In some western mountain and plains regions, dams can store more than 3 year's runoff, while in the Northeast and Northwest, storage is as little as 25% of the annual runoff. Dams partition watersheds; the drainage area per dam varies from 44 km2 (17 miles2) per dam in New England to 811 km2 (313 miles2) per dam in the Lower Colorado basin. Storage volumes, indicators of general hydrologic effects of dams, range from 26,200 m3 km-2 (55 acre-feet mile-2) in the Great Basin to 345,000 m3 km-2 (725 acre-feet mile-2) in the South Atlantic region. The greatest river flow impacts occur in the Great Plains, Rocky Mountains, and the arid Southwest, where storage is up to 3.8 times the mean annual runoff. The nation's dams store 5000 m3 (4 acre-feet) of water per person. Water resource regions have experienced individualized histories of cumulative increases in reservoir storage (and thus of downstream hydrologic and ecologic impacts), but the most rapid increases in storage occurred between the late 1950s and the late 1970s. Since 1980, increases in storage have been relatively minor.

Aquatic systems and watersheds

Treesearch

Rick Kattelmann; Fraser Shilling

2004-01-01

Water is often at the heart of contentious debates over natural resource policy in the Sierra Nevada. Besides the obvious issues of dams, diversions, fish, wetlands, and pollution, connections abound with other resources within the waterways and their watersheds. Whether an argument is over logging, roads, wildfire, endangered species, wilderness, sprawl of foothill...

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

An experimental method to verify soil conservation by check dams on the Loess Plateau, China.

PubMed

Xu, X Z; Zhang, H W; Wang, G Q; Chen, S C; Dang, W Q

2009-12-01

A successful experiment with a physical model requires necessary conditions of similarity. This study presents an experimental method with a semi-scale physical model. The model is used to monitor and verify soil conservation by check dams in a small watershed on the Loess Plateau of China. During experiments, the model-prototype ratio of geomorphic variables was kept constant under each rainfall event. Consequently, experimental data are available for verification of soil erosion processes in the field and for predicting soil loss in a model watershed with check dams. Thus, it can predict the amount of soil loss in a catchment. This study also mentions four criteria: similarities of watershed geometry, grain size and bare land, Froude number (Fr) for rainfall event, and soil erosion in downscaled models. The efficacy of the proposed method was confirmed using these criteria in two different downscaled model experiments. The B-Model, a large scale model, simulates watershed prototype. The two small scale models, D(a) and D(b), have different erosion rates, but are the same size. These two models simulate hydraulic processes in the B-Model. Experiment results show that while soil loss in the small scale models was converted by multiplying the soil loss scale number, it was very close to that of the B-Model. Obviously, with a semi-scale physical model, experiments are available to verify and predict soil loss in a small watershed area with check dam system on the Loess Plateau, China.

National Dam Safety Program. Woodward Dam (Inventory Number NY 507), Lower Hudson River Basin, Orange County, New York. Phase I Inspection Report,

DTIC Science & Technology

1981-06-30

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Applying dam height-storage curve to geomorphic features analysis within virtual geographic environment: a case study of the Hong-Shi-Mao watershed

NASA Astrophysics Data System (ADS)

Wang, Daojun; Gong, Jianhua; Ma, Ainai; Li, Wenhang; Wang, Xijun

2005-10-01

There are generally two kinds of approaches to studying geomorphic features in terms of the quantification level and difference of major considerations. One is the earlier qualitative characterization, and the other is the 2-dimension measurement that includes section pattern and projection pattern. With the development of geo-information technology, especially the 3-D geo-visualization and virtual geographic environments (VGE), 3-dimension measurement and dynamic interactive between users and geo-data/geo-graphics can be developed to understand geomorphic features deeply, and to benefit to the effective applications of such features for geographic projects like dam construction. Storage-elevation curve is very useful for site selection of projects and flood dispatching in water conservancy region, but it is just a tool querying one value from the other one. In fact, storage-elevation curve can represent comprehensively the geomorphic features including vertical section, cross section of the stream and the landform nearby. In this paper, we use quadratic regression equation shaped like y = ax2 + bx + c and the DEM data of Hong-Shi-Mao watershed, Zi Chang County, ShaanXi Province, China to find out the relationship between the coefficients of the equation and the geomorphic features based on VGE platform. It's exciting that the coefficient "a" appear to be correlative strongly with the stream scale, and the coefficient "b" may give an index to the valley shape. In the end, we use a sub-basin named Hao-Jia-Gou of the watershed as an application. The result of correlative research about quadratic regression equation and geomorphic features can save computing and improve the efficiency in silt dam systems planning.

Risk watershed analysis: a new approach to manage torrent control structures

NASA Astrophysics Data System (ADS)

Quefféléan, Yann; Carladous, Simon; Deymier, Christian; Marco, Olivier

2017-04-01

Torrential check dams have been built in French public forests since the 19th century, applying the Restoration and conservation of Mountainous Areas (RTM) laws (1860, 1864, 1882). The RTM department of the National Forestry Office (ONF) helps the government to decide on protective actions to implement within these areas. While more than 100 000 structures were registered in 1964, more than 14 000 check dams are currently registered and maintained within approximatively 380 000 ha of RTM public forests. The RTM department officers thus have a long experience in using check dams for soil restoration, but also in implementing other kinds of torrential protective structures such as sediment traps, embankments, bank protection, and so forth. As a part of the ONF, they are also experienced in forestry engineering. Nevertheless, some limits in torrent control management have been highlighted: - as existing protective structures are ageing, their effectiveness to protect elements at risk must be assessed but it is a difficult task ; - as available budget for maintenance is continuously decreasing, priorities have to be made but decisions are difficult : what are the existing check dams functions? what is their expected effect on torrential hazard? is maintenance cost too important given this expected effect to protect elements at risk? Given these questions, a new policy has been engaged by the RTM department since 2012. A technical overview at the torrential watershed scale is now needed to help better maintenance decisions: it has been called a Risk Watershed Analysis (Etude de Bassin de Risque in French, EBR) and is funded by the government. Its objectives are to: - recall initial objectives of protective structures : therefore, a detailed archive analysis is made ; - describe current elements at risk to protect ; - describe natural hazards at the torrential watershed scale and their evolution since protective structures implementation ; - describe civil engineering

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.

Quantifying and tracing sediment mobilized during the 20th century in the South River watershed, western Massachusetts

NASA Astrophysics Data System (ADS)

Dow, S.; Snyder, N. P.; Ouimet, W. B.; Martini, A. M.; Yellen, B.; Woodruff, J. D.; Newton, R. M.

2016-12-01

New England has a long history of anthropogenic activity affecting the landscape, including deforestation, land use changes, and the construction of dams. Dams in particular have the ability to impound vast quantities of sediment eroded off the landscape. The South River in western Massachusetts is an example of a watershed where mill dam construction coincided with deforestation during the 17th-19th centuries, leading to the impoundment of legacy sediment. Along the river, these deposits act as a source of sediment being released back into the river. The Conway Electric Dam (CED), a 17 m tall dam built in 1906, is located downstream of the mill dams (most of which are no longer intact), and provides a 20th century depositional record for the watershed. The purpose of this study is to quantify sedimentation behind the CED and link this to erosion of upstream mill pond and glacial sediment sources using aerial photography, sediment cores, grainsize, and geochemical analyses. We used aerial photographs to map areal changes of the reservoir from 1940-1980, and topographic profiles generated from LiDAR to estimate a volume of 244,000 m3 of sediment stored behind the CED. We dated layers in cores collected at the site with Hg and 137Cs analyses. Overall, the reservoir exhibits a decreasing rate of sediment infilling occurring from 1940-1980, except for a potentially anomalous increase from 1940-1952. Discharge data containing large storm events were compared to sediment infilling rates to identify if a frequency of large storms could account for high rates of erosion and sediment transport; however, sedimentation at the site does not appear to be solely dependent on these large storm events. Preliminary Hg analyses of deposits from the watershed upstream of the CED indicate higher concentrations in mill pond sediment than glacial sediment. Ongoing work with geochemical tracers can potentially provide a robust understanding of sources and 20th century sediment

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. IWA Publishing 2008.

Modeling the erosion risk potential induced by terraces and their condition in a highly dynamic watershed close to the Three-Gorges-Dam

NASA Astrophysics Data System (ADS)

Schönbrodt, S.; Behrens, T.; Imbery, S.; Scholten, T.

2010-03-01

Globally, the Three-Gorges Ecosystem is currently one of the most anthropogenic influenced regions. Due to the Three-Gorges Dam large areas in the upper catchment of the Yangtze and its major tributaries become inundated. Consequently, high land-use dynamic with resettlements, construction of infrastructure, and new land reclamation for smallholder agriculture and cash crops characterize this area. Therefore, ecological impacts are expected in an unforeseeable dimension. Soil loss is one of the major threats and its control an enormous challenge. Even existing erosion control measures like dry-stone walling bench terraces have to be adapted to this new situation in order to keep their effectiveness. In the highly dynamic watershed of the Xiangxi, a first class tributary to the Yangtze, this study aims to assess and predict the spatial and temporal varying dam-caused soil erosion risk potential. Using a multi-level and multi-scale approach this study seeks to develop an integrative data-based methodology for soil erosion assessment by means of GIS-based erosion modeling using relevant digital terrain data, field investigations and remote sensing. The different scales considered cover the Xiangxi watershed (3.100 km²), the highly dynamic backwater area (500 km²), and two micro-scale study sites (3 km² and 88 km²) subject to flooding and high land-use dynamic. Central features of the Xiangxi watershed are steep slopes artificially fractured by terraces. A preliminary erosion survey has shown a strong connection of the frequency and intensity of erosion and the quality of terrace-maintenance. Terraces with wall disorders and technically poor constructed design show higher soil loss and runoff than well-maintained terraces. Their condition is regarded as a driving erosion factor. Therefore, a conceptual Terrace-Condition-Erosion model (TerraCE) was developed in order to assess to what extent soil erosion depends on the quality of terraces. Central aspects are the

Assessment of check-dam groundwater recharge with water-balance calculations

NASA Astrophysics Data System (ADS)

Djuma, Hakan; Bruggeman, Adriana; Camera, Corrado; Eliades, Marinos

2017-04-01

Studies on the enhancement of groundwater recharge by check-dams in arid and semi-arid environments mainly focus on deriving water infiltration rates from the check-dam ponding areas. This is usually achieved by applying simple water balance models, more advanced models (e.g., two dimensional groundwater models) and field tests (e.g., infiltrometer test or soil pit tests). Recharge behind the check-dam can be affected by the built-up of sediment as a result of erosion in the upstream watershed area. This natural process can increase the uncertainty in the estimates of the recharged water volume, especially for water balance calculations. Few water balance field studies of individual check-dams have been presented in the literature and none of them presented associated uncertainties of their estimates. The objectives of this study are i) to assess the effect of a check-dam on groundwater recharge from an ephemeral river; and ii) to assess annual sedimentation at the check-dam during a 4-year period. The study was conducted on a check-dam in the semi-arid island of Cyprus. Field campaigns were carried out to measure water flow, water depth and check-dam topography in order to establish check-dam water height, volume, evaporation, outflow and recharge relations. Topographic surveys were repeated at the end of consecutive hydrological years to estimate the sediment built up in the reservoir area of the check dam. Also, sediment samples were collected from the check-dam reservoir area for bulk-density analyses. To quantify the groundwater recharge, a water balance model was applied at two locations: at the check-dam and corresponding reservoir area, and at a 4-km stretch of the river bed without check-dam. Results showed that a check-dam with a storage capacity of 25,000 m3 was able to recharge to the aquifer, in four years, a total of 12 million m3 out of the 42 million m3 of measured (or modelled) streamflow. Recharge from the analyzed 4-km long river section without

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.

Long-term Records of Trace Metal Elements in Core Sediments: Anthropogenic Impacts in The Eure River Watershed

NASA Astrophysics Data System (ADS)

Gardes, T.; Debret, M.; Copard, Y.; Patault, E.; Deloffre, J.; Marcotte, S.; Develle, A. L.; Sabatier, P.; Chaumillon, E.; Coulombier, T.; Revillon, S.; Nizou, J.; Laberdesque, Y.; Koltalo, F.

2017-12-01

The Martot Dam is located in the Eure River Watershed (Normandy, France), few hundred meters upstream the Eure-Seine Rivers confluence. In the context of the European Water Framework Directive (2000/60/EC), the French Authorities planned to remove this dam in 2017. Nevertheless, impacts of the removal remain poorly studied. Classically, dam blocked sedimentary transfers downstream, but here, sediments are not blocked behind the dam but stored three hundred meters upstream in a hydraulic annex, called the Martot Pond. Furthermore, this pond is submitted to the tidal flow from the Seine Estuary despite the Martot Dam. The aim of the study is to evaluate the dam removal impacts on sedimentary transfers and re-suspension of contaminated sediments stored in the Martot Pond and the Eure River's channel. Concerning past transfers and sediments accumulation in the Eure River Watershed, sedimentary archives have been cored, before dam removal, at the Martot Pond and the Les Damps Pond (located 10km upstream the latter). Dating of sedimentary cores for both ponds indicates a sedimentation rate around 1 cm y-1. Trace metal elements quantification showed a wide metallic contamination with highest concentrations evidenced during the 1950-1960's (As: 13-22 mg kg-1; Cd: 40-55 mg kg-1; Cr: 170-210 mg kg-1; Cu: 400-490 mg kg-1; Hg: 2.3 mg kg-1; Mn: 1,280-2,200 mg kg-1; Ni: 64-75 mg kg-1; Zn: 905-990 mg kg-1) and the 1990-2000's (Cr: 95-215 mg kg-1; Ni: 100 mg kg-1; Pb: 670-855 mg kg-1). These variations of concentrations along cores can be associated with industrial past of the Eure River Watershed and sources of contamination can be identified. Thereby, Zn, Ni or Hg contamination could be associated with wastes of battery factory released in the Eure River during the economic recovery, while Pb contamination is linked to the activities of a cathode-ray tubes factory. Metals quantification in core materials highlighted anthropogenic impacts in the Eure River Watershed. These

Water contaminations in Karaj dam's rivers and their relationship with outcrop rocks with using GIS method

NASA Astrophysics Data System (ADS)

Shadmehr, Mehdi; Bafekr, Gilava; Pirouz, Mortaza

2010-05-01

Karaj Dam is located in the middle part of Alborz Mountain and its distance from Capital city, Tehran, is 63 kilometers. Watershed area approximately is 1000 square kilometers, average rate of rainfall is 625 mm per year and watershed altitude is between 4900 to 1700 meters from open sea. Karaj Dam is as a drinking water source for Tehran and Karaj cities and 21000 hectares of agricultural irrigation. Our studies is connected with As, Pb, Sb, Hg, Mo contaminant elements . We used 194 rock samples for chemical analysis and 12 water quality control stations. Chemical analysis values of rocks in the GIS divided into different classes with regard to the standard allowable values. We used SRTM data to find major catchments area and small watershed basin area behind the dam. After the necessary calculations, we determined which small basin area can be important to make more elements to pollution. The results compared with 12 water quality control stations and direct connection between the chemical composition of the rocks and water contaminated that comes from that area are very obvious. Our Study shows that natural contaminations can be enter to cycle from the southern part of basin, 14 kilometers from dam to east. Water contaminations is located along Shahrestanak river to Shahrestanak bridge and then to Mahan factory. The catchment's area for this river has highest amount of As, Sb, Pb and water quality control stations close that area show high contamination.

National Dam Inspection Program. Big Elk Lake Dam (NDI I.D. PA-0056 DER I.D. 058-019) Susquehanna River Basin, Elk Lake Stream, Susquehanna County, Pennsylvania. Phase I Inspection Report.

DTIC Science & Technology

1981-03-19

Drainage Area 2.88 square miles(") b. Discharge at Dam Site ( cfs ) Maximum known flood at dam site Unknown Outlet conduit at maximum pool Not...the spillway was determined to be 164 cfs , based on the available 2.7-foot freeboard relative to the crest of the embankment. The Big Elk Lake watershed...computer analysis are presented in Appendix D. The 100-year flood, determined according to the recommended procedure, was found to have a peak of 2290 cfs

Is Dam Removal a Benefit for Environment? Input of Sedimentary Archives

NASA Astrophysics Data System (ADS)

Debret, M.; Laberdesque, Y.; Patault, E.; Copard, Y.; Koltalo, F.; Marcotte, S.; Sabatier, P.; Develle, A. L.; Chaumillon, E.; Coulombier, T.; Deloffre, J.; Fournier, M.; Landemaine, V.; Laignel, B.; Desmet, M.

2016-12-01

In October 2015, the scientific news EOS entitled: « Contaminated sediment and dam removal: problem or opportunity? ». This title clearly highlights the problems that societies of every country are facing: many dam are about to exceed their engineered life expectancies and large quantities of contaminated sediments are stored by theses structures. Moreover in Europe, since the 2000s, the European legislative and regulatory framework highlights the consideration of the morphological operation for hydro-systems. The objective of achieving good ecological status of waters by 2015 brings watershed management authorities to consider the removal of dams to restore the free movement of sediment. But until now, the impacts associated with the removal of structures are poorly studied. The Martot dam, chosen in this study is located on the Eure River (Seine river tributary, north of France). It is an ideal case study, because its coming destruction, for ecological continuity restoration, is a "priority" and a large quantity of contaminated sediments is supposed to be stored upstream, related to high industrial concentration since decades. We investigated the evolution of the hydro-sedimentary transfers on the watershed of the Eure River and determined the nature of the contaminants stored in the sediments that are subject to be remobilized after the dam removal. To achieve these goals, we reconstructed the Eure catchment area history by studying seismic profiles, in-situt high frequency monitoring (since 2 years: flow, electrical conductivity, temperrature, turbidity, suspended particulate matter concentration) and sedimentary cores. Then, the nature, origin and timing of pollutants stored in the Eure sediments were determined. The next step will be to evaluate their bio-accessibility and the danger for trophic chain and evaluate if the removal was a benefit or problem for environment.

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

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

USGS Publications Warehouse

Snyder, Noah P.; Rubin, David M.; Alpers, Charles N.; Childs, Jonathan R.; Curtis, Jennifer A.; Flint, Lorraine E.; Wright, Scott 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

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

American River Watershed Project, California. Part 1: Main Report. Part 2: Final Supplemental Environmental Impact Statement/Environmental Impact Report. Supplemental Information Report

DTIC Science & Technology

1996-03-01

VII-7 VIII-1 Computer generated rendering of flood detention dam ................ VIII-3 VIII-2 American River Watershed Project Schedule...shows a plan view of the dam and plate 19 shows the dam in section and profile. Figure VIII-1 is a computer generated rendering of the dam. Table VIH-1...Williamson Act render the land ineligible for continued protection under that law, the local sponsor would be responsible for compensating the landowners

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

The Chena River Watershed Hydrology Model

DTIC Science & Technology

2012-04-01

Moose Creek Dam Pro- ject and determine the Probable Maximum Flood (PMF) hydrograph. The Chena River water- shed covers 2115 mi2 . It is characterized...Tanana River in Fairbanks, AK (Figure 1). The watershed has a total area of 2115 mi2 , and elevations range from 420 ft at the outlet to 5280 ft at...physical characteristics. Sub- basin Description Area ( mi2 ) Longest flow path (mi) Elevation at divide (ft) Elevation at outlet (ft

Understanding Hydrological Regime Alterations Caused by dams: the Santiago River case in the Andean Region of the Amazon Basin.

NASA Astrophysics Data System (ADS)

Rosero-Lopez, D.; Flecker, A.; Walter, M. T.

2016-12-01

Water resources in South America have been clearly targeted as key sources for hydropower expansion over the next 30 years. Ecuador, among the most biologically diverse countries in the world, has the highest density of hydropower dams, either operational, under construction, or planned, in the Amazon Basin. Ecuador's ambitious plan to change its energy portfolio is conceived to satisfy the country's demand and to empower the country to be the region's first hydroelectric energy exporter. The Santiago watershed located in the southeast part of the country has 39 facilities either under construction or in operation. The Santiago River and its main tributaries (Zamora and Upano) are expected to be impounded by large dams over the next 10 years. In order to understand the magnitude and potential impacts of regional dam development on hydrological regimes, a 35-year historical data set of stream discharge was analyzed. We examined flow regimes for time series between the construction of each dam, starting with the oldest and largest built in 1982 up until the most recent dam built in 2005. Preliminary results indicate a systematic displacement in flow seasonality following post-dam compared to pre-dam conditions. There are also notable differences in the distributions of peaks and pulses in post-dam flows. The range of changes from these results shows that punctuated and cumulative impacts are related to the size of each new impoundment. These observations and their implications to the livelihoods, biota, and ecosystems services in the Santiago watershed need to be incorporated into a broader cost-benefit analysis of hydropower generation in the western Amazon Basin.

The StreamCat Dataset: Accumulated Attributes for NHDPlusV2 Catchments (Version 2.1) for the Conterminous United States: Dam Density and Storage Volume

EPA Pesticide Factsheets

This dataset represents the dam density and storage volumes within individual, local NHDPlusV2 catchments and upstream, contributing watersheds based on National Inventory of Dams (NID) data. Attributes were calculated for every local NHDPlusV2 catchment and accumulated to provide watershed-level metrics.(See Supplementary Info for Glossary of Terms) The NID database contains information about the dam??s location, size, purpose, type, last inspection, regulatory facts, and other technical data. Structures on streams reduce the longitudinal and lateral hydrologic connectivity of the system. For example, impoundments above dams slow stream flow, cause deposition of sediment and reduce peak flows. Dams change both the discharge and sediment supply of streams, causing channel incision and bed coarsening downstream. Downstream areas are often sediment deprived, resulting in degradation, i.e., erosion of the stream bed and stream banks. This database was improved upon by locations verified by work from the USGS National Map (Jeff Simley Group). It was observed that some dams, some of them major and which do exist, were not part of the 2009 NID, but were represented in the USGS National Map dataset, and had been in the 2006 NID. Approximately 1,100 such dams were added, based on the USGS National Map lat/long and the 2006 NID attributes (dam height, storage, etc.) Finally, as clean-up, a) about 600 records with duplicate NIDID were removed, and b) about 300 reco

Factors Influencing Watershed Average Erosion Rates Calculated from Reservoir Sedimentation in Eastern USA

NASA Astrophysics Data System (ADS)

Ahamed, A.; Snyder, N. P.; David, G. C.

2014-12-01

The Reservoir Sedimentation Database (ResSed), a catalogue of reservoirs and depositional data that has recently become publically available, allows for rapid calculation of sedimentation rates and rates of capacity loss over short (annual to decadal) timescales. This study is a statistical investigation of factors controlling watershed average erosion rates (E) in eastern United States watersheds. We develop an ArcGIS-based model that delineates watersheds upstream of ResSed dams and calculate drainage areas to determine E for 191 eastern US watersheds. Geomorphic, geologic, regional, climatic, and land use variables are quantified within study watersheds using GIS. Erosion rates exhibit a large amount of scatter, ranging from 0.001 to 1.25 mm/yr. A weak inverse power law relationship between drainage area (A) and E (R2 = 0.09) is evident, similar to other studies (e.g. Milliman and Syvitski, 1992; Koppes and Montgomery, 2009). Linear regressions reveal no relationship between mean watershed slope (S) and E, possibly due to the relatively low relief of the region (mean S for all watersheds is 6°). Analysis of Variance shows that watersheds in formerly glaciated regions exhibit a statistically significant lower mean E (0.06 mm/year) than watersheds in unglaciated regions (0.12 mm/year), but that watersheds with different dam purposes show no significant differences in mean E. Linear regressions reveal no relationships between E and land use parameters like percent agricultural land and percent impervious surfaces (I), but classification and regression trees indicate that watersheds in highly developed regions (I > 34%) exhibit mean E (0.36 mm/year) that is four times higher than watersheds in less developed (I < 34%) regions (0.09 mm/year). Further, interactions between land use variables emerge in formerly glaciated regions, where increased agricultural land results in higher rates of annual capacity loss in reservoirs (R2 = 0.56). Plots of E versus timescale of

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.

Out, out, dam spot! The geomorphic response of rivers to dam removal.

Treesearch

Jonathan Thompson

2005-01-01

About 75,000 irrigation, flood control, and hydropower dams in the United States are aging, deteriorating, or have outlived their useful lives and purposes. Not surprisingly, dam removal is emerging as both a challenge and opportunity for river management and research. Scientists at the PNW Research Station in Corvallis, Oregon, are using scale models and monitoring...

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...

Spatial Multicriteria Decision Analysis of Flood Risks in Aging-Dam Management in China: A Framework and Case Study

PubMed Central

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

2011-01-01

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. PMID:21655125

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.

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

The Social, Historical, and Institutional Contingencies of Dam Removal

NASA Astrophysics Data System (ADS)

Magilligan, F. J.; Sneddon, C. S.; Fox, C. A.

2017-06-01

Environmental managers in the United States and elsewhere are increasingly perceiving dam removal as a critical tool for river restoration and enhancing watershed resilience. In New England, over 125 dams have been dismantled for ecological and economic rationales. A surprising number of these removals, including many that are ongoing, have generated heated conflicts between restoration proponents and local communities who value their dammed landscapes. Using a comparative case study approach, we examine the environmental conflict around efforts to remove six dams in New England. Each of these removal efforts followed quite different paths and resultant outcomes: successful removal, stalled removal, and failure despite seemingly favorable institutional conditions. Lengthy conflicts often transpired in instances where removals occurred, but these were successfully arbitrated by paying attention to local historical-geographical conditions conducive to removal and by brokering effective compromises between dam owners and the various local actors and stakeholders involved in the removal process. Yet our results across all cases suggest that these are necessary, but not sufficient conditions for restoration through dam removal since a similar set of conditions typified cases where removals are continuously stalled or completely halted. Scholars examining the intersection between ecological restoration and environmental politics should remain vigilant in seeking patterns and generalities across cases of environmental conflict in order to promote important biophysical goals, but must also remain open to the ways in which those goals are thwarted and shaped by conflicts that are deeply contingent on historical-geographical conditions and broader institutional networks of power and influence.

The Social, Historical, and Institutional Contingencies of Dam Removal.

PubMed

Magilligan, F J; Sneddon, C S; Fox, C A

2017-06-01

Environmental managers in the United States and elsewhere are increasingly perceiving dam removal as a critical tool for river restoration and enhancing watershed resilience. In New England, over 125 dams have been dismantled for ecological and economic rationales. A surprising number of these removals, including many that are ongoing, have generated heated conflicts between restoration proponents and local communities who value their dammed landscapes. Using a comparative case study approach, we examine the environmental conflict around efforts to remove six dams in New England. Each of these removal efforts followed quite different paths and resultant outcomes: successful removal, stalled removal, and failure despite seemingly favorable institutional conditions. Lengthy conflicts often transpired in instances where removals occurred, but these were successfully arbitrated by paying attention to local historical-geographical conditions conducive to removal and by brokering effective compromises between dam owners and the various local actors and stakeholders involved in the removal process. Yet our results across all cases suggest that these are necessary, but not sufficient conditions for restoration through dam removal since a similar set of conditions typified cases where removals are continuously stalled or completely halted. Scholars examining the intersection between ecological restoration and environmental politics should remain vigilant in seeking patterns and generalities across cases of environmental conflict in order to promote important biophysical goals, but must also remain open to the ways in which those goals are thwarted and shaped by conflicts that are deeply contingent on historical-geographical conditions and broader institutional networks of power and influence.

Role of the check dam in land development on the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Xu, Xiang-Zhou; Zhang, Luo-Hao; Zhu, Tongxin; Dang, Tian-Min; Zhang, Hong-Wu; Xu, Shi-Guo

2017-04-01

Check dam is one of the most effective measures to reduce flow connectivity, which can retain soil and water, and increase land productivity. More than 100,000 check dams have been built on the Loess Plateau since 1950s. However, quantifying the effect of check dams on water resources and water environments remains a challenge. In this study, an in-depth field investigation together with a credible statistical analysis was carried out in two representative catchments on the Loess Plateau, Nanxiaohegou Catchment and Jiuyuangou Catchment, to assess the effectiveness of check dams in soil, water and nutrients conservation. The results show: (1) Check dam plays an important role in conserving water, soil, and nutrients on the Loess Plateau. About half of the total transported water and more than 80 % of the total transported soil and nutrients, had been locally retained in the selected catchments. Hence check dams had a significant benefit to improve soil fertility in the small watersheds, and reducing water pollution downstream of dams. (2) Compared to terrace farmlands, forest lands and grasslands, check-dam lands were much more important in conserving water, soil and nutrients in the catchments. Nearly 50% of the reduced water and more than 70% of the stored soil and nutrients in the study catchments were solely retained by the check dams, whereas the area of the dam lands was less than 7% of the total conservation land area. (3) Check dams are still effective in large storms even if dams were damaged by floods. It is often assumed that check dams could only retain sediment in small flood events whereas most of the stored soil may be washed out as the dams may be destroyed in a disastrous flood. Furthermore, if a major check dam, namely the key project dam, was built in the gully outlet, the flood could be controlled, and thereupon the dam-break can be also avoided. We suggest that a compensation and incentive policy be implemented on dam building to realize the

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.

Flood hydrology and dam-breach hydraulic analyses of four reservoirs in the Black Hills, South Dakota

USGS Publications Warehouse

Hoogestraat, Galen K.

2011-01-01

Extensive information about the construction of dams or potential downstream hazards in the event of a dam breach is not available for many small reservoirs within the Black Hills National Forest. In 2009, the U.S. Forest Service identified the need for reconnaissance-level dam-breach assessments for four of these reservoirs within the Black Hills National Forest (Iron Creek, Horsethief, Lakota, and Mitchell Lakes) with the potential to flood downstream structures. Flood hydrology and dam-breach hydraulic analyses for the four selected reservoirs were conducted by the U.S. Geological Survey in cooperation with the U.S. Forest service to estimate the areal extent of downstream inundation. Three high-flow breach scenarios were considered for cases when the dam is in place (overtopped) and when a dam break (failure) occurs: the 100-year recurrence 24-hour precipitation, 500-year recurrence peak flow, and the probable maximum precipitation. Inundation maps were developed that show the estimated extent of downstream floodwaters from simulated scenarios. Simulation results were used to determine the hazard classification of a dam break (high, significant, or low), based primarily on the potential for loss of life or property damage resulting from downstream inundation because of the flood surge.The inflow design floods resulting from the two simulated storm events (100-year 24-hour and probable maximum precipitation) were determined using the U.S. Army Corps of Engineers Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS). The inflow design flood for the 500-year recurrence peak flow was determined by using regional regression equations developed for streamflow-gaging stations with similar watershed characteristics. The step-backwater hydraulic analysis model, Hydrologic Engineering Center's River Analysis System (HEC-RAS), was used to determine water-surface profiles of in-place and dam-break scenarios for the three inflow design floods that were

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

USGS Publications Warehouse

Manning, Andrew H.; Caine, Jonathan S.

2007-01-01

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, ΔNe > 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.

A study of water balances over the Tigris-Euphrates watershed

NASA Astrophysics Data System (ADS)

Kavvas, M. L.; Chen, Z. Q.; Anderson, M. L.; Ohara, N.; Yoon, J. Y.; Xiang, Fu

Tigris-Euphrates watershed was considered as one hydrologic unit, and a scientific assessment of its water resources was performed. Accordingly, (a) an inventory of land use/land cover, vegetation, soils, and existing hydraulic structures in the watershed was performed; (b) a regional hydroclimate model, RegHCM-TE, of the watershed was developed, and used to reconstruct historical precipitation data, to perform land hydrologic water balance computations for infiltration, soil water storage, actual evapotranspiration, direct runoff as input for streamflow computations, and to estimate irrigation water demands; and (c) a hydrologic model was developed to route streamflows within the river network of the watershed. Also, an algorithm for operating the reservoirs within the watershed was developed, and utilized to perform dynamic water balance studies under various water supply/demand scenarios to establish efficient utilization of the watershed’s water resources to meet the water demands of the riparian countries in the basin. Within this dynamic water balance framework, it is possible to assess and quantify the effect of sequential river flows on the chronologically sequential water balances over the watershed. The water balance study for the natural flow conditions prior to the development of large dams within TE basin, during the 1957-1969 critical period is presented.

