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At least 1,333 records · Page 74Linked to original sources

Geologic map of the Morena Reservoir 7.5-minute quadrangle, San Diego County, California

Introduction Mapping in the Morena Reservoir 7.5-minute quadrangle began in 1980, when the Hauser Wilderness Area, which straddles the Morena Reservoir and Barrett Lake quadrangles, was mapped for the U.S. Forest Service. Mapping was completed in 1993–1994. The Morena Reservoir quadrangle contains part of a regional-scale Late Jurassic(?) to Early Cretaceous tectonic suture that coincides with the western limit of Jurassic metagranites in this part of the Peninsular Ranges batholith (PRB). This suture, and a nearly coincident map unit consisting of metamorphosed Cretaceous and Jurassic back-arc basinal volcanic and sedimentary rocks (unit KJvs ), mark the boundary between western, predominantly metavolcanic rocks, and eastern, mainly metasedimentary, rocks. The suture is intruded and truncated by the western margin of middle to Late Cretaceous Granite Mountain and La Posta plutons of the eastern zone of the batholith.

California↗

Reservoirs in the United States

Reservoir storage facilities in the United States play an important part in the national economy. Storage facilities have enabled the country to utilize to a much fuller extent one of the most valuable natural resources: water. During recent years the construction of reservoirs has continued at a high rate. This report shows the status of these facilities on January 1, 1954, and describes briefly some of the reasons for growth of reservoir facilities in the United States. Descriptive data are given for reservoirs having a capacity of 5, 000 acre-feet or more and for natural lakes having a usable capacity of 5,000 acre-feet or more. Included are reservoirs and lakes completed as of January 1, 1954, and reservoirs under construction on that date. The total number of such reservoirs and lakes is 1, 300. A descriptive list of reservoirs in the United States was first published by the United States Geological Survey in March 1948. That report, Geological Survey Circular 23, entitled Reservoirs in the United States, included reservoirs completed as of January 1, 1947. Since January 1, 1947, reservoirs representing a total usable capacity of 115,000,000 acre-feet, or an increase of 71 percent, have been constructed or are under construction. Data about these new reservoirs are presented herein, and the data shown for reservoirs constructed before 1947 have been corrected on the basis of the latest available survey to determine reservoir capacity. The total usable capacity of reservoirs and lakes included in this compilation amounts to 278, 120, 000 acre-feet, and the corresponding surface area totals 11, 046, 000 acres.

Water Supply Paper↗

Modeling Hydrodynamics, Water Temperature, and Suspended Sediment in Detroit Lake, Oregon

Detroit Lake is a large reservoir on the North Santiam River in west-central Oregon. Water temperature and suspended sediment are issues of concern in the river downstream of the reservoir. A CE-QUAL-W2 model was constructed to simulate hydrodynamics, water temperature, total dissolved solids, and suspended sediment in Detroit Lake. The model was calibrated for calendar years 2002 and 2003, and for a period of storm runoff from December 1, 2005, to February 1, 2006. Input data included lake bathymetry, meteorology, reservoir outflows, and tributary inflows, water temperatures, total dissolved solids, and suspended sediment concentrations. Two suspended sediment size groups were modeled: one for suspended sand and silt with particle diameters larger than 2 micrometers, and another for suspended clay with particle diameters less than or equal to 2 micrometers. The model was calibrated using lake stage data, lake profile data, and data from a continuous water-quality monitor on the North Santiam River near Niagara, about 6 kilometers downstream of Detroit Dam. The calibrated model was used to estimate sediment deposition in the reservoir, examine the sources of suspended sediment exiting the reservoir, and examine the effect of the reservoir on downstream water temperatures.

