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Evaluation of two juvenile salmon collection devices at Cowlitz Falls Dam, Washington, 2014

Collection of juvenile salmon at Cowlitz Falls Dam is a critical part of the effort to restore salmon in the upper Cowlitz River, Washington. Many of the fish that are not collected pass downstream and enter Riffe Lake, become landlocked, and are lost to the anadromous population. In addition to this loss, the juvenile fish collection system at Cowlitz Falls Dam, which originally consisted of four collection flumes, has failed to achieve annual collection goals since it began operating in 1996. In the years since, the collection flumes have been modified and prototype collection devices have been developed and tested, but these efforts have not substantially increased juvenile fish collection. Studies have shown that juvenile steelhead ( Oncorhynchus mykiss ), coho salmon ( Oncorhynchus kisutch ), and Chinook salmon ( Oncorhynchus tshawytscha ) tend to come close to the entrances of the collection system, but many of these fish fail to enter and eventually pass the dam through turbines or spillways. Tacoma Power developed a prototype weir box in 2009 to increase capture rates of juvenile salmon at the collection entrances. The device was evaluated with radio-tagged coho salmon (318 fish) and Chinook salmon (317 fish), and was found to have a high retention rate; 93 percent of the coho salmon, and 91 percent of the Chinook salmon that entered the device were retained and collected. However, because of safety concerns at the dam, the weir box could not be deployed near a spillway gate where the prototype was tested, so the device was altered and re-deployed at a different location where it was evaluated during 2013. During that year, discovery efficiency (number of fish detected at the entrance divided by the number of fish detected in the forebay) was 98 percent for tagged steelhead and 83 percent for tagged coho salmon. However, none of the steelhead and only 5 percent of the coho salmon entered and were collected through the weir box. These results indicated that the device was not a promising collection alternative during spring months when steelhead and coho salmon are passing the dam. However, collection conditions change during summer months when juvenile Chinook salmon are passing, so the device also was evaluated during summer 2014. In an attempt to improve overall collection efficiency, Tacoma Power developed and tested a new device in 2014, called the Upper Riffe Lake Collector (URLC). The URLC was a floating device designed to collect fish as they moved downstream after passing through turbines at Cowlitz Falls Dam. The design of the URLC included a pontoon barge that supported a large net structure designed to funnel fish into a live box where they could be removed and transported downstream of dams on the Cowlitz River.

Washington

Assessing controls on perched saturated zones beneath the Idaho Nuclear Technology and Engineering Center, Idaho

Waste byproducts associated with operations at the Idaho Nuclear Technology and Engineering Center (INTEC) have the potential to contaminate the eastern Snake River Plain (ESRP) aquifer. Recharge to the ESRP aquifer is controlled largely by the alternating stratigraphy of fractured volcanic rocks and sedimentary interbeds within the overlying vadose zone and by the availability of water at the surface. Beneath the INTEC facilities, localized zones of saturation perched on the sedimentary interbeds are of particular concern because they may facilitate accelerated transport of contaminants. The sources and timing of natural and anthropogenic recharge to the perched zones are poorly understood. Simple approaches for quantitative characterization of this complex, variably saturated flow system are needed to assess potential scenarios for contaminant transport under alternative remediation strategies. During 2009-2011, the U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, employed data analysis and numerical simulations with a recently developed model of preferential flow to evaluate the sources and quantity of recharge to the perched zones. Piezometer, tensiometer, temperature, precipitation, and stream-discharge data were analyzed, with particular focus on the possibility of contributions to the perched zones from snowmelt and flow in the neighboring Big Lost River (BLR). Analysis of the timing and magnitude of subsurface dynamics indicate that streamflow provides local recharge to the shallow, intermediate, and deep perched saturated zones within 150 m of the BLR; at greater distances from the BLR the influence of streamflow on recharge is unclear. Perched water-level dynamics in most wells analyzed are consistent with findings from previous geochemical analyses, which suggest that a combination of annual snowmelt and anthropogenic sources (for example, leaky pipes and drainage ditches) contribute to recharge of shallow and intermediate perched zones throughout much of INTEC. The source-responsive fluxes model was parameterized to simulate recharge via preferential flow associated with intermittent episodes of streamflow in the BLR. The simulations correspond reasonably well to the observed hydrologic response within the shallow perched zone. Good model performance indicates that source-responsive flow through a limited number of connected fractures contributes substantially to the perched-zone dynamics. The agreement between simulated and observed perched-zone dynamics suggest that the source-responsive fluxes model can provide a valuable tool for quantifying rapid preferential flow processes that may result from different land management scenarios.

Scientific Investigations Report

Geology and hydrology of radioactive solid-waste burial grounds at the Hanford Reservation, Washington

The geology and hydrology of radioactive solid waste burial grounds at the Hanford Reservation were investigated, using existing data, by the U.S. Geological Survey as part of the waste management plan of the Richland Operations Office of the Energy Research and Development Administration. The purpose of the investigation was to assist the operations office in characterizing the burial sites as to present environmental safety and as to their suitability for long-term storage (several thousand to tens of thousands of years) of radioactive sol id wastes. The burial ground sites fall into two classifications: (1) those on the low stream terraces adjacent to the Columbia River, mainly in the 100 Areas and 300 Area, and (2) those lying on the high terraces south of Gable Mountain in the 200 Areas. Evaluation of the suitability of the burial grounds for long-term storage was made almost entirely on hydrologic, geologic, and topographic criteria. Of greatest concern was the possibility that radionuclides might be leached from the buried wastes by infiltrating water and carried downward to the water table. The climate is semi-arid and the average annual precipitation is 6.4 inches at the Hanford Meteorological Station. However, the precipitation is seasonally distributed with about 50 percent occurring during the months of November, December, January, and February when evapotranspiration is negligible and conditions for infiltration are most favorable. None of the burial grounds are instrumented with monitoring devices that could be used to determine if radionuclides derived from them are reaching the water table. Burial grounds on the low stream terraces are mainly underlain by permeable materials and the water table lies at relatively shallow depths. Radionuclides conceivably could be leached from these burial grounds by percolating soil water, and radionuclides might reach the Columbia River in a relatively short time. These sites could also be inundated by erosion during a catastrophic flood. For these reasons, they are judged to be unsuited for long-term storage. Local conditions at several of these burial grounds are particularly unfavorable from the standpoint of safety. Depressions and swales at some burial grounds, such as numbers 4 and 5 in the 300 Area in which runoff can collect, enhance the possibility of water infiltrating through the buried wastes and transporting radionuclides to the water table. Also, during a high stage of the Columbia River, the water table conceivably could rise into burial grounds l and 2 of the 100 F Area. Most of the burial grounds on the low terraces contain either (1) reactor components and related equipment bearing activation products, principally cobalt-60, or (2) less hazardous radioactive materials such as uranium. The inventory of activation products in these burial grounds will decay to a safe level in a relatively short period of time (about 100 years), according to estimates made by C. D. Corbit, Douglas United Nuclear, Inc., 1969. The inventory of radionuclides is not considered by the ERDA staff to be complete, however. At these burial grounds containing activation products or less hazardous materials, investigations should be made of the radioactivity in soil and ground water beneath selected representative sites to verify that radionuclides are not migrating from the burial grounds. If migration is detected, field investigations should be made to determine the source or sources of the radionuclides and the desirability of removing the source wastes. Other burial grounds on the low terraces contain plutonium and fission products, which require long-term storage. Both the 300 WYE and the 300 North burial grounds are reported to contain plutonium in large quantities. Burial ground no. l in the 300 Area reportedly also contains plutonium. The inventory records of any other burial grounds on the low terraces suspected of containing plutonium should be reviewed to determine if pl