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

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

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.

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.

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

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

National Dam Inspection Program. Macham Dam (NDI I.D. Number PA-00043 Pennder I.D. Number 8-56) Susquehanna River Basin. Wolcott Creek, Bradford County, Pennsylvania. Phase I Inspection Report,

DTIC Science & Technology

1980-07-01

New York, 1972. 14. Standard Mathematical Tables, 21st Edition, The Chemical Rubber Company , 1973, page 15. 15. Engineering Field Manual, U. S ...Pennsylvania. The structure is situated at the intersection of Wolcott Hollow and Kellogg Roads approximately five miles west of Greenes Landing, Pennsylvania...The dam, reservoir, and watershed are located within the Sayre and Bentley Creek, Pennsylvania7.5 minute U. S . G.S. topographic quadrangles ( see

Geomorphic responses to dam removal in the United States – a two-decade perspective

USGS Publications Warehouse

Major, Jon J.; East, Amy; O'Connor, Jim E.; Grant, Gordon E.; Wilcox, Andrew C.; Magirl, Christopher S.; Collins, Matthias J.; Tullos, Desiree D.; Tsutsumi, Daizo; Laronne, Jonathan B.

2017-01-01

Recent decades have seen a marked increase in the number of dams removed in the United States. Investigations following a number of removals are beginning to inform how, and how fast, rivers and their ecosystems respond to released sediment. Though only a few tens of studies detail physical responses to removals, common findings have begun to emerge. They include: (1) Rivers are resilient and respond quickly to dam removals, especially when removals are sudden rather than prolonged. Rivers can swiftly evacuate large fractions of reservoir sediment (≥50% within one year), especially when sediment is coarse grained (sand and gravel). The channel downstream typically takes months to years—not decades—to achieve a degree of stability within its range of natural variability. (2) Modest streamflows (<2-year return interval flows) can erode and transport large amounts of reservoir sediment. Greater streamflows commonly are needed to access remnant reservoir sediment and transport it downstream. (3) Dam height, sediment volume, and sediment caliber strongly influence downstream response to dam removal. Removals of large dams (≥10 m tall) have had longer-lasting and more widespread downstream effects than more common removals of small dams. (4) Downstream valley morphology and position of a dam within a watershed influence the distribution of released sediment. Valley confinement, downstream channel gradient, locations and depths of channel pools, locations and geometries of extant channel bars, and locations of other reservoirs all influence the downstream fate of released sediment.

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.

Watershed microinfarct pathology and cognition in older persons.

PubMed

Kapasi, Alifiya; Leurgans, Sue E; James, Bryan D; Boyle, Patricia A; Arvanitakis, Zoe; Nag, Sukriti; Bennett, David A; Buchman, Aron S; Schneider, Julie A

2018-05-30

Brain microinfarcts are common in aging and are associated with cognitive impairment. Anterior and posterior watershed border zones lie at the territories of the anterior, middle, and posterior cerebral arteries, and are more vulnerable to hypoperfusion than brain regions outside the watershed areas. However, little is known about microinfarcts in these regions and how they relate to cognition in aging. Participants from the Rush Memory and Aging Project, a community-based clinical-pathologic study of aging, underwent detailed annual cognitive evaluations. We examined 356 consecutive autopsy cases (mean age-at-death, 91 years [SD = 6.16]; 28% men) for microinfarcts from 3 watershed brain regions (2 anterior and 1 posterior) and 8 brain regions outside the watershed regions. Linear regression models were used to examine the association of cortical watershed microinfarcts with cognition, including global cognition and 5 cognitive domains. Microinfarcts in any region were present in 133 (37%) participants, of which 50 had microinfarcts in watershed regions. Persons with multiple microinfarcts in cortical watershed regions had lower global cognition (estimate = -0.56, standard error (SE) = 0.26, p = 0.03) and lower cognitive function in the specific domains of working memory (estimate = -0.58, SE = 0.27, p = 0.03) and visuospatial abilities (estimate = -0.57, SE = 0.27, p = 0.03), even after controlling for microinfarcts in other brain regions, demographics, and age-related pathologies. Neither the presence nor multiplicity of microinfarcts in brain regions outside the cortical watershed regions were related to global cognition or any of the 5 cognitive domains. These findings suggest that multiple microinfarcts in watershed regions contribute to age-related cognitive impairment. Copyright © 2018 Elsevier Inc. All rights reserved.

Nonlinear scaling of the Unit Hydrograph Peaking Factor for dam safety

NASA Astrophysics Data System (ADS)

Pradhan, N. R.; Loney, D.

2017-12-01

Existing U.S. Army Corps of Engineers (USACE) policy suggests unit hydrograph peaking factor (UHPF), the ratio of an observed and modeled event unit hydrograph peak, range between 1.25 and 1.50 to ensure dam safety. It is pertinent to investigate the impact of extreme flood events on the validity of this range through physically based rainfall-runoff models not available during the planning and design of most USACE dams. The UHPF range was analyzed by deploying the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model in the Goose Creek, VA, watershed to develop a UHPF relationship with excess rainfall across various return-period events. An effective rainfall factor (ERF) is introduced to validate existing UHPF guidance as well as provide a nonlinear UHPF scaling relation when effective rainfall does not match that of the UH design event.

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.

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

USDA-ARS?s Scientific Manuscript database

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...

Modeling Potential Surface and Shallow Groundwater Storage Provided by Beaver Ponds Across Watersheds

NASA Astrophysics Data System (ADS)

Hafen, K.; Wheaton, J. M.; Macfarlane, W.

2016-12-01

Damming of streams by North American Beaver (Castor canadensis) has been shown to provide a host of potentially desirable hydraulic and hydrologic impacts. Notably, increases in surface water storage and groundwater storage may alter the timing and delivery of water around individual dams and dam complexes. Anecdotal evidence suggests these changes may be important for increasing and maintaining baseflow and even helping some intermittent streams flow perennially. In the arid west, these impacts could be particularly salient in the face of climate change. However, few studies have examined the hydrologic impacts of beaver dams at scales large enough to provide insight for water management, in part because understanding or modeling these impacts at large spatial scales has been precluded by uncertainty concerning the number of beaver dams a drainage network can support. Using the recently developed Beaver Restoration Assessment Tool (BRAT) to identify possible densities and spatial configurations of beaver dams, we developed a model that predicts the area and volume of surface water storage associated with dams of various sizes, and applied this model at different dam densities across multiple watersheds (HUC12) in northern Utah. We then used model results as inputs to the MODFLOW groundwater model to identify the subsequent changes to shallow groundwater storage. The spatially explicit water storage estimates produced by our approach will be useful in evaluating potential beaver restoration and conservation, and will also provide necessary information for developing hydrologic models to specifically identify the effects beaver dams may have on water delivery and timing.

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

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

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 Canyonmore » 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

Liberated rivers: lessons from 40 years of dam removal

Treesearch

Marie Oliver; Gordon Grant

2017-01-01

In recent decades, dam removal has emerged as a viable national and international strategy for river restoration. According to American Rivers, a river conservation organization, more than 1,100 dams have been removed in the United States in the past 40 years, and more than half of these were demolished in the past decade. This trend is likely to continue as dams age,...

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

Coupled dam safety analysis using WinDAM

USDA-ARS?s Scientific Manuscript database

Windows® Dam Analysis Modules (WinDAM) is a set of modular software components that can be used to analyze overtopping and internal erosion of embankment dams. Dakota is an extensive software framework for design exploration and simulation. These tools can be coupled to create a powerful framework...

Flathead River Focus Watershed Coordinator, 2002 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 Kerrmore » 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

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

Assessment of 21st century drought conditions at Shasta Dam based on dynamically projected water supply conditions by a regional climate model coupled with a physically-based hydrology model.

PubMed

Trinh, T; Ishida, K; Kavvas, M L; Ercan, A; Carr, K

2017-05-15

Along with socioeconomic developments, and population increase, natural disasters around the world have recently increased the awareness of harmful impacts they cause. Among natural disasters, drought is of great interest to scientists due to the extraordinary diversity of their severity and duration. Motivated by the development of a potential approach to investigate future possible droughts in a probabilistic framework based on climate change projections, a methodology to consider thirteen future climate projections based on four emission scenarios to characterize droughts is presented. The proposed approach uses a regional climate model coupled with a physically-based hydrology model (Watershed Environmental Hydrology Hydro-Climate Model; WEHY-HCM) to generate thirteen equally likely future water supply projections. The water supply projections were compared to the current water demand for the detection of drought events and estimation of drought properties. The procedure was applied to Shasta Dam watershed to analyze drought conditions at the watershed outlet, Shasta Dam. The results suggest an increasing water scarcity at Shasta Dam with more severe and longer future drought events in some future scenarios. An important advantage of the proposed approach to the probabilistic analysis of future droughts is that it provides the drought properties of the 100-year and 200-year return periods without resorting to any extrapolation of the frequency curve. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

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.

Physical modeling of stepped spillways

USDA-ARS?s Scientific Manuscript database

Stepped spillways applied to embankment dams are becoming popular for addressing the rehabilitation of aging watershed dams, especially those situated in the urban landscape. Stepped spillways are typically placed over the existing embankment, which provides for minimal disturbance to the original ...

Design of converging stepped spillways

USDA-ARS?s Scientific Manuscript database

Roller compacted concrete (RCC) stepped spillways are growing in popularity for providing overtopping protection for aging watershed dams with inadequate auxiliary spillway capacity and for the construction of new dams. Unobtainable land rights, topographic features, and land use changes caused by ...

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.

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

Status and trends of dam removal research in the United States

Treesearch

J. Ryan Bellmore; Jeffrey J. Duda; Laura S. Craig; Samantha L. Greene; Christian E. Torgersen; Mathias J. Collins; Katherine Vittum

2016-01-01

Aging infrastructure coupled with growing interest in river restoration has driven a dramatic increase in the practice of dam removal. With this increase, there has been a proliferation of studies that assess the physical and ecological responses of rivers to these removals. As more dams are considered for removal, scientific information from these dam-removal studies...

Nearly 400 million people are at higher risk of schistosomiasis because dams block the migration of snail-eating river prawns

USGS Publications Warehouse

Sokolow, Susanne H.; Jones, Isabel J.; Jocque, Merlijn M. T.; La, Diana; Cords, Olivia; Knight, Anika; Lund, Andrea; Wood, Chelsea L.; Lafferty, Kevin D.; Hoover, Christopher M.; Collender, Phillip A.; Remais, Justin V.; Lopez-Carr, David; Fisk, Jonathan; Kuris, Armand M.; De Leo, Giulio A.

2017-01-01

Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socio-economic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277–385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (i) upstream catchments within historical habitats of native prawns, (ii) comparable undammed watersheds, and (iii) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoration of native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease.

Nearly 400 million people are at higher risk of schistosomiasis because dams block the migration of snail-eating river prawns

NASA Astrophysics Data System (ADS)

Sokolow, S. H.; Jones, I. J.; La, D.; Cords, O.; Knight, A.; Lund, A.; Wood, C. L.; Lafferty, K. D.; Kuris, A. M.; Hoover, C.; Collender, P. A.; Remais, J.; Lopez-Carr, D.; De Leo, G.

2016-12-01

Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socioeconomic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277 to 385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (1) upstream catchments within historical habitats of native prawns, (2) comparable undammed watersheds, and (3) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoring native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease.

Land use change impacts on discharge analysis using SWAT model at Ciherang Pondok DAM catchment area

NASA Astrophysics Data System (ADS)

Utamahadi, M. A.; Pandjaitan, N. H.; Rau, M. I.

2018-05-01

The prompt increase of population influenced the requirement for new regions to fulfill people’s primary needs. Its increased land use change and caused many impacts on the environment, including watersheds as well. Ciherang Pondok DAM catchment area is part of Cisadane watershed and was selected as the research area. This research aimed to analyse the water supply and water discharge change caused by the Urban Planning (RTRW) in 2020. The analysis was conducted using soil and water assessment tools (SWAT) model. Stages of this research were catchment area delineation, HRU identification, calibration and validation of models, and prediction of discharge and water demand. The result showed that RTRW of 2020 increased the maximum discharge of 1.6 m3/s and decreased the minimum discharge of 0.01 m3/s, hence the maximum and minimum discharge ratio increased 0.26% from 2016. Output discharge in 2020 at Ciherang Pondok Dam Catchment Area was classified as well, with discharge of 6.72 – 126.2 m3/s, and could fulfil water demand. For the best result, it is better to use climate data from weather stations inside the study area and it is required an improvement in data archiving system.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 Kerrmore » 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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 Kerrmore » 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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 Kerrmore » 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

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

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.

Converging stepped spillways: Simplified momentum analysis approach

USDA-ARS?s Scientific Manuscript database

Roller compacted concrete (RCC) stepped spillways are growing in popularity for providing overtopping protection for aging watershed dams with inadequate auxiliary spillway capacity and for the construction of new dams. Site conditions, such as limited right-of-way, topography, and geological forma...

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

Fragmentation by Dams Threatens Diadromous Fauna in Upstream Protected Areas - the Case of the La Amistad World Heritage Site (Costa Rica and Panama)

NASA Astrophysics Data System (ADS)

McLarney, W.; Mafla Herrera, M.; Arias Moreno, A. M.; Snyder, M. N.

2016-12-01

Biological consequences of fragmenting rivers with dams are especially acute for migratory species, and even moreso for diadromes (animals obliged to travel between marine and fresh water environments in order to complete their life cycles). Diadromy is a worldwide phenomenon, occurring wherever fresh water rivers run to the sea. Worldwide, diadromous behavior has been described for > 300 species of fish in 37 families, as well as for all of the > 800 species of so-called "freshwater" shrimp in 4 families, plus a few crabs and snails. Diadromy is especially prevalent on islands and isthmuses, where rivers are necessarily short and development of primary freshwater fauna limited. One example is the Mesoamerican isthmus, extending from southern Mexico to the Panama/Colombia border. A 2006 study showed more than 300 high (> 15 m.) dams planned for this 8 country region. One example of the consequences emerges from Asociacion ANAI's biomonitoring work over 17 years in one part of Mesoamerica - the watersheds draining the Caribbean slope of the La Amistad World Heritage Site in Costa Rica and Panama. Our work has shown that over 80 % of fish and all of the shrimp in rivers above 100 m. altitude are diadromes. If all currently planned dams are built, we predict that 11 species of fish and shrimp will be extirpated from >90% of the World Heritage Site. Precedent exists in Puerto Rico, where damming has eliminated diadromous fish and all but a remnant of the shrimp from 25% of the island's watersheds. In La Amistad, the consequences, for biodiversity and fishery resources relied upon by neighboring indigenous ethnias are obvious. In Panama, protected area boundaries were drawn to avoid the issue of dams and reservoirs in national parks; our research shows the need for more comprehensive design criteria to prevent extirpations in protected areas.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 canmore » 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.« less

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

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

River-damming, late-Quaternary rockslides in the Ötz Valley region (Tyrol, Austria)

NASA Astrophysics Data System (ADS)

Dufresne, A.; Ostermann, M.; Preusser, F.

2018-06-01

The Ötz Valley and adjacent regions in Tyrol (Austria) have been repeatedly affected by large rockslope failures following deglaciation. Six rockslides, each over 107 m3 in volume, were emplaced into the Ötz and Inn valleys, five of which formed persistent rockslide dams. Even though catastrophic rockslope failures are short-lived events (commonly minutes) they can have long-lasting impacts on the landscape. For example, large fans have built in the Ötz Valley and knickpoints persist at the former dam sites even though the Ötz River has eroded through the deposits during the past thousands of years; exact age-constraints of rockslide dam failure, however, are still scarce. Empirical, geomorphic stability indices from the literature successfully identified the least and the most stable dams of this group, whereas the rest remain inconclusive with some indices variably placing the dams in the stable, unstable, and uncertain categories. This shows (a) that further index calibrations and (b) better age constraints on dam formation and failure are needed, and (c) that the exact processes of dam failure are not always trivial to pinpoint for ancient (partially) breached dams. This study is a contribution towards better constraining the nature and landscape impact of dam formation following large rockslope failures.

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.

ECHETA DAM SPILLWAY. COMING OUT BELOW THE DAM. AT CENTER ...

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

ECHETA DAM SPILLWAY. COMING OUT BELOW THE DAM. AT CENTER OF PHOTO. VIEW TO NORTHEAST. - Echeta Dam & Reservoir, 2.9 miles east of Echeta Road at Echeta Railroad Siding at County Road 293, Echeta, Campbell County, WY

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

The Dams and Monitoring Systems and Case Study: Ataturk and Karakaya Dams

NASA Astrophysics Data System (ADS)

Kalkan, Y.; Bilgi, S.; Gülnerman, A. G.

2017-12-01

Dams are among the most important engineering structures used for flood controls, agricultural purposes as well as drinking and hydroelectric power. Especially after the Second World War, developments on the construction technology, increase the construction of larger capacity dams. There are more than 150.000 dams in the world and almost 1000 dams in Turkey, according to international criteria. Although dams provide benefits to humans, they possess structural risks too. To determine the performance of dams on structural safety, assessing the spatial data is very important. 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 general information on dams and their different monitoring systems by taking into account two different dams and their structural specifications with the required information. The case study in this paper depends on a comparison of the monitoring surveys on Atatürk Dam and Karakaya Dam, which are constructed on Firat River with two different structural

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

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

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.

Video shot boundary detection using region-growing-based watershed method

NASA Astrophysics Data System (ADS)

Wang, Jinsong; Patel, Nilesh; Grosky, William

2004-10-01

In this paper, a novel shot boundary detection approach is presented, based on the popular region growing segmentation method - Watershed segmentation. In image processing, gray-scale pictures could be considered as topographic reliefs, in which the numerical value of each pixel of a given image represents the elevation at that point. Watershed method segments images by filling up basins with water starting at local minima, and at points where water coming from different basins meet, dams are built. In our method, each frame in the video sequences is first transformed from the feature space into the topographic space based on a density function. Low-level features are extracted from frame to frame. Each frame is then treated as a point in the feature space. The density of each point is defined as the sum of the influence functions of all neighboring data points. The height function that is originally used in Watershed segmentation is then replaced by inverting the density at the point. Thus, all the highest density values are transformed into local minima. Subsequently, Watershed segmentation is performed in the topographic space. The intuitive idea under our method is that frames within a shot are highly agglomerative in the feature space and have higher possibilities to be merged together, while those frames between shots representing the shot changes are not, hence they have less density values and are less likely to be clustered by carefully extracting the markers and choosing the stopping criterion.

Hydropower generation, flood control and dam cascades: A national assessment for Vietnam

NASA Astrophysics Data System (ADS)

Nguyen-Tien, Viet; Elliott, Robert J. R.; Strobl, Eric A.

2018-05-01

Vietnam is a country with diverse terrain and climatic conditions and a dependency on hydropower for a significant proportion of its power needs and as such, is particularly vulnerable to changes in climate. In this paper we apply SWAT (Soil and Water Assessment Tool) derived discharge simulation results coupled with regression analysis to estimate the performance of hydropower plants for Vietnam between 1995 and mid-2014 when both power supply and demand increased rapidly. Our approach is to examine the watershed formed from three large inter-boundary basins: The Red River, the Vietnam Coast and the Lower Mekong River, which have a total area of 977,964 km2. We then divide this area into 7,887 sub-basins with an average area of 131.6 km2 (based on level 12 of HydroSHEDS/HydroBASINS datasets) and 53,024 Hydrological Response Units (HRUs). Next we simulate river flow for the 40 largest hydropower plants across Vietnam. Our validation process demonstrates that the simulated flows are significantly correlated with the gauged inflows into these dams and are able to serve as a good proxy for the inflows into hydropower dams in our baseline energy regression, which captures 87.7% of the variation in monthly power generation. In other results we estimate that large dams sacrifice on average around 18.2% of their contemporaneous production for the purpose of flood control. When we assess Vietnam's current alignment of dams we find that the current cascades of large hydropower dams appear to be reasonably efficient: each MWh/day increase in upstream generation adds 0.146 MWh/day to downstream generation. The study provides evidence for the multiple benefits of a national system of large hydropower dams using a cascade design. Such a system may help overcome future adverse impacts from changes in climate conditions. However, our results show that there is still room for improvement in the harmonization of cascades in some basins. Finally, possible adverse hydro

Nearly 400 million people are at higher risk of schistosomiasis because dams block the migration of snail-eating river prawns.

PubMed

Sokolow, Susanne H; Jones, Isabel J; Jocque, Merlijn; La, Diana; Cords, Olivia; Knight, Anika; Lund, Andrea; Wood, Chelsea L; Lafferty, Kevin D; Hoover, Christopher M; Collender, Phillip A; Remais, Justin V; Lopez-Carr, David; Fisk, Jonathan; Kuris, Armand M; De Leo, Giulio A

2017-06-05

Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socio-economic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277-385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (i) upstream catchments within historical habitats of native prawns, (ii) comparable undammed watersheds, and (iii) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoration of native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease

Nearly 400 million people are at higher risk of schistosomiasis because dams block the migration of snail-eating river prawns

PubMed Central

Jones, Isabel J.; Jocque, Merlijn; La, Diana; Cords, Olivia; Knight, Anika; Lund, Andrea; Lafferty, Kevin D.; Hoover, Christopher M.; Collender, Phillip A.; Remais, Justin V.; Lopez-Carr, David; Kuris, Armand M.; De Leo, Giulio A.

2017-01-01

Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socio-economic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277–385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (i) upstream catchments within historical habitats of native prawns, (ii) comparable undammed watersheds, and (iii) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoration of native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease. This

Interpreting Beryllium-7 and Lead-210 fluxes and ratios for age dating fluvial sediments in Difficult Run Watershed, Virginia, USA

NASA Astrophysics Data System (ADS)

Karwan, D. L.; Pizzuto, J. E.; Skalak, K.; Benthem, A.

2016-12-01

The sources and transport of suspended sediments within watersheds of varying sizes remain an important area of study within the geosciences. Short term fallout radionuclides, such as Beryllium-7 (7Be) and Lead-210 (210Pb), and their ratios can be a valuable tool for gaining insight into suspended sediment transport dynamics. We use these techniques in combination with other sediment exchange and transport models to estimate residence and transport time of suspended sediment in nested reaches of the Difficult Run watershed (Virginia, USA) on timescales from storm events to centuries and longer. During several winter and spring 2015-2016 precipitation events, Beryllium-7 to excess Lead-210 ratios vary from 0.4 - 2.5 in direct channel precipitation and 0.2 - 1 on suspended sediment. Previously published age dating models would suggest that the suspended sediments were originally "tagged" by, or in contact with wet fallout of, by Beryllium7 fallout approximately 20-80 days before sampling. Sediments at the upstream reach (watershed size 14 km2) tend to be older ( 75 days), while sediments at the downstream reach (watershed size 117 km2) tend to be newer ( 20 days). We use multiple sediment transport models and hypothesize that fluvial sediments are tagged with direct channel precipitation between the upstream and downstream reach, explaining their apparently younger age. Our analysis includes error propagation as well as a comparison of radioisotope gamma analyses from different labs across multiple institutions.

Geomorphology of the Elwha River and its Delta: Chapter 3 in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal

USGS Publications Warehouse

Warrick, Jonathan A.; Draut, Amy E.; McHenry, Michael L.; Miller, Ian M.; Magirl, Christopher S.; Beirne, Matthew M.; Stevens, Andrew Stevens; Logan, Joshua B.; Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.

2011-01-01

The removal of two dams on the Elwha River will introduce massive volumes of sediment to the river, and this increase in sediment supply in the river will likely modify the shapes and forms of the river and coastal landscape downstream of the dams. This chapter provides the geologic and geomorphologic background of the Olympic Peninsula and the Elwha River with emphasis on the present river and shoreline. The Elwha River watershed was formed through the uplift of the Olympic Mountains, erosion and movement of sediment throughout the watershed from glaciers, and downslope movement of sediment from gravitational and hydrologic forces. Recent alterations to the river morphology and sediment movement through the river include the two large dams slated to be removed in 2011, but also include repeated bulldozing of channel boundaries, construction and maintenance of flood plain levees, a weir and diversion channel for water supply purposes, and engineered log jams to help enhance river habitat for salmon. The shoreline of the Elwha River delta has changed in location by several kilometers during the past 14,000 years, in response to variations in the local sea-level of approximately 150 meters. Erosion of the shoreline has accelerated during the past 80 years, resulting in landward movement of the beach by more than 200 meters near the river mouth, net reduction in the area of coastal wetlands, and the development of an armored low-tide terrace of the beach consisting primarily of cobble. Changes to the river and coastal morphology during and following dam removal may be substantial, and consistent, long-term monitoring of these systems will be needed to characterize the effects of the dam removal project.

Dam removal: Listening in

Treesearch

M. M. Foley; J. R. Bellmore; J. E. O' Connor; J. J. Duda; A. E. East; G. E. Grant; C. W. Anderson; J. A. Bountry; M. J. Collins; P. J. Connolly; L. S. Craig; J. E. Evans; S. L. Greene; F. J. Magilligan; C. S. Magirl; J. J. Major; G. R. Pess; T. J. Randle; P. B. Shafroth; C. E. Torgersen; D. Tullos; A. C. Wilcox

2017-01-01

Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings....

Dam failure analysis for the Lago El Guineo Dam, Orocovis, Puerto Rico

USGS Publications Warehouse

Gómez-Fragoso, Julieta; Heriberto Torres-Sierra,

2016-08-09

The U.S. Geological Survey, in cooperation with the Puerto Rico Electric Power Authority, completed hydrologic and hydraulic analyses to assess the potential hazard to human life and property associated with the hypothetical failure of the Lago El Guineo Dam. The Lago El Guineo Dam is within the headwaters of the Río Grande de Manatí and impounds a drainage area of about 4.25 square kilometers.The hydrologic assessment was designed to determine the outflow hydrographs and peak discharges for Lago El Guineo and other subbasins in the Río Grande de Manatí hydrographic basin for three extreme rainfall events: (1) a 6-hour probable maximum precipitation event, (2) a 24-hour probable maximum precipitation event, and (3) a 24-hour, 100-year recurrence rainfall event. The hydraulic study simulated a dam failure of Lago El Guineo Dam using flood hydrographs generated from the hydrologic study. The simulated dam failure generated a hydrograph that was routed downstream from Lago El Guineo Dam through the lower reaches of the Río Toro Negro and the Río Grande de Manatí to determine water-surface profiles developed from the event-based hydrologic scenarios and “sunny day” conditions. The Hydrologic Engineering Center’s Hydrologic Modeling System (HEC–HMS) and Hydrologic Engineering Center’s River Analysis System (HEC–RAS) computer programs, developed by the U.S. Army Corps of Engineers, were used for the hydrologic and hydraulic modeling, respectively. The flow routing in the hydraulic analyses was completed using the unsteady flow module available in the HEC–RAS model.Above the Lago El Guineo Dam, the simulated inflow peak discharges from HEC–HMS resulted in about 550 and 414 cubic meters per second for the 6- and 24-hour probable maximum precipitation events, respectively. The 24-hour, 100-year recurrence storm simulation resulted in a peak discharge of about 216 cubic meters per second. For the hydrologic analysis, no dam failure conditions are

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 troutmore » 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.« less

Using a High-Resolution Ensemble Modeling Method to Inform Risk-Based Decision-Making at Taylor Park Dam, Colorado

NASA Astrophysics Data System (ADS)

Mueller, M.; Mahoney, K. M.; Holman, K. D.

2015-12-01

The Bureau of Reclamation (Reclamation) is responsible for the safety of Taylor Park Dam, located in central Colorado at an elevation of 9300 feet. A key aspect of dam safety is anticipating extreme precipitation, runoff and the associated inflow of water to the reservoir within a probabilistic framework for risk analyses. The Cooperative Institute for Research in Environmental Sciences (CIRES) has partnered with Reclamation to improve understanding and estimation of precipitation in the western United States, including the Taylor Park watershed. A significant challenge is that Taylor Park Dam is located in a relatively data-sparse region, surrounded by mountains exceeding 12,000 feet. To better estimate heavy precipitation events in this basin, a high-resolution modeling approach is used. The Weather Research and Forecasting (WRF) model is employed to simulate events that have produced observed peaks in streamflow at the location of interest. Importantly, an ensemble of model simulations are run on each event so that uncertainty bounds (i.e., forecast error) may be provided such that the model outputs may be more effectively used in Reclamation's risk assessment framework. Model estimates of precipitation (and the uncertainty thereof) are then used in rainfall runoff models to determine the probability of inflows to the reservoir for use in Reclamation's dam safety risk analyses.

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

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.

Classification of the alterations of beaver dams to headwater streams in northeastern Connecticut, U.S.A.

NASA Astrophysics Data System (ADS)

Burchsted, Denise; Daniels, Melinda D.

2014-01-01

Of the many types of barriers to water flow, beaver dams are among the smallest, typically lasting less than a decade and rarely exceeding 1.5 m in height. They are also among the most frequent and common obstructions in rivers, with a density often exceeding ten dams per km, a frequency of construction within a given network on a time scale of years, and a historic extent covering most of North America. Past quantification of the geomorphologic impact of beaver dams has primarily been limited to local impacts within individual impoundments and is of limited geographic scope. To assess the impact of beaver dams at larger scales, this study examines channel shape and sediment distribution in thirty river reaches in northeastern Connecticut, U.S.A. The study reaches fall within the broader categories of impounded and free-flowing segments, leaving a third segment class of beaver meadows requiring additional study. Each of the study reaches were classified at the reach scale as free-flowing, valley-wide beaver pond, in-channel beaver pond, and downstream of beaver dam. The bankfull channel width to depth ratios and channel widths normalized by watershed area vary significantly across the study reach classes. Additionally, reaches modified by beaver dams have finer sediment distributions. This paper provides the first quantitative geomorphic descriptions of the in-channel beaver pond and reaches downstream of beaver dams. Given the different channel shapes and sediment distributions, we infer that geomorphic processes are longitudinally decoupled by these frequent barriers that control local base level. These barriers generate heterogeneity within a river network by greatly increasing the range of channel morphology and by generating patches controlled by different processes. Therefore, in spite of the small size of individual beaver dams, the cumulative effect of multiple dams has the potential to modify processes at larger spatial scales. To improve assessment of the

Multi-source water pollution in the Upper Citarum watershed, Indonesia, with special reference to its spatiotemporal variation.

PubMed

Parikesit; Salim, H; Triharyanto, E; Gunawan, B; Sunardi; Abdoellah, O S; Ohtsuka, R

2005-01-01

The Citarum River in West Java is the largest water supplier to the Saguling Dam, which plays a major role in electric power generation for the entire Java Island and is used for the aquaculture of marketed fish. To elucidate the extent of degradation in water quality and its causes in the Upper Citarum watershed, physical, chemical and biological parameters for water samples collected from various sites were analyzed. The results demonstrate large site-to-site variations in water qualities and pollutant loads derived from various human activities such as agriculture, cattle raising and the textile industry. To halt worsening conditions of the Citarum watershed, integrated mitigation efforts should be made, taking biophysical pollution mechanisms and local socioeconomic conditions into account.