Scientific Investigations Report↗

Derivation of homogeneous streamflow records for the Green River basin, Kentucky

Four flood-control reservoirs, Green River Lake, Nolin River Lake, Barren River Lake, and Rough River Lake, were completed in the Green River basin of Kentucky between 1959 and 1969. A digital computer model of these reservoirs and the stream reaches from the reservoirs downstream to the Green River at Calhoun, Ky., was developed to simulate mean daily streamflows. Simulations of 1941 through 1971 water year streamflows were made for both the pre-reservoir and post-reservoir basin conditions, thus supplying homogeneous data sets for low-flow analyses of eight stream sites. The 7-day, 10-year recurrence interval, minimum discharges of the simulated regulated flows exceed those of the simulated natural flows by about 30 cubic feet per second for the Barren River at Bowling Green, Ky., and about 260 cubic feet per second for the Green River at Calhous, Ky. Analyses of the pre-reservoir simulations show that, for seven of the stream sites, the model yields streamflow which have annual minimum 7-day average discharges that are not significantly different, at the 95 percent significance level, from those of the observed flows. Results of the post-reservoir simulations show that actual reservoir operation was not closely matched by the model. Therefore, the low-flow characteristics of the simulated regulated streamflows are merely estimates of those that could be expected if the basin were regulated according to the modeled reservoir operating criteria. (USGS)

Open-File Report↗

Analysis of ambient conditions and simulation of hydrodynamics and water-quality characteristics in Beaver Lake, Arkansas, 2001 through 2003

Beaver Lake is a large, deep-storage reservoir located in the upper White River Basin in northwestern Arkansas. The purpose of this report is to describe the ambient hydrologic and water-quality conditions in Beaver Lake and its inflows and describe a two-dimensional model developed to simulate the hydrodynamics and water quality of Beaver Lake from 2001 through 2003. Water-quality samples were collected at the three main inflows to Beaver Lake; the White River near Fayetteville, Richland Creek at Goshen, and War Eagle Creek near Hindsville. Nutrient concentrations varied among the tributaries because of land use and contributions of nutrients from point sources. The median concentrations of total ammonia plus organic nitrogen were greater for the White River than Richland and War Eagle Creeks. The greatest concentrations of nitrite plus nitrate and total nitrogen, however, were observed at War Eagle Creek. Phosphorus concentrations were relatively low, with orthophosphorus and dissolved phosphorus concentrations mostly below the laboratory reporting limit at the three sites. War Eagle Creek had significantly greater median orthophosphorus and total phosphorus concentrations than the White River and Richland Creek. Dissolved organic-carbon concentrations were significantly greater at the White River than at War Eagle and Richland Creeks. The White River also had significantly greater turbidity than War Eagle Creek and Richland Creek. The temperature distribution in Beaver Lake exhibits the typical seasonal cycle of lakes and reservoirs located within similar latitudes. Beaver Lake is a monomictic system, in which thermal stratification occurs annually during the summer and fall and complete mixing occurs in the winter. Isothermal conditions exist throughout the winter and early spring. Nitrogen concentrations varied temporally, longitudinally, and vertically in Beaver Lake for 2001 through 2003. Nitrite plus nitrate concentrations generally decreased from the upstream portion of Beaver Lake to the downstream portion and generally were greater in the hypolimnion. Total ammonia plus organic nitrogen concentrations also decreased from the upstream end of Beaver Lake to the downstream end and were substantially greater in the hypolimnion of Beaver Lake. Phosphorus concentrations mostly were near or below laboratory detection limits in the epilimnion and metalimnion in Beaver Lake and were substantially greater in the hypolimnion in the upstream and middle parts of the reservoir. Measured total and dissolved organic carbon in Beaver Lake was relatively uniform spatially, longitudinally, and vertically in the reservoir from January 2001 through December 2003. Chlorophyll a concentrations measured at sites in the upstream portion of the lake were significantly greater than at the other sites in the downstream portion of Beaver Lake. During the study period, water clarity in Beaver Lake was significantly greater at the downstream end of the reservoir than at the upstream end. The greatest Secchi depths at the downstream end of the reservoir generally were observed in 2001 compared to 2002 and 2003, but did not have a seasonal pattern as observed at sites in the middle and upstream portion of the reservoir. Similar to Secchi depth results, turbidity results indicated greater water clarity in the downstream portion of Beaver Lake compared to the upstream portion. Turbidity also was greater in the hypolimnion than in the epilimnion in the reservoir during the stratification season. A two-dimensional, laterally averaged, hydrodynamic, and water-quality model using CE-QUAL-W2 Version 3.1 was developed for Beaver Lake and calibrated based on vertical profiles of temperature and dissolved oxygen, and water-quality constituent concentrations collected at various depths at four sites in the reservoir from April 2001 to April 2003. Simulated temperatures and dissolved-oxygen concentrations compared reasonably well with measured t

Scientific Investigations Report↗

Selenium in the Kootenai River Basin, Montana and Idaho, United States, and British Columbia, Canada