Open-File Report

Geohydrology and simulation of ground-water flow in the carbonate rocks of the Valley Creek basin, eastern Chester County, Pennsylvania

Sixty-eight percent of the 22.6-square-mile Valley Creek basin is underlain by Cambrian and Ordovician limestone and dolomite. Ground water flows through a network of interconnected secondary openings; primary porosity is virtually nonexistent. Some of these openings have been enlarged by solution. Secondary porosity and permeability exhibit great spatial variability, and the yield and specific capacity of wells are highly variable. The number of water-bearing zones decreases with depth. Fifty percent of water-bearing zones are encountered within 100 feet of the land surface, and 81 percent are within 200 feet. Most ground-water flow in the Valley Creek basin is local and discharges to nearby streams. Ground-water discharge comprised an average of 76 percent of the flow of Valley Creek during 1983--87, including both natural ground- water discharge and quarry pumpage discharged to Valley Creek. Discharge from the Cedar Hollow quarry comprised 21 to 26 percent of the base flow of Valley Creek; the average was 23 percent. The average natural base flow of Valley Creek would be 8 percent lower if the quarry were not operating. Regional ground-water flow is to the northeast to the Schuylkill River. On the western side of the Valley Creek basin, the ground-water divide is 1/2 mile west of the surface-water divide. An estimated 0.75 million gallons per day of ground water flows from the adjacent West Valley Creek basn eastward into the Valley Creek basin. A ground-water divide is not present on the eastern side of the basin; the water table slopes gently eastward toward the Schuylkill River. On the northeaster side, an estimated 1.76 million gallons per day of ground water flows northeastward out of the basin to the Schuylkill River beneath the surface-water divide. On the southeaster side, an estimated 0.85 million gallons per day of ground water flows beneath the surface-water divide into the basin. Annual water budgets and an average water budget were calculated for 1983-87 for the 20.8-square-mile area bove the streamflow-gaging station. Annual precipitation for 1983-87 ranged from 40.61 to 56.55 inches and averaged 47.25 inches; annual streamflow ranged from 15.55 to 28.57 inches and averaged 22.31 inches; annual evapotranspiration ranged from 18.21 to 24.83 inches and averaged 22.90 inches; and annual recharge ranged from 15.89 to 26.84 inches and averaged 21.04 inches. The Valley Creek basin was modeled as a two-dimensional water-table aquifer. Recharge to, ground-water flow through, and discharge from the rocks of Chester valley were simulated. In order to include the natural hydrologic boundaries of the ground-water-flwo system, the 66.4-square-mile area between the Brandywine Creek and the Schuylkill River was modeled. The model was calibrated under stead-state conditions using avareage recharge and evapotranspiration rates. Aquifer hydraulic conductivity was estimated from specific-capacity and quifer-test data. The average (1983-87) annual water budget for hte Valley Creek basin was simualted. The effect of increased ground-water development on base flow and underflow was simulated by locating a hypothetical well field produceing 4 million gallons per day in different parts of the basin. Pumpage from a well field near surface-water divides would induce as much as an additional 1.41 inches per year of underflow from an adjacent surface-water basin. Pumpage from a well field near the center of the basin would affect base flow more than underflow. Increased seepage of ground water into quarries as a result of their expansion was simulated as increased withdrawal by pumping. A 100-percent increase in the pumping rate of the Cedar Hollow quarry, from 3.93 to 7.86 million gallons per day, owuld reduce the natural base flow of Valley Creek by 18 percent. However, the quarry pumpage would be discharged to Valley Creek, thereby increasing the base flow at the gaging station by

Pennsylvania

Quality-assurance results for routine water analyses in U.S. Geological Survey laboratories, water year 1998

The U.S. Geological Survey operates a quality-assurance program based on the analyses of reference samples for two laboratories: the National Water Quality Laboratory and the Quality of Water Service Unit. Reference samples that contain selected inorganic, nutrient, and low-level constituents are prepared and submitted to the laboratory as disguised routine samples. The program goal is to estimate precision and bias for as many analytical methods offered by the participating laboratories as possible. Blind reference samples typically are submitted at a rate of 2 to 5 percent of the annual environmental-sample load for each constituent. The samples are distributed to the laboratories throughout the year. The reference samples are subject to the identical laboratory handling, processing, and analytical procedures as those applied to environmental samples and, therefore, have been used as an independent source to verify bias and precision of laboratory analytical methods and ambient water-quality measurements. The results are stored permanently in the National Water Information System and the Blind Sample Project's data base. During water year 1998, 95 analytical procedures were evaluated at the National Water Quality Laboratory and 63 analytical procedures were evaluated at the Quality of Water Service Unit. An overall evaluation of the inorganic and low-level constituent data for water year 1998 indicated 77 of 78 analytical procedures at the National Water Quality Laboratory met the criteria for precision. Silver (dissolved, inductively coupled plasma-mass spectrometry) was determined to be imprecise. Five of 78 analytical procedures showed bias throughout the range of reference samples: chromium (dissolved, inductively coupled plasma-atomic emission spectrometry), dissolved solids (dissolved, gravimetric), lithium (dissolved, inductively coupled plasma-atomic emission spectrometry), silver (dissolved, inductively coupled plasma-mass spectrometry), and zinc (dissolved, inductively coupled plasma-mass spectrometry). At the National Water Quality Laboratory during water year 1998, lack of precision was indicated for 2 of 17 nutrient procedures: ammonia as nitrogen (dissolved, colorimetric) and orthophosphate as phosphorus (dissolved, colorimetric). Bias was indicated throughout the reference sample range for ammonia as nitrogen (dissolved, colorimetric, low level) and nitrate plus nitrite as nitrogen (dissolved, colorimetric, low level). All analytical procedures tested at the Quality of Water Service Unit during water year 1998 met the criteria for precision. One of the 63 analytical procedures indicated a bias throughout the range of reference samples: aluminum (whole-water recoverable, inductively coupled plasma-atomic emission spectrometry, trace).

Water-Resources Investigations Report

Simulation of Hydrologic-System Responses to Ground-Water Withdrawals in the Hunt-Annaquatucket-Pettaquamscutt Stream-Aquifer System, Rhode Island