Assessment of the quality of water by hierarchical cluster and variance analyses of the Koudiat Medouar Watershed, East Algeria

NASA Astrophysics Data System (ADS)

Tiri, Ammar; Lahbari, Noureddine; Boudoukha, Abderrahmane

2017-12-01

The assessment of surface water in Koudiat Medouar watershed is very important especially when it comes to pollution of the dam waters by discharges of wastewater from neighboring towns in Oued Timgad, who poured into the basin of the dam, and agricultural lands located along the Oued Reboa. To this end, the multivariable method was used to evaluate the spatial and temporal variation of the water surface quality of the Koudiat Medouar dam, eastern Algeria. The stiff diagram has identified two main hydrochemical facies. The first facies Mg-HCO3 is reflected in the first sampling station (Oued Reboa) and in the second one (Oued Timgad), while the second facies Mg-SO4 is reflected in the third station (Basin Dam). The results obtained by the analysis of variance show that in the three stations all parameters are significant, except for Na, K and HCO3 in the first station (Oued Reboa) and the EC in the second station (Oued Timgad) and at the end NO3 and pH in the third station (Basin Dam). Q-mode hierarchical cluster analysis showed that two main groups in each sampling station. The chemistry of major ions (Mg, Ca, HCO3 and SO4) within the three stations results from anthropogenic impacts and water-rock interaction sources.

Dam break analysis and flood inundation map of Krisak dam for emergency action plan

NASA Astrophysics Data System (ADS)

Juliastuti, Setyandito, Oki

2017-11-01

The Indonesian Regulation which refers to the ICOLD Regulation (International Committee on Large Dam required have the Emergency Action Plan (EAP) guidelines because of the dams have potential failure. In EAP guidelines there is a management of evacuation where the determination of the inundation map based on flood modeling. The purpose of the EAP is to minimize the risk of loss of life and property in downstream which caused by dam failure. This paper will describe about develop flood modeling and inundation map in Krisak dam using numerical methods through dam break analysis (DBA) using hydraulic model Zhong Xing HY-21. The approaches of dam failure simulation are overtopping and piping. Overtopping simulation based on quadrangular, triangular and trapezium fracture. Piping simulation based on cracks of orifice. Using results of DBA, hazard classification of Krisak dam is very high. The nearest village affected dam failure is Singodutan village (distance is 1.45 kilometer from dam) with inundation depth is 1.85 meter. This result can be used by stakeholders such as emergency responders and the community at risk in formulating evacuation procedure.

Status and trends of dam removal research in the United States

USGS Publications Warehouse

Bellmore, James; Duda, Jeff; Craig, Laura; Greene, Samantha L.; Torgersen, Christian E.; Collins, Mathias J.; Vittum, Katherine

2017-01-01

Aging infrastructure coupled with growing interest in river restoration has driven a dramatic increase in the practice of dam removal. With this increase, there has been a proliferation of studies that assess the physical and ecological responses of rivers to these removals. As more dams are considered for removal, scientific information from these dam-removal studies will increasingly be called upon to inform decisions about whether, and how best, to bring down dams. This raises a critical question: what is the current state of dam-removal science in the United States? To explore the status, trends, and characteristics of dam-removal research in the U.S., we searched the scientific literature and extracted basic information from studies on dam removal. Our literature review illustrates that although over 1200 dams have been removed in the U.S., fewer than 10% have been scientifically evaluated, and most of these studies were short in duration ( < 4 years) and had limited (1–2 years) or no pre-removal monitoring. The majority of studies focused on hydrologic and geomorphic responses to removal rather than biological and water-quality responses, and few studies were published on linkages between physical and ecological components. Our review illustrates the need for long-term, multidisciplinary case studies, with robust study designs, in order to anticipate the effects of dam removal and inform future decision making.

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

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

NASA Astrophysics Data System (ADS)

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

2014-11-01

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. Using α254 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.

What are check dams made for? An historical perspective from the French experience

NASA Astrophysics Data System (ADS)

Piton, Guillaume; Carladous, Simon; Recking, Alain

2015-04-01

The mitigation of torrent related hazards is an important issue in mountainous regions. Structural mitigation measures have been implemented on hill slopes and in streambeds for more than 150 years in all Europe. Check dams play a key role in these mitigation plans and can have highly variable functions (horizontal and vertical stabilization of streambeds, consolidation of hillslopes' toe, retention of sediments, modulations of high solid discharges, lowering of streambed slope, etc.). Thousands of structures had been built more than a century ago. Since their construction, land uses evolved, torrent control works, associated with reforestation, curtailed a part of the sediment production. According to field experience, defining the initial and current functions of some old structures can remain challenging in some cases. To better understand for which purposes thousands of these structures were built during the 19th and 20th centuries , we analyzed old books to determine: what was the history of the comprehension of the processes involved in torrent related hazards? and; how the use of check dams evolved to take into account this improving comprehension? i.e. how the human actions on watercourses co-evolved with scientific knowledge from the early 19th centuries to nowadays? The presentation does not aim to determine who, the first, addressed any scientific question: equivalent history and scientific works took place in all regions of the world at different time and the French were not the first to build check dams and to undertook watershed scale mitigation plans. But the French example is interesting because the torrent control works were planned in mountainous regions at the country scale (the Alps, the Pyrenees and the Massif Central). Initial plans were to reforest mountains, relying on civil engineering works if needed. Their implementation , through the French Mountain Lands' reforestation and grass seeding laws of 1860 and 1864, proved to be difficult for

A Coupled Approach with Stochastic Rainfall-Runoff Simulation and Hydraulic Modeling for Extreme Flood Estimation on Large Watersheds

NASA Astrophysics Data System (ADS)

Paquet, E.

2015-12-01

The SCHADEX method aims at estimating the distribution of peak and daily discharges up to extreme quantiles. It couples a precipitation probabilistic model based on weather patterns, with a stochastic rainfall-runoff simulation process using a conceptual lumped model. It allows exploring an exhaustive set of hydrological conditions and watershed responses to intense rainfall events. Since 2006, it has been widely applied in France to about one hundred watersheds for dam spillway design, and also aboard (Norway, Canada and central Europe among others). However, its application to large watersheds (above 10 000 km²) faces some significant issues: spatial heterogeneity of rainfall and hydrological processes and flood peak damping due to hydraulic effects (flood plains, natural or man-made embankment) being the more important. This led to the development of an extreme flood simulation framework for large and heterogeneous watersheds, based on the SCHADEX method. Its main features are: Division of the large (or main) watershed into several smaller sub-watersheds, where the spatial homogeneity of the hydro-meteorological processes can reasonably be assumed, and where the hydraulic effects can be neglected. Identification of pilot watersheds where discharge data are available, thus where rainfall-runoff models can be calibrated. They will be parameters donors to non-gauged watersheds. Spatially coherent stochastic simulations for all the sub-watersheds at the daily time step. Identification of a selection of simulated events for a given return period (according to the distribution of runoff volumes at the scale of the main watershed). Generation of the complete hourly hydrographs at each of the sub-watersheds outlets. Routing to the main outlet with hydraulic 1D or 2D models. The presentation will be illustrated with the case-study of the Isère watershed (9981 km), a French snow-driven watershed. The main novelties of this method will be underlined, as well as its

Determining the effects of dams on subdaily variation in river flows at a whole-basin scale

USGS Publications Warehouse

Zimmerman, J.K.H.; Letcher, B.H.; Nislow, K.H.; Lutz, K.A.; Magilligan, F.J.

2010-01-01

River regulation can alter the frequency and magnitude of subdaily flow variations causing major impacts on ecological structure and function. We developed an approach to quantify subdaily flow variation for multiple sites across a large watershed to assess the potential impacts of different dam operations (flood control, run-of-river hydropower and peaking hydropower) on natural communities. We used hourly flow data over a 9-year period from 30 stream gages throughout the Connecticut River basin to calculate four metrics of subdaily flow variation and to compare sites downstream of dams with unregulated sites. Our objectives were to (1) determine the temporal scale of data needed to characterize subdaily variability; (2) compare the frequency of days with high subdaily flow variation downstream of dams and unregulated sites; (3) analyse the magnitude of subdaily variation at all sites and (4) identify individual sites that had subdaily variation significantly higher than unregulated locations. We found that estimates of flow variability based on daily mean flow data were not sufficient to characterize subdaily flow patterns. Alteration of subdaily flows was evident in the number of days natural ranges of variability were exceeded, rather than in the magnitude of subdaily variation, suggesting that all rivers may exhibit highly variable subdaily flows, but altered rivers exhibit this variability more frequently. Peaking hydropower facilities had the most highly altered subdaily flows; however, we observed significantly altered ranges of subdaily variability downstream of some flood-control and run-of-river hydropower dams. Our analysis can be used to identify situations where dam operating procedures could be modified to reduce the level of hydrologic alteration. ?? 2009 John Wiley & Sons, Ltd.

National Dam Safety Program. Elm Creek Dam (Dam Number 16), (Inventory Number N.Y. 593), Conewango Creek Watershed, Allegheny River Basin, Cattaraugus County, New York. Phase I Inspection Report,

DTIC Science & Technology

1981-08-18

HYDRAULICS/HYDROLOGY 5.1 Drainage Area Characteristics 5-1 5.2 Design Data 5-1 5.3 Analysis Criteria 5-1 5.4 Reservoir Capacity 5-2 5.5 Experience...Data 5-2 5.6 Overtopping Potential 5-2 5.7 Analysis of Downstream Impacts 5-2 5.8 Evaluation 5-2 SECTION 6 STRUCTURAL STABILITY 6.1 Visual Observations...elevation is 1587.0 ft. (MSL). 5.3 Analysis Criteria The analysis of the spillway capacity of the dam and the storage of the reservoir was performed using

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…

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.

Bedload transport over run-of-river dams, Delaware, U.S.A.

NASA Astrophysics Data System (ADS)

Pearson, Adam J.; Pizzuto, Jim

2015-11-01

We document the detailed morphology and bed sediment size distribution of a stream channel upstream and downstream of a 200-year-old run-of-river dam on the Red Clay Creek, a fifth order stream in the Piedmont of northern Delaware, and combine these data with HEC-RAS modeling and bedload transport computations. We hypothesize that coarse bed material can be carried through run-of-river impoundments before they completely fill with sediment, and we explore mechanisms to facilitate this transport. Only 25% of the accommodation space in our study site is filled with sediment, and maximum water depths are approximately equal to the dam height. All grain-size fractions present upstream of the impoundment are also present throughout the impoundment. A characteristic coarse-grained sloping ramp leads from the floor of the impoundment to the crest of the dam. A 2.3-m-deep plunge pool has been excavated below the dam, followed immediately downstream by a mid-channel bar composed of coarse bed material similar in size distribution to the bed material of the impoundment. The mid-channel bar stores 1472 m3 of sediment, exceeding the volume excavated from the plunge pool by a factor of 2.8. These field observations are typical of five other sites nearby and suggest that all bed material grain-size fractions supplied from upstream can be transported through the impoundment, up the sloping ramp, and over the top of the dam. Sediment transport computations suggest that all grain sizes are in transport upstream and within the impoundment at all discharges with return periods from 1 to 50 years. Our computations suggest that transport of coarse bed material through the impoundment is facilitated by its smooth, sandy bed. Model results suggest that the impoundment is currently aggrading at 0.26 m/year, but bed elevations may be recovering after recent scour from a series of large floods during water year 2011-2012. We propose that impoundments upstream of these run-of-river dams

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.

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, Niel; 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

Estimated splash and training wall height requirements for stepped chutes applied to embankment dams

USDA-ARS?s Scientific Manuscript database

Aging embankment dams are commonly plagued with insufficient spillway capacity. To provide increased spillway capacity, stepped chutes are frequently applied as an overtopping protection system for embankment dams. Stepped chutes with sufficient length develops aerated flow. The aeration and flow...

Characterization of a dam Mutant of Serratia marcescens and Nucleotide Sequence of the dam Region

PubMed Central

Ostendorf, Tammo; Cherepanov, Peter; de Vries, Johann; Wackernagel, Wilfried

1999-01-01

The DNA of Serratia marcescens has N6-adenine methylation in GATC sequences. Among 2-aminopurine-sensitive mutants isolated from S. marcescens Sr41, one was identified which lacked GATC methylation. The mutant showed up to 30-fold increased spontaneous mutability and enhanced mutability after treatment with 2-aminopurine, ethyl methanesulfonate, or UV light. The gene (dam) coding for the adenine methyltransferase (Dam enzyme) of S. marcescens was identified on a gene bank plasmid which alleviated the 2-aminopurine sensitivity and the higher mutability of a dam-13::Tn9 mutant of Escherichia coli. Nucleotide sequencing revealed that the deduced amino acid sequence of Dam (270 amino acids; molecular mass, 31.3 kDa) has 72% identity to the Dam enzyme of E. coli. The dam gene is located between flanking genes which are similar to those found to the sides of the E. coli dam gene. The results of complementation studies indicated that like Dam of E. coli and unlike Dam of Vibrio cholerae, the Dam enzyme of S. marcescens plays an important role in mutation avoidance by allowing the mismatch repair enzymes to discriminate between the parental and newly synthesized strands during correction of replication errors. PMID:10383952

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 D.; 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.

Sediment deposition and trends and transport of phosphorus and other chemical constituents, Cheney Reservoir watershed, south-central Kansas

USGS Publications Warehouse

Mau, D.P.

2001-01-01

Sediment deposition, water-quality trends, and mass transport of phosphorus, nitrogen, selected trace elements, and selected pesticides within the Cheney Reservoir watershed in south-central Kansas were investigated using bathymetric survey data and reservoir bottom-sediment cores. Sediment loads in the reservoir were investigated by comparing 1964 topographic data to 1998 bathymetric survey data. Approximately 7,100 acre-feet of sediment deposition occurred in Cheney Reservoir from 1965 through 1998. As of 1998, sediment had filled 27 percent of the reservoir's inactive conservation storage pool, which is less than the design estimate of 34 percent. Mean annual sediment deposition was 209 acre-feet per year, or 0.22 acre-feet per year per square mile, and the mean annual sediment load was 453 million pounds per year. During the 3-year period from 1997 through 1999, 23 sediment cores were collected from the reservoir, and subsamples were analyzed for nutrients (phosphorus and nitrogen species), selected trace elements, and selected organic pesticides. Mean concentrations of total phosphorus in reservoir bottom sediment ranged from 94 milligrams per kilogram at the upstream end of the reservoir to 710 milligrams per kilogram farther downstream near the reservoir dam. The mean concentration for all sites was 480 milligrams per kilogram. Total phosphorus concentrations were greatest when more silt- and clay-sized particles were present. The implications are that if anoxic conditions (inadequate oxygen) occur near the dam, phosphorus could be released from the sediment and affect the drinking-water supply. Analysis of selected cores also indicates that total phosphorus concentrations in the reservoir sediment increased over time and were probably the result of nonpoint-source activities in the watershed, such as increased fertilizer use and livestock production. Mean annual phosphorus loading to Cheney Reservoir was estimated to be 226,000 pounds per year on the basis

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.

Channel response to sediment release: insights from a paired analysis of dam removal

USGS Publications Warehouse

Collins, Mathias J.; Snyder, Noah P.; Boardman, Graham; Banks, William S.; Andrews, Mary; Baker, Matthew E.; Conlon, Maricate; Gellis, Allen; McClain, Serena; Miller, Andrew; Wilcock, Peter

2017-01-01

Dam removals with unmanaged sediment releases are good opportunities to learn about channel response to abruptly increased bed material supply. Understanding these events is important because they affect aquatic habitats and human uses of floodplains. A longstanding paradigm in geomorphology holds that response rates to landscape disturbance exponentially decay through time. However, a previous study of the Merrimack Village Dam (MVD) removal on the Souhegan River in New Hampshire, USA, showed that an exponential function poorly described the early geomorphic response. Erosion of impounded sediments there was two-phased. We had an opportunity to quantitatively test the two-phase response model proposed for MVD by extending the record there and comparing it with data from the Simkins Dam removal on the Patapsco River in Maryland, USA. The watershed sizes are the same order of magnitude (102 km2), and at both sites low-head dams were removed (~3–4 m) and ~65 000 m3 of sand-sized sediments were discharged to low-gradient reaches. Analyzing four years of repeat morphometry and sediment surveys at the Simkins site, as well as continuous discharge and turbidity data, we observed the two-phase erosion response described for MVD. In the early phase, approximately 50% of the impounded sediment at Simkins was eroded rapidly during modest flows. After incision to base level and widening, a second phase began when further erosion depended on floods large enough to go over bank and access impounded sediments more distant from the newly-formed channel. Fitting functional forms to the data for both sites, we found that two-phase exponential models with changing decay constants fit the erosion data better than single-phase models. Valley width influences the two-phase erosion responses upstream, but downstream responses appear more closely related to local gradient, sediment re-supply from the upstream impoundments, and base flows.

Riparian soil development linked to forest succession above and below dams along the Elwha River, Washington, USA

USGS Publications Warehouse

Perry, Laura G; Shafroth, Patrick B.; Perakis, Steven

2017-01-01

Riparian forest soils can be highly dynamic, due to frequent fluvial disturbance, erosion, and sediment deposition, but effects of dams on riparian soils are poorly understood. We examined soils along toposequences within three river segments located upstream, between, and downstream of two dams on the Elwha River to evaluate relationships between riparian soil development and forest age, succession, and channel proximity, explore dam effects on riparian soils, and provide a baseline for the largest dam removal in history. We found that older, later-successional forests and geomorphic surfaces contained soils with finer texture and greater depth to cobble, supporting greater forest floor mass, mineral soil nutrient levels, and cation exchange. Forest stand age was a better predictor than channel proximity for many soil characteristics, though elevation and distance from the channel were often also important, highlighting how complex interactions between fluvial disturbance, sediment deposition, and biotic retention regulate soil development in this ecosystem. Soils between the dams, and to a lesser extent below the lower dam, had finer textures and higher mineral soil carbon, nitrogen, and cation exchange than above the dams. These results suggested that decreased fluvial disturbance below the dams, due to reduced sediment supply and channel stabilization, accelerated soil development. In addition, reduced sediment supply below the dams may have decreased soil phosphorus. Soil δ15N suggested that salmon exclusion by the dams had no discernable effect on nitrogen inputs to upstream soils. Recent dam removal may alter riparian soils further, with ongoing implications for riparian ecosystems.

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…

Watershed analysis

Treesearch

Alan Gallegos

2002-01-01

Watershed analyses and assessments for the Kings River Sustainable Forest Ecosystems Project were done on about 33,000 acres of the 45,500-acre Big Creek watershed and 32,000 acres of the 85,100-acre Dinkey Creek watershed. Following procedures developed for analysis of cumulative watershed effects (CWE) in the Pacific Northwest Region of the USDA Forest Service, the...

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.

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.

WATERSHED INFORMATION - SURF YOUR WATERSHED

EPA Science Inventory

Surf Your Watershed is both a database of urls to world wide web pages associated with the watershed approach of environmental management and also data sets of relevant environmental information that can be queried. It is designed for citizens and decision makers across the count...

Seismic risk assessment for Poiana Uzului (Romania) buttress dam on Uz river

NASA Astrophysics Data System (ADS)

Moldovan, Iren-Adelina; Toma-Danila, Dragos; Paerele, Cosmin Marian; Emilian Toader, Victorin; Petruta Constantin, Angela; Ghita, Cristian

2017-04-01

The most important specific requirements towards dams' safety is the seismic risk assessment. This objective will be accomplished by rating the dams into seismic risk classes using the theory of Bureau and Ballentine, 2002, and Bureau (2003), taking into account the maximum expected peak ground motions at dams' site, the structures vulnerability and the downstream risk characteristics. The maximum expected values for ground motions at dams' site have been obtained using probabilistic seismic hazard assessment approaches. The structural vulnerability was obtained from dams' characteristics (age, high, water volume) and the downstream risk was assessed using human, economical, touristic, historic and cultural heritage information from the areas that might be flooded in the case of a dam failure. A couple of flooding scenarios have been performed. The results of the work consist of local and regional seismic information, specific characteristics of dam, seismic hazard values for different return periods and risk classes. The studies realized in this paper have as final goal to provide in the near future the local emergency services with warnings of a potential dam failure and ensuing flood as a result of a large earthquake occurrence, allowing further public training for evacuation. Acknowledgments This work was partially supported by the Partnership in Priority Areas Program - PNII, under MEN-UEFISCDI, DARING Project no. 69/2014 and the Nucleu Program - PN 16-35, Project no. 03 01 and 01 06.

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 ...

Dynamic decision making for dam-break emergency management - Part 2: Application to Tangjiashan landslide dam failure

NASA Astrophysics Data System (ADS)

Peng, M.; Zhang, L. M.

2013-02-01

Tangjiashan landslide dam, which was triggered by the Ms = 8.0 Wenchuan earthquake in 2008 in China, threatened 1.2 million people downstream of the dam. All people in Beichuan Town 3.5 km downstream of the dam and 197 thousand people in Mianyang City 85 km downstream of the dam were evacuated 10 days before the breaching of the dam. Making such an important decision under uncertainty was difficult. This paper applied a dynamic decision-making framework for dam-break emergency management (DYDEM) to help rational decision in the emergency management of the Tangjiashan landslide dam. Three stages are identified with different levels of hydrological, geological and social-economic information along the timeline of the landslide dam failure event. The probability of dam failure is taken as a time series. The dam breaching parameters are predicted with a set of empirical models in stage 1 when no soil property information is known, and a physical model in stages 2 and 3 when knowledge of soil properties has been obtained. The flood routing downstream of the dam in these three stages is analyzed to evaluate the population at risk (PAR). The flood consequences, including evacuation costs, flood damage and monetized loss of life, are evaluated as functions of warning time using a human risk analysis model based on Bayesian networks. Finally, dynamic decision analysis is conducted to find the optimal time to evacuate the population at risk with minimum total loss in each of these three stages.

Integrated Data-Archive and Distributed Hydrological Modelling System for Optimized Dam Operation

NASA Astrophysics Data System (ADS)

Shibuo, Yoshihiro; Jaranilla-Sanchez, Patricia Ann; Koike, Toshio

2013-04-01

Analysis System, a Japanese national project for collecting, integrating and analyzing massive amount of global scale observation data, meaning that the present system is applicable worldwide. We demonstrate the integrated system with observed extreme events in Angat Watershed, the Philippines, and Upper Tone River basin, Japan. The results show promising performance for operational use of the system to support river and dam managers' decision-making.

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.

The geomorphic influences of beaver dams and failures of beaver dams

NASA Astrophysics Data System (ADS)

Butler, David R.; Malanson, George P.

2005-10-01

Uncounted millions of beaver ponds and dams existed in North America prior to European contact and colonization. These ponds acted as sediment traps that contained tens to hundreds of billions of cubic meters of sediment that would otherwise have passed through the fluvial system. Removal of beavers by overtrapping in the 16th-19th centuries severely reduced their number and the number of ponds and dams. Dam removal altered the fluvial landscape of North America, inducing sediment evacuation and entrenchment in concert with widespread reduction in the wetlands environments. Partial recovery of beaver populations in the 20th century has allowed reoccupation of the entirety of the pre-contact range, but at densities of only one-tenth the numbers. Nevertheless, modern beaver ponds also trap large volumes of sediment in the high hundred millions to low billions of cubic meters range. Failure of beaver dams is a more common phenomenon than often assumed in the literature. During the past 20 years, numerous cases of dam failure have been documented that resulted in outburst floods. These floods have been responsible for 13 deaths and numerous injuries, including significant impacts on railway lines.

Riparian Vegetation Encroachment Ratios in rivers below large Dams

NASA Astrophysics Data System (ADS)

Garcia de Jalón, Diego; Martínez-Fernández, Vanesa; González del Tánago, Marta

2017-04-01

Large Dams and reservoirs change the natural flow regime and consequently cause many alterations in riparian vegetation dynamics which may be assessed at different spatial and temporal scales. In Mediterranean regions flow regulation is frequently associated with irrigation. Regulated rivers with this purpose very often show reduced discharges during the wet season when the reservoir is being filled and increased discharges during the dry season when irrigation takes place. This type of regulation frequently promotes riparian vegetation growth as soil moisture levels are increased during summer when a natural drought would otherwise limit its growth. Additionally, flow regulation by large dams promotes the aging of late seral riparian vegetation reducing the frequency of flood disturbance and consequently, the potential recruitment of pioneer species. In this work we study the response of woody riparian vegetation to flow regulation by large dams in four rivers from Central Spain: Jarama, Manzanares, Guadalix and Alberche. The aim is to quantify the annual vegetation encroachment ratios and to develop a model to understand the main controlling factors, such as floodplain and channel traits; flow regulation intensity; type of regulation; present vegetation canopy; distance to the dam; and time since dam commissioning. A temporal comparison using aerial photographs from 1956, 1966, 1972, 1991, 2011 and 2014 was done in thirteen river reaches downstream from large dams, to evaluate their morphological evolution.. Floodplain dimensions and channel and riparian vegetation changes were assessed by comparing different pre-dam and post-dam conditions. Recent coloured photographs with 0.5 m spatial resolution and older black-and-white photographs at 1:33 000 spatial scale were supplied by the National Geographic Institute of Spain (www.ign.es) and the Statistical Institute (www.madrid.org/nomecalles/Inicio.icm) from Madrid Community. Similar visual scales were used to cope

Changes in liveweight and behaviour of alpaca dams and offspring following weaning.

PubMed

Pollard, J C; Littlejohn, R P; Davis, G H

1993-12-01

The effects of offspring sex, weight, age, and level of interaction with the dam on responses to weaning were examined to assist in the development of a weaning protocol for alpacas. In the first study, preand post-weaning activities, and weight change over Days -12-0,0-7 and 7-16 with respect to weaning, were recorded for 20 dam-offspring (hembra-cria) pairs aged 81-200 days. Pre-weaning changes in dam and offspring weights were positively related (P<0.05). Although heavier crias tended to be found closer to their dams than lighter crias (P<0.05) no additional effect of age on the dam-offspring relationship was found. Following weaning, cria growth rates were low over Days 0-7 but improved over Days 7-16, and hembra weight change followed the same pattern. Over Days 0-2, grazing and sitting activities of hembras and crias were replaced by standing and walking along paddock fencelines, although by Day 2 fenceline activities had decreased (P<0.05). Crias which were more frequently observed at fencelines had lower post-weaning growth rates (P<0.05). In the second study, pre-weaning sucking behaviour, and weight change over Days -30-0, 0-8 and 8-16 with respect to weaning, were recorded for 19 hembra-cria pairs aged 124-160 days. During 10 hours of observation on Days -5 and -4, the total duration of sucking by individual crias varied from 0-18 minutes, and the mean +/- SEM duration of sucking was 1.94 +/- 0.113 minutes. Cria sucking behaviour was positively related to growth rate prior to and weight at weaning (P<0.05). As in the first study, pre-weaning changes in dam and offspring weights were positively related (P<0.05). Following weaning, growth rates of the crias were depressed and the hembras lost weight over Days 0-8 and 8-16. The changes in growth rate and behaviour in Studies 1 and 2 indicated that weaning can be stressful for hembras and crias. However, there was no evidence from either study that pre-weaning behavioural or physical characteristics were

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

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).

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, 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.

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

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. © 2014 Blackwell Verlag GmbH.

Arizona watershed framework in the Verde River watershed

Treesearch

Ren Northrup

2000-01-01

The Arizona Department of Environmental Quality, Water Quality Division drafted a six-step approach to guide its staff and local participants in developing and implementing watershed management plans. From January 1999 through June 2000, the draft Arizona Statewide Watershed Framework will be tested in Arizona's Verde River watershed. This concept proofing...

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. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Soils of Walker Branch Watershed

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.« less

Experimental research on the dam-break mechanisms of the Jiadanwan landslide dam triggered by the Wenchuan earthquake in China.

PubMed

Xu, Fu-gang; Yang, Xing-guo; Zhou, Jia-wen; Hao, Ming-hui

2013-01-01

Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The different factors that impact the dam-break process include upstream flow, the boulder effect, dam size, and channel discharge. The development of the discharge channel and the failure of the landslide dam are monitored by digital video and still cameras. Experimental results show that the upstream inflow and the dam size are the main factors that impact the dam-break process. An excavated discharge channel, especially a trapezoidal discharge channel, has a positive effect on reducing peak flow. The depth of the discharge channel also has a significant impact on the dam-break process. The experimental results are significant for landslide dam management and flood disaster prevention and mitigation.

Experimental Research on the Dam-Break Mechanisms of the Jiadanwan Landslide Dam Triggered by the Wenchuan Earthquake in China

PubMed Central

Xu, Fu-gang; Yang, Xing-guo; Hao, Ming-hui

2013-01-01

Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The different factors that impact the dam-break process include upstream flow, the boulder effect, dam size, and channel discharge. The development of the discharge channel and the failure of the landslide dam are monitored by digital video and still cameras. Experimental results show that the upstream inflow and the dam size are the main factors that impact the dam-break process. An excavated discharge channel, especially a trapezoidal discharge channel, has a positive effect on reducing peak flow. The depth of the discharge channel also has a significant impact on the dam-break process. The experimental results are significant for landslide dam management and flood disaster prevention and mitigation. PMID:23844387

Effects of hillslope gully stabilization on erosion and sediment production in the Torreon Wash watershed, New Mexico, 2009–12

USGS Publications Warehouse

Matherne, Anne Marie; Tillery, Anne C.; Douglas-Mankin, Kyle R.

2018-04-10

Sediment erosion and deposition in two sets of paired (treated and untreated) upland drainages in the Torreon Wash watershed, upper Rio Puerco Basin, New Mexico, were examined over a 3 1/2-year period from spring 2009 through fall 2012. The objective was to evaluate the effectiveness of shallow, loose-stone check dams, or “one-rock dams,” as a hillslope gully erosion stabilization and mitigation method, and its potential for retaining upland eroded soils and decreasing delivery of sediment to lower ephemeral stream channels. Two high-resolution topographic surveys, completed at the beginning and end of the study period, were used to assess the effects of the mitigation measures at paired-drainage sites in both Penistaja Arroyo and Papers Wash watersheds, and at six main-stem-channel cross-section clusters along Penistaja Arroyo and Torreon Wash in the Torreon Wash watershed.For both drainage pairs, the treated drainage had greater sediment aggradation near the channel than the untreated drainage. Erosion was the dominant geomorphic process in the untreated Penistaja Arroyo drainage, whereas aggradation was the dominant process in the other three drainages. For the Penistaja Arroyo paired drainages, the treated site showed a 51-percent increase in area aggraded and 67-percent increase in volume aggraded per area analyzed over the untreated site. Both Papers Wash drainages showed net aggradation, but with similar treatment effect, with the treated site showing a 29-percent increase in area aggraded and 60-percent increase in volume aggraded per area analyzed over the untreated site. In the untreated Penistaja Arroyo drainage, the calculated minimum erosion rate was 0.0055 inches per year (in/yr; 0.14 millimeters per year [mm/yr]), whereas the calculated aggradation rates for the three drainages for which aggradation was the dominant geomorphic process were 0.0063 in/yr (0.16 mm/yr) for the Penistaja Arroyo treated drainage, 0.012 in/yr (0.31 mm/yr) for the Papers

National Dam Safety Program. Stony Brook Watershed Dam Site Number 7 (NJ00344), Raritan River Basin, Stony Brook, Mercer County, New Jersey. Phase 1 Inspection Report.

DTIC Science & Technology

1980-02-01

for Permit for Construction and Repair of Dam" filed on March 16, 1959. f. Design and Construction History Design data on file with NJDEP include: 1...LAr- Us a-2. hr’s. LA9~ WATF=R? SiQ_~~- SL- !E q VOL ( YFv - mcA>-) (Acmr-- =T.) 2o4~ 2-Ito STORCH ENGINEERS shootL... of 11. Project FmnnK Wmr=X---A-1

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.

