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USGS2007

Estimates of ground-water recharge to the Yakima River Basin aquifer system, Washington, for predevelopment and current land-use and land-cover conditions

Two models were used to estimate ground-water recharge to the Yakima River Basin aquifer system, Washington for predevelopment (estimate of natural conditions) and current (a multi-year, 1995-2004, composite) land-use and land-cover conditions. The models were the Precipitation-Runoff Modeling System (PRMS) and the Deep Percolation Model (DPM) that are contained in the U.S. Geological Survey's Modular Modeling System. Daily values of recharge were estimated for water years 1950-98 using previously developed PRMS-watershed models for four mainly forested upland areas, and for water years 1950-2003 using DPM applied to 17 semiarid to arid areas in the basin. The mean annual recharge under predevelopment conditions was estimated to be about 11.9 in. or 5,450 ft 3 /s (about 3.9 million acre-ft) for the 6,207 mi 2 in the modeled area. In the modeled areas, recharge ranged from 0.08 in. (1.2 ft 3 /s) to 34 in. (2,825 ft 3 /s). About 97 percent of the recharge occurred in the 3,667 mi 2 area included in the upland-area models, but much of this quantity is not available to recharge the bedrock hydrogeologic units. Only about 1.0 in., or 187 ft 3 /s (about 0.14 million acre-ft), was estimated to occur in the 2,540 mi 2 area included in the semiarid to arid lowland modeled areas. The mean annual recharge to the aquifer system under current conditions was estimated to be about 15.6 in., or 7,149 ft 3 /s (about 5.2 million acre-ft). The increase in recharge is due to the application of irrigation water to croplands. The annual quantity of irrigation was more than five times the annual precipitation for some of the modeled areas. Mean annual actual evapotranspiration was estimated to have increased from predevelopment conditions by more than 1,700 ft 3 /s (about 1.2 million acre-ft) due to irrigation.

Washington↗

USGS2009

Geochemical investigation of the Arbuckle-Simpson Aquifer, South-Central Oklahoma, 2004-06

A geochemical reconnaissance investigation of the Arbuckle-Simpson aquifer in south-central Oklahoma was initiated in 2004 to characterize the ground-water quality at an aquifer scale, to describe the chemical evolution of ground water as it flows from recharge areas to discharge in wells and springs, and to determine the residence time of ground water in the aquifer. Thirty-six water samples were collected from 32 wells and springs distributed across the aquifer for chemical analysis of major ions, trace elements, isotopes of oxygen and hydrogen, dissolved gases, and age-dating tracers. In general, the waters from wells and springs in the Arbuckle-Simpson aquifer are chemically suitable for all regulated uses, such as public supplies. Dissolved solids concentrations are low, with a median of 347 milligrams per liter (mg/L). Two domestic wells produced water with nitrate concentrations that exceeded the U.S. Environmental Protection Agency's nitrate maximum contaminant level (MCL) of 10 mg/L. Samples from two wells in the confined part of the aquifer exceeded the secondary maximum contaminant level (SMCL) for chloride of 250 mg/L and the SMCL of 500 mg/L for dissolved solids. Water samples from these two wells are not representative of water samples from the other wells and springs completed in the unconfined part of the aquifer. No other water samples from the Arbuckle-Simpson geochemical reconnaissance exceeded MCLs or SMCLs, although not every chemical constituent for which the U.S. Environmental Protection Agency has established a MCL or SMCL was analyzed as part of the Arbuckle-Simpson geochemical investigation. The major ion chemistry of 34 of the 36 samples indicates the water is a calcium bicarbonate or calcium magnesium bicarbonate water type. Calcium bicarbonate water type is found in the western part of the aquifer, which is predominantly limestone. Calcium magnesium bicarbonate water is found in the eastern part of the aquifer, which is predominantly a dolomite. The major ion chemistry for these 34 samples is consistent with a set of water-rock interactions. Rainfall infiltrates the soil zone, where the host rock, limestone or dolomite, dissolves as a result of uptake of carbon dioxide gas. Some continued dissolution of dolomite and precipitation of calcite occur as the water flows through the saturated zone. The major ion chemistry of the two samples from wells completed in the confined part of the aquifer indicates the water is a sodium chloride type. Geochemical inverse modeling determined that mixing of calcite-saturated recharge water with brine and dissolving calcite, dolomite, and gypsum accounts for the water composition of these two samples. One of the two samples, collected at Vendome Well in Chickasaw National Recreation Area, had a mixing fraction of brine of about 1 percent. The brine component of the sample at Vendome Well is likely to account for the relatively large concentrations of many of the trace elements (potassium, fluoride, bromide, iodide, ammonia, arsenic, boron, lithium, selenium, and strontium) measured in the water sample. Carbon-14, helium-3/tritium, and chlorofluorocarbons were used to calculate ground-water ages, recharge temperatures, and mixtures of ground water in the Arbuckle-Simpson aquifer. Thirty four of 36 water samples recharged the aquifer after 1950, indicating that water is moving quickly from recharge areas to discharge at streams and springs. Two exceptions to this classification were noted in samples 6 and 15 (Vendome Well). Ground-water ages determined for these two samples by using carbon-14 are 34,000 years (site 6) and 10,500 years (site 15). Concentrations of dissolved argon, neon, and xenon in water samples were used to determine the temperature of the water when it recharged the aquifer. The mean annual air temperature at Ada, Oklahoma, is 16 degrees Celsius (C) and the median temperature of the 30 reconnaissance water samples was 18.1 C. The av