A numerical-modeling study was done to better understand hydrologic-system responses to ground-water withdrawals in the Hunt-Annaquatucket-Pettaquamscutt (HAP) stream-aquifer system of Rhode Island. System responses were determined by use of steady-state and transient numerical ground-water-flow models. These models were initially developed in the late 1990s as part of a larger study of the stream-aquifer system. The models were modified to incorporate new data made available since the original study and to meet the objectives of this study. Changes made to the models did not result in substantial changes to simulated ground-water levels, hydrologic budgets, or streamflows compared to those calculated by the original steady-state and transient models. Responses of the hydrologic system are described primarily by changes in simulated streamflows and ground-water levels throughout the basin and by changes to flow conditions in the aquifer in three wetland areas immediately east of the Lafayette State Fish Hatchery, which lies within the Annaquatucket River Basin in the town of North Kingstown. Ground water is withdrawn from the HAP aquifer at 14 large-capacity production wells, at an industrial well, and at 3 wells operated by the Rhode Island Department of Environmental Management at the fish hatchery. A fourth well has been proposed for the hatchery and an additional production well is under development by the town of North Kingstown. The primary streams of interest in the study area are the Hunt, Annaquatucket, and Pettaquamscutt Rivers and Queens Fort Brook. Total model-calculated streamflow depletions in these rivers and brook resulting from withdrawals at the production, industrial, and fish-hatchery wells pumping at average annual 2003 rates are about 4.8 cubic feet per second (ft3/s) for the Hunt River, 3.3 ft3/s for the Annaquatucket River, 0.5 ft3/s for the Pettaquamscutt River, and 0.5 ft3/s for Queens Fort Brook. The actual amount of streamflow reduction in the Annaquatucket River caused by pumping actually is less, 1.1 ft3/s, because ground water that is pumped at the fish-hatchery wells (2.2 ft3/s) is returned to the Annaquatucket River after use at the hatchery. One of the primary goals of the study was to evaluate the response of the hydrologic system to simulated withdrawals at the proposed well at the fish hatchery. Withdrawal rates at the proposed well would range from zero during April through September of each year to a maximum of 260 gallons per minute [about 0.4 million gallons per day (Mgal/d)] in March of each year. The average annual withdrawal rate at the fish hatchery resulting from the addition of the proposed well would increase by only 0.13 ft3/s, or about 5 percent of the 2003 withdrawal rate. The increased pumping rate at the hatchery would further reduce the average annual flow in Queens Fort Brook by less than 0.05 ft3/s and in the Annaquatucket River by about 0.1 ft3/s (which includes some model error). A new production well in the Annaquatucket River Basin is under development by the town of North Kingstown. A simulated pumping rate of 1.0 Mgal/d (1.6 ft3/s) at this new well resulted in additional streamflow depletions, compared to those calculated for the 2003 withdrawal conditions, of 0.8 and 0.2 ft3/s in the Annaquatucket and Pettaquamscutt Rivers, respectively. The source of water for about 30 percent of the well's pumping rate, or about 0.5 ft3/s, is derived from ground-water inflow from the Chipuxet River Basin across a natural ground-water drainage divide that separates the Annaquatucket and Chipuxet River Basins; the remaining 0.1 ft3/s of simulated pumping consists of reduced evapotranspiration from the water table. Model-calculated changes in water levels in the aquifer for the various withdrawal conditions simulated in this study indicate that ground-water-level declines caused by pumping are generally less than 5 feet (ft). However, ground-water-level declines of as

Open-File Report

Evaluation of Streamflow Losses Along the Gunnison River from Whitewater Downstream to the Redlands Canal Diversion Dam, near Grand Junction, Colorado, Water Years 1995-2003

In 2003, the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, Upper Colorado River Endangered Fish Recovery Program, Colorado River Water Conservation District, Colorado Division of Water Resources, and Bureau of Reclamation, initiated a study to characterize streamflow losses along a reach of the Gunnison River from the town of Whitewater downstream to the Redlands Canal diversion dam. This describes the methods and results of the study that include: (1) a detailed mass-balance analysis of historical discharge records that were available for the three streamflow-gaging stations along the study reach; and (2) two sets of discharge measurements that were made at the three stations and at four additional locations. Data for these existing streamflow-gaging stations were compiled and analyzed: (1) Gunnison River near Grand Junction (Whitewater station); (2) Gunnison River below Redlands Canal diversion dam (below-Redlands-dam station); and (3) Redlands Canal near Grand Junction (Redlands-Canal station). Data for water years 1995-2003 were used for the mass-balance analysis. Four intermediate sites (M1, M2, M3, and M4) were selected for discharge measurements in addition to the existing stations. The study reach is the approximate 12-mile reach of the Gunnison River from the Whitewater station downstream to the Redlands Canal diversion dam, which is about 3 miles upstream from the confluence with the Colorado River. For the mass-balance analysis, differences between the sum of the annual cumulative daily mean discharge at the two downstream stations and the annual cumulative daily mean discharges at the upstream station ranged from about -8,700 to -69,800 acre-feet (about -.8 to -1.1 percent), indicating that the downstream discharges generally were less than the upstream discharges. Moving 3-day daily mean discharge averages also were computed for each of the three stations to smooth out some of the abrupt differences between the downstream and upstream daily mean discharges. During water years 1995-2002, differences between the downstream and upstream moving 3-day daily mean discharges ranged from about -200 to +100 cubic feet per second (ft3/s) during one-half of each year, but the differences had absolute values as large as about 500 to 1,000 ft3/s during the other one-half of the year. The differences as a percentage of the upstream discharge ranged from 0 to -10 percent within the interquartile range and were as small or large as about -60 to +50. Two sets of discharge measurements were obtained during water year 2003. For measurement set 1 (February 5-6), discharge was measured 5-8 times over a 24-hour period at sites M1-M4, where measured discharges ranged from 527 to 608 ft3/s. Discharge was measured once each day at the Whitewater and below-Redlands-dam stations to verify discharge rating shifts; the Redlands Canal was not in operation at this time, so measurements were not needed at the Redlands-Canal station. Recorded 15-minute (unit) discharges ranged from about 575 to 615 ft3/s at the Whitewater station and from about 560 to 600 ft3/s at the below-Redlands-dam station during the February 5-6 period. Because of the inherent error in discharge measurements (5 percent for measurements rated good), and because the mean discharge at the below-Redlands-dam station, about 580 ft3/s, was only about 2.5 percent smaller than the mean discharge at the Whitewater station, about 595 ft3/s, it is concluded that there was no measurable streamflow loss along the study reach during measurement set 1. For measurement set 2 (May 14-15), discharge in the Gunnison River was about 2,000 ft3/s and increasing because of high-elevation snowmelt. Five discharge measurements were made at site M2 and discharge ranged from 1,668 to 2,117 ft3/s. Measured discharges at the gaging stations were 2,730 ft3/s at the Whitewater station, 1,268 ft3/s at the below-Redlands-dam station, and 819 ft3/s at the

Scientific Investigations Report

Historical land-use changes and potential effects on stream disturbance in the Ozark Plateaus, Missouri

Land-use changes have been blamed for creating disturbance in the morphology of streams in the Ozark Plateaus, Missouri (hereafter referred to as the "Ozarks"). Historical evidence and stratigraphic observations document that streams have been aggraded by substantial quantities of gravel beginning sometime at or near the time of European settlement of the Ozarks. Before European settlement, streams were depositing a mixed sediment load of gravel bedload and silty overbank sediment. Observations of early explorers conspicuously lack descriptions of extensive gravel bars; observations of geologists working during the middle to late 1800's before significant landuse disturbance, however, include descriptions of large quantities of gravel in stream banks and beds. The first change in land cover as settlement progressed from the early 1800's to approximately 1880 was replacement of valley-bottom forest with cultivated fields and pastures. At the same time, suppression of wildfires in the uplands caused an increase of woodland with woody understory at the expense of grassland and oak savannah. Valley-bottom clearing probably initiated some direct disturbance of stream channels, but fire suppression would have decreased runoff and sediment yield from uplands. Beginning sometime from 1870 to 1880 and continuing until 1920, commercial timber companies began large operations in the Ozarks to harvest shortleaf pine for sawlogs and oak for railroad ties. Selective cutting of large timber, use of livestock for skidding logs from the forest, and avoidance of the steeper slopes minimized the effect of this phase of logging on runoff and sediment supply of uplands and valley-side slopes. Continued decreases in the erosional resistance of valley bottoms through clearing and road building and the incidence of extreme regional floods from 1895 to 1915 probably caused initiation of moderate stream disturbance. This hypothesis is supported by historical and oral-historical observations that stream instability began before the peak of upland destabilization from 1920 to 1960. The post-Timber-boom period (1920-60) included the institution of annual burning of uplands and cut-over valley-side slopes, increased grazing on open range, and increased use of marginal land for cultivated crops. Models for landuse controls on annual runoff, storm runoff, and soil erosion indicate that this period should have been the most effective in creating stream disturbance. Written historical sources and oral-historical accounts indicate that erosion was notable mainly on lands in row-crop cultivation. Oral-history respondents consistently recall that smaller streams had more discharge for longer periods from 1920 to 1960 than from 1960 to 1993; many additionally observed that floods are "flashier" under present-day (1993) conditions. Changes in the timing of hydrographs probably relate to changes in upland and riparian zone vegetation that decreased storage and flow resistance. Probably the most destabilizing effect on Ozarks stream channels during this period was caused by livestock on the open range that concentrated in valley bottoms and destroyed riparian vegetation in the channels and on banks. Destruction of riparian vegetation in small valleys may have encouraged headward migration of channels, resulting in extension of the drainage network and accelerated release of gravel from storage in the small valleys. This hypothesis is supported by lack of other sources for the large quantity of gravel in Ozarks streams and oral-historical observations that gravel came out of the runs, rather than from slopes. From 1960 to 1993, cultivated fields and total improved land in farms decreased, but cattle populations continued to increase. This increase in grazing density has the potential to maintain runoff and sediment delivery to streams at rates higher than natural background rates. Whereas some riparian zones have been allowed to grow up into bottom-land forest, this stabilizing effect occurs on only a small part of valley-bottom land. Recovery processes aided by riparian vegetation are limited by channel instability and frequent, large floods.