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.

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…

Adjustments in channel morphology due to land-use changes and check dam installation in mountain torrents of Calabria (Southern Italy)

NASA Astrophysics Data System (ADS)

Fortugno, Diego; Zema, Demetrio Antonio; Bombino, Giuseppe; Tamburino, Vincenzo; Quinonero Rubio, Juan Manuel; Boix-Fayos, Carolina

2016-04-01

reforestation in increasing hillslope protection from erosion and disconnectivity of water and sediment flows towards the active channel. The residual sediment deficit circulating in the watershed suggests the need of slight management interventions, as, for instance, the conversion of the existing check dams into open structures, allowing a definite channel and coast stability.

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

Restore McComas Watershed; Meadow Creek Watershed, 2002-2003 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 throughoutmore » 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.« less

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

A ravenous river reclaims its true course: the tale of Marmot Dam''s demise

Treesearch

Noreen Parks; Gordon Grant

2009-01-01

Removing dams that are outdated, unsafe, or pose significant economic or environmental costs has emerged in the last 10 years as a major river restoration strategy. The removal of the 45-foot-high Marmot Dam on the Sandy River in 2007 resulted in the biggest sediment release accompanying any dam removal to date. It also provided an unprecedented opportunity...

33 CFR 100.1102 - Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam...

Code of Federal Regulations, 2011 CFR

2011-07-01

... River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). 100.1102 Section... Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). (a) General. Sponsors are... Roadrunner Resort and Headgate Dam). Bullhead City Boat Drags Sponsor: Sunshine Promotions Date: 2 to 4...

33 CFR 100.1102 - Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam...

Code of Federal Regulations, 2010 CFR

2010-07-01

... River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). 100.1102 Section... Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). (a) General. Sponsors are... Roadrunner Resort and Headgate Dam). Bullhead City Boat Drags Sponsor: Sunshine Promotions Date: 2 to 4...

Life cycle efficiency of beef production: II. Relationship of cow efficiency ratios to traits of the dam and progeny weaned.

PubMed

Davis, M E; Rutledge, J J; Cundiff, L V; Hauser, E R

1983-10-01

Several measures of life cycle cow efficiency were calculated using weights and individual feed consumptions recorded on 160 dams of beef, dairy and beef X dairy breeding and their progeny. Ratios of output to input were used to estimate efficiency, where outputs included weaning weights of progeny plus salvage value of the dam and inputs included creep feed consumed by progeny plus feed consumed by the dam over her entire lifetime. In one approach to estimating efficiency, inputs and outputs were weighted by probabilities that were a function of the cow herd age distribution and percentage calf crop in a theoretical herd. The second approach to estimating cow efficiency involved dividing the sum of the weights by the sum of the feed consumption values, with all pieces of information being given equal weighting. Relationships among efficiency estimates and various traits of dams and progeny were examined. Weights, heights, and weight:height ratios of dams at 240 d of age were not correlated significantly with subsequent efficiency of calf production, indicating that indirect selection for lifetime cow efficiency at an early age based on these traits would be ineffective. However, females exhibiting more efficient weight gains from 240 d to first calving tended to become more efficient dams. Correlations of efficiency with weight of dam at calving and at weaning were negative and generally highly significant. Height at withers was negatively related to efficiency. Ratio of weight to height indicated that fatter dams generally were less efficient. The effect of milk production on efficiency depended upon the breed combinations involved. Dams calving for the first time at an early age and continuing to calve at short intervals were superior in efficiency. Weaning rate was closely related to life cycle efficiency. Large negative correlations between efficiency and feed consumption of dams were observed, while correlations of efficiency with progeny weights and feed

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...

Channel and hillslope processes revisited in the Arroyo de los Frijoles watershed near Santa Fe, New Mexico

USGS Publications Warehouse

Gellis, Allen C.; Emmett, William W.; Leopold, Luna Bergere

2005-01-01

Detailed documentation of geomorphic changes in the landscape of more than a few years is rarely possible. Channel cross sections, channel profiles, sediment deposition behind dams, and hillslope-erosion plots, originally benchmarked within several watersheds outside Santa Fe, New Mexico, in the 1950’s and 1960’s, for a 1966 report that documented processes and rates of arid-region sediment production and deposition, were resurveyed in the mid-1990’s. Many of the original study sites were relocated and surveyed in the mid-1990’s to determine subsequent channel and hillslope changes and to determine whether trends of channel and hillslope aggradation and degradation that were evident in the 1950’s and 1960’s have continued. In general, the net change in channel geometry has been small over the last 30–40 years. The average change in cross-sectional area of 32 resurveyed cross sections was erosion of 0.27 square meter, which equates to a 4-percent increase in cross-sectional area. The average net change in thalweg elevation for 51 resurveyed cross sections was degradation of 0.04 meter. Unpublished data (1964–68) from the scour chains showed that 371 chains had an average scour of 0.14 ± 0.14 meter and that 372 chains showed an average fill of 0.13 + 0.11 meter. Scour, found in the original study (1958–64) to be proportional to the square root of discharge, was confirmed with the addition of unpublished data (1964–68). The observed channel changes have no consistent trend, compared either to results observed in the original 1966 study or to distance from the watershed divide. The conclusion drawn in the original study was that most channels were aggrading; the resurvey showed that aggradation did not continue.An increase in housing and population in the Arroyo de los Frijoles watershed since the 1950’s has led to more roads. Channel degradation is most noticeable at road crossings. The greatest degradation of the main channel Arroyo de los

Dams and Levees: Safety Risks

NASA Astrophysics Data System (ADS)

Carter, N. T.

2017-12-01

The nation's flood risk is increasing. The condition of U.S. dams and levees contributes to that risk. Dams and levee owners are responsible for the safety, maintenance, and rehabilitation of their facilities. Dams-Of the more than 90,000 dams in the United States, about 4% are federally owned and operated; 96% are owned by state and local governments, public utilities, or private companies. States regulate dams that are not federally owned. The number of high-hazard dams (i.e., dams whose failure would likely result in the loss of human life) has increased in the past decade. Roughly 1,780 state-regulated, high-hazard facilities with structural ratings of poor or unsatisfactory need rehabilitation. Levees-There are approximately 100,000 miles of levees in the nation; most levees are owned and maintained by municipalities and agricultural districts. Few states have levee safety programs. The U.S. Army Corps of Engineers (Corps) inspects 15,000 miles of levees, including levees that it owns and local levees participating in a federal program to assist with certain post-flood repairs. Information is limited on how regularly other levees are inspected. The consequence of a breach or failure is another aspect of risk. State and local governments have significant authority over land use and development, which can shape the social and economic impacts of a breach or failure; they also lead on emergency planning and related outreach. To date, federal dam and levee safety efforts have consisted primarily of (1) support for state dam safety standards and programs, (2) investments at federally owned dams and levees, and (3) since 2007, creation of a national levee database and enhanced efforts and procedures for Corps levee inspections and assessments. In Public Law 113-121, enacted in 2014, Congress (1) directed the Corps to develop voluntary guidelines for levee safety and an associated hazard potential classification system for levees, and (2) authorized support for the

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.

Health impacts of large dams

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Integrating Disciplines, Sectors, and Societies to Improve the Definition and Implementation of Environmental Flows for Dammed Amazonian Rivers

NASA Astrophysics Data System (ADS)

Kaplan, D. A.; Livino, A.; Arias, M. E.; Crouch, T. D.; Anderson, E.; Marques, E.; Dutka-Gianelli, J.

2017-12-01

The Amazon River watershed is the world's largest river basin and provides US$30 billion/yr in ecosystem services to local populations, national societies, and humanity at large. The Amazon is also a relatively untapped source of hydroelectricity for Latin America, and construction of >30 large hydroelectric dams and >170 small dams is currently underway. Hydropower development will have a cascade of physical, ecological, and social effects at local to global scales. While Brazil has well-defined environmental impact assessment and mitigation programs, these efforts often fail to integrate data and knowledge across disciplines, sectors, and societies throughout the dam planning process. Resulting failures of science, policy, and management have had widespread environmental, economic, and social consequences, highlighting the need for an improved theoretical and practical framework for understanding the impacts of Amazon dams and guiding improved management that respects the needs and knowledge of diverse set of stakeholders. We present a conceptual framework that links four central goals: 1) connecting research in different disciplines (interdisciplinarity); 2) incorporating new knowledge into decision making (adaptive management); 3) including perspectives and participation of non-academic participants in knowledge generation (transdisciplinarity); and 4) extending the idea of environmental flows ("how much water does a river need?") to better consider human uses and users through the concept of fluvial anthropology ("how much water does a society need?"). We use this framework to identify opportunities for improved integration strategies within the (Brazilian) hydroelectric power plant planning and implementation "lifecycle." We applied this approach to the contentious Belo Monte dam, where compliance with regulatory requirements, including monitoring for environmental flows, exemplifies the opportunity for applying adaptive management, but also highlights an

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,...

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,...

Dam operations affect route-specific passage and survival of juvenile Chinook salmon at a main-stem diversion dam

USGS Publications Warehouse

Perry, Russell W.; Kock, Tobias J.; Couter, Ian I; Garrison, Thomas M; Hubble, Joel D; Child, David B

2016-01-01

Diversion dams can negatively affect emigrating juvenile salmon populations because fish must pass through the impounded river created by the dam, negotiate a passage route at the dam and then emigrate through a riverine reach that has been affected by reduced river discharge. To quantify the effects of a main-stem diversion dam on juvenile Chinook salmon in the Yakima River, Washington, USA, we used radio telemetry to understand how dam operations and river discharge in the 18-km reach downstream of the dam affected route-specific passage and survival. We found evidence of direct mortality associated with dam passage and indirect mortality associated with migration through the reach below the dam. Survival of fish passing over a surface spill gate (the west gate) was positively related to river discharge, and survival was similar for fish released below the dam, suggesting that passage via this route caused little additional mortality. However, survival of fish that passed under a sub-surface spill gate (the east gate) was considerably lower than survival of fish released downstream of the dam, with the difference in survival decreasing as river discharge increased. The probability of fish passing the dam via three available routes was strongly influenced by dam operations, with passage through the juvenile fish bypass and the east gate increasing with discharge through those routes. By simulating daily passage and route-specific survival, we show that variation in total survival is driven by river discharge and moderated by the proportion of fish passing through low-survival or high-survival passage routes.

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

Hydrological simulation of a small ungauged agricultural watershed Semrakalwana of Northern India

NASA Astrophysics Data System (ADS)

Mishra, Himanshu; Denis, Derrick Mario; Suryavanshi, Shakti; Kumar, Mukesh; Srivastava, Santosh Kumar; Denis, Anjelo Francis; Kumar, Rajendra

2017-10-01

A study was conducted to develop a hydrological model for agriculture dominated Semra watershed (4.31 km2) and Semrakalwana village at Allahabad using a semi distributed Soil and Water Assessment Tool (SWAT) model. In model evaluation it was found that the SWAT does not require much calibration, and therefore, can be employed in unguaged watershed. A seasonal (Kharif, Rabi and Zaid seasons) and annual water budget analysis was performed to quantify various components of the hydrologic cycle. The average annual surface runoff varied from 379 to 386 mm while the evapotranspiration of the village was in the range of 359-364 mm. The average annual percolation and return flow was found to be 265-272 mm and 147-255 mm, respectively. The initial soil water content of the village was found in the range of 328-335 mm while the final soil water content was 356-362 mm. The study area fall under a rain-fed river basin (Tons River basin) with no contribution from snowmelt, the winter and summer season is highly affected by less water availability for crops and municipal use. Seasonal (Rabi, Kharif and Zaid crop seasons) and annual water budget of Semra watershed and Semrakalwana village evoke the need of conservation structures such as check dams, farm ponds, percolation tank, vegetative barrier, etc. to reduce monsoon runoff and conserve it for basin requirements for winter and summer period.

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…

Fragility Analysis of Concrete Gravity Dams

NASA Astrophysics Data System (ADS)

Tekie, Paulos B.; Ellingwood, Bruce R.

2002-09-01

Concrete gravity dams are an important part ofthe nation's infrastructure. Many dams have been in service for over 50 years, during which time important advances in the methodologies for evaluation of natural phenomena hazards have caused the design-basis events to be revised upwards, in some cases significantly. Many existing dams fail to meet these revised safety criteria and structural rehabilitation to meet newly revised criteria may be costly and difficult. A probabilistic safety analysis (PSA) provides a rational safety assessment and decision-making tool managing the various sources of uncertainty that may impact dam performance. Fragility analysis, which depicts fl%e uncertainty in the safety margin above specified hazard levels, is a fundamental tool in a PSA. This study presents a methodology for developing fragilities of concrete gravity dams to assess their performance against hydrologic and seismic hazards. Models of varying degree of complexity and sophistication were considered and compared. The methodology is illustrated using the Bluestone Dam on the New River in West Virginia, which was designed in the late 1930's. The hydrologic fragilities showed that the Eluestone Dam is unlikely to become unstable at the revised probable maximum flood (PMF), but it is likely that there will be significant cracking at the heel ofthe dam. On the other hand, the seismic fragility analysis indicated that sliding is likely, if the dam were to be subjected to a maximum credible earthquake (MCE). Moreover, there will likely be tensile cracking at the neck of the dam at this level of seismic excitation. Probabilities of relatively severe limit states appear to be only marginally affected by extremely rare events (e.g. the PMF and MCE). Moreover, the risks posed by the extreme floods and earthquakes were not balanced for the Bluestone Dam, with seismic hazard posing a relatively higher risk.

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.

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. Published by Elsevier B.V.

Comparison of mercury mass loading in streams to atmospheric deposition in watersheds of Western North America: Evidence for non-atmospheric mercury sources

USGS Publications Warehouse

Domagalski, Joseph L.; Majewski, Michael S.; Alpers, Charles N.; Eckley, Chris S.; Eagles-Smith, Collin A.; Schenk, Liam N.; Wherry, Susan

2016-01-01

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.

Phase I Inspection Report. National Dam Safety Program. Round Valley South Dam, Hunterdon County, New Jersey.

DTIC Science & Technology

1978-05-01

1 . REPORT NUMB» NJ00015 2. GOVT ACCESSION NO ’base I Inspection Report* lational Dam Safety Program* found Valley South Dam> ’Hunterdon...Springfield, Virginia, 22151. 1 «. KEY WOROS (Continue on rereree elde II neeeeeery end Identity by block number) National Dam Safety Program Dam...IW,. 1 ,W,,.^U„UI,H..l,. 1 ,«.M,.„—II SECURITY CLASSIFICATION OP THIS PAOEfWhan Dmtm gnlafQ SECURITY CLASSIFICATION OF THIS PAGEfWhan Data Fnr.r.di

Biodiveristy and Stability of Aboriginal Salmon Fisheries in the Fraser River Watershed

NASA Astrophysics Data System (ADS)

Nesbitt, H. K.; Moore, J.

2015-12-01

Natural watersheds are hierarchical networks that may confer stability to ecosystem functions through integration of upstream biodiversity, whereby upstream asset diversification stabilizes the aggregate downstream through the portfolio effect. Here we show that riverine structure and its associated diversity confer stability of salmon catch and lengthened fishing seasons for Aboriginal fisheries on the Fraser River (1370km) in BC, Canada, the second longest dam-free salmon migration route in North America. In Canada, Aboriginal people have rights to fish for food, social, and ceremonial (FSC) purposes. FSC fisheries are located throughout the Fraser watershed and have access to varying levels of salmon diversity based on their location. For instance, fisheries at the mouth of the river have access to all of the salmon that spawn throughout the entire watershed, thus integrating across the complete diversity profile of the entire river. In contrast, fisheries in the headwaters have access to fewer salmon species and populations and thus fish from a much less diverse portfolio. These spatial gradients of diversity within watersheds provide a natural contrast for quantifying the effects of different types of diversity on interannual resource stability and seasonal availability. We acquired weekly and yearly catch totals from 1983 to 2012 (30 years) for Chinook, chum, coho, pink, and sockeye salmon for 21 FSC fishing sites throughout the Fraser River watershed from Fisheries and Oceans Canada. We examined how both population- and species-level diversity affects catch stability and season length at each site by quantifying year-to-year variability and within-year season length respectively. Salmon species diversity made fisheries up to 28% more stable in their catch than predicted with 3.7 more weeks to fish on average. Fisheries with access to high population diversity had up to 3.8 times more stable catch and 3 times longer seasons than less diverse fisheries. We

Assessing Risks of Mine Tailing Dam Failures

NASA Astrophysics Data System (ADS)

Concha Larrauri, P.; Lall, U.

2017-12-01

The consequences of tailings dam failures can be catastrophic for communities and ecosystems in the vicinity of the dams. The failure of the Fundão tailings dam at the Samarco mine in 2015 killed 19 people with severe consequences for the environment. The financial and legal consequences of a tailings dam failure can also be significant for the mining companies. For the Fundão tailings dam, the company had to pay 6 billion dollars in fines and twenty-one executives were charged with qualified murder. There are tenths of thousands of active, inactive, and abandoned tailings dams in the world and there is a need to better understand the hazards posed by these structures to downstream populations and ecosystems. A challenge to assess the risks of tailings dams in a large scale is that many of them are not registered in publicly available databases and there is little information about their current physical state. Additionally, hazard classifications of tailings dams - common in many countries- tend to be subjective, include vague parameter definitions, and are not always updated over time. Here we present a simple methodology to assess and rank the exposure to tailings dams using ArcGIS that removes subjective interpretations. The method uses basic information such as current dam height, storage volume, topography, population, land use, and hydrological data. A hazard rating risk was developed to compare the potential extent of the damage across dams. This assessment provides a general overview of what in the vicinity of the tailings dams could be affected in case of a failure and a way to rank tailings dams that is directly linked to the exposure at any given time. One hundred tailings dams in Minas Gerais, Brazil were used for the test case. This ranking approach could inform the risk management strategy of the tailings dams within a company, and when disclosed, it could enable shareholders and the communities to make decisions on the risks they are taking.

The socio-economics dynamics of Dam on Rural Communities: A case study of Oyan Dam, Nigeria

NASA Astrophysics Data System (ADS)

Ayeni, Amidu; Ojifo, Lawrence

2018-06-01

Dams construction and operations have many benefits, nevertheless, they have also led to lots of negative social, health and human impacts. It is based on this that this study assesses the potential and socio-economics dynamics of Oyan dam between 1980 and 2016. The data used for this study include water level and discharge records of the dam between 2007 and 2016, Landsat imageries of 1984 and 2016 and socio-economic datasets for the period. Analysis of the dam potentials (water supply, agriculture and hydropower) and socio-economic impacts of the dam were carried out using basic statistical tools, land use change anaysis and field survey using questionnaire, structured interview with major stakeholders and personal observation. The results revealed that the water level and storage of the Oyan dam had a relative reduction of about 2 % as well as non-stationarity pattern of water abstraction and production for the period. The landuse classes show all classes decreased in extent except the cultivated landuse that acrued an increased of 19.9 % between 1984 and 2016. Furthermore, commercial water supply varied significantly between 2010 and 2016 while irrigation scheme is grossly under-utilized from the inception in 1983 to 2016. Finally, the result of socio-economic impacts revealed that majority of the selected communities' members are actually not benefiting from the dam and their livelihoods are not from the dam.

Sediment Transport Over Run-of-River Dams

NASA Astrophysics Data System (ADS)

O'Brien, M.; Magilligan, F. J.; Renshaw, C. E.

2016-12-01

Dams have numerous documented effects that can degrade river habitat downstream. One significant effect of large dams is their ability to trap sediment delivered from upstream. This trapping can alter sediment transport and grain size downstream - effects that often motivate dam removal decisions. However, recent indirect observations and modeling studies indicate that small, run-of-river (ROR) dams, which do not impede discharge, may actually leak sediment downstream. However, there are no direct measurements of sediment flux over ROR dams. This study investigates flow and sediment transport over four to six different New England ROR dams over a summer-fall field season. Sediment flux was measured using turbidity meters and tracer (RFID) cobbles. Sediment transport was also monitored through an undammed control site and through a river where two ROR dams were recently removed. These data were used to predict the conditions that contribute to sediment transport and trapping. Year 1 data show that tracer rocks of up to 61 mm were transported over a 3 m ROR dam in peak flows of 84% of bankfull stage. These tracer rocks were transported over and 10 m beyond the dam and continue to move downstream. During the same event, comparable suspended sediment fluxes of up to 81 g/s were recorded both upstream and downstream of the dam at near-synchronous timestamps. These results demonstrate the potential for sediment transport through dammed rivers, even in discharge events that do not exceed bankfull. This research elucidates the effects of ROR dams and the controls on sediment transport and trapping, contributions that may aid in dam management decisions.

Hydraulics of embankment-dam breaching

NASA Astrophysics Data System (ADS)

Walder, J. S.; Iverson, R. M.; Logan, M.; Godt, J. W.; Solovitz, S.

2012-12-01

Constructed or natural earthen dams can pose hazards to downstream communities. Experiments to date on earthen-dam breaching have focused on dam geometries relevant to engineering practice. We have begun experiments with dam geometries more like those of natural dams. Water was impounded behind dams constructed at the downstream end of the USGS debris-flow flume. Dams were made of compacted, well-sorted, moist beach sand (D50=0.21 mm), 3.5 m from toe to toe, but varying in height from 0.5 to 1 m; the lower the dam, the smaller the reservoir volume and the broader the initially flat crest. Breaching was started by cutting a slot 30-40 mm wide and deep in the dam crest after filling the reservoir. Water level and pore pressure within the dam were monitored. Experiments were also recorded by an array of still- and video cameras above the flume and a submerged video camera pointed at the upstream dam face. Photogrammetric software was used to create DEMs from stereo pairs, and particle-image velocimetry was used to compute the surface-velocity field from the motion of tracers scattered on the water surface. As noted by others, breaching involves formation and migration of a knickpoint (or several). Once the knickpoint reaches the upstream dam face, it takes on an arcuate form whose continued migration we determined by measuring the onset of motion of colored markers on the dam face. The arcuate feature, which can be considered the head of the "breach channel", is nearly coincident with the transition from subcritical to supercritical flow; that is, it acts as a weir that hydraulically controls reservoir emptying. Photogenic slope failures farther downstream, although the morphologically dominant process at work, play no role at all in hydraulic control aside from rare instances in which they extend upstream so far as to perturb the weir, where the flow cross section is nearly self-similar through time. The domain downstream of the critical-flow section does influence

Effects of dams and geomorphic context on riparian forests of the Elwha River, Washington

USGS Publications Warehouse

Shafroth, Patrick B.; Perry, Laura G; Rose, Chanoane A; Braatne, Jeffrey H

2016-01-01

Understanding how dams affect the shifting habitat mosaic of river bottomlands is key for protecting the many ecological functions and related goods and services that riparian forests provide and for informing approaches to riparian ecosystem restoration. We examined the downstream effects of two large dams on patterns of forest composition, structure, and dynamics within different geomorphic contexts and compared them to upstream reference conditions along the Elwha River, Washington, USA. Patterns of riparian vegetation in river segments downstream of the dams were driven largely by channel and bottomland geomorphic responses to a dramatically reduced sediment supply. The river segment upstream of both dams was the most geomorphically dynamic, whereas the segment between the dams was the least dynamic due to substantial channel armoring, and the segment downstream of both dams was intermediate due to some local sediment supply. These geomorphic differences were linked to altered characteristics of the shifting habitat mosaic, including older forest age structure and fewer young Populus balsamifera subsp. trichocarpa stands in the relatively static segment between the dams compared to more extensive early-successional forests (dominated by Alnus rubra and Salix spp.) and pioneer seedling recruitment upstream of the dams. Species composition of later-successional forest communities varied among river segments as well, with greater Pseudotsuga menziesii and Tsuga heterophylla abundance upstream of both dams, Acer spp. abundance between the dams, and P. balsamifera subsp. trichocarpa and Thuja plicata abundance below both dams. Riparian forest responses to the recent removal of the two dams on the Elwha River will depend largely on channel and geomorphic adjustments to the release, transport, and deposition of the large volume of sediment formerly stored in the reservoirs, together with changes in large wood dynamics.

The effect of dams and seasons on malaria incidence and anopheles abundance in Ethiopia

PubMed Central

2013-01-01

Background Reservoirs created by damming rivers are often believed to increase malaria incidence risk and/or stretch the period of malaria transmission. In this paper, we report the effects of a mega hydropower dam on P. falciparum malaria incidence in Ethiopia. Methods A longitudinal cohort study was conducted over a period of 2 years to determine Plasmodium falciparum malaria incidence among children less than 10 years of age living near a mega hydropower dam in Ethiopia. A total of 2080 children from 16 villages located at different distances from a hydropower dam were followed up from 2008 to 2010 using active detection of cases based on weekly house to house visits. Of this cohort of children, 951 (48.09%) were females and 1059 (51.91%) were males, with a median age of 5 years. Malaria vectors were simultaneously surveyed in all the 16 study villages. Frailty models were used to explore associations between time-to-malaria and potential risk factors, whereas, mixed-effects Poisson regression models were used to assess the effect of different covariates on anopheline abundance. Results Overall, 548 (26.86%) children experienced at least one clinical malaria episode during the follow up period with mean incidence rate of 14.26 cases/1000 child-months at risk (95% CI: 12.16 - 16.36). P. falciparum malaria incidence showed no statistically significant association with distance from the dam reservoir (p = 0.32). However, P. falciparum incidence varied significantly between seasons (p < 0.01). The malaria vector, Anopheles arabiensis, was however more abundant in villages nearer to the dam reservoir. Conclusions P. falciparum malaria incidence dynamics were more influenced by seasonal drivers than by the dam reservoir itself. The findings could have implications in timing optimal malaria control interventions and in developing an early warning system in Ethiopia. PMID:23566411

Brazil's Amazonian dams: Ecological and socioeconomic impacts

NASA Astrophysics Data System (ADS)

Fearnside, P. M.

2016-12-01

Brazil's 2015-2024 Energy Expansion Plan calls for 11 hydroelectric dams with installed capacity ≥ 30 MW in the country's Amazon region. Dozens of other large dams are planned beyond this time horizon, and dams with < 30 MW installed capacity number in the hundreds. Amazonian dams have substantial environmental and socioeconomic impacts. Loss of forest to flooding is one, the Balbina and Tucuruí Dams being examples (each 3000 km2). If the Babaquara/Altamira Dam is built it will flood as much forest as both of these combined. Some planned dams imply loss of forest in protected areas, for example on the Tapajós River. Aquatic and riparian ecosystems are lost, including unique biodiversity. Endemic fish species in rapids on the Xingu and Tapajós Rivers are examples. Fish migrations are blocked, such as the commercially important "giant catfish" of the Madeira River. Dams emit greenhouse gases, including CO2 from the trees killed and CH4 from decay under anoxic conditions at the bottom of reservoirs. Emissions can exceed those from fossil-fuel generation, particularly over the 20-year period during which global emissions must be greatly reduced to meet 1.5-2°C limit agreed in Paris. Carbon credit for dams under the Climate Convention causes further net emission because the dams are not truly "additional." Anoxic environments in stratified reservoirs cause methylation of mercury present in Amazonian soils, which concentrates in fish, posing a health risk to human consumers. Population displacement is a major impact; for example, the Marabá Dam would displace 40,000 people, mostly traditional riverside dwellers (ribeirinhos). Various dams impact indigenous peoples, such as the Xingu River dams (beginning with Belo Monte) and the São Luiz do Tapajós and Chacorão Dams on the Tapajós River. Brazil has many energy options other than dams. Much energy use has little benefit for the country, such as exporting aluminum. Electric showerheads use 5% of the country

Mitigating Dam Impacts Using Environmental Flow Releases

NASA Astrophysics Data System (ADS)

Richter, B. D.

2017-12-01

One of the most ecologically disruptive impacts of dams is their alteration of natural river flow variability. Opportunities exist for modifying the operations of existing dams to recover many of the environmental and social benefits of healthy ecosystems that have been compromised by present modes of dam operation. The potential benefits of dam "re-operation" include recovery of fish, shellfish, and other wildlife populations valued both commercially and recreationally, including estuarine species; reactivation of the flood storage and water purification benefits that occur when floods are allowed to flow into floodplain forests and wetlands; regaining some semblance of the naturally dynamic balance between river erosion and sedimentation that shapes physical habitat complexity, and arresting problems associated with geomorphic imbalances; cultural and spiritual uses of rivers; and many other socially valued products and services. Assessing the potential benefits of dam re-operation begins by characterizing the dam's effects on the river flow regime, and formulating hypotheses about the ecological and social benefits that might be restored by releasing water from the dam in a manner that more closely resembles natural flow patterns. These hypotheses can be tested by implementing a re-operation plan, tracking the response of the ecosystem, and continually refining dam operations through adaptive management. This presentation will highlight a number of land and water management strategies useful in implementing a dam re-operation plan, with reference to a variety of management contexts ranging from individual dams to cascades of dams along a river to regional energy grids. Because many of the suggested strategies for dam re-operation are predicated on changes in the end-use of the water, such as reductions in urban or agricultural water use during droughts, a systemic perspective of entire water management systems will be required to attain the fullest possible

Assessing changes in failure probability of dams in a changing climate

NASA Astrophysics Data System (ADS)

Mallakpour, I.; AghaKouchak, A.; Moftakhari, H.; Ragno, E.

2017-12-01

Dams are crucial infrastructures and provide resilience against hydrometeorological extremes (e.g., droughts and floods). In 2017, California experienced series of flooding events terminating a 5-year drought, and leading to incidents such as structural failure of Oroville Dam's spillway. Because of large socioeconomic repercussions of such incidents, it is of paramount importance to evaluate dam failure risks associated with projected shifts in the streamflow regime. This becomes even more important as the current procedures for design of hydraulic structures (e.g., dams, bridges, spillways) are based on the so-called stationary assumption. Yet, changes in climate are anticipated to result in changes in statistics of river flow (e.g., more extreme floods) and possibly increasing the failure probability of already aging dams. Here, we examine changes in discharge under two representative concentration pathways (RCPs): RCP4.5 and RCP8.5. In this study, we used routed daily streamflow data from ten global climate models (GCMs) in order to investigate possible climate-induced changes in streamflow in northern California. Our results show that while the average flow does not show a significant change, extreme floods are projected to increase in the future. Using the extreme value theory, we estimate changes in the return periods of 50-year and 100-year floods in the current and future climates. Finally, we use the historical and future return periods to quantify changes in failure probability of dams in a warming climate.

Malaria and water resource development: the case of Gilgel-Gibe hydroelectric dam in Ethiopia.