Selenium entering the 90-mile long transboundary Koocanusa Reservoir (also called Lake Koocanusa) in southeastern British Columbia, Canada, and northwestern Montana, United States, has been measured at concentrations above State and Federal water-quality and aquatic life standards. The reservoir is within the international Kootenai (or “Kootenay” in Canada) drainage basin, which contains critical habitat for native fish species and is impounded by Libby Dam 16 miles upstream from Libby, Montana. Since 1984, selenium concentrations have ranged from below detection to greater than 8 micrograms per liter in the Elk River, measured 2.2 miles above its discharge into Koocanusa Reservoir at a British Columbia environmental monitoring station (site 0200016). Selenium is a required micro-nutrient, but elevated concentrations in water bioaccumulate in egg-laying fish and birds, causing various sublethal effects and death. One possible source of selenium in the Kootenai River Basin is the excavation of bedrock in the Elk River Valley to access coal seams for metallurgical steelmaking and coal production. Five open-pit coal mines are operating in this region of southeastern British Columbia that produce about 21 million tons of metallurgical coal annually. Site-specific selenium standards were established for the reservoir in 2020 following collaborative work by the U.S. Geological Survey, Montana Department of Environmental Quality, the British Columbia Ministry of Environment and Climate Change Strategy, the Lake Koocanusa Monitoring and Research Working Group, and the Selenium Technical Subcommittee. The standards of 0.8 microgram per liter for dissolved selenium in the water column and 15.1 milligrams per kilogram dry weight for fish egg (ovary) tissue (in addition to the muscle and wholebody standards) were adopted into Montana State law in 2020 and approved by the U.S. Environmental Protection Agency in 2021.

British Columbia, Idaho, Montana↗

Bathymetry and capacity of Chambers Lake, Chester County, Pennsylvania

Introduction Chambers Lake is a manmade reservoir on Birch Run, a tributary to West Branch Brandywine Creek in Chester County, Pennsylvania. The lake was created in 1994 after the completion of Multi-Purpose Dam PA-436F (Hibernia Dam), which was built under the Watershed Protection & Flood Control Prevention Act (U.S. Soil Conservation Service, 1991). Hibernia dam is 1,700 feet upstream from the confluence of Birch Run with West Branch Brandywine Creek. The primary objectives for Hibernia Dam were to provide (1) flood control, (2) a supplemental source of water supply for the greater City of Coatesville public water system, and (3) recreational opportunities. The drainage basin of Chambers Lake encompasses approximately 4.5 square miles, and the lake covers a surface area of about 95 acres at normal pool, which is at an elevation of 579.2 feet above the North American Vertical Datum of 1988 (NAVD 88) [580.0 feet above the National Geodetic Vertical Datum of 1929 (NGVD 29)]. The crest of the auxiliary spillway of the dam is 586.6 feet above NAVD 88. The elevation of the auxiliary spillway is important to this investigation because this elevation defines the flood storage capacity of Chambers Lake. Water levels exceeding this elevation are routed through the auxiliary spillway and flow through adjoining woodland to Birch Run. The U.S. Geological Survey (USGS), in cooperation with Chester County Water Resources Authority (CCWRA) and the County of Chester, surveyed the bathymetry and selected above-water features of Chambers Lake in September 2014. The purpose of the survey was to develop an accurate representation of the surface of the bottom of Chambers Lake and to determine the stage area and reservoir-storage capacity relation as of September 2014. CCWRA is responsible for operation of the dam and water-supply reservoir. Since construction, CCWRA has used a stage–storage capacity relation developed from the original survey conducted in the 1990s to estimate the volume of water available for water supply and the available flood storage. The bathymetric mapping effort was initiated due to interest in potential changes in current (2014) storage capacity when compared to the stage–storage capacity relation developed during design. The generated bathymetric surface may serve as a baseline to which temporal changes in storage capacity, owing to sedimentation and other factors, can be compared. In addition, these data will improve the overall accuracy of the stage–storage capacity table that CCWRA uses for reservoir and flood management operations. This report describes the methods used to create a bathymetric map of Chambers Lake for the computation of reservoir storage capacity as of September 2014. The product is a bathymetric map and a table showing the storage capacity of the reservoir at 2-foot increments from minimum usable elevation up to full capacity at the crest of the auxiliary spillway.