Water Supply Paper

Controls on sediment transport and storage in the Little Snake, Yampa, and Green Rivers in the vicinities of Dinosaur National Monument and Ouray National Wildlife Refuge, Colorado and Utah, with implications for fish habitat in the middle Green River

The transport of sand and finer sediment in the Yampa and Green river network is typically in disequilibrium with the local sediment supply because of the partial decoupling of the sources of water and sediment: most of the water is supplied farther upstream than most of the sediment. This decoupling leads to sand being transported in the main-stem rivers as elongating sand waves following sand resupply during tributary floods. Because of the large amount of sand supplied to the Yampa River by the Little Snake River, Yampa River annual floods generate sand waves that migrate downstream in the Green River causing longitudinal patterns in bed-sand grain size that, in turn, lead to large spatial changes in sand transport. These changes in bed-sand grain size dominate over changes in water discharge in regulating sand transport in the sand-bedded reaches of these rivers. Furthermore, at any given discharge, these changes in bed-sand grain size dominate over all other processes in regulating sand transport in both sand- and gravel-bedded reaches of these rivers. Consequently, erosion or deposition of sand, and the associated changes in fish habitat in the Uinta Basin segment of the Green River are only indirectly related to Green River discharge and Flaming Gorge Dam operations. Owing to the longitudinal patterns of bed-sand grain size associated with the downstream migration of sand waves generated by the Yampa River, a multi-year sequence of large, and likely slightly declining, annual floods on the Yampa River is the probable mechanism that increases backwater fish habitat in the Uinta Basin segment of the Green River. Cross-section resurveys indicate that the Uinta Basin (Jensen to Ouray) segment of the Green River has undergone sand erosion caused by slight channel widening since the 1990s (a channel response in opposition to that observed farther downstream in Canyonlands National Park during this period). These resurveys indicate that sand deposition leads to a decrease in channel complexity whereas sand erosion generally leads to an increase in channel complexity. The backwaters used as native fish nursery habitat consist of deep pools downstream from and adjacent to large bank-attached sandbars; thus, more extensive backwater habitat equates to greater channel complexity. The generation of the sand wave during the first large Yampa River flood in a sequence (that is, the year-1 flood) causes fining of the bed sand near Jensen. The downstream coarsening associated with bed sand that is finer near Jensen than downstream near Ouray causes a downstream decrease in sand transport in the Uinta Basin segment, leading to net sand deposition and decreased channel complexity. Continued downstream migration of this sand wave during the following year’s annual flood (that is, the year-2 flood) then causes downstream fining, leading to erosion of sand and increased channel complexity in this segment. Although the year-1 Yampa River flood supplies the sand and deposits the large sandbars required to form backwaters, and thereby makes possible future backwater habitat, these floods cause a temporary reduction in backwater habitat in the Uinta Basin segment because they tend to cause net sand deposition. It is the subsequent out-year Yampa River floods of likely equal or lesser magnitude that maintain or increase backwater habitat because these are the floods that convey sand through or erode sand from this segment. These typically smaller out-year Yampa River floods rework the sandbars deposited during the year-1 annual flood, thereby leading to the increases in both backwater area and volume that have been measured upon recession of these floods. Although artificial floods released from Flaming Gorge Dam might be used to simulate the habitat maintenance achieved by out-year Yampa River floods, the limited sand supply and stage associated with such dam releases precludes their use as a replacement for the sandbar-depositing role of year-1 Yampa River floods that is a prerequisite for backwater formation in the Uinta Basin segment of the Green River.

Colorado, Utah

Historical land-use changes and potential effects on stream disturbance in the Ozark Plateaus, Missouri

Land-use changes have been blamed for creating disturbance in the morphology of streams in the Ozark Plateaus, Missouri (hereafter referred to as the Ozarks). Historical evidence and stratigraphic observations document that streams have been aggraded by substantial quantities of gravel beginning sometime at or near the time of European settlement of the Ozarks. Before European settlement, streams were depositing a mixed sediment load of gravel bedload and silty over-bank sediment. Observations of early explorers conspicuously lack descriptions of extensive gravel bars; observations of geologists working during the middle to late 1800's before significant land-use disturbance, however, include descriptions of large quantities of gravel in stream banks and beds. The first change in land cover as settlement progressed from the early 1800's to approximately 1880 was replacement of valley-bottom forest with cultivated fields and pastures. At the same time, suppression of wildfires in the uplands caused an increase of woodland with woody understory at the expense of grassland and oak savannah. Valley-bottom clearing probably initiated some direct disturbance of stream channels, but fire suppression would have decreased runoff and sediment yield from uplands. Beginning sometime during 1870 to 1880 and continuing until 1920, commercial timber companies began large operations in the Ozarks harvesting shortleaf pine for sawlogs and oak for railroad ties. Selective cutting of large timber, use of livestock for skidding logs from the forest, and avoidance of the steeper slopes minimized the effect of this phase of logging on runoff and sediment supply of uplands and valley-side slopes. Continued decreases in the erosional resistance of valley bottoms through clearing and road building, and the incidence of extreme regional floods from 1895 to 1915, probably caused initiation of moderate stream disturbance. This hypothesis is supported by historical and oral-historical observations that stream instability began before the peak of upland destabilization from 1920 to 1960. The post-Timber-boom period (1920 to 1960) included the institution of annual burning of uplands and cut-over valley-side slopes, increased grazing on open range, and increased use of marginal land for cultivated crops. Models for land-use controls on annual runoff, storm runoff, and soil erosion indicate this period should have been the most effective in creating stream disturbance. Written historical sources and oral-historical accounts indicate that erosion was notable mainly on lands in row-crop cultivation. Oral-history respondents consistently recall that smaller streams had more discharge for longer periods during 1920 to 1960 than during 1960 to 1993; many additionally observed that floods are "flashier" under present-day (1993) conditions. Changes in the timing of hydrographs probably relate to changes in upland and riparian zone vegetation that decreased storage and flow resistance. Probably the most destabilizing effect on Ozarks stream channels during this period was caused by livestock on the open range that concentrated in valley bottoms and destroyed riparian vegetation in the channels and on banks. Destruction of riparian vegetation in small valleys may have encouraged headward migration of channels, resulting in extension of the drainage network and accelerated release of gravel from storage in the small valleys. This hypothesis is supported by lack of other sources for the large quantity of gravel in Ozarks streams and oral-historical observations that gravel came out of the runs, rather than from slopes. From 1960 to 1993, cultivated fields and total improved land in farms decreased, but cattle populations continued to increase. This increase in grazing density has the potential to maintain runoff and sediment delivery to streams at rates higher than natural background rates. Whereas some riparian zones have been allowed to grow up into bottom-land forest, this stabilizing effect occurs on only a small part of valley-bottom land. Recovery processes aided by riparian vegetation are limited by channel instability and frequent, large floods.