PubMed

Yewhalaw, Delenasaw; Legesse, Worku; Van Bortel, Wim; Gebre-Selassie, Solomon; Kloos, Helmut; Duchateau, Luc; Speybroeck, Niko

2009-01-29

Ethiopia plans to increase its electricity power supply by five-fold over the next five years to fulfill the needs of its people and support the economic growth based on large hydropower dams. Building large dams for hydropower generation may increase the transmission of malaria since they transform ecosystems and create new vector breeding habitats. The aim of this study was to assess the effects of Gilgel-Gibe hydroelectric dam in Ethiopia on malaria transmission and changing levels of prevalence in children. A cross-sectional, community-based study was carried out between October and December 2005 in Jimma Zone, south-western Ethiopia, among children under 10 years of age living in three 'at-risk' villages (within 3 km from dam) and three 'control' villages (5 to 8 km from dam). The man-made Gilgel-Gibe dam is operating since 2004. Households with children less than 10 years of age were selected and children from the selected households were sampled from all the six villages. This included 1,081 children from 'at-risk' villages and 774 children from 'control' villages. Blood samples collected from children using finger prick were examined microscopically to determine malaria prevalence, density of parasitaemia and identify malarial parasite species. Overall 1,855 children (905 girls and 950 boys) were surveyed. A total of 194 (10.5%) children were positive for malaria, of which, 117 (60.3%) for Plasmodium vivax, 76 (39.2%) for Plasmodium falciparum and one (0.5%) for both P. vivax and P. falciparum. A multivariate design-based analysis indicated that, while controlling for age, sex and time of data collection, children who resided in 'at-risk' villages close to the dam were more likely to have P. vivax infection than children who resided farther away (odds ratio (OR) = 1.63, 95% CI = 1.15, 2.32) and showed a higher OR to have P. falciparum infection than children who resided in 'control' villages, but this was not significant (OR = 2.40, 95% CI = 0.84, 6.88). A

Malaria and water resource development: the case of Gilgel-Gibe hydroelectric dam in Ethiopia

PubMed Central

Yewhalaw, Delenasaw; Legesse, Worku; Van Bortel, Wim; Gebre-Selassie, Solomon; Kloos, Helmut; Duchateau, Luc; Speybroeck, Niko

2009-01-01

Background Ethiopia plans to increase its electricity power supply by five-fold over the next five years to fulfill the needs of its people and support the economic growth based on large hydropower dams. Building large dams for hydropower generation may increase the transmission of malaria since they transform ecosystems and create new vector breeding habitats. The aim of this study was to assess the effects of Gilgel-Gibe hydroelectric dam in Ethiopia on malaria transmission and changing levels of prevalence in children. Methods A cross-sectional, community-based study was carried out between October and December 2005 in Jimma Zone, south-western Ethiopia, among children under 10 years of age living in three 'at-risk' villages (within 3 km from dam) and three 'control' villages (5 to 8 km from dam). The man-made Gilgel-Gibe dam is operating since 2004. Households with children less than 10 years of age were selected and children from the selected households were sampled from all the six villages. This included 1,081 children from 'at-risk' villages and 774 children from 'control' villages. Blood samples collected from children using finger prick were examined microscopically to determine malaria prevalence, density of parasitaemia and identify malarial parasite species. Results Overall 1,855 children (905 girls and 950 boys) were surveyed. A total of 194 (10.5%) children were positive for malaria, of which, 117 (60.3%) for Plasmodium vivax, 76 (39.2%) for Plasmodium falciparum and one (0.5%) for both P. vivax and P. falciparum. A multivariate design-based analysis indicated that, while controlling for age, sex and time of data collection, children who resided in 'at-risk' villages close to the dam were more likely to have P. vivax infection than children who resided farther away (odds ratio (OR) = 1.63, 95% CI = 1.15, 2.32) and showed a higher OR to have P. falciparum infection than children who resided in 'control' villages, but this was not significant (OR = 2

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.

How far downstream do dams impact streamflow?

NASA Astrophysics Data System (ADS)

Troy, T.

2017-12-01

Water infrastructure can be a double-edged sword. For example, dams can provide significant flood protection and stable water supplies, but they negatively impact river ecosystems. As the United States enters an era of dam decommissioning instead of dam building, it raises the question of how far downstream dams provide protection against flood peaks and sustaining environmental flows. This study uses USGS streamflow observations, the National Inventory of Dams, and VIC-modeled streamflow as a proxy for naturalized streamflow to evaluate the scale at which dams impact a variety of hydrologic signatures such as flood return period flows, streamflow variability, and low flows. Results over the Delaware River show that the impact of dams quickly dissipates as one moves downstream, but this is due to the basin's characteristics. This analysis is performed over the contiguous United States, quantifying the length scale of impact as a function of dam capacity, position on the river network, and the hydroclimatology.

Reconstructing western Grand Canyon's lava dams and their failure mechanisms: new insights from geochemical correlation and 40Ar/39Ar dating

NASA Astrophysics Data System (ADS)

Crow, R.; Karlstrom, K. E.; McIntosh, W. C.; Peters, L.; Dunbar, N. W.

2010-12-01

New geochemical analyzes and 40Ar/39Ar dating of lava dam remnants allows for the more accurate reconstruction of the timing, extent, and structure of western Grand Canyon’s lava dams. Whole-rock major, trace, and rare-earth element (REE) analyzes on over 60 basaltic lava dam remnants, cascades, plugs, and basaltic alluvium, show compositional variation from basanites to alkali basalts to tholeiites. Whitmore Canyon flows, for example, are some of the only tholeiitic flows and have a distinguishable trace and REE composition, which allows for correlation of dam remnants. Over 30 new high-precision 40Ar/39Ar dates also aid in remnant correlation and establish a better-constrained sequence of intra-canyon lava dams. Reliable 40Ar/39Ar dates on western Grand Canyon’s intra-canyon basalts range from ca. 100 ka to 840 ka (new date). The best understood lava dam formed from tholeiitic flows that erupted on the north rim, flowed down Whitmore side canyon and blocked a 6-km-long reach of the Grand Canyon. The youngest of these flows is unique because we know its age (200ka), its composition (tholeiitic), and the exact area where it entered Grand Canyon. The highest flow in the resulting dam, Whitmore Cascade, is capped with very coarse basaltic alluvium that previous workers have attributed to an upstream catastrophic dam failure event at about 200 ka. However, strong similarities between the geochemistry and age of the alluvium with the underlying Whitmore Cascade flow suggest that the alluvial deposit is related to failure of the 200 ka Whitmore Cascade dam itself. Similarly the 100 ka Upper Gray Ledge flow is commonly overlain by a balsaltic alluvium that is indistinguishable in terms of age and geochemistry from the underlying Upper Gray Ledge flow. These observations lead to a new model for Grand Canyon lava dams by which lava dams undergo multi-staged failure where the upstream parts of dams fail quickly (sometimes catastrophically) but downstream parts are

Water-quality reconnaissance of the Middle and North Branch Park River watersheds, northeastern North Dakota

USGS Publications Warehouse

Ackerman, D.J.

1980-01-01

In order to design a network to monitor the effects of works of improvement in the Middle and North Branch Park River watersheds, and to determine the major factors controlling water-quality conditions in the watersheds, an evaluation of sediment transport, water chemistry, and biology was conducted during the spring and early summer of 1978.Major factors controlling water quality are geology, stream gradient, ground-water seepage, and the duration of streamflow.Sediment loads originate on the Pembina Escarpment. The coarse silt and sand parts of these loads are deposited on the Lake Agassiz Plain. Transport of sediment is lowered and flow duration is increased on the Middle Branch Park River due to the presence of small dams. Observations suggest that bedload transport is a significant process, particularly in the upstream reaches. However, no quantitative bedload data were collected.During periods of low flow, analyses of water from the rivers in both watersheds show downstream increases in sodium and chloride due to ground-water seepage or the unregulated flow of wells. Diversity of benthic invertebrates indicates water-quality conditions are better on the Middle Branch Park River than on the North Branch, and are better at upstream sites than at downstream sites. A program through which the Soil Conservation Service can monitor the effects of present and future works of improvement on the watersheds was designed. The monitoring program consists of intensive sampling at four locations for sediment and water chemistry during spring and early summer runoff events and by profiles of water chemistry during summer base runoff.

Sustainability of dams-an evaluation approach

NASA Astrophysics Data System (ADS)

Petersson, E.

2003-04-01

Situated in the stream bed of a river, dams and reservoirs interrupt the natural hydrological cycle. They are very sensitive to all kinds of changes in the catchment, among others global impacts on land use, climate, settlement structures or living standards. Vice versa dams strongly affect the spatially distributed, complex system of ecology, economy and society in the catchment both up- and downstream of the reservoir. The occurrence of negative impacts due to large dams led to serious conflicts about future dams. Nevertheless, water shortages due to climatic conditions and their changes, that are faced by enormous water and energy demands due to rising living standards of a growing world population, seem to require further dam construction, even if both supply and demand management are optimised. Although environmental impact assessments are compulsory for dams financed by any of the international funding agencies, it has to be assumed that the projects lack sustainability. Starting from an inventory of today's environmental impact assessments as an integral part of a feasibility study the presentation will identify their inadequacies with regard to the sustainability of dams. To improve the sustainability of future dams and avoid the mistakes of the past, the planning procedures for dams have to be adapted. The highly complex and dynamical system of interrelated physical and non-physical processes, that involves many different groups of stakeholders, constitutes the need for a model-oriented decision support system. In line with the report of the World Commission of Dams an integrated analysis and structure of the complex interrelations between dams, ecology, economy and society will be presented. Thus the system, that a respective tool will be based on, is analysed. Furthermore an outlook will be given on the needs of the potential users of a DSS and how it has to be embedded in the overall planning process. The limits of computer-based decision-support in the

National Dam Inspection Program. Converse Lake Dam (CT 00044). Connecticut Coastal Basin, Greenwich, Connecticut. Phase I Inspection Report.

DTIC Science & Technology

1980-02-01

Guidelines for Safety Inspection of Dams, and with good engineering judgement and practice, and is hereby submitted for approval. ’ /00s~rs H W. NT’EGAN...below the top of the dam, with water flowing over the spillway. b. Dam Crest - The top of the dam is a concrete cap and is in good condition (Photo 1...the masonry portion is not substantial the dam is not safe. Masonry on water side is a good job of cement rubble. Top width is 7’. But it is doubtful

Damming the rivers of the Amazon basin

NASA Astrophysics Data System (ADS)

Latrubesse, Edgardo M.; Arima, Eugenio Y.; Dunne, Thomas; Park, Edward; Baker, Victor R.; D'Horta, Fernando M.; Wight, Charles; Wittmann, Florian; Zuanon, Jansen; Baker, Paul A.; Ribas, Camila C.; Norgaard, Richard B.; Filizola, Naziano; Ansar, Atif; Flyvbjerg, Bent; Stevaux, Jose C.

2017-06-01

More than a hundred hydropower dams have already been built in the Amazon basin and numerous proposals for further dam constructions are under consideration. The accumulated negative environmental effects of existing dams and proposed dams, if constructed, will trigger massive hydrophysical and biotic disturbances that will affect the Amazon basin’s floodplains, estuary and sediment plume. We introduce a Dam Environmental Vulnerability Index to quantify the current and potential impacts of dams in the basin. The scale of foreseeable environmental degradation indicates the need for collective action among nations and states to avoid cumulative, far-reaching impacts. We suggest institutional innovations to assess and avoid the likely impoverishment of Amazon rivers.

Damming the rivers of the Amazon basin.

PubMed

Latrubesse, Edgardo M; Arima, Eugenio Y; Dunne, Thomas; Park, Edward; Baker, Victor R; d'Horta, Fernando M; Wight, Charles; Wittmann, Florian; Zuanon, Jansen; Baker, Paul A; Ribas, Camila C; Norgaard, Richard B; Filizola, Naziano; Ansar, Atif; Flyvbjerg, Bent; Stevaux, Jose C

2017-06-14

More than a hundred hydropower dams have already been built in the Amazon basin and numerous proposals for further dam constructions are under consideration. The accumulated negative environmental effects of existing dams and proposed dams, if constructed, will trigger massive hydrophysical and biotic disturbances that will affect the Amazon basin's floodplains, estuary and sediment plume. We introduce a Dam Environmental Vulnerability Index to quantify the current and potential impacts of dams in the basin. The scale of foreseeable environmental degradation indicates the need for collective action among nations and states to avoid cumulative, far-reaching impacts. We suggest institutional innovations to assess and avoid the likely impoverishment of Amazon rivers.

Behavior and dam passage of juvenile Chinook salmon at Cougar Reservoir and Dam, Oregon, March 2011 - February 2012

USGS Publications Warehouse

Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Haner, Philip V.; Sprando, Jamie M.; Smith, Collin D.; Evans, Scott D.; Hatton, Tyson W.

2013-01-01

The movements and dam passage of juvenile Chinook salmon implanted with acoustic transmitters and passive integrated transponder tags were studied at Cougar Reservoir and Dam, near Springfield, Oregon. The purpose of the study was to provide information to aid with decisions about potential alternatives for improving downstream passage conditions for juvenile salmonids in this flood-control reservoir. In 2011, a total of 411 hatchery fish and 26 wild fish were tagged and released during a 3-month period in the spring, and another 356 hatchery fish and 117 wild fish were released during a 3-month period in the fall. A series of 16 autonomous hydrophones throughout the reservoir and 12 hydrophones in a collective system near the dam outlet were used to determine general movements and dam passage of the fish over the life of the acoustic transmitter, which was expected to be about 3 months. Movements within the reservoir were directional, and it was common for fish to migrate repeatedly from the head of the reservoir downstream to the dam outlet and back to the head of the reservoir. Most fish were detected near the temperature control tower at least once. The median time from release near the head of the reservoir to detection within about 100 meters of the dam outlet at the temperature control tower was between 5.7 and 10.8 days, depending on season and fish origin. Dam passage events occurred over a wider range of dates in the spring and summer than in the fall and winter, but dam passage numbers were greatest during the fall and winter. A total of 10.5 percent (43 of 411) of the hatchery fish and 15.4 percent (4 of 26) of the wild fish released in the spring are assumed to have passed the dam, whereas a total of 25.3 percent (90 of 356) of the hatchery fish and 16.9 percent (30 of 117) of the wild fish released in the fall are assumed to have passed the dam. A small number of fish passed the dam after their transmitters had stopped working and were detected at

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.

Connections between residence time distributions and watershed characteristics across the continental US

NASA Astrophysics Data System (ADS)

Condon, L. E.; Maxwell, R. M.; Kollet, S. J.; Maher, K.; Haggerty, R.; Forrester, M. M.

2016-12-01

Although previous studies have demonstrated fractal residence time distributions in small watersheds, analyzing residence time scaling over large spatial areas is difficult with existing observational methods. For this study we use a fully integrated groundwater surface water simulation combined with Lagrangian particle tracking to evaluate connections between residence time distributions and watershed characteristics such as geology, topography and climate. Our simulation spans more than six million square kilometers of the continental US, encompassing a broad range of watershed sizes and physiographic settings. Simulated results demonstrate power law residence time distributions with peak age rages from 1.5 to 10.5 years. These ranges agree well with previous observational work and demonstrate the feasibility of using integrated models to simulate residence times. Comparing behavior between eight major watersheds, we show spatial variability in both the peak and the variance of the residence time distributions that can be related to model inputs. Peak age is well correlated with basin averaged hydraulic conductivity and the semi-variance corresponds to aridity. While power law age distributions have previously been attributed to fractal topography, these results illustrate the importance of subsurface characteristics and macro climate as additional controls on groundwater configuration and residence times.

Dams and Rivers: A Primer on the Downstream Effects of Dams

USGS Publications Warehouse

Collier, Michael; Webb, Robert H.; Schmidt, John C.

1996-01-01

The U.S. Geological Survey is charged with monitoring the water and mineral resources of the United States. Beginning in 1889, the Survey established a network of water gaging stations across most of the country's rivers; some also measured sediment content of the water. Consequently, we now have valuable long-term data with which to track water supply, sediment transport, and the occurrence of floods. Many variables affect the flow of water from mountain brook to river delta. Some are short-term perturbations like summer thunderstorms. Others occur over a longer period of time, like the El Ninos that might be separated by a decade or more. We think of these variables as natural occurrences, but humans have exerted some of the most important changes -- water withdrawals for agriculture, inter-basin transfers, and especially the construction of an extensive system of dams. Dams have altered the flow of many of the Nation's rivers to meet societal needs. We expect floods to be contained. Irrigation is possible where deserts once existed. And water is released downstream not according to natural cycles but as dictated by a region's hour-by-hour needs for water or electricity. As a result, river channels below dams have changed dramatically. Depending on annual flow, flood peaks, and a river's sediment load, we might see changes such as sand building up in one channel, vegetation crowding into another, and extensive bank erosion in another. This Circular explores the emerging scientific arena of change in rivers below dams. This science tries first to understand and then anticipate changes to river beds and banks, and to riparian habitats and animal communities. To some degree, these downstream changes can be influenced by specific strategies of dam management. Scientists and resource managers have a duty to assemble this information and present it without bias to the rest of society. Society can then more intelligently choose a balance between the benefits and adverse

Using supercomputers for the time history analysis of old gravity dams

NASA Astrophysics Data System (ADS)

Rouve, G.; Peters, A.

Some of the old masonry dams that were built in Germany at the beginning of this century are a matter of concern today. In the course of time certain deterioration caused or amplified by aging has appeared and raised questions about the safety of these old dams. The Finite Element Method, which in the past two decades has found a widespread application, offers a suitable tool to re-evaluate the safety of these old gravity dams. The reliability of the results, however, strongly depends on the knowledge of the material parameters. Using historical records and observations a numerical back-analysis models has been developed to simulate the behaviour of these old masonry structures and to estimate their material properties by calibration. Only an implementation on a fourth generation vector computer made the application of this large model possible in practice.

Advances on the Failure Analysis of the Dam-Foundation Interface of Concrete Dams.

PubMed

Altarejos-García, Luis; Escuder-Bueno, Ignacio; Morales-Torres, Adrián

2015-12-02

Failure analysis of the dam-foundation interface in concrete dams is characterized by complexity, uncertainties on models and parameters, and a strong non-linear softening behavior. In practice, these uncertainties are dealt with a well-structured mixture of experience, best practices and prudent, conservative design approaches based on the safety factor concept. Yet, a sound, deep knowledge of some aspects of this failure mode remain unveiled, as they have been offset in practical applications by the use of this conservative approach. In this paper we show a strategy to analyse this failure mode under a reliability-based approach. The proposed methodology of analysis integrates epistemic uncertainty on spatial variability of strength parameters and data from dam monitoring. The purpose is to produce meaningful and useful information regarding the probability of occurrence of this failure mode that can be incorporated in risk-informed dam safety reviews. In addition, relationships between probability of failure and factors of safety are obtained. This research is supported by a more than a decade of intensive professional practice on real world cases and its final purpose is to bring some clarity, guidance and to contribute to the improvement of current knowledge and best practices on such an important dam safety concern.

Teaching Practical Watershed Science to non-Watershed Science Majors

NASA Astrophysics Data System (ADS)

Fassnacht, S. R.; Laituri, M.; Layden, P.; Coleman, R.

2008-12-01

The Warner College of Natural Resources (WCNR) at Colorado State University (CSU) has had a long tradition of integrating field measurements into the classroom, dating back to the first forestry summer camp held in 1917 at the CSU Pingree Park mountain campus. In the early 1960s, the Cooperative Watershed Management Unit coordinated efforts to understand and analyse the basic resources of the area, with an emphasis on the geology, hydrology, and climate. Much of this understand is now used as the Abiotic (Geology and Watershed) component of a five-credit, four-week course offered twice each summer at Pingree Park. With the exception of Geology students who have their own field course, this Natural Resources Ecology and Measurements course (NR 220) is required for all WCNR undergraduate students. These majors include Watershed Science, Forestry, Rangeland Ecology, Fisheries, Wildlife Biology, Conservation Biology, and Recreation and Tourism. Since most of these are students are much better trained in biological and/or social sciences rather than physical sciences, a challenge for the Watershed professor is to teaching practical Watershed Science to non-Watershed Science majors. This presentation describes how this challenge is met and how this course helps broaden the knowledge base of Natural Resources students.

WinDAM C earthen embankment internal erosion analysis software

USDA-ARS?s Scientific Manuscript database

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...

Facilitating fish passage at ultra low head dams: An alternative to dam removal

USGS Publications Warehouse

Odeh, M.

2004-01-01

Ecosystem sustainability and returning the biological integrity to rivers continue to change the landscape of fish passage technology. Installing a conventional fishways has a limited degree of success in accommodating fish passage needs. Recently, the option of total dam removal has been gaining momentum among resource managers, conservationists, and even engineers. Certain dams, however, cannot be removed, and conventional fishways are either too expensive to build or the real estate is simply not available; yet freedom of passage must be attained. At the Little Falls Dam on the Potomac River a notch in the crest of the dam was installed to accommodate passage of fish. The notch has three labyrinth weirs used for energy dissipation. Water velocities are maintained at less than about 4 m/s anywhere within the passage structure during migratory season of the target species (American shad). Construction of this novel design was recently completed (March 2000) and future biological evaluations are ongoing. Copyright ASCE 2004.

Key Impact Factors on Dam Break Fatalities

NASA Astrophysics Data System (ADS)

Huang, D.; Yu, Z.; Song, Y.; Han, D.; Li, Y.

2016-12-01

Dam failures can lead to catastrophes on human society. However, there is a lack of research about dam break fatalities, especially on the key factors that affect fatalities. Based on the analysis of historical dam break cases, most studies have used the regression analysis to explore the correlation between those factors and fatalities, but without implementing optimization to find the dominating factors. In order to understand and reduce the risk of fatalities, this study has proposed a new method to select the impact factors on the fatality. It employs an improved ANN (Artificial Neural Network) combined with LOOCV (Leave-one-out cross-validation) and SFS (Stepwise Forward Selection) approach to explore the nonlinear relationship between impact factors and life losses. It not only considers the factors that have been widely used in the literature but also introduces new factors closely involved with fatalities. Dam break cases occurred in China from 1954 to 2013 are summarized, within which twenty-five cases are selected with a comprehensive coverage of geographic position and temporal variation. Twelve impact factors are taken into account as the inputs, i.e., severity of dam break flood (SF), population at risk (PR), public understanding of dam break (UB), warning time (TW), evacuation condition (EC), weather condition during dam break (WB), dam break mode (MB), water storage (SW), building vulnerability (VB), dam break time (TB), average distance from the affected area to the dam (DD) and preventive measures by government (PG).From those, three key factors of SF, MB and TB are chosen. The proposed method is able to extract the key factors, and the derived fatality model performs well in various types of dam break conditions.

Modeling the Capacity of Riverscapes to Support Dam-Building Beaver

NASA Astrophysics Data System (ADS)

Macfarlane, W.; Wheaton, J. M.

2012-12-01

Beaver (Castor canadensis) dam-building activities lead to a cascade of aquatic and riparian effects that increase the complexity of streams. As a result, beaver are increasingly being used as a critical component of passive stream and riparian restoration strategies. We developed the spatially-explicit Beaver Assessment and Restoration Tool (BRAT) to assess the capacity of the landscape in and around streams and rivers to support dam-building activity for beaver. Capacity was assessed in terms of readily available nation-wide GIS datasets to assess key habitat capacity indicators: water availability, relative abundance of preferred food/building materials and stream power. Beaver capacity was further refined by: 1) ungulate grazing capacity 2) proximity to human conflicts (e.g., irrigation diversions, settlements) 3) conservation/management objectives (endangered fish habitat) and 4) projected benefits related to beaver re-introductions (e.g., repair incisions). Fuzzy inference systems were used to assess the relative importance of these inputs which allowed explicit incorporation of uncertainty resulting from categorical ambiguity of inputs into the capacity model. Results indicate that beaver capacity varies widely within the study area, but follows predictable spatial patterns that correspond to distinct River Styles and landscape units. We present a case study application and verification/validation data from the Escalante River Watershed in southern Utah, and show how the models can be used to help resource managers develop and implement restoration and conservation strategies employing beaver that will have the greatest potential to yield increases in biodiversity and ecosystem services.

The future role of dams in the United States of America

NASA Astrophysics Data System (ADS)

Ho, Michelle; Lall, Upmanu; Allaire, Maura; Devineni, Naresh; Kwon, Hyun Han; Pal, Indrani; Raff, David; Wegner, David

2017-02-01

xml:id="wrcr22481-sec-1001" numbered="no">Storage and controlled distribution of water have been key elements of a human strategy to overcome the space and time variability of water, which have been marked by catastrophic droughts and floods throughout the course of civilization. In the United States, the peak of dam building occurred in the mid-20th century with knowledge limited to the scientific understanding and hydrologic records of the time. Ecological impacts were considered differently than current legislative and regulatory controls would potentially dictate. Additionally, future costs such as maintenance or removal beyond the economic design life were not fully considered. The converging risks associated with aging water storage infrastructure and uncertainty in climate in addition to the continuing need for water storage, flood protection, and hydropower result in a pressing need to address the state of dam infrastructure across the nation. Decisions regarding the future of dams in the United States may, in turn, influence regional water futures through groundwater outcomes, economic productivity, migration, and urban growth. We advocate for a comprehensive national water assessment and a formal analysis of the role dams play in our water future. We emphasize the urgent need for environmentally and economically sound strategies to integrate surface and groundwater storage infrastructure in local, regional, and national water planning considerations. A research agenda is proposed to assess dam failure impacts and the design, operation, and need for dams considering both paleo and future climate, utilization of groundwater resources, and the changing societal values toward the environment.

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 of...

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 substantial...

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 of...

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 substantial...

National Program for Inspection of Non-Federal Dams. Tihonet Pond Number 2 Dam (MA 00030), Massachusetts Coastal Basin, Wareham, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1981-07-01

INSPECTION REPORT IDENTIFICATION NO.: MA 00030 S NAME OF DAM : TIHONET POND NO.2 DAM TOWN : WAREHAM COUNTY AND STATE : PLYMOUTH , MASSACHUSETTS STREAM...northeast of this dam serves to impound the water of Tihonet Pond also. This dam is referred to as Dam # 14 on Plymouth County Inspection Reports and...1. Approximately 1800 ft. northeast of this dam a second dam is located. This dam is referred to as Dam # 14 on Plymouth County . Inspection Reports

Advancement in Watershed Modelling Using Dynamic Lateral and Longitudinal Sediment (Dis)connectivity Prediction

NASA Astrophysics Data System (ADS)

Mahoney, D. T.; al Aamery, N. M. H.; Fox, J.

2017-12-01

The authors find that sediment (dis)connectivity has seldom taken precedence within watershed models, and the present study advances this modeling framework and applies the modeling within a bedrock-controlled system. Sediment (dis)connectivity, defined as the detachment and transport of sediment from source to sink between geomorphic zones, is a major control on sediment transport. Given the availability of high resolution geospatial data, coupling sediment connectivity concepts within sediment prediction models offers an approach to simulate sediment sources and pathways within a watershed's sediment cascade. Bedrock controlled catchments are potentially unique due to the presence of rock outcrops causing longitudinal impedance to sediment transport pathways in turn impacting the longitudinal distribution of the energy gradient responsible for conveying sediment. Therefore, the authors were motivated by the need to formulate a sediment transport model that couples sediment (dis)connectivity knowledge to predict sediment flux for bedrock controlled catchments. A watershed-scale sediment transport model was formulated that incorporates sediment (dis)connectivity knowledge collected via field reconnaissance and predicts sediment flux through coupling with the Partheniades equation and sediment continuity model. Sediment (dis)connectivity was formulated by coupling probabilistic upland lateral connectivity prediction with instream longitudinal connectivity assessments via discretization of fluid and sediment pathways. Flux predictions from the upland lateral connectivity model served as an input to the instream longitudinal connectivity model. Disconnectivity in the instream model was simulated via the discretization of stream reaches due to barriers such as bedrock outcroppings and man-made check dams. The model was tested for a bedrock controlled catchment in Kentucky, USA for which extensive historic water and sediment flux data was available. Predicted sediment

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

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Marshall Ford Dam and Reservoir... Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex. The Secretary of the... and Reservoir in the interest of flood control as follows: (a) Water Control Plan—(1) General...

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

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Marshall Ford Dam and Reservoir... Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex. The Secretary of the... and Reservoir in the interest of flood control as follows: (a) Water Control Plan—(1) General...

National Program for Inspection of Non-Federal Dams. Upper Eddy Pond Dam (VT 00231), Richelieu River Basin, Rutland, Vermont. Phase I Inspection Report.

DTIC Science & Technology

1981-04-01

crest. There Is a pond drain about 18 inches in dimeter which is reported to be Inoperable. The top of dam stor-5 age is estimated to be 51 acre-fot...related to lateral movements and/or settlement of the rubbish fill. The dumped material should be removed and the embankment regraded. The seep- age area...drain- age area. 6 5.2 DESIGN DATA No hydraulic or hydrologic design data or criteria were available. 5.3 EXPERIENCE DATA There is no evidence of recent

Modeling the capacity of riverscapes to support beaver dams

NASA Astrophysics Data System (ADS)

Macfarlane, William W.; Wheaton, Joseph M.; Bouwes, Nicolaas; Jensen, Martha L.; Gilbert, Jordan T.; Hough-Snee, Nate; Shivik, John A.

2017-01-01

The construction of beaver dams facilitates a suite of hydrologic, hydraulic, geomorphic, and ecological feedbacks that increase stream complexity and channel-floodplain connectivity that benefit aquatic and terrestrial biota. Depending on where beaver build dams within a drainage network, they impact lateral and longitudinal connectivity by introducing roughness elements that fundamentally change the timing, delivery, and storage of water, sediment, nutrients, and organic matter. While the local effects of beaver dams on streams are well understood, broader coverage network models that predict where beaver dams can be built and highlight their impacts on connectivity across diverse drainage networks are lacking. Here we present a capacity model to assess the limits of riverscapes to support dam-building activities by beaver across physiographically diverse landscapes. We estimated dam capacity with freely and nationally-available inputs to evaluate seven lines of evidence: (1) reliable water source, (2) riparian vegetation conducive to foraging and dam building, (3) vegetation within 100 m of edge of stream to support expansion of dam complexes and maintain large colonies, (4) likelihood that channel-spanning dams could be built during low flows, (5) the likelihood that a beaver dam is likely to withstand typical floods, (6) a suitable stream gradient that is neither too low to limit dam density nor too high to preclude the building or persistence of dams, and (7) a suitable river that is not too large to restrict dam building or persistence. Fuzzy inference systems were used to combine these controlling factors in a framework that explicitly also accounts for model uncertainty. The model was run for 40,561 km of streams in Utah, USA, and portions of surrounding states, predicting an overall network capacity of 356,294 dams at an average capacity of 8.8 dams/km. We validated model performance using 2852 observed dams across 1947 km of streams. The model showed

Urban Watershed Forestry Manual Part 1: Methods for Increasing Forest Cover in a Watershed

Treesearch

Karen Cappiella; Tom Schueler; Tiffany Wright

2005-01-01

This manual is one in a three-part series on using trees to protect and restore urban watersheds. A brief description of each part follows. Part 1: Methods for Increasing Forest Cover in a Watershed introduces the emerging topic of urban watershed forestry. This part also presents new methods for the watershed planner or forester to systematically measure watershed...

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

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…

Route-Specific Passage Proportions and Survival Rates for Fish Passing through John Day Dam, The Dalles Dam, and Bonneville Dam in 2010 and 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ploskey, Gene R.; Weiland, Mark A.; Carlson, Thomas J.

This report fulfills a request of the U.S. Army Engineer District, Portland, Oregon, to produce an interim report of estimates of route-specific fish passage proportions and survival rates for lower Columbia River dams in 2010 and 2011. The estimates are needed to update the Compass Model for the Columbia River Treaty and the new Biological Opinion before detail technical reports are published in late 2012. This report tabulates route-specific fish-passage proportions and survival rates for steelhead and Chinook salmon smolts passing through various sampled routes at John Day Dam, The Dalles Dam, and Bonneville Dam in 2010 and 2011. Resultsmore » were compiled from analyses of data acquired in spring 2010 and 2011 studies that were specifically designed to estimate dam-passage and forebay-to-tailrace survival rates, travel time metrics, and spill passage efficiency, as stipulated by the 2008 Federal Columbia River Power System Biological Opinion and the Columbia Basin Fish Accords. The study designs allowed for estimation of route-specific fish passage proportions and survival rates as well as estimation of forebay-passage survival, all of which are summarized herein.« less

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

Dam operations may improve aquatic habitat and offset negative effects of climate change.