Pennsylvania↗

Summary of selected characteristics of large reservoirs in the United States and Puerto Rico, 1988

This report presents selected characteristics of 2,728 reservoirs and controlled natural lakes located within the 50 States of the United States and the Commonwealth of Puerto Rico. Data are presented for reservoirs that have normal capacities of at least 5,000 acre-ft or maximum capacities of at least 25,000 acre-ft and that were completed as of January 1, 1988. Reservoir data include: location, maximum capacity, normal capacity, surface area, drainage area, year completed, and use. The normal capacities of the 2,728 reservoirs and controlled natural lakes total more than 467 million acre-ft, and the combined surface areas for 2,362 of those reservoirs total almost 16 million acres. More than 9% (259) of the reservoirs are located in California. The total normal capacity of reservoirs in California is more than 40 million acre-ft (about 8.6% of the total normal capacity for the United States and Puerto Rico), and the total surface area is almost 700,000 acres (about 4.4% of the listed total surface area for the United States and Puerto Rico). (USGS)

Open-File Report↗

Water resources inventory of Connecticut Part 7: upper Connecticut River basin

The 508 square miles of the upper Connecticut River basin in north-central Connecticut include the basins of four major tributaries: the Scantic, Park, and Hockanum Rivers, and the Farmington River downstream from Tariffville. Precipitation over this area averaged 44 inches per year during 1931-60. In this period, an additional 3,800 billion gallons of water per year entered the basin in the main stem of the Connecticut River at the Massachusetts state line, about 230 billion gallons per year in the Farmington River at Tariffville, and about 10 billion gallons per year in the Seantic River at the Massachusetts state line. Some water was also imported from outside the basin by water-supply systems. About half the precipitation, 22.2 inches, was lost from the basin by evapotranspiration; the remainder flowed out of the study area in the Connecticut River at Portland. Variations in streamflow at 41 long-term continuous-record gaging stations are summarized in standardized graphs and tables that can be used to estimate streamflow characteristics at other sites. For example, mean-flow and two low-flow characteristics: (1) the 7-day annual minimum flow for 2-year and (2) 10-year recurrence intervals, have been determined for many partial-record stations throughout the basin. Of the 30 principal lakes, ponds, and reservoirs, two have usable storage capacities of more than 1 billion gallons. The maximum safe draft rate (regulated flow) of the largest of these, Shenipsit Lake at Rockville, is 6.5 million gallons per day for the 2-year and 30-year recurrence intervals (median and lowest annual flow). Floods have occurred within each month of the year but in different years. The greatest known flood on the Connecticut River was in March 1936; it had a peak flow of 130,000 cubic feet per second at Hartford. Since then, major floods have been reduced by flood-control measures. The major aquifers underlying the basin are composed of unconsolidated materials (stratified drift and till) and bedrock. Stratified drift overlies till and bedrock in valleys and lowlands in the eastern and western parts and in most of the broad central valley. The stratified drift generally ranges in thickness from 10 feet in small valleys to more than 200 feet in the Connecticut River Valley. Bedrock underlies the entire basin and is composed of (1) interbedded sedimentary and igneous rocks and (2) crystalline rocks. Ground-water sources yield from several million gallons per day from large well fields to 1 gallon per minute from single wells. Yields of 100 gal/min or more are most commonly obtained from screened wells tapping stratified-drift aquifers; amounts can be calculated by use of a series of graphs in conjunction with estimates of aquifer transmissivity and thickness. Eighteen areas underlain by good aquifers are selected as the most favorable locations for large-scale development of ground water. Selection of these areas is based on estimates of aquifer characteristics and the amount of water potentially available from induced infiltration of streamflow at low-flow conditions. Small to moderate water supplies can generally be obtained from any of the aquifers. Wells in bedrock yield at least a few gallons per minute at most sites. The probability of obtaining an adequate yield for domestic supply is greater in sedimentary than in crystalline bedrock and is also greater in stratified-drift overburden than in till. Where unaffected by man's activities, the water is of the calcium magnesium bicarbonate type, is generally low to moderate in dissolved-solids concentration, and ranges from soft to hard. In general, streamflow is less mineralized than ground water, particularly when it consists largely of direct runoff. However, streams become more highly mineralized during low-flow conditions, when most flow consists of more highly mineralized water discharged from aquifers. The median dissolved-solids concentration in water from 25 stream sites was 113 mg/L (milligrams per liter) during high flow, and 148 mg/L during low flow within the study period. Iron and manganese occur naturally in objectionable concentrations in some streams draining swamps and in some waters draining from sedimentary bedrock which contains iron- and manganese-bearing minerals. Man's activities have affected the water quality of streams in much of the area, particularly in the Hockanum and Park River basins. The degradation in quality in these streams is shown by wide and erratic changes in dissolved-solids concentration, excessive amounts of trace elements, a low dissolved-oxygen content, and abnormally high temperatures. Ground water within this area is degraded principally by induced infiltration of surface water that contains chemical wastes, by leachate from wastes stored or disposed of on the ground, and by effluents discharged from septic tanks. The quantity and quality of water are satisfactory for a wide variety of uses, and, with suitable treatment, the water may be used for most purposes. The total amount of water used in 1968 was more than 100 billion gallons. About 80 percent of this was used for industrial purposes, and 90 percent of the industrial water was obtained from surface-water sources. About 85 percent of the population was supplied with water for domestic use by 15 major public and municipal systems and 25 private associations. Analyses of water from the 13 largest systems show generally good quality.