Oklahoma↗

USGS2011

Gulkana Glacier, Alaska-Mass balance, meteorology, and water measurements-1997-2001

The measured winter snow, maximum winter snow, net, and annual balances for 1997-2001 in the Gulkana Glacier basin are determined at specific points and over the entire glacier area using the meteorological, hydrological, and glaciological data. We provide descriptions of glacier geometry to aid in estimation of conventional and reference surface mass balances and descriptions of ice motion to aid in the understanding of the glacier's response to its changing geometry. These data provide annual estimates for area altitude distribution, equilibrium line altitude, and accumulation area ratio during the study interval. New determinations of historical area altitude distributions are given for 1900 and annually from 1966 to 2001. As original weather instrumentation is nearing the end of its deployment lifespan, we provide new estimates of overlap comparisons and precipitation catch efficiency. During 1997-2001, Gulkana Glacier showed a continued and accelerated negative mass balance trend, especially below the equilibrium line altitude where thinning was pronounced. Ice motion also slowed, which combined with the negative mass balance, resulted in glacier retreat under a warming climate. Average annual runoff augmentation by glacier shrinkage for 1997-2001 was 25 percent compared to the previous average of 13 percent, in accordance with the measured glacier volume reductions.

Alaska↗

USGS2013

Methods and results of peak-flow frequency analyses for streamgages in and bordering Minnesota, through water year 2011

Peak-flow frequency analyses were completed for 409 streamgages in and bordering Minnesota having at least 10 systematic peak flows through water year 2011. Selected annual exceedance probabilities were determined by fitting a log-Pearson type III probability distribution to the recorded annual peak flows. A detailed explanation of the methods that were used to determine the annual exceedance probabilities, the historical period, acceptable low outliers, and analysis method for each streamgage are presented. The final results of the analyses are presented.