PubMed

Benjankar, Rohan; Tonina, Daniele; McKean, James A; Sohrabi, Mohammad M; Chen, Quiwen; Vidergar, Dmitri

2018-05-01

Dam operation impacts on stream hydraulics and ecological processes are well documented, but their effect depends on geographical regions and varies spatially and temporally. Many studies have quantified their effects on aquatic ecosystem based mostly on flow hydraulics overlooking stream water temperature and climatic conditions. Here, we used an integrated modeling framework, an ecohydraulics virtual watershed, that links catchment hydrology, hydraulics, stream water temperature and aquatic habitat models to test the hypothesis that reservoir management may help to mitigate some impacts caused by climate change on downstream flows and temperature. To address this hypothesis we applied the model to analyze the impact of reservoir operation (regulated flows) on Bull Trout, a cold water obligate salmonid, habitat, against unregulated flows for dry, average, and wet climatic conditions in the South Fork Boise River (SFBR), Idaho, USA. Copyright © 2018 Elsevier Ltd. All rights reserved.

Watershed assessment-watershed analysis: What are the limits and what must be considered

Treesearch

Robert R. Ziemer

2000-01-01

Watershed assessment or watershed analysis describes processes and interactions that influence ecosystems and resources in a watershed. Objectives and methods differ because issues and opportunities differ.

Snowmelt hydrograph interpretation: Revealing watershed scale hydrologic characteristics of the Yellowstone volcanic plateau

USGS Publications Warehouse

Payton, Gardner W.; Susong, D.D.; Kip, Solomon D.; Heasler, H.

2010-01-01

Snowmelt hydrograph analysis and groundwater age dates of cool water springs on the Yellowstone volcanic plateau provide evidence of high volumes of groundwater circulation in watersheds comprised of quaternary Yellowstone volcanics. Ratios of maximum to minimum mean daily discharge and average recession indices are calculated for watersheds within and surrounding the Yellowstone volcanic plateau. A model for snowmelt recession is used to separate groundwater discharge from overland runoff, and compare groundwater systems. Hydrograph signal interpretation is corroborated with chlorofluorocarbon (CFC) and tritium concentrations in cool water springs on the Yellowstone volcanic plateau. Hydrograph parameters show a spatial pattern correlated with watershed geology. Watersheds comprised dominantly of quaternary Yellowstone volcanics are characterized by slow streamflow recession, low maximum to minimum flow ratios. Cool springs sampled within the Park contain CFC's and tritium and have apparent CFC age dates that range from about 50 years to modern. Watersheds comprised of quaternary Yellowstone volcanics have a large volume of active groundwater circulation. A large, advecting groundwater field would be the dominant mechanism for mass and energy transport in the shallow crust of the Yellowstone volcanic plateau, and thus control the Yellowstone hydrothermal system. ?? 2009 Elsevier B.V.

National Program for Inspection of Non-Federal Dams. Bristol Reservoir Number 5 Dam (CT 00366), Farmington River Basin, Harwinton, Connecticut. Phase I Inspection Report.

DTIC Science & Technology

1980-07-01

age control and/or monitoring measures as needed. 2. Investigate the condition of the corrugated metal outlet pipe and make any necessary repairs. 3...BACKGROUND. USARMY ENGINEER DIV NEW ENGLAND BRISTOL RES. NO. 5 DAM Coll O .ENIER NATIONAL PROGRAM OF TR. TO POLAND R IVER WALTHAM ! ASCUE INSPECTION

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…

Application of Watershed Scale Models to Predict Nitrogen Loading From Coastal Plain Watersheds

Treesearch

George M. Chescheir; Glenn P Fernandez; R. Wayne Skaggs; Devendra M. Amatya

2004-01-01

DRAINMOD-based watershed models have been developed and tested using data collected from an intensively instrumented research site on Kendricks Creek watershed near Plymouth. NC. These models were applied to simulate the hydrology and nitrate nitrogen (NO3-N) loading from two other watersheds in the Coastal Plain of North Carolina, the 11600 ha Chicod Creek watershed...

National Program of Inspection of Non-Federal Dams.

DTIC Science & Technology

1982-05-01

actions to improve the .;,.fety of Federal dams . 3 B. PROGRAM REVITALIZATION Subsequent to the failure of the Teton Dam , near Newdale, Idaho, in June...development of hydrostatic heads sufficient to create in the area downstream of the dam sand boils that erode materials by the phenomenon known as " piping " and...Eh irmmhhhommlm mhhhhmmmmhhlo US Arm op National Program of Inspection of Non-Federal Dams Final Report to Congress The National Dam Inspection Act of

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.

Rubber dam use less stressful for children and dentists.

PubMed

Innes, Nicola

2012-06-01

Randomised controlled trial, single centre and operator. 72 patients (6-16 years) assessed as compliant, with no allergies, not on significant medication were divided into two groups by 'drawing sealed lots'. 234 fully erupted teeth were sealed. Molars and/or premolars were sealed dependant on age. Teeth were pre-cleaned with prophy paste. In the controls, teeth were isolated with buccal and lingual cotton rolls and salivary ejector in the intervention group a rubber dam was used. The same etching, rinsing and placement protocol was used in both arms. Outcomes were: patients' subjective measures of pain using a visual analogue scale; blood pressure (before and after treatment), breath rate, pulse rate and skin resistance at five time points. The operator's pulse rate was measured and they completed a questionnaire on subjective mental and physical stress following treatment. Treatment times were recorded. The breath rate was significantly (P < 0.05) lower and the skin resistance level was significantly higher during treatment with rubber dam compared to the control group. Subjective pain perception was significantly lower for the test group. The treatment time needed for the fissure sealing procedure was 12.4% less in the test group. The authors state; '... in the hands of an experienced dentist, isolation with rubber dam is less stressful for children and adolescents than isolation with cotton rolls, and can save valuable treatment time.' The operator's stress measures were lower with rubber dam and treatment time was reduced.

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…

Large dams and alluvial rivers in the Anthropocene: The impacts of the Garrison and Oahe Dams on the Upper Missouri River

USGS Publications Warehouse

Skalak, Katherine; Benthem, Adam J.; Schenk, Edward R.; Hupp, Cliff R.; Galloway, Joel M.; Nustad, Rochelle A.; Wiche, Gregg J.

2013-01-01

The Missouri River has had a long history of anthropogenic modification with considerable impacts on river and riparian ecology, form, and function. During the 20th century, several large dam-building efforts in the basin served the needs for irrigation, flood control, navigation, and the generation of hydroelectric power. The managed flow provided a range of uses, including recreation, fisheries, and habitat. Fifteen dams impound the main stem of the river, with hundreds more on tributaries. Though the effects of dams and reservoirs are well-documented, their impacts have been studied individually, with relatively little attention paid to their interaction along a river corridor. We examine the morphological and sedimentological changes in the Upper Missouri River between the Garrison Dam in ND (operational in 1953) and Oahe Dam in SD (operational in 1959). Through historical aerial photography, stream gage data, and cross sectional surveys, we demonstrate that the influence of the upstream dam is still a major control of river dynamics when the backwater effects of the downstream reservoir begin. In the “Anthropocene”, dams are ubiquitous on large rivers and often occur in series, similar to the Garrison Dam Segment. We propose a conceptual model of how interacting dams might affect river geomorphology, resulting in distinct and recognizable morphologic sequences that we term “Inter-Dam sequence” characteristic of major rivers in the US.

Residence times and nitrate transport in ground water discharging to streams in the Chesapeake Bay Watershed

USGS Publications Warehouse

Lindsey, Bruce D.; Phillips, Scott; Donnelly, Colleen A.; Speiran, Gary K.; Plummer, Niel; Bohlke, John Karl; Focazio, Michael J.; Burton, William C.; Busenberg, Eurybiades

2003-01-01

One of the major water-quality problems in the Chesapeake Bay is an overabundance of nutrients from the streams and rivers that discharge to the Bay. Some of these nutrients are from nonpoint sources such as atmospheric deposition, agricultural manure and fertilizer, and septic systems. The effects of efforts to control nonpoint sources, however, can be difficult to quantify because of the lag time between changes at the land surface and the response in the base-flow (ground water) component of streams. To help resource managers understand the lag time between implementation of management practices and subsequent response in the nutrient concentrations in the base-flow component of streamflow, a study of ground-water discharge, residence time, and nitrate transport in springs throughout the Chesapeake Bay Watershed and in four smaller watersheds in selected hydrogeomorphic regions (HGMRs) was conducted. The four watersheds were in the Coastal Plain Uplands, Piedmont crystalline, Valley and Ridge carbonate, and Valley and Ridge siliciclastic HGMRs.A study of springs to estimate an apparent age of the ground water was based on analyses for concentrations of chlorofluorocarbons in water samples collected from 48 springs in the Chesapeake Bay Watershed. Results of the analysis indicate that median age for all the samples was 10 years, with the 25th percentile having an age of 7 years and the 75th percentile having an age of 13 years. Although the number of samples collected in each HGMR was limited, there did not appear to be distinct differences in the ages between the HGMRs. The ranges were similar between the major HGMRs above the Fall Line (modern to about 50 years), with only two HGMRs of small geographic extent (Piedmont carbonate and Mesozoic Lowland) having ranges of modern to about 10 years. The median values of all the HGMRs ranged from 7 to 11 years. Not enough samples were collected in the Coastal Plain for comparison. Spring samples showed slightly younger

National Program for Inspection of Non-Federal Dams. Lovejoy Pond Dam ME-00022, Androscoggin River Basin, North Wayne, Maine. Phase I Inspection Report.

DTIC Science & Technology

1979-04-01

programs for non-Federal dams. (3) To update, verify and complete the National Inventory of Dams. 1.2 DESCRIPTION OF PROJECT a. Location. The Lovejoy Pond...BUREAU OF STANDARDS- 1963-A 41 ANDROSCOGGIN RIVER BASIN NORTH WAYNE ,MAINE LOVEJOY POND DAM ME-00022 0 PHASE I INSPECTION REPORT NATIONAL DAM INSPECTION...side of necessar mnd idenifIr bioc Sigmmber) DAMS, INSPECTION, DAM SAFETY, * Androscoggin River Basin North Wayne, Maine Lovejoy Pond * 20. ABSTRACT

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...

Influence of Partial Dam Removal on Change of Channel Morphology and Physical Habitats: A Case Study of Yu-Sheng River

NASA Astrophysics Data System (ADS)

Hao Weng, Chung; Yeh, Chao Hsien

2017-04-01

The rivers in Taiwan have the characteristic of large slope gradient and fast flow velocity caused by rugged terrain. And Taiwan often aces many typhoons which will bring large rainfall in the summer. In early Taiwan, river management was more focus on flood control, flood protection and disaster reduction. In recent years, the rise of ecological conservation awareness for the precious fish species brings spotlight on the Taiwan salmon (Oncorhynchus masou formosanus) which lives in the river section of this study. In order to make sure ecological corridor continuing, dam removal is the frequently discussed measure in recent years and its impact on environmental is also highly concerned. Since the dam removal may causes severe changes to the river channel, the action of dam removal needs careful evaluation. As one of the endangered species, Taiwan salmon is considered a national treasure of Taiwan and it was originally an offshore migration of the Pacific salmon. After the ice age and geographical isolation, it becomes as an unique subspecies of Taiwan and evolved into landlocked salmon. Now the Taiwan salmon habitats only exists in few upstream creeks and the total number of wild Taiwan salmon in 2015 was about 4,300. In order to expand the connectivity of the fish habitats in Chi-Jia-Wan creek basin, several dam removal projects had completed with good results. Therefore, this paper focuses on the dam removal of Yu-Sheng creek dam. In this paper, a digital elevation model (DEM) of about 1 kilometer channel of the Yu-Sheng creek dam is obtained by unmanned aerial vehicle (UAV). Using CCHE2D model, the simulation of dam removal will reveal the impact on channel morphology. After model parameter identification and verification, this study simulated the scenarios of three historical typhoon events with recurrence interval of two years, fifteen years, and three decades under four different patterns of dam removal to identify the the head erosion, flow pattern, and

Engineering and Ecological Aspects of Dam Removal-An Overview

DTIC Science & Technology

2006-09-01

indicated. Figure 3. Teton Dam failure, Idaho, 1976 BENEFITS AND COSTS OF DAMS Dams have provided and continue to provide a diverse...ERDC TN-EMRRP-SR-80 1 Engineering and Ecological Aspects of Dam Removal—An Overview September 2006 By Jock Conyngham1, J. Craig Fischenich1...High ______________________________________________________________________ OVERVIEW Decommissioning and removing dams has

Juvenile salmonid monitoring in the White Salmon River, Washington, post-Condit Dam removal, 2016

USGS Publications Warehouse

Jezorek, Ian G.; Hardiman, Jill M.

2017-06-23

Condit Dam, at river kilometer 5.3 on the White Salmon River, Washington, was breached in 2011 and removed completely in 2012, allowing anadromous salmonids access to habitat that had been blocked for nearly 100 years. A multi-agency workgroup concluded that the preferred salmonid restoration alternative was natural recolonization with monitoring to assess efficacy, followed by a management evaluation 5 years after dam removal. Limited monitoring of salmon and steelhead spawning has occurred since 2011, but no monitoring of juveniles occurred until 2016. During 2016, we operated a rotary screw trap at river kilometer 2.3 (3 kilometers downstream of the former dam site) from late March through May and used backpack electrofishing during summer to assess juvenile salmonid distribution and abundance. The screw trap captured primarily steelhead (Oncorhynchus mykiss; smolts, parr, and fry) and coho salmon (O. kisutch; smolts and fry). We estimated the number of steelhead smolts at 3,851 (standard error = 1,454) and coho smolts at 1,093 (standard error = 412). In this document, we refer to O. mykiss caught at the screw trap as steelhead because they were actively migrating, but because we did not know migratory status of O. mykiss caught in electrofishing surveys, we simply refer to them as O. mykiss or steelhead/rainbow trout. Steelhead and coho smolts tagged with passive integrated transponder tags were subsequently detected downstream at Bonneville Dam on the Columbia River. Few Chinook salmon (O. tshawytscha) fry were captured, possibly as a result of trap location or effects of a December 2015 flood. Sampling in Mill, Buck, and Rattlesnake Creeks (all upstream of the former dam site) showed that juvenile coho were present in Mill and Buck Creeks, suggesting spawning had occurred there. We compared O. mykiss abundance data in sites on Buck and Rattlesnake Creeks to pre-dam removal data. During 2016, age-0 O. mykiss were more abundant in Buck Creek than in 2009 or

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.

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.

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.

Seismic performance of arch dams on non-homogeneous and discontinuous foundations (a case study: Karun 4 Dam)

NASA Astrophysics Data System (ADS)

Ferdousi, A.

2017-06-01

The present study set out to investigate the nonlinear seismic response of the dam-reservoir-rock foundation system, taking into consideration the effects of change in the material properties of discontinuous foundation. To this end, it is important to provide the proper modeling of truncated boundary conditions at the far-end of rock foundation and reservoir fluid domain and to correctly apply the in situ stresses for rock foundation. The nonlinear seismic response of an arch dam mainly depends on the opening and sliding of the dam body's contraction joints and foundation discontinuities, failure of the jointed rock and concrete materials, etc. In this paper, a time domain dynamic analysis of the 3D dam-reservoir-foundation interaction problem was performed by developing a nonlinear Finite Element program. The results of the analysis of Karun-4 Dam revealed the essential role of modeling discontinuities and boundary conditions of rock foundation under seismic excitation.

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...

Dams and transnational advocacy: Political opportunities in transnational collective action

NASA Astrophysics Data System (ADS)

Fu, Teng

Possible arguments to explain the gradual decline in big dam development and its site transferring from developed to developing countries include technical, economic, and political factors. This study focuses on the political argument---the rise of transnational anti-dam advocacy and its impact on state policy-making. Under what conditions does transnational anti-dam advocacy matter? Under what conditions does transnational advocacy change state dam policies (delay, scale down, or cancel)? It examines the role of transnational anti-dam actors in big dam building in a comparative context in Asia. Applying the social movement theory of political opportunity structure (POS) and using the qualitative case-study method, the study provides both within-case and cross-case analyses. Within-case analysis is utilized to explain the changing dynamics of big dam building in China (Three Gorges Dam and proposed Nu/Salween River dam projects), and to a lesser extent, Sardar Sarovar Project in India and Nam Theun 2 Dam in Laos. Different domestic and international POS (DPOS and IPOS) impact the strategies and outcomes of anti-dam advocacies in these countries. The degree of openness of the POS directly affects the capacity of transnational efforts in influencing state dam policies. The degree of openness or closure is measured by specific laws, institutions, discourse, or elite allies (or the absence of these) for the participation of non-state actors on big dam issues at a particular moment. This degree of openness is relative, varying over time, across countries and regions. This study finds that the impact of transnational anti-dam activism is most effective when both DPOS and IPOS are relatively open. Transnational anti-dam advocacy is least effective in influencing state dam policies when both DPOS and IPOS are relatively closed. Under a relatively open DPOS and closed IPOS, transnational anti-dam advocacy is more likely to successfully change state dam policies and even

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sunaryo,, E-mail: sunaryo@ub.ac.id, 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 contactmore » 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

Watershed Central: Harnessing a social media tool to organize local technical knowledge and find the right watershed resources for your watershed

EPA Science Inventory

Watershed Central was developed to be a bridge between sharing and searching for information relating to watershed issues. This is dependent upon active user support through additions and updates to the Watershed Central Wiki. Since the wiki is user driven, the content and applic...

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

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.

Low summer water temperatures influence occurrence of naturalized salmonids across a mountain watershed

USGS Publications Warehouse

Mullner, S.A.; Hubert, W.A.

2005-01-01

We investigated relationships between the absence of salmonids and low summer water temperatures across a 150-km2 Rocky Mountain watershed. A model predicting maximum July water temperature (MJT) from measurements of perennial stream length, wetted width, and midrange basin elevation was developed from temperature data obtained at 20 sites across the watershed. The model was used to predict MJT in 75 reaches across the watershed where salmonids were sampled. The lowest predicted MJT in reaches where age-0 and juvenile-adult brook trout Salvelinus fontinalis were observed was 9??C. The lowest predicted MJT in reaches where age-0 progeny of the genus Oncorhynchus spp. (i.e., rainbow trout O. mykiss or cutthroat trout O. clarkii) were observed was 13??C and where Oncorhynchus spp. adults where observed was 12??C. The probability of occurrence of both age-0 and adult brook trout and Oncorhynchus spp. increased as MJT increased above these thresholds. Our results indicate that low MJT in some portions of a mountain watershed can be related to the absence of salmonids. Consequently, data on MJT may provide managers with a means of assessing where summer water temperatures are not suitable for establishment of naturalized salmonid populations. ?? Copyright by the American Fisheries Society 2005.

National Program for Inspection of Non-Federal Dams. Houghton Pond Dam (MA 00444), Charles River Basin, Holliston, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1979-07-01

RD-A154 892 NATIONAL PROGRAM FOR INSPECTION OF NON-FEDERAL DAMS i/I HOUGHTON POND DAM (MA..(U) CORPS OF ENGINEERS WALTHAM UNCLASSIFIED N NEN ENGLAND...HOUGHTON POND DAM MA 00444 PHASE I INSPECTION REPORT _ NATIONAL DAM INSPECTION PROGRAM DTIC EECTE CD JUN4 985 -LJE DEPARTMENT OF THE ARMY NEW ENGLAND...16 SUPPLEMENTARY NOTES Co ver program reads: Phase I Inspection Report, National Dam Inspection Program ; however, the official title of the program

Establishing spatial trends in water chemistry and stable isotopes (δ15N and δ13C) in the Elwha River prior to dam removal and salmon recolonization

USGS Publications Warehouse

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

2011-01-01

Two high-head dams on the Elwha River in Washington State (USA) have changed the migratory patterns of resident and anadromous fish, limiting Pacific salmon to the lower 7.9 km of a river that historically supported large Pacific salmon runs. To document the effects of the dams prior to their removal, we measured carbon and nitrogen stable isotope ratios of primary producers, benthic macroinvertebrates, and fish, and water chemistry above, between and below the dams. We found that δ15N was significantly higher in fish, stoneflies, black flies, periphyton and macroalgae where salmon still have access. Fish and chloroperlid stoneflies were enriched in δ13C, but the values were more variable than in δ15N. For some taxa, there were also differences between the two river sections that lack salmon, suggesting that factors other than marine-derived nutrients are structuring longitudinal isotopic profiles. Consistent with trophic theory, macroalgae had the lowest δ15N, followed by periphyton, macroinvertebrates and fish, with a range of 6.9, 6.2 and 7.7‰ below, between, and above the dams, respectively. Water chemistry analyses confirmed earlier reports that the river is oligotrophic. Phosphorous levels in the Elwha were lower than those found in other regional rivers, with significant differences among regulated, unregulated and reference sections. The removal of these dams, among the largest of such projects ever attempted, is expected to facilitate the return of salmon and their marine-derived nutrients (MDN) throughout the watershed, possibly altering the food web structure, nutrient levels and stable isotope values that we documented.

Modern (1992–2011) and projected (2012–99) peak snowpack and May–July runoff for the Fort Peck Lake and Lake Sakakawea watersheds in the Upper Missouri River Basin

USGS Publications Warehouse

Stamm, John F.; Todey, Dennis; Mayes Bousted, Barbara; Rossi, Shawn; Norton, Parker A.; Carter, Janet M.

2016-02-09

Annual peak snowpack was projected to have a downward trend for the Fort Peck Lake watershed and an upward trend for the lower Lake Sakakawea watershed. Projections of May–July runoff had a significant downward trend for the Fort Peck Lake, lower Lake Sakakawea, and Lake Sakakawea (combination of Fort Peck Lake and lower Lake Sakakawea) watersheds. Downward trends in projected May–July runoff indicated that power production at Fort Peck Dam might be affected particularly in the later part of the simulation (2061–99); however, confidence in projected May–July runoff for the later part of the simulation was less certain because bias-corrected air temperatures from CCSM3 and CCSM4 commonly fell outside of the observed range used for calibration. Projected May–July runoff combined for the Fort Peck Lake and lower Lake Sakakawea watersheds were on the order of magnitude of the 2011 flood for 1 simulation year for each of the CCSM-based simulations. High peak snowpack and precipitation in April, May, and June in the plains was associated with large May–July runoff events; therefore, high precipitation at lower elevations in the Fort Peck Lake and lower Lake Sakakawea watersheds was a factor in the simulation of extreme runoff events at the magnitude of the 2011 flood.

SCS-CN and GIS-based approach for identifying potential water harvesting sites in the Kali Watershed, Mahi River Basin, India

NASA Astrophysics Data System (ADS)

Ramakrishnan, D.; Bandyopadhyay, A.; Kusuma, K. N.

2009-08-01

The Kali sub-watershed is situated in the semi-arid region of Gujarat, India and forms a part of the Mahi River Watershed. This watershed receives an average annual rainfall of 900mm mainly between July and September. Due to high runoff potential, evapo-transpiration and poor infiltration, drought like situation prevails in this area from December to June almost every year. In this paper, augmentation of water resource is proposed by construction of runoff harvesting structures like check dam, percolation pond, farm pond, well and subsurface dyke. The site suitability for different water harvesting structures is determined by considering spatially varying parameters like runoff potential, slope, fracture pattern and micro-watershed area. GIS is utilised as a tool to store, analyse and integrate spatial and attribute information pertaining to runoff, slope, drainage and fracture. The runoff derived by SCS-CN method is a function of runoff potential which can be expressed in terms of runoff coefficient (ratio between the runoff and rainfall) which can be classified into three classes, viz., high (>40%), moderate (20-40%) and low (<20%). In addition to IMSD, FAO specifications for water harvesting/recharging structures, parameters such as effective storage, rock mass permeability are herein considered to augment effective storage. Using the overlay and decision tree concepts in GIS, potential water harvesting sites are identified. The derived sites are field investigated for suitability and implementation. In all, the accuracy of the site selection at implementation level varies from 80-100%.

78 FR 62627 - Sam Rayburn Dam Rate

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-22

..., Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative, Inc. (Contract No... Schedule SRD-08, Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative... ADMINISTRATION RATE SCHEDULE SRD-13 \\1\\ WHOLESALE RATES FOR HYDRO POWER AND ENERGY SOLD TO SAM RAYBURN DAM...

Outlet Works for Cerrillos Dam, Cerrillos River, and Portugues Dam, Portugues River, Puerto Rico; Hydraulic Model Investigation.

DTIC Science & Technology

1979-03-01

Tests were conducted on a 1:24-scale model of the outlet works for the Cerrillos and Portugues Dams located in Puerto Rico. The purpose of the model... Portugues outlet works were designed to provide for river diversion during construction of the dams. When the dams are completed, the flow will be regulated... Portugues . However, the stilling basins were designed for 2500 cfs (Cerrillos) and 1100 cfs ( Portugues ), the bank-full capacities downstream. Therefore

A pre-dam-removal assessment of sediment transport for four dams on the Kalamazoo River between Plainwell and Allegan, Michigan

USGS Publications Warehouse

Syed, Atiq U.; Bennett, James P.; Rachol, Cynthia M.

2005-01-01

Four dams on the Kalamazoo River between the cities of Plainwell and Allegan, Mich., are in varying states of disrepair. The Michigan Department of Environmental Quality (MDEQ) and U.S. Environmental Protection Agency (USEPA) are considering removing these dams to restore the river channels to pre-dam conditions. This study was initiated to identify sediment characteristics, monitor sediment transport, and predict sediment resuspension and deposition under varying hydraulic conditions. The mathematical model SEDMOD was used to simulate streamflow and sediment transport using three modeling scenarios: (1) sediment transport simulations for 730 days (Jan. 2001 to Dec. 2002), with existing dam structures, (2) sediment transport simulations based on flows from the 1947 flood at the Kalamazoo River with existing dam structures, and (3) sediment transport simulations based on flows from the 1947 flood at the Kalamazoo River with dams removed. Sediment transport simulations based on the 1947 flood hydrograph provide an estimate of sediment transport rates under maximum flow conditions. These scenarios can be used as an assessment of the sediment load that may erode from the study reach at this flow magnitude during a dam failure. The model was calibrated using suspended sediment as a calibration parameter and root mean squared error (RMSE) as an objective function. Analyses of the calibrated model show a slight bias in the model results at flows higher than 75 m3/s; this means that the model-simulated suspended-sediment transport rates are higher than the observed rates; however, the overall calibrated model results show close agreement between simulated and measured values of suspended sediment. Simulation results show that the Kalamazoo River sediment transport mechanism is in a dynamic equilibrium state. Model results during the 730-day simulations indicate significant sediment erosion from the study reach at flow rates higher than 55 m3/s. Similarly, significant

Interaction of Dams and Landslides--Case Studies and Mitigation

USGS Publications Warehouse

Schuster, Robert L.

2006-01-01

In the first half of the 20th century, engineering geology and geotechnical engineering were in their infancy, and dams were often built where landslides provided valley constrictions, often without expert site investigation. Only the most important projects were subjected to careful geologic examination. Thus, dams were often built without complete understanding of the possible geotechnical problems occurring in foundations or abutments. Most of these dams still exist, although many have undergone costly repairs because of stability or leakage problems. Today, however, every effort is made in the selection of damsites, including those sited on landslides, to provide foundations and abutments that are generally impervious and capable of withstanding the stresses imposed by the proposed dam and reservoir, and possible landslides. By means of a literature search, technical interviews, and field inventory, I have located 254 large (at least 10 m high) dams worldwide that directly interact with landslides; that is, they have been built on pre-existing landslides or have been subjected to landslide activity during or after construction. A table (Appendix table A) summarizes dam characteristics, landslide conditions, and remedial measures at each of the dams. Of the 254 dams, 164 are earthfill, 23 are rockfill, and 18 are earthfill-rockfill; these are flexible dam types that generally perform better on the possibly unstable foundations provided by landslides than do more rigid concrete dams. Any pre-existing landslides that might impinge on the foundation or abutments of a dam should be carefully investigated. If a landslide is recognized in a dam foundation or abutment, the landslide deposits commonly are avoided in siting the dam or are removed during stripping of the dam foundation and abutment contacts. Contrarily, it has often been found to be technically feasible and economically desirable to site and construct dams on known landslides or on the remnants of these

DAM_Explorer: A Modeling Framework for Assessing the Physical Response of Streams to Dam Removal

DTIC Science & Technology

2009-06-01

ERDC TN-EMRRP-SR-65 1 DAM_Explorer: A Modeling Framework for Assessing the Physical Response of Streams to Dam Removal By Jock Conyngham1 and...physical and temporal increments for staged removals) is anticipated. POINTS OF CONTACT For additional information contact Jock N. Conyngham (406-541

Non-Fluvial Controls of Erosion, Sediment Transport and Fluvial Morphology in a mid-Atlantic Piedmont Watershed, White Clay Creek, Pennsylvania, U.S.A.

NASA Astrophysics Data System (ADS)

McCarthy, K.; Affinito, R. A.; Pizzuto, J. E.; Stotts, S.; Henry, T.; Krauthauser, M.; O'Neal, M. A.

2017-12-01

Quantifying contemporary sediment budgets is essential for restoration and ecosystem management of mid-Atlantic watersheds, but relevant processes and controls are poorly understood. In the 153 km2 White Clay Creek watershed in southeastern Pennsylvania, longitudinal profiles reflect migration of knickpoints though bedrock over Quaternary timescales. In bank exposures along stream valleys, saprolite, bedrock, and matrix-supported cobbly and bouldery diamicton (likely colluvial) commonly underlie finer-grained clay, silt, sand, and gravel deposits of valley floor depositional environments. Overbank sedimentation rates were quantified by measuring the thickness of sediment deposited over the roots of floodplain trees. The sampled trees range in age from 25-270 years with median sediment accumulation rates of approximately 2 mm/yr (range 0-10 mm/yr). Rates of bank retreat (measured from historical aerial imagery or root-exposure dendrochronology) vary from 6-36 cm/yr, with median rates of 10 cm/yr. While bank erosion rates are subject to a variety of controls, including channel curvature, the density of riparian trees, and freeze-thaw processes, the strongest influence appears to be the grain size and thickness of bouldery diamicton exposed along the toes of retreating banks. Cobbles and boulders supplied by eroding diamicton also mantle the bed of the channel, such that 33- 80% of the bed material remains immobile at bankfull stage. A conceptual model of fluvial processes and sediment budgets for these channels must account for the watershed's history of changing climate, tectonics, and land use, requiring mapping of bedrock, colluvium, former mill dam sediments, and other non-alluvial deposits and controls. Efforts to apply hydraulic geometry principles (requiring a precise adjustment to contemporary hydraulic and sediment regime) or to treat these channels as traditional "threshold" rivers are unlikely to be successful.

Thermal effects of dams in the Willamette River basin, Oregon

USGS Publications Warehouse

Rounds, Stewart A.