Connecticut↗

Competing risks and the development of adaptive management plans for water resources: Field reconnaissance investigation of risks to fishes and other aquatic biota exposed to endocrine disrupting chemicals (edcs) in lake mead, Nevada USA

The analysis and characterization of competing risks for water resources rely on a wide spectrum of tools to evaluate hazards and risks associated with their management. For example, waters of the lower Colorado River stored in reservoirs such as Lake Mead present a wide range of competing risks related to water quantity and water quality. These risks are often interdependent and complicated by competing uses of source waters for sustaining biological resources and for supporting a range of agricultural, municipal, recreational, and industrial uses. USGS is currently conducting a series of interdisciplinary case-studies on water quality of Lake Mead and its source waters. In this case-study we examine selected constituents potentially entering the Lake Mead system, particularly endocrine disrupting chemicals (EDCs). Worldwide, a number of environmental EDCs have been identified that affect reproduction, development, and adaptive behaviors in a wide range of organisms. Many EDCs are minimally affected by current treatment technologies and occur in treated sewage effluents. Several EDCs have been detected in Lake Mead, and several substances have been identified that are of concern because of potential impacts to the aquatic biota, including the sport fishery of Lake Mead and endangered razorback suckers (Xyrauchen texanus) that occur in the Colorado River system. For example, altered biomarkers relevant to reproduction and thyroid function in fishes have been observed and may be predictive of impaired metabolism and development. Few studies, however, have addressed whether such EDC-induced responses observed in the field have an ecologically significant effect on the reproductive success of fishes. To identify potential linkages between EDCs and species of management concern, the risk analysis and characterization in this reconnaissance study focused on effects (and attendant uncertainties) that might be expressed by exposed populations. In addition, risk reduction measures that may be of interest to resource managers are considered relative to emerging contaminants in treated effluents, interdependencies among biological resources at risk, and uses of reservoir waters derived from multiple inflows of widely varying qualities. ??2009 ASCE.

Nevada↗

Ground-water conditions in Salt Lake Valley, Utah, 1969-83, and predicted effects of increased withdrawals from wells

This report was prepared in cooperation with several organizations in the Salt Lake Valley and with the Central Utah Water Conservancy District to present results of a study to determine changes in the ground-water conditions in Salt Lake Valley, Utah, from 1969 to 1983, and to predict the aquifer response to projected withdrawals. The average annual recharge and discharge from the ground-water reservoir in Salt Lake Valley, Utah, during 1969-82 were estimated to be about 352,000 and 353,000 acre-feet per year. Withdrawals from wells increased from 107,000 acre-feet per year during 1964-68 to 117,000 acre-feet per year during 1969-82. The greatest increase in use was for public supply and institutions which increased from 35,000 acre-feet per year during 1964-68 to 46,700 acre-feet per year during 1969-82. From 1969 to 1983 water levels declined from 5 to 15 feet in the southeast part of the valley where pumpage from large public supply wells was greater during 1969-82 than during previous years. From February-March 1969 to February-March 1983 the quantity of ground water in storage in Salt Lake Valley increased by about 33,000 acre-feet. A digital-computer model was calibrated to simulate, in three-dimensions, the ground-water flow in the principal and shallow-unconfined aquifers in Salt Lake Valley. Simulations were made to project the response to continuing withdrawals through 2020. Alternative pumping rates used were (1) the 1982 rate of pumpage and (2) increasing the 1982 rate of pumpage by 65,000 acre-feet. The simulation at the increased rate of pumpage indicated that drawdowns would reach 40-60 feet in the area east of Sandy. About 75 percent of the increased withdrawal was salvaged from water that otherwise would have been discharged to the Jordan River and its tributaries.