Missouri

Environmental Setting of the Sugar Creek and Leary Weber Ditch Basins, Indiana, 2002-04

The Leary Weber Ditch Basin is nested within the Sugar Creek Basin in central Indiana. These basins make up one of the five study sites in the Nation selected for the Agricultural Chemicals: Sources, Transport, and Fate topical study, a part of the U.S. Geological Survey’s National Water-Quality Assessment Program. In this topical study, identifying the natural factors and human influences affecting water quality in the Leary Weber Ditch and Sugar Creek Basins are the focus of the assessment. A detailed comparison between the environmental settings of these basins is presented. Specifics of the topical study design as implemented in the Leary Weber Ditch and Sugar Creek Basins are described. The Leary Weber Ditch and Sugar Creek Basins have moderate temperatures with well-defined winter and summer seasons. The mean annual precipitation is 39.5 inches, with the majority of rainfall in spring and early summer and the lowest amount of precipitation in winter. Yearly, an average of 25 inches of moisture moves into the atmosphere as a result of evapotranspiration. Physiographically, both basins are contained completely within the New Castle Till Plains and Drainageways. The gradients of the valleys of Leary Weber Ditch and Sugar Creek differ substantially. Most of the Sugar Creek Basin and the entire Leary Weber Ditch Basin overlie a combination of Devonian limestone and dolomite bedrock. Unconsolidated materials (sand and gravel) overlie much of the bedrock in the basins. Soils are either loam or silt loam, generally deep, poorly drained, medium textured, and nearly level. The potential for surface erosion is negligible because runoff is slow. Available water capacity is high. Natural fertility and organic matter are moderate. Soils are naturally suited to row crops. Agriculture is the principal land use in the Leary Weber Ditch and Sugar Creek Basins. Respectively, 87 percent and 75 percent of the total land area in these basins are used for row crops. The cropped areas within the basins are divided nearly equally between corn and soybeans. Farming practices in the area employ a wide range of tools to promote growth and inhibit vegetative competition; these include the use of fertilizers, herbicides, and pesticides. Tile drains are used extensively to improve yields and make the soils farmable. Irrigation and manure application in the study area are minimal. Most of the study area is in Hancock County, Indiana. The county population is approximately 61,000. There are no large cities in either basin; most residents live in small communities or rural areas. Water use in Hancock County totalled 6.37 million gallons per day during 2002. Drinking water comes entirely from ground water. The U.S. Geological Survey operates streamflow-gaging stations at Sugar Creek at New Palestine and at Leary Weber Ditch at Mohawk within the study area. Mean daily streamflow for Sugar Creek is higher than streamflow at Leary Weber Ditch. Through most of its length, Sugar Creek is a gaining stream and base flow is supported by ground-water sources. At Leary Weber Ditch, there is little to no streamflow when tile drains are dry. Modifications to the natural hydrology of the study area include a large system of tile drains, the intersection of Sugar Creek by several major roads, and outflows from nearby wastewater-treatment plants. Leary Weber Ditch is affected only by tile drains.

Indiana

Simulation of ground-water flow in the Mojave River basin, California

The proximity of the Mojave River ground-water basin to the highly urbanized Los Angeles region has led to rapid growth in population and, consequently, to an increase in the demand for water. The Mojave River, the primary source of surface water for the region, normally is dry-except for a small stretch of perennial flow and periods of flow after intense storms. Thus, the region relies almost entirely on ground water to meet its agricultural and municipal needs. Ground-water withdrawal since the late 1800's has resulted in discharge, primarily from pumping wells, that exceeds natural recharge. To better understand the relation between the regional and the floodplain aquifer systems and to develop a management tool that could be used to estimate the effects that future stresses may have on the ground-water system, a numerical ground-water flow model of the Mojave River ground-water basin was developed, in part, on the basis of a previously developed analog model. The ground-water flow model has two horizontal layers; the top layer (layer 1) corresponds to the floodplain aquifer and the bottom layer (layer 2) corresponds to the regional aquifer. There are 161 rows and 200 columns with a horizontal grid spacing of 2,000 by 2,000 feet. Two stress periods (wet and dry) per year are used where the duration of each stress period is a function of the occurrence, quantity of discharge, and length of stormflow from the headwaters each year. A steady-state model provided initial conditions for the transient-state simulation. The model was calibrated to transient-state conditions (1931-94) using a trial-and-error approach. The transient-state simulation results are in good agreement with measured data. Under transient-state conditions, the simulated floodplain aquifer and regional aquifer hydrographs matched the general trends observed for the measured water levels. The simulated streamflow hydrographs matched wet stress period average flow rates and times of no flow at the Barstow and Afton Canyon gages. Steady-state particle-tracking was used to estimate travel times for mountain-front and streamflow recharge. The simulated travel times for mountain-front recharge to reach the area west of Victorville were about 5,000 to 6,000 years; this result is in reasonable agreement with published results. Steady-state particle-tracking results for streamflow recharge indicate that in most subareas along the river, the particles quickly leave and reenter the river. The complaint that resulted in the adjudication of the Mojave River ground-water basin alleged that the cumulative water production upstream of the city of Barstow had overdrafted the ground-water basin. In order to ascertain the effect of pumping on ground-water and surface-water relations along the Mojave River, two pumping simulations were compared with the 1931-90 transient-state simulation (base case). The first simulation assumed 1931-90 pumping in the upper region (Este, Oeste, Alto, and Transition zone model subareas) but with no pumping in the remainder of the basin, and the second assumed 1931-90 pumping in the lower region (Centro, Harper Lake, Baja, Coyote Lake, and Afton Canyon model subareas) but with no pumping in remainder of the basin. In the upper region, assuming pumping only in the upper region, there was no change in storage, recharge from the Mojave River, ground-water discharge to the Mojave River, or evapotranspiration when compared with the base case. In the lower region, assuming pumping only in the upper region, there was storage accretion, decreased recharge from the Mojave River, increased ground-water discharge to the Mojave River, and increased evapotranspiration when compared with the base case. In the upper region, assuming pumping only in the lower region, there was storage accretion, decreased recharge from the Mojave River, increased ground-water discharge to the Mojave River, and increased evapotranspiration when compared with the base case. In the lower region, assuming pumping only in the lower region, there was less storage depletion, increased recharge from the Mojave River, increased ground-water discharge to the Mojave River, and increased evapotranspiration when compared with the base case. Overall, pumping in the lower region does not negatively affect the upper region; however, pumping in the upper region negatively affects the lower region by decreasing recharge from the Mojave River. Streamflow, pumpage, and water-level data from calendar years 1995-99 were used to validate the calibrated ground-water flow model, that is, to test that the ground-water flow model will duplicate measured data for a noncalibration period without modification of the model parameters. In general, the simulated results are in good agreement with the measured data, and the simulated hydrographs for wells in the floodplain and regional aquifers follow the measured water-level trends. Simulated streamflow data for the 1995-99 wet and dry stress periods at the Lower Narrows, Barstow, and Afton Canyon were compared with the measured data for average streamflow for the same periods; in general, the model reflects 1995-99 streamflow conditions. The simulation results also indicate that the streambed conductance values calibrated to the 1931-94 conditions reasonably simulate the 1995-99 conditions and therefore can be used for predictive purposes. To visualize the magnitude, spatial distribution, and timing of water-level changes in the basin through time, simulated hydraulic heads for 1932-99 were compared with simulated hydraulic heads for 1931. Greater than average annual inflows to the Mojave River from the headwaters during the late 1930's and throughout much of the 1940's resulted in simulated hydraulic heads that were higher than the 1931 hydraulic heads along the Mojave River in most model subareas. Parts of the Baja and Harper Lake model subareas had declines in the simulated hydraulic head because of the increase in agricultural pumpage. By 1960, the simulated hydraulic heads were lower than the simulated hydraulic heads for 1931 in all model subareas of the floodplain and the regional aquifers because of pumpage. After 1960, the size and the magnitude of the areas of the regional aquifer for which simulated hydraulic heads were lower than those for 1931 continued to increase until the end of the simulation (1999). Along the Mojave River, hydraulic heads fluctuated in the floodplain aquifer in response to recharge during years with large inflows with little apparent effect on the simulated hydraulic heads in the regional aquifer. Three water-management alternatives were evaluated to determine their effect on ground-water resources using the calibrated ground-water flow model. The water-management alternatives consider the artificial recharge of imported water allocated to the Mojave Water Agency (MWA): the first assumes that zero percent of the MWA allocation is available (alternative 1), the second assumes that 50 percent of the MWA allocation is available (alternative 2), and the third assumes that 100 percent of the MWA allocation is available (alternative 3). Each of the three water-management alternatives were evaluated for a 20-year drought. Streamflow conditions were simulated using the 20-year drought of 1945-64 with associated calibrated stream parameters. Management alternative 1 results in a reduction in ground-water recharge from the Mojave River compared with average recharge for 1995-99; this reduction is reflected in simulated hydraulic-head declines between 1999 and 2019 of as much as 45 feet. Management alternatives 2 and 3 result in no change in recharge from the Mojave River for management alternative 2 and a small increase for management alternative 3 when compared with recharge for management alternative 1. The artificial recharge of imported water causes increases in simulated hydraulic head for both management alternatives at each of the artificial-recharge sites. Some of the increases are related to water that recharges into areas of low transmissivity which implies that the recharge operations may benefit from being distributed over a larger area.