2010-01-01

Methods were developed to assess the effects of dams on streamflow and water temperature in the Willamette River and its major tributaries. These methods were used to estimate the flows and temperatures that would occur at 14 dam sites in the absence of upstream dams, and river models were applied to simulate downstream flows and temperatures under a no-dams scenario. The dams selected for this study include 13 dams built and operated by the U.S. Army Corps of Engineers (USACE) as part of the Willamette Project, and 1 dam on the Clackamas River owned and operated by Portland General Electric (PGE). Streamflows in the absence of upstream dams for 2001-02 were estimated for USACE sites on the basis of measured releases, changes in reservoir storage, a correction for evaporative losses, and an accounting of flow effects from upstream dams. For the PGE dam, no-project streamflows were derived from a previous modeling effort that was part of a dam-relicensing process. Without-dam streamflows were characterized by higher peak flows in winter and spring and much lower flows in late summer, as compared to with-dam measured flows. Without-dam water temperatures were estimated from measured temperatures upstream of the reservoirs (the USACE sites) or derived from no-project model results (the PGE site). When using upstream data to estimate without-dam temperatures at dam sites, a typical downstream warming rate based on historical data and downstream river models was applied over the distance from the measurement point to the dam site, but only for conditions when the temperature data indicated that warming might be expected. Regressions with measured temperatures from nearby or similar sites were used to extend the without-dam temperature estimates to the entire 2001-02 time period. Without-dam temperature estimates were characterized by a more natural seasonal pattern, with a maximum in July or August, in contrast to the measured patterns at many of the tall dam sites

Skiff-based Sonar/LiDAR Survey to Calibrate Reservoir Volumes for Watershed Sediment Yield Studies: Carmel River Example

NASA Astrophysics Data System (ADS)

Smith, D. P.; Kvitek, R.; Quan, S.; Iampietro, P.; Paddock, E.; Richmond, S. F.; Gomez, K.; Aiello, I. W.; Consulo, P.

2009-12-01

Models of watershed sediment yield are complicated by spatial and temporal variability of geologic substrate, land cover, and precipitation parameters. Episodic events such as ENSO cycles and severe wildfire are frequent enough to matter in the long-term average yield, and they can produce short-lived, extreme geomorphic responses. The sediment yield from extreme events is difficult to accurately capture because of the obvious dangers associated with field measurements during flood conditions, but it is critical to include extreme values for developing realistic models of rainfall-sediment yield relations, and for calculating long term average denudation rates. Dammed rivers provide a time-honored natural laboratory for quantifying average annual sediment yield and extreme-event sediment yield. While lead-line surveys of the past provided crude estimates of reservoir sediment trapping, recent advances in geospatial technology now provide unprecedented opportunities to improve volume change measurements. High-precision digital elevation models surveyed on an annual basis, or before-and-after specific rainfall-runoff events can be used to quantify relations between rainfall and sediment yield as a function of landscape parameters, including spatially explicit fire intensity. The Basin-Complex Fire of June and July 2008 resulted in moderate to severe burns in the 114 km^2 portion of the Carmel River watershed above Los Padres Dam. The US Geological Survey produced a debris flow probability/volume model for the region indicating that the reservoir could lose considerable capacity if intense enough precipitation occurred in the 2009-10 winter. Loss of Los Padres reservoir capacity has implications for endangered steelhead and red-legged frogs, and groundwater on municipal water supply. In anticipation of potentially catastrophic erosion, we produced an accurate volume calculation of the Los Padres reservoir in fall 2009, and locally monitored hillslope and fluvial

Q-BIC3 - A Québec-Bavarian international collaboration for adapting regional watershed management to climate change

NASA Astrophysics Data System (ADS)

Ludwig, Ralf

2010-05-01

Adapting to the impacts of climate change is certainly one of the major challenges in water resources management over the next decades. Adaptation to climate change risks is most crucial in this domain, since projected increase in mean air temperature in combination with an expected increase in the temporal variability of precipitation patterns will contribute to pressure on current water availability, allocation and management practices. The latter often involve the utilization of valuable infrastructure, such as dams, reservoirs and water intakes, for which adaptation options must by developed over long-term and often dynamic planning horizons. Research to establish novel methodologies for improved adaptation to climate change is thus very important and only beginning to emerge in regional watershed management. The presented project Q-BIC³, funded by the Bavarian Minstry for the Environment and the Québec Ministère du Développement économique, de l'Innovation et de l'Exportation, aims to develop and apply a newly designed spectrum of tools to support the improved assessment of adaptation options to climate change in regional watershed management. It addresses in particular selected study sites in Québec and Bavaria. The following key issues have been prioritized within Q-BIC³: i) The definition of potential adaptation options in the context of climate change for pre-targeted water management key issues using a subsequent and logical chain of modelling tools (climate, hydrological and water management modeling tools) ii) The definition of an approach that accounts for hydrological projection uncertainties in the search for potential adaptation options in the context of climate change iii) The investigation of the required complexity in hydrological models to estimate climate change impacts and to develop specific adaptation options for Québec and Bavaria watersheds. iv) The development and prototyping of a regionally transferable and modular modelling

Spatial-Temporal Heterogeneity in Regional Watershed Phosphorus Cycles Driven by Changes in Human Activity over the Past Century

NASA Astrophysics Data System (ADS)

Hale, R. L.; Grimm, N. B.; Vorosmarty, C. J.

2014-12-01

An ongoing challenge for society is to harness the benefits of phosphorus (P) while minimizing negative effects on downstream ecosystems. To meet this challenge we must understand the controls on the delivery of anthropogenic P from landscapes to downstream ecosystems. We used a model that incorporates P inputs to watersheds, hydrology, and infrastructure (sewers, waste-water treatment plants, and reservoirs) to reconstruct historic P yields for the northeastern U.S. from 1930 to 2002. At the regional scale, increases in P inputs were paralleled by increased fractional retention, thus P loading to the coast did not increase significantly. We found that temporal variation in regional P yield was correlated with P inputs. Spatial patterns of watershed P yields were best predicted by inputs, but the correlation between inputs and yields in space weakened over time, due to infrastructure development. Although the magnitude of infrastructure effect was small, its role changed over time and was important in creating spatial and temporal heterogeneity in input-yield relationships. We then conducted a hierarchical cluster analysis to identify a typology of anthropogenic P cycling, using data on P inputs (fertilizer, livestock feed, and human food), infrastructure (dams, wastewater treatment plants, sewers), and hydrology (runoff coefficient). We identified 6 key types of watersheds that varied significantly in climate, infrastructure, and the types and amounts of P inputs. Annual watershed P yields and retention varied significantly across watershed types. Although land cover varied significantly across typologies, clusters based on land cover alone did not explain P budget patterns, suggesting that this variable is insufficient to understand patterns of P cycling across large spatial scales. Furthermore, clusters varied over time as patterns of climate, P use, and infrastructure changed. Our results demonstrate that the drivers of P cycles are spatially and temporally

Walter Bouldin Dam failure and reconstruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1978-09-01

Walter Bouldin is one of several hydroelectric developments of Alabama Power Company. On February 10, 1975, an earth embankment section of Walter Bouldin Dam was breached, causing total evacuation of the forebay reservoir and rendering the 225-MW power plant inoperable. The Federal Power Commission instituted an investigation of the dam failure, and a report on the investigation was published in February 1976. Subsequently, an evidentiary hearing was held before an administrative law judge who issued his initial decision on August 19, 1976. The Commission, on April 21, 1977, issued its Opinion No. 795 in which it adopted the initial decisionmore » with modifications and terminated the investigation of failure of Walter Bouldin Dam. Opinion No. 795 directs the staff of the Bureau of Power to prepare, for the future guidance of the Commission, a report on the deficiencies which were found in its investigation, together with advice as to how such deficiencies have been and should be remedied. Also, it directs the staff of the Bureau of Power to address certain general recommendations included in the initial decision. This report was prepared in response to that directive and summaries information on the dam failure and its investigation; the evidentiary hearing; the judge's recommendations, the reconstruction of the Bouldin Dam; and the evalution and status of the Federal Energy Regulatory Commission Dam safety program. (LCL)« less

Innovative resettlement schemes planned for the Numata Dam project

NASA Astrophysics Data System (ADS)

Nakayama, Mikiyasu

2003-10-01

The Numata Dam, planned for the Tone River basin of Gunma Prefecture, was the largest dam construction project ever considered in Japan. This dam construction project, however, did not materialize. The proposal for the Numata Dam was first launched in 1959, at a time when the Tokyo Metropolitan area was mushrooming, both in population and industrial activity. The Numata Dam was supposed to be a prioritized dam construction project to alleviate the then anticipated water shortage in the Tokyo Metropolitan area. The Numata Dam plan experienced fierce opposition from those who would have been obliged to resettle, whereas those in Tokyo and the surrounding metropolitan area welcomed the plan. The major concern of the planned Numata Dam was the number of resettlers, which was then estimated to be around 3000 families. The resettlement plan developed for the Numata Dam included some innovative concepts, which may be applicable even today, for dam construction projects in the developing world. The plan included such ideas as (a) having resettlers share existing farmland with the present owners provided improvements were made to increase productivity, (b) paying rent to resettlers, and (c) establishing the Tone River Development Agency. After more than a decade of debate, both at national and local levels, the Numata Dam project was finally discarded through a decision of the Prime Minister in 1972. The resettlement schemes elaborated for the Numata Dam still appear to be innovative. Such schemes may be applied to projects in the developing world, in particular, in nations that are about to take off with economic development. Copyright

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…

National Dam Safety Program. Lake Muskoday Dam (Inventory Number N.Y. 341) Delaware River Basin, Sullivan County, New York. Phase I Inspection Report,

DTIC Science & Technology

1981-09-14

DACW-51-81-C-0006 . PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT PROJECT. TASK AREA & WORK UNIT NUMBERS ~ Flaherty-Giauara Associates...olie It neceary and Idontily b block number) Dam Safety National Dam Safety Program Visual Inspection Lake Muskoday Dam Hydrology, Structural Stability...DELAWARE RIVER BASIN LAKE MUSKODAY DAM SULLIVAN COUNTY, NEW YORK INVENTORY No.NY341 PHASE I INSPECTION REPORT NATIONAL DAM SAFETY PROGRAM J T C NEW YORK

Numerical Modeling of Sliding Stability of RCC dam

NASA Astrophysics Data System (ADS)

Mughieda, O.; Hazirbaba, K.; Bani-Hani, K.; Daoud, W.

2017-06-01

Stability and stress analyses are the most important elements that require rigorous consideration in design of a dam structure. Stability of dams against sliding is crucial due to the substantial horizontal load that requires sufficient and safe resistance to develop by mobilization of adequate shearing forces along the base of the dam foundation. In the current research, the static sliding stability of a roller-compacted-concrete (RCC) dam was modelled using finite element method to investigate the stability against sliding. A commercially available finite element software (SAP 2000) was used to analyze stresses in the body of the dam and foundation. A linear finite element static analysis was performed in which a linear plane strain isoperimetric four node elements was used for modelling the dam-foundation system. The analysis was carried out assuming that no slip will occur at the interface between the dam and the foundation. Usual static loading condition was applied for the static analysis. The greatest tension was found to develop in the rock adjacent to the toe of the upstream slope. The factor of safety against sliding along the entire base of the dam was found to be greater than 1 (FS>1), for static loading conditions.

Documented historical landslide dams from around the world

USGS Publications Warehouse

Costa, John E.; Schuster, Robert L.

1991-01-01

This data compilation consists of dBase IV1 data files of the location, date, triggering mechanism, kind, size, failure time and mechanism, breach dimensions, subsequent controls, materials, and references for 463 historical landslide dams and associated natural reservoirs that have been recorded throughout the World. The data base presented in this report is a compilation of information on the characteristics of 463 landslide dams from around the World. It forms a basis on which to assess potential threats from existing landslide dams, or newly-formed landslide dams. The data base includes only landslide dams that have formed in historical times - that is, those formed during times when humans were able to record their occurrence, and the information transferred through various means of written and/or oral documentation. There have been far more prehistoric landslide dams about which relatively little is known. None of these is included in this data base. The focus on historical landslide dams allows insights into this natural process that will aid in understanding their role as a significant geologic process in recent Earth history.

National Dam Safety Program. Tomahawk Lake Dam (Inventory Number N.Y. 618), Lower Hudson River Basin, Orange County, New York. Phase I Inspection Report,

DTIC Science & Technology

1981-08-14

Guidelines for Safety Inspection of Dams. d. Hazard Classification - Cherry Hill Road crosses the channel 1600 feet downstream from the dam and Tuthill...Road crosses the channel 1.5 miles below the dam. A home is located within 5 feet of the stream elevation, about 10 feet from the stream, and...below the dam. Cherry Hill Road crosses the channel 1600 feet downstream of the dam and Tuthill Road crosses the channel 1.5 miles below the dam. A home

Performance of National Maps of Watershed Integrity at Watershed Scales

EPA Science Inventory

Watershed integrity, the capacity of a watershed to support and maintain ecological processes essential to the sustainability of services provided to society, can be influenced by a range of landscape and in-stream factors. Ecological response data from four intensively monitored...

Soil loss estimation and prioritization of sub-watersheds of Kali River basin, Karnataka, India, using RUSLE and GIS.

PubMed

Markose, Vipin Joseph; Jayappa, K S

2016-04-01

Most of the mountainous regions in tropical humid climatic zone experience severe soil loss due to natural factors. In the absence of measured data, modeling techniques play a crucial role for quantitative estimation of soil loss in such regions. The objective of this research work is to estimate soil loss and prioritize the sub-watersheds of Kali River basin using Revised Universal Soil Loss Equation (RUSLE) model. Various thematic layers of RUSLE factors such as rainfall erosivity (R), soil erodibility (K), topographic factor (LS), crop management factor (C), and support practice factor (P) have been prepared by using multiple spatial and non-spatial data sets. These layers are integrated in geographic information system (GIS) environment and estimated the soil loss. The results show that ∼42 % of the study area falls under low erosion risk and only 6.97 % area suffer from very high erosion risk. Based on the rate of soil loss, 165 sub-watersheds have been prioritized into four categories-very high, high, moderate, and low erosion risk. Anthropogenic activities such as deforestation, construction of dams, and rapid urbanization are the main reasons for high rate of soil loss in the study area. The soil erosion rate and prioritization maps help in implementation of a proper watershed management plan for the river basin.

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.

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. 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

53. AVALON DAM Photographic copy of historic photo, August ...

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

53. AVALON DAM - Photographic copy of historic photo, August 9, 1893 (original print located at the Carlsbad Irrigation District offices, Carlsbad, New Mexico) photographer unknown 'EDDY DAM. LOOKING EAST.' VIEW OF COLLAPSED DAM - Carlsbad Irrigation District, Avalon Dam, On Pecos River, 4 miles North of Carlsbad, Carlsbad, Eddy County, NM

Removing Dams: Project-Level Policy and Scientific Research Needs (Invited)

NASA Astrophysics Data System (ADS)

Graber, B.

2010-12-01

More than 800 dams have been removed around the country, mostly “small” dams, under 25 feet in height. The total number of removals, however, is small relative to the number of deteriorating dams and the ecological impacts those structures continue to have on native riverine species and natural river function. The number of dam removal projects is increasing as aging dams continue to deteriorate and riverine species continue to decline. Practitioners and regulators need to find cost-effective project approaches that minimize short-term environmental impacts and maximize long-term benefits while keeping project costs manageable. Dam removals can be a regulatory challenge because they inherently have short-term impacts in order to achieve larger, self-sustaining, long-term benefits. These short-term impacts include sediment movement, construction access roads, and habitat conversion from lacustrine to riverine. Environmental regulations are designed to prevent degradation and have presented challenges for projects designed to benefit the environment. For example, a short-term release of sediment may exceed water quality standards for some period of time, but lead to a long-term beneficial project. Other regulatory challenges include permitting the loss of wetland area for increased native river function, or allowing the release of some level of contaminated sediment when the downstream sediment is similarly contaminated. Dam removal projects raise a range of engineering and scientific questions on effective implementation techniques such as appropriate sediment management approaches, construction equipment access approaches, invasive species management, channel/floodplain reconstruction, and active versus passive habitat rehabilitation. While practitioners have learned and refined implementation approaches over the last decade, more input is needed from researchers to help assess the effectiveness of those techniques, and to provide more effective techniques

Geodetic deformation monitoring at Pendidikan Diponegoro Dam

NASA Astrophysics Data System (ADS)

Yuwono, Bambang Darmo; Awaluddin, Moehammad; Yusuf, M. A.; Fadillah, Rizki

2017-07-01

Deformation monitoring is one indicator to assess the feasibility of Dam. In order to get the correct result of the deformation, it is necessary to determine appropriate deformation monitoring network and the observation data should be analyse and evaluated carefully. Measurement and analysis of deformation requires relatively accurate data and the precision is high enough, one of the observation method that used is GPS (Global Positioning System). The research was conducted at Pendidikan Undip Dams is Dam which is located in Tembang. Diponegoro Dam was built in 2013 and a volume of 50.86 m3 of water, inundation normal width of up to 13,500 m2. The main purpose of these building is not only for drainage but also for education and micro hydro power plant etc. The main goal of this reasearch was to monitor and analyze the deformation at Pendidikan Undip Dam and to determaine whether GPS measurement could meet accuracy requirement for dam deformation measurements. Measurements were made 2 times over 2 years, 2015 and 2016 using dual frequency GPS receivers with static methods and processed by Scientific Software GAMIT 10.6

National Dam Safety Program. Still Lake Dam (Inventory Number N.Y. 1266), Long Island Basin, Westchester County, New York. Phase I Inspection Report,

DTIC Science & Technology

1981-08-05

Location The dam is located in Ossining , Westchester County, New York. The dam is located approximately four miles north- east of the City of... Ossining . c. Size Classification The dam has a structural height of 16 feet and a reservoir storage capacity of 150 acre-feet. The dam is clas- sified as...President of the Association is Mr. Barry Shainman, Adams Road, Ossining , New York, 10562, Telephone No. (914) 762-118C. f. Purpose Still Lake Dam

Variations in turbidity in streams of the Bull Run Watershed, Oregon 1989-90

USGS Publications Warehouse

LaHusen, Richard G.

1994-01-01

In this study, turbidity is used to help explain spatial and temporal patterns of erosion and sediment transport.Automated turbidity sampling in streams in the Bull Run watershed during water years 1989 and 1990, showed turbidity levels, in general, are remarkably low, with levels below 1 NTU (nephelometric turbidity unit) about 90 percent of the time. However, ephemeral increases in turbidity in streams of the Bull Run watershed occur in direct response to storms. Turbidity is caused by abundant organic particles as well as by materials eroded from unconsolidated geologic materials located along roads, stream channels, or stream banks. Seasonal and within-storm decreases in turbidity are attributed to depletion of accumulated particle supplies. During winter storms, erosion caused by rainfall intensities greater than 0.25 inches in 3 hours is sufficient to increase stream turbidities from less than 1 NTU to as much as 100 NTUs. Large-scale storms or floods cause persistent effects because mass erosion or scour of channel armor increases available sediment supply.Spatial variability in turbidity is evident only during storms when erosion and sediment-transport processes are active. Parts of the Rhododendron Formation are particularly prone to channel and mass erosion during large storms. Eroding glacial deposits in sections of Log Creek affected by a 1964 dam-break flood also cause high stream turbidity relative to other streams in the watershed.Analysis of characteristics of magnetic minerals in sediment sources and deposits was unproductive as a means to identify source areas of suspended sediment because high concentrations of magnetite in all samples of the volcanic rocks masked differences of less magnetic minerals in the samples.

A Corresponding Study of Water Quality Evaluation of the Pasquotank Watershed in Northeastern North Carolina

NASA Astrophysics Data System (ADS)

Stevenson, J.; Walthall, S.; McKenzie, R.; Dixon, R.

2015-12-01

The Pasquotank River Watershed covers 450 sq miles in the Coastal Plain of NE North Carolina. It flows from the Great Dismal Swamp at the VA/NC border into the Albemarle Sound. The watershed provides a transition between spawning grounds and waters of the Albemarle Sound. Forested swamp wetlands border much of the waterways. Increased agricultural and urban development has greatly affected water quality during recent years. Test were completed along the tributaries and the river itself, adding to the previously data from 2011, 2013, and 2014. Streams tested were the Newbegun Creek, Knobbs Creek, Areneuse Creek, Mill Dam Creek, and Sawyers Creek. These streams cover a large area of the watershed and provide a wide variety of shore development from swampland and farmland to industrial development. Samples were tested for pH, salinity, total dissolved solids, and conductivity. Air/water temperature, dissolved oxygen, wind speed/direction, and turbidity/clarity measurements were taken in the field. The results were placed into an online database and correlated to the location of the sample using Google Maps®. Analysis tools were developed to compare the data from all years. Excel spreadsheets were developed to look more closely at individual points and tests for each point. This database was connected to a data visualization page utilizing Google Maps®. The results show variations for the individual water quality scores, but the overall water quality score for all the tested water sources remained at a comparable level from previous years. Mill Dam Creek rose above the previous three scores of 48 (2011), 47 (2013), and 49 (2014) and achieved a medium water quality score of 57. Areneuse Creek improved in water quality with a medium water quality score of 60. Sawyers Creek became the lowest scoring waterway tested at 35. Knobbs Creek decreased from previous years with a water quality score of 42. For a fourth consecutive testing year, Newbegun Creek fell within the

The role of interior watershed processes in improving parameter estimation and performance of watershed models.

PubMed

Yen, Haw; Bailey, Ryan T; Arabi, Mazdak; Ahmadi, Mehdi; White, Michael J; Arnold, Jeffrey G

2014-09-01

Watershed models typically are evaluated solely through comparison of in-stream water and nutrient fluxes with measured data using established performance criteria, whereas processes and responses within the interior of the watershed that govern these global fluxes often are neglected. Due to the large number of parameters at the disposal of these models, circumstances may arise in which excellent global results are achieved using inaccurate magnitudes of these "intra-watershed" responses. When used for scenario analysis, a given model hence may inaccurately predict the global, in-stream effect of implementing land-use practices at the interior of the watershed. In this study, data regarding internal watershed behavior are used to constrain parameter estimation to maintain realistic intra-watershed responses while also matching available in-stream monitoring data. The methodology is demonstrated for the Eagle Creek Watershed in central Indiana. Streamflow and nitrate (NO) loading are used as global in-stream comparisons, with two process responses, the annual mass of denitrification and the ratio of NO losses from subsurface and surface flow, used to constrain parameter estimation. Results show that imposing these constraints not only yields realistic internal watershed behavior but also provides good in-stream comparisons. Results further demonstrate that in the absence of incorporating intra-watershed constraints, evaluation of nutrient abatement strategies could be misleading, even though typical performance criteria are satisfied. Incorporating intra-watershed responses yields a watershed model that more accurately represents the observed behavior of the system and hence a tool that can be used with confidence in scenario evaluation. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Recovery of sockeye salmon in the Elwha River, Washington, after dam removal: Dependence of smolt production on the resumption of anadromy by landlocked kokanee

USGS Publications Warehouse

Hansen, Adam G.; Gardner, Jennifer R.; Beauchamp, David A.; Paradis, Rebecca; Quinn, Thomas P.

2016-01-01

Pacific salmon Oncorhynchus spp. are adept at colonizing habitat that has been reopened to anadromous passage. Sockeye Salmon O. nerka are unique in that most populations require lakes to fulfill their life history. Thus, for Sockeye Salmon to colonize a system, projects like dam removals must provide access to lakes. However, if the lakes contain landlocked kokanee (lacustrine Sockeye Salmon), the recovery of Sockeye Salmon could be mediated by interactions between the two life history forms and the processes associated with the resumption of anadromy. Our objective was to evaluate the extent to which estimates of Sockeye Salmon smolt production and recovery are sensitive to the resumption of anadromy by kokanee after dam removal. We informed the analysis based on the abiotic and biotic features of Lake Sutherland, which was recently opened to passage after dam removal on the Elwha River, Washington. We first developed maximum expectations for the smolt-producing capacity of Lake Sutherland by using two predictive models developed from Sockeye Salmon populations in Alaska and British Columbia: one model was based on the mean seasonal biomass of macrozooplankton, and the other was based on the euphotic zone volume of the lake. We then constructed a bioenergetics-based simulation model to evaluate how the capacity of Lake Sutherland to rear yearling smolts could change with varying degrees of anadromy among O. nerka fry. We demonstrated that (1) the smolt-producing capacity of a nursery lake for juvenile Sockeye Salmon changes in nonlinear ways with changes in smolt growth, mortality, and the extent to which kokanee resume anadromy after dam removal; (2) kokanee populations may be robust to changes in abundance after dam removal, particularly if lakes are located higher in the watershed on tributaries separate from where dams were removed; and (3) the productivity of newly establishing Sockeye Salmon can vary considerably depending on whether the population becomes

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)

The blind men meet the elephant at the dam: Alternative spatial and taxonomic components reveal different insights about how low-head dams impact fish biodiversity

USGS Publications Warehouse

Fencl, Jane S.; Mather, Martha E.; Smith, Joseph M.; Hitchman, Sean M.

2017-01-01

Dams are ubiquitous environmental impacts that threaten aquatic ecosystems. The ability to compare across research studies is essential to conserve the native biodiversity that is impacted by the millions of low‐head dams that currently fragment streams and rivers. Here, we identify a previously unaddressed obstacle that impedes this generalization. Specifically, divergent spatial and taxonomic approaches that result from different conceptualizations of the dam‐biodiversity problem can produce conflicting science‐based conclusions about the same dam impact. In this research, using the same dammed and undammed sites, we evaluated the scientific generality of different conceptualizations of the dam‐biodiversity problem. We compared two different but commonly used spatial approaches—(1) above dam–below dam vs. (2) undammed–dammed comparisons—and 11 different, commonly used taxonomic approaches (three assemblage summaries, eight guilds). Sites above the dam structure had less diverse fish assemblages than sites below dams, whereas sites below the dam structure were similar to undammed sites. Thus, spatial approach 1 detected a large dam effect and spatial approach 2 detected a small dam effect. Similarly, some taxonomic responses (species richness, diversity, abundance, and number of guilds) detected large dam effects; other responses detected small (riffle specialist guild) or no dam effects (pool generalists). In summary, our results showed that how the problem was framed altered scientific conclusions and created different dam realities. The metaphor of how individual blind men disagree about the structure of an elephant, based on examinations of different body parts, reinforces the need for a coordinated, holistic perspective on dam research. Although no single approach is adequate for all problems, identifying the form, consequences of, and relationships among different research conceptualizations will set the stage for future syntheses of dam�

25 CFR 173.16 - Reserved area, Coolidge Dam.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Reserved area, Coolidge Dam. 173.16 Section 173.16... area, Coolidge Dam. No permit for any commercial business or other activity (except boating concessions...-fourths of a mile from the center of the Coolidge Dam, Arizona. ...

25 CFR 173.16 - Reserved area, Coolidge Dam.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 25 Indians 1 2011-04-01 2011-04-01 false Reserved area, Coolidge Dam. 173.16 Section 173.16... area, Coolidge Dam. No permit for any commercial business or other activity (except boating concessions...-fourths of a mile from the center of the Coolidge Dam, Arizona. ...

East Fork Watershed Cooperative: Toward better system-scale watershed management

EPA Science Inventory

The East Fork Watershed Cooperative is a group intent on understanding how to best manage water quality in a large mixed-use Midwestern watershed system. The system contains a reservoir that serves as a source of drinking water and is popular for water recreation. The reservoir i...

Hungry Horse Dam Fisheries Mitigation : Fish Passage and Habitat Improvement in the Upper Flathead River Basin, 1991-1996 Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knotek, W.Ladd; Deleray, Mark; Marotz, Brian L.

1997-08-01

In the past 50 years, dramatic changes have occurred in the Flathead Lake and River system. Degradation of fishery resources has been evident, in part due to deterioration of aquatic habitat and introduction of non-endemic fish and invertebrate species. Habitat loss has been attributed to many factors including the construction and operation of Hungry Horse Dam, unsound land use practices, urban development, and other anthropogenic and natural disturbances. Fish migration has also been limited by barriers such as dams and impassible culverts. Cumulatively, these factors have contributed to declines in the distribution and abundance of native fish populations. Recovery ofmore » fish populations requires that a watershed approach be developed that incorporates long-term aquatic habitat needs and promotes sound land use practices and cooperation among natural resource management agencies. In this document, the authors (1) describe completed and ongoing habitat improvement and fish passage activities under the Hungry Horse Fisheries Mitigation Program, (2) describe recently identified projects that are in the planning stage, and (3) develop a framework for identifying prioritizing, implementing, and evaluating future fish habitat improvement and passage projects.« less

National Program for Inspection of Non-Federal Dams. Lost Wilderness Lake Southern Dam (Twining Pond Dam) (MA 00321), Farmington River Basin, Tolland, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1979-12-01

11j11_1.25 1111.4 ~lL MICROCOPY RESOLUTION TEST CHAR’ N-’ fIFA N A I ANI Fl 0 Lf) FARMINGTON RIVER BASIN L TOLLAND, MASSACHUSETTS It LOST WILDERNESS LAKE...of *• Non-Federal Dams; use cover date for date of report. I. K EY WORDS (Contonue on reverse side I# noco..iny md idon ll y by block RiMI0ber) DAMS...It necessary and ~en1Y & y block mnmbovj The dam is an earthen embankment 440 ft. long and 27 ft. high with a drop inlet 7-: principal spillway

Gypsum-karst problems in constructing dams in the USA

USGS Publications Warehouse

Johnson, K.S.

2008-01-01

Gypsum is a highly soluble rock and is dissolved readily to form caves, sinkholes, disappearing streams, and other karst features that typically are also present in limestones and dolomites. Gypsum karst is widespread in the USA and has caused problems at several sites where dams were built, or where dam construction was considered. Gypsum karst is present (at least locally) in most areas where gypsum crops out, or is less than 30-60 m below the land surface. These karst features can compromise on the ability of a dam to hold water in a reservoir, and can even cause collapse of a dam. Gypsum karst in the abutments or foundation of a dam can allow water to pass through, around, or under a dam, and solution channels can enlarge quickly, once water starts flowing through such a karst system. The common procedure for controlling gypsum karst beneath the dam is a deep cut-off trench, backfilled with impermeable material, or a close-spaced grout curtain that hopefully will fill all cavities. In Oklahoma, the proposed Upper Mangum Dam was abandoned before construction, because of extensive gypsum karst in the abutments and impoundment area. Catastrophic failure of the Quail Creek Dike in southwest Utah in 1989 was due to flow of water through an undetected karstified gypsum unit beneath the earth-fill embankment. The dike was rebuilt, at a cost of US $12 million, with construction of a cut-off trench 600 m long and 25 m deep. Other dams in the USA with severe gypsum-karst leakage problems in recent years are Horsetooth and Carter Lake Dams, in Colorado, and Anchor Dam, in Wyoming. ?? 2007 Springer-Verlag.

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

Plugs or flood-makers? The unstable landslide dams of eastern Oregon

NASA Astrophysics Data System (ADS)

Safran, E. B.; O'Connor, J. E.; Ely, L. L.; House, P. K.; Grant, G.; Harrity, K.; Croall, K.; Jones, E.