Minnesota↗

USGS1999

Deposition of selenium and other constituents in reservoir bottom sediment of the Solomon River Basin, north-central Kansas

The Solomon River drains approximately 6,840 square miles of mainly agricultural land in north-central Kansas. The Bureau of Reclamation, U.S. Department of the Interior, has begun a Resource Management Assessment (RMA) of the Solomon River Basin to provide the necessary data for National Environmental Policy Act (NEPA) compliance before renewal of long-term water-service contracts with irrigation districts in the basin. In May 1998, the U.S. Geological Survey (USGS) collected bottom-sediment cores from Kirwin and Webster Reservoirs, which are not affected by Bureau irrigation, and Waconda Lake, which receives water from both Bureau and non-Bureau irrigated lands. The cores were analyzed for selected physical properties, total recoverable metals, nutrients, cesium-137, and total organic carbon. Spearman's rho correlations and Kendall's tau trend tests were done for sediment concentrations in cores from each reservoir. Selenium, arsenic, and strontium were the only constituents that showed an increasing trend in concentrations for core samples from more than one reservoir. Concentrations and trends for these three constituents were compared to information on historical irrigation to determine any causal effect. Increases in selenium, arsenic, and strontium concentrations can not be completely explained by Bureau irrigation. However, mean selenium, arsenic, and strontium concentrations in sediment from all three reservoirs may be related to total irrigated acres (Bureau and non-Bureau irrigation) in the basin. Selenium, arsenic, and strontium loads were calculated for Webster Reservoir to determine if annual loads deposited in the reservoir were increasing along with constituent concentrations. Background selenium, arsenic, and strontium loads in Webster Reservoir are significantly larger than post-background loads.

Kansas↗

USGS2003

Flow origin, drainage area, and hydrologic characteristics for headwater streams in the mountaintop coal-mining region of Southern West Virginia, 2000-01

Characteristics of perennial and intermittent headwater streams were documented in the mountaintop removal coal-mining region of southern West Virginia in 2000?01. The perennial-flow origin points were identified in autumn during low base-flow conditions. The intermittent-flow origin points were identified in late winter and early spring during high base-flow conditions. Results of this investigation indicate that the median drainage area upstream of the origin of intermittent flow was 14.5 acres, and varied by an absolute median of 3.4 acres between the late winter measurements of 2000 and early spring measurements of 2001. Median drainage area in the northeastern part of the study unit was generally larger (20.4 acres), with a lower median basin slope (322 feet per mile) than the southwestern part of the study unit (12.9 acres and 465 feet per mile, respectively). Both of the seasons preceding the annual intermittent flow visits were much drier than normal. The West Virginia Department of Environmental Protection reports that the median size of permitted valley fills in southern West Virginia is 12.0 acres, which is comparable to the median drainage area upstream of the ephemeralintermittent flow point (14.5 acres). The maximum size of permitted fills (480 acres), however, is more than 10 times the observed maximum drainage area upstream of the ephemeral-intermittent flow point (45.3 acres), although a single valley fill may cover more than one drainage area. The median drainage area upstream of the origin of perennial flow was 40.8 acres, and varied by an absolute median of 18.0 acres between two annual autumn measurements. Only basins underlain with mostly sandstone bedrock produced perennial flow. Perennial points in the northeast part of the study unit had a larger median drainage area (70.0 acres) and a smaller median basin slope (416 feet per mile) than perennial points in the southwest part of the study unit (35.5 acres and 567 feet per mile, respectively). Some streams were totally dry for one or both of the annual October visits. Both of the seasons preceding the October visits had near normal to higher than normal precipitation. These dry streams were adjacent to perennial streams draining similarly sized areas, suggesting that local conditions at a firstorder- stream scale determine whether or not there will be perennial flow. Headwater-flow rates varied little from year to year, but there was some variation between late winter and early spring and autumn. Flow rates at intermittent points of flow origin ranged from 0.001 to 0.032 cubic feet per second, with a median of 0.017 cubic feet per second. Flow rates at perennial points of flow origin ranged from 0.001 to 0.14 cubic feet per second, with a median of 0.003 cubic feet per second.