California

Summary of sediment data from the Yampa river and upper Green river basins, Colorado and Utah, 1993-2002

The water resources of the Upper Colorado River Basin have been extensively developed for water supply, irrigation, and power generation through water storage in upstream reservoirs during spring runoff and subsequent releases during the remainder of the year. The net effect of water-resource development has been to substantially modify the predevelopment annual hydrograph as well as the timing and amount of sediment delivery from the upper Green River and the Yampa River Basins tributaries to the main-stem reaches where endangered native fish populations have been observed. The U.S. Geological Survey, in cooperation with the Colorado Division of Wildlife and the U.S. Fish and Wildlife Service, began a study to identify sediment source reaches in the Green River main stem and the lower Yampa and Little Snake Rivers and to identify sediment-transport relations that would be useful in assessing the potential effects of hydrograph modification by reservoir operation on sedimentation at identified razorback spawning bars in the Green River. The need for additional data collection is evaluated at each sampling site. Sediment loads were calculated at five key areas within the watershed by using instantaneous measurements of streamflow, suspended-sediment concentration, and bedload. Sediment loads were computed at each site for two modes of transport (suspended load and bedload), as well as for the total-sediment load (suspended load plus bedload) where both modes were sampled. Sediment loads also were calculated for sediment particle-size range (silt-and-clay, and sand-and-gravel sizes) if laboratory size analysis had been performed on the sample, and by hydrograph season. Sediment-transport curves were developed for each type of sediment load by a least-squares regression of logarithmic-transformed data. Transport equations for suspended load and total load had coefficients of determination of at least 0.72 at all of the sampling sites except Little Snake River near Lily, Colorado. Bedload transport equations at the five sites had coefficients of determination that ranged from 0.40 (Yampa River at Deerlodge Park, Colorado) to 0.80 (Yampa River above Little Snake River near Maybell, Colorado). Transport equations for silt and clay-size material had coefficients of determination that ranged from 0.46 to 0.82. Where particle-size data were available (Yampa River at Deerlodge Park, Colorado, and Green River near Jensen, Utah), transport equations for the smaller particle sizes (fine sand) tended to have higher coefficients of determination than the equations for coarser sizes (medium and coarse sand, and very coarse sand and gravel). Because the data had to be subdivided into at least two subsets (rising-limb, falling-limb and, occasionally, base-flow periods), the seasonal transport equations generally were based on relatively few samples. All transport equations probably could be improved by additional data collected at strategically timed periods.

Scientific Investigations Report

USGS—An Unparalleled Scientific Asset

The U.S. Geological Survey (USGS) delivers information critical to powering our economy, managing our natural resources, and keeping Americans safe and healthy. 1 Mapping the Nation $21B Geologic maps save users an estimated 15% in annual costs: a value of between $14B and $21B. $25.6B in annual value to users of imagery from Landsat satellites, which were codeveloped by NASA and the USGS and operated through their lifespans by the USGS. $13.5B in annual benefits is generated by the USGS's 3D Elevation Program. Securing America’s Energy Independence 44% USGS-identified undiscovered geothermal energy is equal to 44% of current U.S. electricity generation. 29.4B barrels of oil and 391.6 trillion cubic feet of gas in recoverable resources are available on U.S. public lands based on USGS assessments. Protecting Americans’ Health and Safety $424B in recent wildland fire damages highlight the need for USGS fire science, which supports efforts to protect communities and reduce risk. USGS earthquake, volcano, landslide, and coastal hazard monitoring and information save lives and minimize costs; for example, $2.8M can be saved because of USGS enhanced information about a Mauna Loa eruption. $4.5B is the estimated cost of annual flooding. Through a network of over 11,885 streamgages, the USGS supports public safety and enables forecasts, early warning systems, and management actions that protect lives and property. Supporting National Security $3.1B The USGS identified a $3.1B risk to the American economy if China restricts gallium imports. This is one example underscoring the importance of the USGS mapping critical minerals, investigating supply chains, and producing the Nation’s critical minerals list. Enhancing Our Lands and Waters $21B in estimated annual costs results from invasive species. The USGS’s invasive species research informs approaches used to reduce their effects on agriculture, water infrastructure, disease transmission, fisheries, and outdoor recreation. USGS innovations support early warnings for harmful algal blooms—over $2M in yearly benefits are provided to Kansas alone. $45B USGS science informs the management of big game (such as deer and elk). The big-game hunting industry contributes $45B to the U.S. economy. Fostering American Prosperity $4.1T Mineral commodities are necessary for the $4.1T in value added to the GDP by major industries that consume processed mineral materials and employ 1 million workers. Because of this, USGS data on mineral supply, demand, and trade are highly valued. 45,000 metric tons Rare earths power the growing technology economy, including cell phones, electric vehicles, and medical devices. For over 70 years, USGS work has supported the discovery of rare earth resources in California’s Mountain Pass area, which produced 45,000 metric tons of rare earth concentrates in 2024—over 11% of the global supply. Guarding American Food Security $70.2B USGS science informs early warning systems and management strategies to mitigate disease outbreaks in agriculture—critical research on highly pathogenic avian influenza, for example, helps safeguard the $70B value in poultry and egg production. $11.8B USGS groundwater tools are vital for agriculture; for example, in the Mississippi Alluvial Plain, 65% of farming relies on groundwater to support its $11.8B annual industry. 1 Values throughout are given in billions (B), millions (M), and trillions (T) of U.S. dollars. GDP is “Gross Domestic Product.” Percentages are shown as %.