Utah↗

Ground-water conditions in Salt Lake Valley, Utah, 1969-83, and predicted effects of increased withdrawals from wells

This report was prepared in cooperation with several organizations in the Salt Lake Valley and with the Central Utah Water Conservancy District to present results of a study to determine changes in the ground-water conditions in Salt Lake Valley, Utah, from 1969 to 1983, and to predict the aquifer response to projected withdrawals. The average annual recharge and discharge from the ground-water reservoir in Salt Lake Valley, Utah, during 1969-82 were estimated to be about 352,000 and 353,000 acre-feet per year. Withdrawals from wells increased from 107,000 acre-feet per year during 1964-68 to 117,000 acre-feet per year during 1969-82. The greatest increase in use was for public supply and institutions which increased from 35,000 acre-feet per year during 1964-68 to 46,700 acre-feet per year during 1969-82.

Utah↗

Transit losses and traveltimes for reservoir releases during drought conditions along the Neosho River from Council Grove Lake to Iola, east-central Kansas

Knowledge of the transit losses and water-wave traveltimes in the Neosho River for varying reservoir-release volumes and durations is necessary for proper management of water supply. Two reaches were studied along the Neosho River in east-central Kansas. The upper reach is from Council Grove Lake to John Redmond Reservoir, a distance of 83.0 river miles. The lower reach is from John Redmond Reservoir to Iola, Kansas, a distance of 56.3 river miles. Channel and aquifer characteristics were estimated from available data and used in a streamflow routing model. These estimated characteristics were verified using the model by comparing simulated reservoir releases to observed reservoir releases. The verified model then was used to simulate transit losses (or gains) and traveltimes for selected reservoir release volumes and durations from Council Grove Lake to Iola. Transit losses and traveltimes were investigated for the selected reservoir releases while under a severe drought antecedent streamflow condition (zero base flow) and a less severe drought antecedent streamflow condition (2% drought base flows). The largest total transit loss from Council Grove Lake to Iola occurred during the severe drought antecedent streamflow condition, small reservoir release rates, and long reservoir release durations. The total transit loss included water that was temporarily lost to bank storage. For a severe drought condition, transit losses ranged from 1,100 acre-ft for a release volume of 1,840 acre-ft for a duration of 50 days to 6 ,280 acre-ft for a release volume of 6,280 acre-ft for a duration of 365 days. For a less severe drought condition, transit losses ranged from 860 acre-ft to 3,234 acre-ft for the same release volumes and durations as for the severe drought condition. (Author 's abstract)

Kansas↗

Transport and accumulation of radionuclides and stable elements in a Missouri River Reservoir

Several long sediment cores from the Cheyenne River Embayment of Lake Oahe, a 250-km-long Missouri River reservoir in South Dakota, have been analyzed for radionuclides and stable elements. The combination of fine-scale sampling and rapid sedimentation produces radionuclide distributions that can be used to estimate the detailed chronology of particle transport processes in the Oahe reservoir system. A self-consistent and quantitative treatment of the 137 Cs data suggests processes to which characteristic times may be associated. Times that characterize system-wide processes include (1) an integration time of several years reflecting retention of the sediment-bound tracer in regions within or external to the reservoir, (2) a relaxation time of approximately 15 years reflecting a decreasing rate of sediment accumulation ascribed to shoreline stabilization, (3) a time of a few months characterizing the breadth of riverine signatures in cores due to integration effects in the Cheyenne River system and deltaic deposits, and (4) times of a few years associated with propagation of riverine load signatures along the embayment. The distribution of total sedimentary arsenic confirms the validity of the variable sedimentation model. In 1977, a tailings retention facility was built at the Homestake Mine site, and the unrestricted input of As ceased. As a result of this remedial action, the concentration of sedimentary As decreased dramatically. In the upper section of the core, above the depth represented by the year 1976, the concentration of As decreases tenfold. In this same core the distribution of lithologically discriminating chemical elements, calcium and vanadium, relate to major flow events in the Cheyenne River basin. Because there is minimal diagenesis of chemical constituents in these rapidly accumulating sediments, stable element signatures, in addition to radiotracers, may be used to reconstruct hydrologic events in drainage basins that contribute sediment to lakes and reservoirs.