Water-Resources Investigations Report↗

USGS1979

Flood characteristics of Alaskan streams

Peak discharge data for Alaskan streams are summarized and analyzed. Multiple-regression equations relating peak discharge magnitude and frequency to climatic and physical characteristics of 260 gaged basins were determined in order to estimate average recurrence interval of floods at ungaged sites. These equations are for 1.25-, 2-, 5-, 10-, 25-, and 50-year average recurrence intervals. In this report, Alaska was divided into two regions, one having a maritime climate with fall and winter rains and floods, the other having spring and summer floods of a variety or combinations of causes. Average standard errors of the six multiple-regression equations for these two regions were 48 and 74 percent, respectively. Maximum recorded floods at more than 400 sites throughout Alaska are tabulated. Maps showing lines of equal intensity of the principal climatic variables found to be significant (mean annual precipitation and mean minimum January temperature), and location of the 260 sites used in the multiple-regression analyses are included. Little flood data have been collected in western and arctic Alaska, and the predictive equations are therefore less reliable for those areas. (Woodard-USGS)

Alaska↗

USGS1990

A water-resources data-network evaluation for Monterey County, California, phase 3: Northern Salinas River drainage basin

This report evaluates existing data collection networks and possible additional data collection to monitor quantity and quality of precipitation, surface water, and groundwater in the northern Salinas River drainage basin, California. Of the 34 precipitation stations identified, 20 were active and are concentrated in the northwestern part of the study area. No precipitation quality networks were identified, but possible data collection efforts include monitoring for acid rain and pesticides. Six of ten stream-gaging stations are active. Two surface water quality sites are sampled for suspended sediment, specific conductance, and chloride; one U.S. Geological Survey NASOAN site and one site operated by California Department of Water Resources make up the four active sampling locations; reactivation of 45 inactive surface water quality sites might help to achieve objectives described in the report. Three local networks measure water levels in 318 wells monthly, during peak irrigation, and at the end of the irrigation season. Water quality conditions are monitored in 379 wells; samples are collected in summer to monitor saltwater intrusion near Castroville and are also collected annually throughout the study area for analysis of chloride, specific conductance, and nitrate. An ideal baseline network would be an evenly spaced grid of index wells with a density of one per section. When baseline conditions are established, representative wells within the network could be monitored periodically according to specific data needs. (USGS)

California↗

USGS2010

Comparison of mercury in water, bottom sediment, and zooplankton in two Front Range reservoirs in Colorado, 2008-09

The U.S. Geological Survey, in cooperation with the Colorado Department of Public Health and Environment, conducted a study to investigate environmental factors that may contribute to the bioaccumulation of mercury in two Front Range reservoirs. One of the reservoirs, Brush Hollow Reservoir, currently (2009) has a fish-consumption advisory for mercury in walleye (Stizostedion vitreum), and the other, Pueblo Reservoir, which is nearby, does not. Water, bottom sediment, and zooplankton samples were collected during 2008 and 2009, and a sediment-incubation experiment was conducted in 2009. Total mercury concentrations were low in midlake water samples and were not substantially different between the two reservoirs. The only water samples with detectable methylmercury were collected in shallow areas of Brush Hollow Reservoir during spring. Mercury concentrations in reservoir bottom sediments were similar to those reported for stream sediments from unmined basins across the United States. Despite higher concentrations of fish-tissue mercury in Brush Hollow Reservoir, concentrations of methylmercury in sediment were as much as 3 times higher in Pueblo Reservoir. Mercury concentrations in zooplankton were at the low end of concentrations reported for temperate lakes in the Northeastern United States and were similar between sites, which may reflect the seasonal timing of sampling. Factors affecting bioaccumulation of mercury were assessed, including mercury sources, water quality, and reservoir characteristics. Atmospheric deposition was determined to be the dominant source of mercury; however, due to the proximity of the reservoirs, atmospheric inputs likely are similar in both study areas. Water-quality constituents commonly associated with elevated concentrations of mercury in fish (pH, alkalinity, sulfate, nutrients, and dissolved organic carbon) did not appear to explain differences in fish-tissue mercury concentrations between the reservoirs. Low methylmercury concentrations in hypolimnetic water indicate low potential for increased methylmercury production following the development of anoxic conditions in summer. Based on the limited dataset, water-level fluctuations and shoreline characteristics appear to best explain differences in fish-tissue mercury concentrations between the reservoirs. Due to the shallow depth and the large annual water-level fluctuations at Brush Hollow Reservoir, proportionally larger areas of shoreline at Brush Hollow Reservoir are subjected to annual reflooding compared to Pueblo Reservoir. Moreover, presence of macrophyte beds and regrowth of terrestrial vegetation likely increase the organic content of near-shore sediments in Brush Hollow Reservoir, which may stimulate methylmercury production in littoral areas subject to reflooding. Results of a laboratory incubation experiment were consistent with this hypothesis.