General Information Product

Summary appraisals of the nation's ground-water resources – Souris-Red-Rainy region

A broad-perspective analysis of the ground-water resources and present and possible future water development and management in the Souris-Red-Rainy Region is presented. The region includes the basins of the Souris River within Montana and North Dakota; the Red River of the North in South Dakota, North Dakota, and Minnesota; and the Rainy River within Minnesota. The region includes 59,645 square miles, mostly in North Dakota and Minnesota. The terrain is relatively flat, but ranges in altitude from 2,541 to 750 feet. Annual average precipitation ranges from 14 inches in the west to 28 inches in the east and about 75 percent of it is rain. The mean annual snowfall ranges from 32 inches in the west to 64 inches in the east. Temperatures range from -55° to 118° F (-48.3° to 47.8° C). Irrigation is needed at least part of the time to assure crop production, particularly in the western part of the region. Sand and gravel deposits in the drift form the most important freshwater aquifers. Other aquifers are found in at least parts of the region in the Precambrian, Paleozoic, Cretaceous, and Tertiary rocks. The potentiometric surface in the bedrock aquifers generally decreases in altitude toward the Red River of the North, indicating that the general direction of ground-water movement is toward the river. Ground water with less than 3,000 milligrams per liter dissolved solids is available throughout the region. Ground water with less than 1,000 milligrams per liter occurs in most of the region east of the Red River of the North and in most of the shallow aquifers west of the river. The total volume of water available from storage having less than 3,000 milligrams per liter dissolved solids is estimated to be 5x10 8 acre-feet. In addition to the fresh and slightly saline water, the region has abundant highly mineralized water that can be considered as a resource. Yields of wells in individual bedrock aquifers are generally less than 100 gallons per minute but locally yields may be as much as 500 gallons per minute and more. Yields in drift aquifers are frequently less than 100 gallons per minute but range from 5 to 1,000 gallons per minute. In a few places outwash yields more than 1,000 gallons per minute. Ground water is the sole or a primary source of water supply in much of the region, including supplies for irrigation, domestic and livestock, municipal, and industrial needs. Reportedly, the potential irrigation development is 1,550,000 acres, as compared with 50,200 acres in 1975. Both ground- and surface-water supplies would be required to meet these demands. Rural domestic and livestock water supplies are derived almost entirely from ground-water sources. Smaller communities and towns generally rely on ground water, and the cities and industries use ground water, surface water, or both. The municipalities using surface water generally depend upon reservoir storage. Water quality rather than quantity is the greater water-supply problem for many communities in the region. Increased demands on both ground-water and surface-water supplies likely will be made in the future. Storage of surface water in the ground-water reservoirs during times of surplus for withdrawal during times of scarcity would aid in meeting these demands. The surplus (flood) water is of better chemical quality than underlying ground water in parts of the western half of the region. Freshwater could be stored in saline- or freshwater aquifers, and pumped out later, as needed. Thus, the ground-water reservoirs have a definite present and potential role in water management. To understand the hydrologic system for management purposes there is a need to determine more adequately the geologic and hydrologic characteristics of existing aquifers and the location of new aquifers. Also, as pumping and other stresses on any part of the hydrologic system affect other parts of the system, monitoring programs ideally should be started and maintained to detect changes and determine effects of the stresses. Many alternatives are available for managing water in the region. Some of these are operational and others are undergoing research. Adequate hydrologic information is needed to aid in solving problems of water supply, use, and pollution.

Minnesota, Montana, North Dakota, South Dakota

Summary appraisals of the Nation's ground-water resources; Souris-Red-Rainy region

A broad-perspective analysis of the ground-water resources and present and possible future water development and management in the Souris-Red-Rainy Region is presented. The region includes the basins of the Souris River within Montana and North Dakota; the Red River of the North in South Dakota, North Dakota, and Minnesota; and the Rainy River within Minnesota. The region includes 59,645 square miles, mostly in North Dakota and Minnesota. The terrain is relatively flat, but ranges in altitude from 2,541 to 750 feet. Annual average precipitation ranges from 14 inches in the west to 28 inches in the east and about 75 percent of it is rain. The mean annual snow fall ranges from 32 inches in the west to 64 inches in the east. Temperatures range from -55° to 118°F (-48.3° to 47.8°C). Irrigation is needed at least part of the time to assure crop production, particularly in the western part of the region. Sand and gravel deposits in the drift form the most important fresh-water aquifers. Other aquifers are found in at least parts of the region in the Precambrian, Paleozoic, Cretaceous, and Tertiary rocks. The potentiometric surface in the bedrock generally decreases in altitude toward the Red River of the North, indicating that the general direction of ground-water movement is toward the river. Ground-water with less than 3,000 milligrams per liter dissolved solids is available throughout the region. Ground water with less than 1,000 milligrams per liter occurs in most of the region east of the Red River of the North and in most of the shallow aquifers west of the river. The total volume of water available from storage having less than 3,000 milligrams per liter dissolved solids is estimated to be 5 x 10 8 acre-feet. In addition to the fresh and slightly saline water, the region has abundant highly mineralized water that can be considered as a resource. Yields of wells in individual bedrock aquifers are generally less than 100 gallons per minute but locally yields may be as much as 500 gallons per minute and more. Yields in drift aquifers are frequently less than 100 gallons per minute but range from 5 to 1,000 gallons per minute. In a few places outwash yields more than 1,000 gallons per minute. Ground water is the sole or a primary source of water supply in much of the region, including supplies for irrigation, domestic and livestock, municipal, and industrial needs. Reportedly, the potential irrigation development is 1,550,000 acres, as compared with 50,200 acres in 1975. Both ground- and surface-water supplies would be required to meet these demands. Rural domestic and livestock water supplies are derived almost entirely from ground-water sources. Smaller communities and towns generally rely on ground water, and the cities and industries use ground water, surface water, or both. The municipalities using surface water generally depend upon reservoir storage. Water quality rather than quantity is the greater water-supply problem for many communities in the region. Increased demands on both ground-water and surface-water supplies likely will be made in the future. Storage of surface water in the ground-water reservoirs during times of surplus for withdrawal during times of scarcity would aid in meeting these demands. The surplus (flood) water is of better chemical quality than underlying ground water in parts of the western half of the region. Fresh water could be stored in saline- or fresh-water aquifers, and pumped out later, as needed. Thus, the ground-water reservoirs have a definite present and potential role in water management. To understand the hydrologic system for management purposes there is a need to determine more adequately the geologic and hydrologic characteristics of existing aquifers and the location of new aquifers. Also, as pumping and other stresses on any part of the hydrologic system affect other parts of the system, monitoring programs ideally should be started and maintained to detect changes and determine effects of the stresses. Many alternatives are available for managing water in the region. Some of these are operational and others are undergoing research. Adequate hydrologic information is needed to aid in solving problems of water supply, use and pollution.