South Dakota↗

Geomorphology of the lower Copper River, Alaska

The Copper River, located in southcentral Alaska, drains an area of more than 24,000 square miles. About 30 miles above its mouth, this large river enters Miles Lake, a proglacial lake formed by the retreat of Miles Glacier. Downstream from the outlet of Miles Lake, the Copper River flows past the face of Childs Glacier before it enters a large, broad, alluvial flood plain. The Copper River Highway traverses this flood plain and in 1996, 11 bridges were located along this section of the highway. These bridges cross parts or all of the Copper River and in recent years, some of these bridges have sustained serious damage due to the changing course of the Copper River. Although the annual mean discharge of the lower Copper River is 57,400 cubic feet per second, most of the flow occurs during the summer months from snowmelt, rainfall, and glacial melt. Approximately every six years, an outburst flood from Van Cleve Lake, a glacier-dammed lake formed by Miles Glacier, releases approximately 1 million acre-feet of water into the Copper River. At the peak outflow rate from Van Cleve Lake, the flow of the Copper River will increase an additional 140,000 and 190,000 cubic feet per second. Bedload sampling and continuous seismic reflection were used to show that Miles Lake traps virtually all the bedload being transported by the Copper River as it enters the lake from the north. The reservoir-like effect of Miles Lake results in the armoring of the channel of the Copper River downstream from Miles Lakes, past Childs Glacier, until it reaches the alluvial flood plain. At this point, bedload transport begins again. The lower Copper River transports 69 million tons per year of suspended sediment, approximately the same quantity as the Yukon River, which drains an area of more than 300,000 square miles. By correlating concurrent flows from a long-term streamflow- gaging station on the Copper River with a short-term streamflow-gaging station at the outlet of Miles Lake, long-term flow characteristics of the lower Copper River were synthesized. Historical discharge and cross-section data indicate that as late as 1970, most of the flow of the lower Copper River was through the first three bridges of the Copper River Highway as it begins to traverse the alluvial flood plain. In the mid 1980's, a percentage of the flow had shifted away from these three bridges and in 1995, only 51 percent of the flow of the Copper River passed through them. Eight different years of aerial photography of the lower Copper River were analyzed using Geographical Information System techniques. This analysis indicated that no major channel changes were caused by the 1964 earthquake. A flood in 1981 that had a recurrence interval of more than 100 years caused significant channel changes in the lower Copper River. A probability analysis of the lower Copper River indicated stable areas and the long-term locations of channels. By knowing the number of times a particular area has been occupied by water and the last year an area was occupied by water, areas of instability can be located. A Markov analysis of the lower Copper River indicated that the tendency of the flood plain is to remain in its current state. Large floods of the magnitude of the 1981 event are believed to be the cause of major changes in the lower Copper River.