2015-11-01

Landslides into valley bottoms can affect longitudinal profiles of rivers, thereby influencing landscape evolution through base-level changes. Large landslides can hinder river incision by temporarily damming rivers, but catastrophic failure of landslide dams may generate large floods that could promote incision. Dam stability therefore strongly modulates the effects of landslide dams and might be expected to vary among geologic settings. Here, we investigate the morphometry, stability, and effects on adjacent channel profiles of 17 former and current landslide dams in eastern Oregon. Data on landslide dam dimensions, former impoundment size, and longitudinal profile form were obtained from digital elevation data constrained by field observations and aerial imagery; while evidence for catastrophic dam breaching was assessed in the field. The dry, primarily extensional terrain of low-gradient volcanic tablelands and basins contrasts with the tectonically active, mountainous landscapes more commonly associated with large landslides. All but one of the eastern Oregon landslide dams are ancient (likely of order 103 to 104 years old), and all but one has been breached. The portions of the Oregon landslide dams blocking channels are small relative to the area of their source landslide complexes (0.4-33.6 km2). The multipronged landslides in eastern Oregon produce marginally smaller volume dams but affect much larger channels and impound more water than do landslide dams in mountainous settings. As a result, at least 14 of the 17 (82%) large landslide dams in our study area appear to have failed cataclysmically, producing large downstream floods now marked by boulder outwash, compared to a 40-70% failure rate for landslide dams in steep mountain environments. Morphometric indices of landslide dam stability calibrated in other environments were applied to the Oregon dams. Threshold values of the Blockage and Dimensionless Blockage Indices calibrated to worldwide data sets

Anthropogenic impacts on the optical characteristics and biodegradability of dissolved and particulate organic matter in the Han River watershed, South Korea

NASA Astrophysics Data System (ADS)

Shirina Begum, Most; Jin, Hyojin; Yoon, Tae Kyung; Park, Ji-Hyung

2016-04-01

To understand how anthropogenic perturbations such as dams and pollution modify the chemical characteristics and biological transformations of riverine organic matter during transit through urbanized watersheds, we compared the optical characteristics and biodegradability of dissolved organic matter (DOM) and particulate organic matter (POM) along different reaches and urban tributary streams of the Han River watershed during short-term incubations. Laboratory incubations were conducted for 5-7 days at 20-25 oC with filtered or unfiltered water samples collected from up-, mid-, and downstream reaches with different levels of anthropogenic perturbations and three urban streams along the downstream reach that receive effluents from waste water treatment facilities in the metropolitan Seoul. Optical parameters such as ultraviolet absorbance at 254 nm, absorption coefficients at 254 nm and 350 nm, fluorescence index, humic-like fluorescence, microbial humic-like fluorescence, and protein-like fluorescence, and spectral slope at 350-400 nm were significantly correlated with increasing concentration of biodegradable dissolved organic carbon (BDOC) in filtered and unfiltered sample along the Han River up-, mid-, down-, and urban streams. The concentrations of BDOC in the urban streams were 6-12 times higher than in the filtered and unfiltered main-stem river samples, with significantly higher values in presence of POM in the unfiltered samples than in the filtered samples. In a separate 5-day incubation experiment with the unfiltered water sample from a downstream location of the Han River and its urban tributary water in isolation or mixed , the rate of concurrent biodegradation of both DOM and POM, as measured by the cumulative rate of CO2 production, was higher in the mixture than the average rate of the separately incubated samples, indicating the priming effect of mixed organic materials on the biodegradation of allochthonous organic materials from the other site

Geomorphic mapping to support river restoration on the Trinity River downstream from Lewiston Dam, California, 1980-2011

USGS Publications Warehouse

Curtis, Jennifer A.; Guerrero, Timothy M.

2015-01-01

Historic land use, dam construction, water storage, and flow diversions in the Trinity River watershed have resulted in downstream geomorphic change, loss of salmonid habitat, and declines in salmonid populations. The USGS in cooperation with the Trinity River Restoration Program, a multi-agency partnership tasked with implementing federally mandated restoration, completed a geomorphic change assessment to inform the planning process for future restoration work. This report documents an ARCMAP geodatabase (v.10.0) containing geomorphic features digitized from a series of rectified orthophotographs (http://dx.doi.org/10.5066/F7TT4P04). Upland, riparian, and channel features were digitized from six available base images (1980, 1997, 2001, 2006, 2009, and 2011). This report describes the structure of the geodatabase and the methods used to delineate individual geomorphic features.

Effects of removing Good Hope Mill Dam on selected physical, chemical, and biological characteristics of Conodoguinet Creek, Cumberland County, Pennsylvania

USGS Publications Warehouse

Chaplin, Jeffrey J.; Brightbill, Robin A.; Bilger, Michael D.

2005-01-01

The implications of dam removal on channel characteris-tics, water quality, benthic invertebrates, and fish are not well understood because of the small number of removals that have been studied. Comprehensive studies that document the effects of dam removal are just beginning to be published, but most research has focused on larger dams or on the response of a sin-gle variable (such as benthic invertebrates). This report, pre-pared in cooperation with the Conodoguinet Creek Watershed Association, provides an evaluation of how channel morphol-ogy, bed-particle-size distribution, water quality, benthic inver-tebrates, fish, and aquatic habitat responded after removal of Good Hope Mill Dam (a small 'run of the river' dam) from Conodoguinet Creek in Cumberland County, Pa. Good Hope Mill Dam was a 6-foot high, 220-foot wide concrete structure demolished and removed over a 3-day period beginning with the initial breach on November 2, 2001, at 10:00 a.m. eastern standard time. To isolate the effects of dam removal, data were collected before and after dam removal at five monitoring stations and over selected reaches upstream, within, and downstream of the impoundment. Stations 1, 2, and 5 were at free-flowing control locations 4.9 miles upstream, 2.5 miles upstream, and 5 miles downstream of the dam, respec-tively. Stations 3 and 4 were located where the largest responses were anticipated, 115 feet upstream and 126 feet downstream of the dam, respectively Good Hope Mill Dam was not an effective barrier to sedi-ment transport. Less than 3 inches of sediment in the silt/clay-size range (less than 0.062 millimeters) coated bedrock within the 7,160-foot (1.4-mile) impoundment. The bedrock within the impoundment was not incised during or after dam removal, and the limited sediment supply resulted in no measurable change in the thalweg elevation downstream of the dam. The cross-sec-tional areas at stations 3 and 4, measured 17 days and 23 months after dam removal, were within

Meta-analysis of environmental effects of beaver in relation to artificial dams

NASA Astrophysics Data System (ADS)

Ecke, Frauke; Levanoni, Oded; Audet, Joachim; Carlson, Peter; Eklöf, Karin; Hartman, Göran; McKie, Brendan; Ledesma, José; Segersten, Joel; Truchy, Amélie; Futter, Martyn

2017-11-01

Globally, artificial river impoundment, nutrient enrichment and biodiversity loss impair freshwater ecosystem integrity. Concurrently, beavers, ecosystem engineers recognized for their ability to construct dams and create ponds, are colonizing sites across the Holarctic after widespread extirpation in the 19th century, including areas outside their historical range. This has the potential to profoundly alter hydrology, hydrochemistry and aquatic ecology in both newly colonized and recolonized areas. To further our knowledge of the effects of beaver dams on aquatic environments, we extracted 1366 effect sizes from 89 studies on the impoundment of streams and lakes. Effects were assessed for 16 factors related to hydrogeomorphology, biogeochemistry, ecosystem functioning and biodiversity. Beaver dams affected concentrations of organic carbon in water, mercury in water and biota, sediment conditions and hydrological properties. There were no overall adverse effects caused by beaver dams or ponds on salmonid fish. Age was an important determinant of effect magnitude. While young ponds were a source of phosphorus, there was a tendency for phosphorus retention in older systems. Young ponds were a source methylmercury in water, but old ponds were not. To provide additional context, we also evaluated similarities and differences between environmental effects of beaver-constructed and artificial dams (767 effect sizes from 75 studies). Both are comparable in terms of effects on, for example, biodiversity, but have contrasting effects on nutrient retention and mercury. These results are important for assessing the role of beavers in enhancing and/or degrading ecological integrity in changing Holarctic freshwater systems.

Tailings dam-break flow - Analysis of sediment transport

NASA Astrophysics Data System (ADS)

Aleixo, Rui; Altinakar, Mustafa

2015-04-01

A common solution to store mining debris is to build tailings dams near the mining site. These dams are usually built with local materials such as mining debris and are more vulnerable than concrete dams (Rico et al. 2008). of The tailings and the pond water generally contain heavy metals and various toxic chemicals used in ore extraction. Thus, the release of tailings due to a dam-break can have severe ecological consequences in the environment. A tailings dam-break has many similarities with a common dam-break flow. It is highly transient and can be severely descructive. However, a significant difference is that the released sediment-water mixture will behave as a non-Newtonian flow. Existing numerical models used to simulate dam-break flows do not represent correctly the non-Newtonian behavior of tailings under a dam-break flow and may lead to unrealistic and incorrect results. The need for experiments to extract both qualitative and quantitative information regarding these flows is therefore real and actual. The present paper explores an existing experimental data base presented in Aleixo et al. (2014a,b) to further characterize the sediment transport under conditions of a severe transient flow and to extract quantitative information regarding sediment flow rate, sediment velocity, sediment-sediment interactions a among others. Different features of the flow are also described and analyzed in detail. The analysis is made by means of imaging techniques such as Particle Image Velocimetry and Particle Tracking Velocimetry that allow extracting not only the velocity field but the Lagrangian description of the sediments as well. An analysis of the results is presented and the limitations of the presented experimental approach are discussed. References Rico, M., Benito, G., Salgueiro, AR, Diez-Herrero, A. and Pereira, H.G. (2008) Reported tailings dam failures: A review of the European incidents in the worldwide context , Journal of Hazardous Materials, 152, 846

Integrated Watershed Management using the Watershed Management Optimization Support Tool (WMOST)

EPA Science Inventory

Integrated watershed management is an effective planning strategy to balance tradeoffs between competing water uses within a watershed. WMOST is an Excel-based decision tool to aid planners in making cost effective decisions that meet water quantity and quality regulations. WMOST...

21 CFR 872.6300 - Rubber dam and accessories.

Code of Federal Regulations, 2012 CFR

2012-04-01

... center intended to isolate a tooth from fluids in the mouth during dental procedures, such as filling a... center. The device includes the rubber dam, rubber dam clamp, rubber dam frame, and forceps for a rubber... sexually transmitted diseases through oral sex; those devices are classified as condoms in § 884.5300 of...

21 CFR 872.6300 - Rubber dam and accessories.

Code of Federal Regulations, 2011 CFR

2011-04-01

... center intended to isolate a tooth from fluids in the mouth during dental procedures, such as filling a... center. The device includes the rubber dam, rubber dam clamp, rubber dam frame, and forceps for a rubber... sexually transmitted diseases through oral sex; those devices are classified as condoms in § 884.5300 of...

21 CFR 872.6300 - Rubber dam and accessories.

Code of Federal Regulations, 2014 CFR

2014-04-01

... center intended to isolate a tooth from fluids in the mouth during dental procedures, such as filling a... center. The device includes the rubber dam, rubber dam clamp, rubber dam frame, and forceps for a rubber... sexually transmitted diseases through oral sex; those devices are classified as condoms in § 884.5300 of...

21 CFR 872.6300 - Rubber dam and accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... center intended to isolate a tooth from fluids in the mouth during dental procedures, such as filling a... center. The device includes the rubber dam, rubber dam clamp, rubber dam frame, and forceps for a rubber... sexually transmitted diseases through oral sex; those devices are classified as condoms in § 884.5300 of...

21 CFR 872.6300 - Rubber dam and accessories.

Code of Federal Regulations, 2013 CFR

2013-04-01

... center intended to isolate a tooth from fluids in the mouth during dental procedures, such as filling a... center. The device includes the rubber dam, rubber dam clamp, rubber dam frame, and forceps for a rubber... sexually transmitted diseases through oral sex; those devices are classified as condoms in § 884.5300 of...

The remains of the dam: what have we learned from 15 years of US dam removals?

Treesearch

Gordon E. Grant; Sarah L. Lewis

2015-01-01

Important goals for studying dam removal are to learn how rivers respond to large and rapid introductions of sediment, and to develop predictive models to guide future dam removals. Achieving these goals requires organizing case histories systematically so that underlying physical mechanisms determining rates and styles of sediment erosion, transport, and deposition...

Harvesting river water through small dams promote positive environmental impact.

PubMed

Agoramoorthy, Govindasamy; Chaudhary, Sunita; Chinnasamy, Pennan; Hsu, Minna J

2016-11-01

While deliberations relating to negative consequences of large dams on the environment continue to dominate world attention, positive benefits provided by small dams, also known as check dams, go unobserved. Besides, little is known about the potential of check dams in mitigating global warming impacts due to less data availability. Small dams are usually commissioned to private contractors who do not have clear mandate from their employers to post their work online for public scrutiny. As a result, statistics on the design, cost, and materials used to build check dams are not available in public domain. However, this review paper presents data for the first time on the often ignored potential of check dams mitigating climate-induced hydrological threats. We hope that the scientific analysis presented in this paper will promote further research on check dams worldwide to better comprehend their eco-friendly significance serving society.

Efficiency evaluation of agricultural underground dam in South Korea

NASA Astrophysics Data System (ADS)

Myoung, W.; Song, S. H.; Yong, H. H.

2017-12-01

Climate change has resulted in severe droughts in a rice-planting season (i.e., April to June) in South Korea since 2012. Therefore, all time high-amount water resources in rice-farming seasons (i.e., April to October) were required against natural crises like droughts. The underground dam, which is able to increase groundwater amounts in the alluvium aquifer, has been considered to be an alternative for securing more groundwater resources. In this study, irrigation efficiencies of five pre-existing agricultural underground dams in South Korea were evaluated during the drought periods. A total amount of groundwater storage capacities in alluvial aquifers of these five ones were estimated approximate 15 × 107 m3: above 4 × 106 m3 for two underground dams (Ian, Namsong), 2 3 × 106 m3, for 2 dams (Oksung, Wooil), below 2 × 106 m3 for 1 dam (Gocheon), respectively. Irrigating amounts of groundwater accounted for three underground dams (Ian, Namsong, Gocheon), supplied in rice-farming season are 8.5 × 105 m3/year, 8.3 × 105 m3/year, 6.3 × 105 m3/year, respectively. The total demand of agricultural water in these underground dams is 2.0 × 106 m3/year, 1.9 × 106 m3/year, 2.2 × 106 m3/year, respectively. Irrigating amounts of groundwater accounted for whole of rice-farming area in South Korea is 4.3 × 108 m3/year whereas total demand of agricultural water is 9.4 × 109 m3/year. Groundwater were pumped from the radial collector wells located in the upstream from the underground dams. Oksung underground dam, one representative underground dam located in Chungnam province in South Korea, irrigated approximate 3 × 105 m3 during a dried rice-planting season (between April to June) in 2017. It was three times more than usual (9 × 104 m3). Groundwater levels during the same period maintained above 5.55 m, which was slightly lower than usual (6.00 m). Results of Oksung underground dam demonstrated that underground dams in South Korea were effectively operated against

Large-scale dam removal on the Elwha River, Washington, USA: source-to-sink sediment budget and synthesis

USGS Publications Warehouse

Warrick, Jonathan A.; Bountry, Jennifer A.; East, Amy E.; Magirl, Christopher S.; Randle, Timothy J.; Gelfenbaum, Guy R.; Ritchie, Andrew C.; Pess, George R.; Leung, Vivian; Duda, Jeff J.

2015-01-01

Understanding landscape responses to sediment supply changes constitutes a fundamental part of many problems in geomorphology, but opportunities to study such processes at field scales are rare. The phased removal of two large dams on the Elwha River, Washington, exposed 21 ± 3 million m3, or ~ 30 million tonnes (t), of sediment that had been deposited in the two former reservoirs, allowing a comprehensive investigation of watershed and coastal responses to a substantial increase in sediment supply. Here we provide a source-to-sink sediment budget of this sediment release during the first two years of the project (September 2011–September 2013) and synthesize the geomorphic changes that occurred to downstream fluvial and coastal landforms. Owing to the phased removal of each dam, the release of sediment to the river was a function of the amount of dam structure removed, the progradation of reservoir delta sediments, exposure of more cohesive lakebed sediment, and the hydrologic conditions of the river. The greatest downstream geomorphic effects were observed after water bodies of both reservoirs were fully drained and fine (silt and clay) and coarse (sand and gravel) sediments were spilling past the former dam sites. After both dams were spilling fine and coarse sediments, river suspended-sediment concentrations were commonly several thousand mg/L with ~ 50% sand during moderate and high river flow. At the same time, a sand and gravel sediment wave dispersed down the river channel, filling channel pools and floodplain channels, aggrading much of the river channel by ~ 1 m, reducing river channel sediment grain sizes by ~ 16-fold, and depositing ~ 2.2 million m3 of sand and gravel on the seafloor offshore of the river mouth. The total sediment budget during the first two years revealed that the vast majority (~ 90%) of the sediment released from the former reservoirs to the river passed through the fluvial system and was discharged to the coastal

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

Plugs or flood-makers? the unstable landslide dams of eastern Oregon

USGS Publications Warehouse

Safran, Elizabeth B.; O'Connor, Jim E.; Ely, Lisa L.; House, P. Kyle; Grant, Gordon E.; Harrity, Kelsey; Croall, Kelsey; Jones, Emily

2015-01-01

Landslides into valley bottoms can affect longitudinal profiles of rivers, thereby influencing landscape evolution through base-level changes. Large landslides can hinder river incision by temporarily damming rivers, but catastrophic failure of landslide dams may generate large floods that could promote incision. Dam stability therefore strongly modulates the effects of landslide dams and might be expected to vary among geologic settings. Here, we investigate the morphometry, stability, and effects on adjacent channel profiles of 17 former and current landslide dams in eastern Oregon. Data on landslide dam dimensions, former impoundment size, and longitudinal profile form were obtained from digital elevation data constrained by field observations and aerial imagery; while evidence for catastrophic dam breaching was assessed in the field. The dry, primarily extensional terrain of low-gradient volcanic tablelands and basins contrasts with the tectonically active, mountainous landscapes more commonly associated with large landslides. All but one of the eastern Oregon landslide dams are ancient (likely of order 103 to 104 years old), and all but one has been breached. The portions of the Oregon landslide dams blocking channels are small relative to the area of their source landslide complexes (0.4–33.6 km2). The multipronged landslides in eastern Oregon produce marginally smaller volume dams but affect much larger channels and impound more water than do landslide dams in mountainous settings. As a result, at least 14 of the 17 (82%) large landslide dams in our study area appear to have failed cataclysmically, producing large downstream floods now marked by boulder outwash, compared to a 40–70% failure rate for landslide dams in steep mountain environments. Morphometric indices of landslide dam stability calibrated in other environments were applied to the Oregon dams. Threshold values of the Blockage and Dimensionless Blockage Indices calibrated to worldwide

Watershed councils: it takes a community to restore a watershed

Treesearch

Marie Oliver; Rebecca Flitcroft

2011-01-01

Regulation alone cannot solve complex ecological problems on private lands that are managed for diverse uses. Executing coordinated restoration projects at the watershed scale is only possible with the cooperation and commitment of all stakeholders. Locally organized, nonregulatory watershed councils have proven to be a powerful method of engaging citizens from all...

MANAGING URBAN WATERSHED PATHOGEN CONTAMINATION

EPA Science Inventory

This document is written as a resource for state and local watershed managers who have the responsibility of managing pathogen contamination in urban watersheds. In addition it can be an information source for members of the public interested in watershed mitigation efforts aime...

National Program for Inspection of Non-Federal Dams. Ludlow Dam (MA 00547) and Cherry Valley Dam (MA 00548), Chicopee River Basin, Ludlow, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1978-08-01

operates to pump water from Settling Basin to Filter * Float Wells Beds above the location of Ludlow Dam. Crane Hoist Elevator Hydraulic Systum Service...outlet Channel beyond Emergency Spillway at Cherry Valley Dam Overflow StutueoBra ro aa atryVe Photogaph #1 P 0 Photograph #12 Contrls forw Slif Gaes ate

36 CFR 251.35 - Petersburg watershed.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Petersburg watershed. 251.35... 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, as...

36 CFR 251.35 - Petersburg watershed.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Petersburg watershed. 251.35... 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, as...

36 CFR 251.35 - Petersburg watershed.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Petersburg watershed. 251.35... 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, as...

36 CFR 251.35 - Petersburg watershed.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Petersburg watershed. 251.35... 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, as...

36 CFR 251.35 - Petersburg watershed.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Petersburg watershed. 251.35... 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, as...

Hydrologic calibration of paired watersheds using a MOSUM approach

DOE PAGES

Ssegane, H.; Amatya, D. M.; Muwamba, A.; ...

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

Identifying and Classifying Pollution Hotspots to Guide Watershed Management in a Large Multiuse Watershed.

PubMed

Su, Fangli; Kaplan, David; Li, Lifeng; Li, Haifu; Song, Fei; Liu, Haisheng

2017-03-03

In many locations around the globe, large reservoir sustainability is threatened by land use change and direct pollution loading from the upstream watershed. However, the size and complexity of upstream basins makes the planning and implementation of watershed-scale pollution management a challenge. In this study, we established an evaluation system based on 17 factors, representing the potential point and non-point source pollutants and the environmental carrying capacity which are likely to affect the water quality in the Dahuofang Reservoir and watershed in northeastern China. We used entropy methods to rank 118 subwatersheds by their potential pollution threat and clustered subwatersheds according to the potential pollution type. Combining ranking and clustering analyses allowed us to suggest specific areas for prioritized watershed management (in particular, two subwatersheds with the greatest pollution potential) and to recommend the conservation of current practices in other less vulnerable locations (91 small watersheds with low pollution potential). Finally, we identified the factors most likely to influence the water quality of each of the 118 subwatersheds and suggested adaptive control measures for each location. These results provide a scientific basis for improving the watershed management and sustainability of the Dahuofang reservoir and a framework for identifying threats and prioritizing the management of watersheds of large reservoirs around the world.

Identifying and Classifying Pollution Hotspots to Guide Watershed Management in a Large Multiuse Watershed

PubMed Central

Su, Fangli; Kaplan, David; Li, Lifeng; Li, Haifu; Song, Fei; Liu, Haisheng

2017-01-01

In many locations around the globe, large reservoir sustainability is threatened by land use change and direct pollution loading from the upstream watershed. However, the size and complexity of upstream basins makes the planning and implementation of watershed-scale pollution management a challenge. In this study, we established an evaluation system based on 17 factors, representing the potential point and non-point source pollutants and the environmental carrying capacity which are likely to affect the water quality in the Dahuofang Reservoir and watershed in northeastern China. We used entropy methods to rank 118 subwatersheds by their potential pollution threat and clustered subwatersheds according to the potential pollution type. Combining ranking and clustering analyses allowed us to suggest specific areas for prioritized watershed management (in particular, two subwatersheds with the greatest pollution potential) and to recommend the conservation of current practices in other less vulnerable locations (91 small watersheds with low pollution potential). Finally, we identified the factors most likely to influence the water quality of each of the 118 subwatersheds and suggested adaptive control measures for each location. These results provide a scientific basis for improving the watershed management and sustainability of the Dahuofang reservoir and a framework for identifying threats and prioritizing the management of watersheds of large reservoirs around the world. PMID:28273834

Watershed Effects on Streamflow Quantity and Quality in Six Watersheds of Gwinnett County, Georgia

USGS Publications Warehouse

Landers, Mark N.; Ankcorn, Paul D.; McFadden, Keith W.

2007-01-01

Watershed management is critical for the protection and enhancement of streams that provide multiple benefits for Gwinnett County, Georgia, and downstream communities. Successful watershed management requires an understanding of how stream quality is affected by watershed characteristics. The influence of watershed characteristics on stream quality is complex, particularly for the nonpoint sources of pollutants that affect urban watersheds. The U.S. Geological Survey (USGS), in cooperation with Gwinnett County Department of Water Resources (formerly known as Public Utilities), established a water-quality monitoring program during late 1996 to collect comprehensive, consistent, high-quality data for use by watershed managers. Between 1996 and 2003, more than 10,000 analyses were made for more than 430 water-quality samples. Continuous-flow and water-quality data have been collected since 1998. Loads have been computed for selected constituents from 1998 to 2003. Changing stream hydrology is a primary driver for many other water-quality and aquatic habitat effects. Primary factors affecting stream hydrology (after watershed size and climate) within Gwinnett County are watershed slope and land uses. For the six study watersheds in Gwinnett County, watershedwide imperviousness up to 12 percent does not have a well-defined influence on stream hydrology, whereas two watersheds with 21- and 35-percent impervious area are clearly impacted. In the stream corridor, however, imperviousness from 1.6 to 4.4 percent appears to affect baseflow and stormflow for all six watersheds. Relations of concentrations to discharge are used to develop regression models to compute constituent loads using the USGS LOAD ESTimator model. A unique method developed in this study is used to calibrate the model using separate baseflow and stormflow sample datasets. The method reduced model error and provided estimates of the load associated with the baseflow and stormflow parts of the hydrograph

The design of the intelligent monitoring system for dam safety

NASA Astrophysics Data System (ADS)

Yuan, Chun-qiao; Jiang, Chen-guang; Wang, Guo-hui

2008-12-01

Being a vital manmade water-control structure, a dam plays a very important role in the living and production of human being. To make a dam run safely, the best design and the superior construction quality are paramount; moreover, with working periods increasing, various dynamic, alternative and bad loads generate little by little various distortions on the dam structure inevitably, which shall lead to potential safety problems or further a disaster (dam burst). There are many signs before the occurrence of a dam accident, so the timely and effective surveying on the distortion of a dam is important. On the basis of the cause supra, two intelligent (automatic) monitoring systems about the dam's safety based on the RTK-GPS technology and the measuring robot has been developed. The basic principle, monitoring method and monitoring process of these two intelligent (automatic) monitoring systems are introduced. It presents examples of monitor and puts forward the basic rule of dam warning based on data of actual monitor.

SEISMIC RESPONSE OF DAM WITH SOIL-STRUCTURE INTERACTION.

USGS Publications Warehouse

Bycroft, G.N.; Mork, P.N.

1987-01-01

An analytical solution to the response of a long trapezoidal-section dam on a foundation consisting of an elastic half-space and subjected to simulated earthquake motion is developed. An optimum seismic design is achieved when the cross section of the dam is triangular. The effect of soil structure interaction is to lower the strain occurring in the dam.

Watershed Restoration Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 themore » 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.« less

Recent sediment studies refute Glen Canyon Dam hypothesis

USGS Publications Warehouse

Rubin, David M.; Topping, David J.; Schmidt, John C.; Hazel, Joe; Kaplinski, Matt; Melis, Theodore S.

2002-01-01

Recent studies of sedimentology hydrology, and geomorphology indicate that releases from Glen Canyon Dam are continuing to erode sandbars and beaches in the Colorado River in Grand Canyon National Park, despite attempts to restore these resources. The current strategy for dam operations is based on the hypothesis that sand supplied by tributaries of the Colorado River downstream from the dam will accumulate in the channel during normal dam operations and remain available for restoration floods. Recent work has shown that this hypothesis is false, and that tributary sand inputs are exported downstream rapidly typically within weeks or months under the current flow regime.

Behavior and dam passage of juvenile Chinook salmon and juvenile steelhead at Detroit Reservoir and Dam, Oregon, March 2012-February 2013

USGS Publications Warehouse

Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Evans, Scott D.; Haner, Philip V.; Hatton, Tyson W.; Kofoot, Eric E.; Sprando, Jamie M.; Smith, Collin D.

2014-01-01

The in-reservoir movements and dam passage of individual juvenile Chinook salmon (Oncorhynchus tshawytscha) and juvenile steelhead (Oncorhynchus mykiss) were studied at Detroit Reservoir and Dam, near Detroit, Oregon, during 2012 and 2013. The goal of the study was to provide data to inform decisions about future downstream passage alternatives and factors affecting downstream passage rates with the existing dam configuration. In 2012, 468 juvenile Chinook salmon and 200 juvenile steelhead were tagged and released during a 3-month period in the spring, and another 514 juvenile Chinook salmon were tagged and released during a 3-month period in the fall. The fish were surgically implanted with a small acoustic transmitter with an expected life of about 3 months and a passive integrated transponder tag with an indefinite life, and were released into the two main tributaries several kilometers upstream of the reservoir. Juvenile Chinook salmon migrated from the release sites to the reservoir in a greater proportion than juvenile steelhead, but once in the reservoir, juvenile steelhead migrated to the forebay faster and had a higher dam passage rate than juvenile Chinook salmon. The routes available for passing water and fish varied throughout the year, with low reservoir elevations in winter and high reservoir elevations in summer in accordance with the flood-control purpose of the dam. Most dam passage was through the spillway during the spring and summer, when the reservoir elevation was high and the spillway and powerhouse were the most common routes in operation, and via the powerhouse during the fall and winter period, when the reservoir elevation was low and the regulating outlet and powerhouse were the most common routes in operation. Few tagged fish passed when the powerhouse was the only route in operation. Dam passage rates during the spring and summer were greatest at night, increased with dam discharge, and were greater when water was passed freely over the

Physically-based extreme flood frequency with stochastic storm transposition and paleoflood data on large watersheds

NASA Astrophysics Data System (ADS)

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

2014-03-01

Traditionally, deterministic flood procedures such as the Probable Maximum Flood have been used for critical infrastructure design. Some Federal agencies now use hydrologic risk analysis to assess potential impacts of extreme events on existing structures such as large dams. Extreme flood hazard estimates and distributions are needed for these efforts, with very low annual exceedance probabilities (⩽10-4) (return periods >10,000 years). An integrated data-modeling hydrologic hazard framework for physically-based extreme flood hazard estimation is presented. Key elements include: (1) a physically-based runoff model (TREX) coupled with a stochastic storm transposition technique; (2) hydrometeorological information from radar and an extreme storm catalog; and (3) streamflow and paleoflood data for independently testing and refining runoff model predictions at internal locations. This new approach requires full integration of collaborative work in hydrometeorology, flood hydrology and paleoflood hydrology. An application on the 12,000 km2 Arkansas River watershed in Colorado demonstrates that the size and location of extreme storms are critical factors in the analysis of basin-average rainfall frequency and flood peak distributions. Runoff model results are substantially improved by the availability and use of paleoflood nonexceedance data spanning the past 1000 years at critical watershed locations.

Hydrogeophysical investigations at Hidden Dam, Raymond, California

USGS Publications Warehouse

Minsley, Burke J.; Burton, Bethany L.; Ikard, Scott; Powers, Michael H.

2011-01-01

Self-potential and direct current resistivity surveys are carried out at the Hidden Dam site in Raymond, California to assess present-day seepage patterns and better understand the hydrogeologic mechanisms that likely influence seepage. Numerical modeling is utilized in conjunction with the geophysical measurements to predict variably-saturated flow through typical two-dimensional dam cross-sections as a function of reservoir elevation. Several different flow scenarios are investigated based on the known hydrogeology, as well as information about typical subsurface structures gained from the resistivity survey. The flow models are also used to simulate the bulk electrical resistivity in the subsurface under varying saturation conditions, as well as the self-potential response using petrophysical relationships and electrokinetic coupling equations.The self-potential survey consists of 512 measurements on the downstream area of the dam, and corroborates known seepage areas on the northwest side of the dam. Two direct-current resistivity profiles, each approximately 2,500 ft (762 m) long, indicate a broad sediment channel under the northwest side of the dam, which may be a significant seepage pathway through the foundation. A focusing of seepage in low-topography areas downstream of the dam is confirmed from the numerical flow simulations, which is also consistent with past observations. Little evidence of seepage is identified from the self-potential data on the southeast side of the dam, also consistent with historical records, though one possible area of focused seepage is identified near the outlet works. Integration of the geophysical surveys, numerical modeling, and observation well data provides a framework for better understanding seepage at the site through a combined hydrogeophysical approach.

Guidelines for Calculating and Routing a Dam-Break Flood.

DTIC Science & Technology

1977-01-01

flow, Teton Dam . 20. ABSTRACT (Continue an reverse aide If necessary and Identify by block number) This report described procedures necessary to calculate...and route a dam -break flood using an existing generalized unsteady open channel flow model. The recent Teton Dam event was reconstituted to test the...methodology may be obtained from The Hydrologic Engineering Center. The computer program was applied to the Teton Dam data set to demonstrate the level of

WATERSHED INFORMATION NETWORK

EPA Science Inventory

Resource Purpose:The Watershed Information Network is a set of about 30 web pages that are organized by topic. These pages access existing databases like the American Heritage Rivers Services database and Surf Your Watershed. WIN in itself has no data or data sets.
L...