Minnesota, Montana, North Dakota, South Dakota

Relation between selected water-quality variables and lake level in Upper Klamath and Agency Lakes, Oregon

Upper Klamath Lake is a large (140 square-mile), shallow (mean depth about 8 ft) lake in south-central Oregon that the historical record indicates has been eutrophic since its discovery by non-Native Americans. In recent decades, however, the lake has had annual occurrences of near- monoculture blooms of the blue-green alga Aphanizomenon flos-aquae. In 1988 two sucker species endemic to the lake, the Lost River sucker (Deltistes luxatus) and the shortnose sucker (Chasmistes brevirostris), were listed as endangered by the U.S. Fish and Wildlife Service, and it has been proposed that the poor water quality conditions associated with extremely long and productive blooms are contributing to the decline of those species. It has also been proposed that the low lake levels made possible by the construction of a dam at the outlet from the lake in 1921 have contributed to worsening water quality through a variety of possible mechanisms (Jacob Kann, Klamath Tribes, written commun., 1995). One such mechanism would be an increase in internal phosphorus loading from resuspended sediments (Jacoby and others, 1982), resulting from an increase in bottom shear stresses at lower lake levels (Laenen and LeTourneau, 1996), leading in turn to more intense algal blooms. Another possible mechanism is an earlier triggering of algal blooms. When early spring lake levels are low, greater light intensity at the sediment surface might speed recruitment of algal cells from the sediments. Sediment recruitment has been shown to be an important contributor to water column biomass increases in A. flos aquae (Barbiero and Kann, 1994) and Gloeotrichia echinulata (Barbiero, 1993). An earlier bloom could result in poor water quality conditions occurring earlier in the year, when young-of-the-year fish may be more susceptible to those conditions. Lake level can also influence water quality directly. An increased frequency of sediment resuspension at lower lake levels could increase chemical and biological oxygen demand, resulting in decreased dissolved oxygen concentrations. Sediment oxygen demand also may be enhanced at lower lake levels because it is concentrated over a smaller volume of water. Some compensation for increased oxygen demand at lower lake levels might be provided by increased reaeration, if the water column mixes from top to bottom more frequently. Based on the analysis of data that they have been collecting for several years, the Klamath Tribes recently recommended that the Bureau of Reclamation (Reclamation) modify the operating plan for the dam to make the minimum lake levels for the June-August period more closely resemble pre-dam conditions (Jacob Kann, written commun., 1995). The U.S. Geological Survey (USGS) was asked to analyze the available data for the lake and to assess whether the evidence exists to conclude that year-to-year differences in certain lake water-quality variables are related to year-to-year differences in lake level. The results of the analysis will be used as scientific input in the process of developing an operating plan for the Link River Dam.

Oregon

Nutrient, suspended sediment, and trace element loads in the Blackstone River Basin in Massachusetts and Rhode Island, 2007 to 2009

Nutrients, suspended sediment, and trace element loads in the Blackstone River and selected tributaries were estimated from composite water-quality samples in order to better understand the distribution and sources of these constituents in the river basin. The flow-proportional composite water-quality samples were collected during sequential 2-week periods at six stations along the river’s main stem, at three stations on tributaries, and at four wastewater treatment plants in the Massachusetts segment of the basin from June 2007 to September 2009. Samples were collected at an additional station on the Blackstone River near the mouth in Pawtucket, Rhode Island, from September 2008 to September 2009. The flow-proportional composite samples were used to estimate average daily loads during the sampling periods; annual loads for water years 2008 and 2009 also were estimated for the monitoring station on the Blackstone River near the Massachusetts-Rhode Island border. The effects of hydrologic conditions and net attenuation of nitrogen were investigated for loads in the Massachusetts segment of the basin. Sediment resuspension and contaminant loading dynamics were evaluated in two Blackstone River impoundments, the former Rockdale Pond (a breached impoundment) and Rice City Pond. Total nitrogen and phosphorus loads along the Blackstone River in Massachusetts showed similar general patterns during the sampling periods monitored in this study. Total nitrogen loads were relatively low at the farthest upstream monitoring station in Millbury, Massachusetts (typically less than 430 kilograms per day (kg/d) for total nitrogen and 37 kg/d for total phosphorus). Loads typically increased (5- to 10-fold for nitrogen and 6- to 15-fold for phosphorus) downstream from the first, large wastewater treatment plant along the river, the Upper Blackstone Water Pollution Control Abatement District in Millbury. Further downstream, total nitrogen and phosphorus loads remained elevated but variable (typically about 1,000 to 3,000 kg/d for nitrogen and about 100 to 370 kg/d for phosphorus) from Millbury to the Massachusetts-Rhode Island border near Millville, Mass. Monitored tributaries of the Blackstone River and wastewater treatment plants other than the Upper Blackstone Water Pollution Control Abatement District rarely contributed more than a small fraction of the total nitrogen and phosphorus loads observed at the main stem monitoring stations. Loads of suspended sediment also were substantially larger along the river’s main stem than in tributaries during most sampling periods. Very large loads of suspended sediment from the West River tributary during several sampling periods may have been associated with flood-control operations. The estimated annual load of total nitrogen in the Blackstone River at Millville, about 1.3 miles upstream from the Massachusetts-Rhode Island border, was 936,000 kilograms (kg) (2,600 kg/d) in water year 2008 and 878,000 kg (2,400 kg/d) in water year 2009. The estimated annual load of total phosphorus at Millville was 81,400 kg in water year 2008 (223 kg/d) and 80,900 kg (222 kg/d) in water year 2009. The estimated annual load of suspended sediment in was 4,940,000 kg (13,600 kg/d) in water year 2008 and 7,040,000 kg (19,300 kg/d) in water year 2009. The higher load in water year 2009 likely reflects several large storms in summer 2009, which resulted in streamflows in the Blackstone River that were 10 times the typical July flows. Loads of total nitrogen, total phosphorus, and trace elements were almost always lower in the Blackstone River at Millville than in the river near its mouth at the Pawtucket monitoring station, when loads were monitored at both stations in the latter part of water year 2008 and in water year 2009. Loads of suspended sediment at Millville and Pawtucket varied by about the same range, but were usually lower at Pawtucket than at Millville. Total nitrogen loads were higher during sampling periods when the base-flow contribution to streamflow was substantially less than the runoff contribution than in sampling periods when the base-flow dominated. During these sampling periods when the runoff component of streamflow was relatively large, loads of total nitrogen in wastewater discharge from Upper Blackstone Water Pollution Control Abatement District also were high but also constituted smaller fractions of the total nitrogen loads in the river. Nitrogen attenuation may have occurred during some sampling periods, based on net changes in total nitrogen load between consecutive monitoring stations, especially in the Blackstone River reach between the South Grafton and Uxbridge monitoring stations. Analysis of the representative constituents (total phosphorus, total chromium, and suspended sediment) upstream and downstream of impoundments indicated that the existing impoundments, such as Rice City Pond, can be sources of particulate contaminant loads in the Blackstone River. Loads of particulate phosphorus, particulate chromium, and suspended sediment were consistently higher downstream from Rice City Pond than upstream during high-flow events, and there was a positive, linear relation between streamflow and changes in these constituents from upstream to downstream of the impoundment. Thus, particulate contaminants were mobilized from Rice City Pond during high-flow events and transported downstream. In contrast, downstream loads of particulate phosphorus, particulate chromium, and suspended sediment were generally lower than or equal to upstream loads for the former Rockdale Pond impoundment. Sediments associated with the former impoundment at Rockdale Pond, breached in the late 1960s, did not appear to be mobilized during the high-flow events monitored during this study.

Massachusetts, Rhode Island