Open-File Report↗

Geomorphology of the lower Copper River, Alaska

The Copper River, located in southcentral Alaska, drains an area of more than 24,000 square miles. About 30 miles above its mouth, this large river enters Miles Lake, a proglacial lake formed by the retreat of Miles Glacier. Downstream from the outlet of Miles Lake, the Copper River flows past the face of Childs Glacier before it enters a large, broad, alluvial flood plain. The Copper River Highway traverses this flood plain and in 1995, 11 bridges were located along this section of the highway. These bridges cross parts of the Copper River and in recent years, some of these bridges have sustained serious damage due to the changing course of the Copper River. Although the annual mean discharge of the lower Copper River is 57,400 cubic feet per second, most of the flow occurs during the summer months from snowmelt, rainfall, and glacial melt. Approximately every six years, an outburst flood from Van Cleve Lake, a glacier-dammed lake formed by Miles Glacier, releases approximately 1 million acre-feet of water into the Copper River. When the outflow rate from Van Cleve Lake reaches it peak, the flow of the Copper River will increase between 150,000 to 190,000 cubic feet per second. Data collected by bedload sampling and continuous seismic reflection indicated that Miles Lake traps virtually all the bedload being transported by the Copper River as it enters the lake from the north. The reservoir-like effect of Miles Lake results in the armoring of the channel of the Copper River downstream from Miles Lake, past Childs Glacier, until it reaches the alluvial flood plain. At this point, bedload transport begins again. The lower Copper River transports 69 million tons per year of suspended sediment, approximately the same quantity as the Yukon River, which drains an area of more than 300,000 square miles. By correlating concurrent flows from a long-term streamflow-gaging station on the Copper River with a short-term streamflow-gaging station at the outlet of Miles Lake, long-term flow characteristics of the lower Copper River were synthesized. Historical discharge and cross-section data indicate that as late as 1970, most of the flow of the lower Copper River was through the first three bridges of the Copper River Highway as it begins to traverse the alluvial flood plain. In the mid 1980's, a percentage of the flow had shifted away from these three bridges and in 1995, only 51 percent of the flow of the Copper River passed through them. Eight different years of aerial photography of the lower Copper River were analyzed using Geographical Information System techniques. This analysis indicated that no major channel changes were caused by the 1964 earthquake. However, a flood in 1981 that had a recurrence interval of more than 100 years caused significant channel changes in the lower Copper River. A probability analysis of the lower Copper River indicated stable areas and the long-term locations of channels. By knowing the number of times a particular area has been occupied by water and the last year an area was occupied by water, areas of instability can be located. A Markov analysis of the lower Copper River indicated that the tendency of the flood plain is to remain in its current state. Large floods of the magnitude of the 1981 event are believed to be the cause of major changes in the lower Copper River.

Professional Paper↗

Estimation of Monthly Evaporation from Lake Ashtabula in North Dakota, Orwell Lake in Minnesota, and Lake Traverse in Minnesota and South Dakota, 1931-2001

Reservoirs on tributaries of the Red River of the North provide water for Fargo and Grand Forks, N. Dak., and other cities along the river. Adequate estimates of evaporative losses from the reservoirs are needed to determine the total water supply in the Basin. Many equations could be used to estimate lake or reservoir evaporation. However, in addition to measurements of air temperature, the equations require measurements of net radiation, wind speed, and relative humidity. Evaporation and air temperature data from energy budget evaporation sites at Wetland P1 in North Dakota and at Williams Lake in Minnesota are available. Air temperature data collected from climate stations near Lake Ashtabula in North Dakota, from Orwell Lake in Minnesota, and from Lake Traverse in Minnesota and South Dakota also are available. Therefore, the combined data sets were used to estimate monthly evaporation from Lake Ashtabula, Orwell Lake, and Lake Traverse. Averaged monthly mean air temperatures determined for each reservoir study site were used to calculate monthly evaporation data sets for 1931-2001. Results from the procedure that estimates reservoir evaporation indicate that slight downward trends in annual evaporation occurred from 1931-2001. The trends may have been caused by the selected time period of the study, which began with the drought conditions in the mid 1930's and ended with the more wet conditions in the late 1990's. Average annual evaporation values for each reservoir for 1931-2001 correspond well with published average annual lake evaporation values for 1946-55.

Water-Resources Investigations Report↗

Effects of coal mining on the water quality and sedimentation of Lake Tuscaloosa and selected tributaries, North River basin, Alabama

Lake Tuscaloosa, a reservoir on North River, is the primary source of water supply for the city of Tuscaloosa, Alabama, and surrounding areas. Between October 1982 and September 1983, 14 sites in the North River basin were sampled to determine if surface coal mining has impacted the quality of water in the lake and selected tributaries. Water draining mined basins showed increases in specific conductance, sulfate concentrations , and dissolved and total recoverable iron and manganese concentrations after mining started in 1975. Although water in the reservoir has become more mineralized with only an estimated 5 percent of the basin mined, total dissolved solids concentrations are still very low, ranging from 28 to 35 milligrams per liter at the dam. The quality of water at most sites was, except for pH, iron, and manganese, within secondary drinking water standards. The pH of water from streams draining either mined or unmined basins was generally less than 6.5. Sedimentation has occurred at most measured lake cross sections since impoundment. However, natural factors such as steep overland and channel slopes, may cause more sedimentation in the lake from unmined basins than from coal mining in a different basin. (USGS)

Water-Resources Investigations Report↗