Colorado↗

USGS1984

Water resources and potential hydrologic effects of oil-shale development in the southeastern Uinta Basin, Utah and Colorado

Proposed oil-shale mining in northeastern Utah is expected to impact the water resources of a 3,000-square-mile area. This report summarizes a comprehensive hydrologic investigation of the area which resulted in 13 published reports. Hydrologic information obtained during 1974-80 was used to evaluate the availability of water and to evaluate potential impacts of an oil-shale industry on the water resources. The study area is the southeastern part of the Uinta Basin, Utah and Colorado, where the hydrology is extremely variable. The normal annual precipitation averages 11 inches and varies with altitude. It ranges from less than 8 inches at altitudes below 5,000 feet along the White and Green Rivers to more than 20 inches where altitudes exceed 9,000 feet on the Roan Plateau. The White and Green Rivers are large streams that flow through the area. They convey an average flow of 4.3 million acre-feet per year from outside drainage areas of about 34,000 square miles, which is more than 150 times as much flow as that originating within the area. Streams originating in areas where precipitation is less than 10 inches are ephemeral. Mean annual runoff from the study area is about 28,000 acre-feet and ranges from less than 0.1 to 1.6 inches, depending on the location. At any given site, runoff varies greatly-from year to year and season to season. Potential evapotranspiration is large, exceeding precipitation in all years. Three major aquifers occur in the area. They are alluvial deposits of small areal extent along the major stream valleys; the bird's-nest aquifer of the Parachute Creek Member of the Green River Formation, which is limited to the central part of the study area; and the Douglas Creek aquifer of the Douglas Creek Member of the Green River Formation, which underlies most of the area. Total recoverable water in storage in the three aquifers is about 18 million acre-feet. Yields of individual wells and interference between wells limit the maximum practical withdrawal to about 20,000 acre-feet per year. An oil-shale industry in the southeastern Uinta Basin with a peak production of 400,000 barrels of oil per day would require a water supply of about 70,000 acre-feet per year. Sources of water supply considered for such an industry were: diversion from the natural flow of the White River, a proposed reservoir on the White River, diversion from the White River combined with proposed off-stream storage in Hells Hole Canyon, diversion from the Green River, and conjunctive use of ground and surface water. The proposed reservoir on the White River would trap about 90 percent of the sediment moving in the river and in turn would release almost sediment-free water. Possible impacts are changes in channel gradient in the downstream 18 miles of the White River and changes in bank stability. In some parts of the area, annual sheet-erosion rates are as great as 2.2 acre-feet per square mile but sediment yield to the White River is less than might be expected because the runoff is small. If process water from retort operations or water used in the construction of surface facilities is discharged into a normally dry streambed, increased channel erosion and sediment in tributary streams could result in increased sediment loads in the White River. In addition, sediment yields from retorted-shale piles with minimum slopes could exceed 0.1 acrefoot per square mile during a common storm. Thus, without safeguards, the useful life of any proposed reservoir or holding pond could be decreased considerably. Leachate water from retorted-shale piles has large concentrations of sodium and sulfate, and the chemical composition of retort waters differs considerably from that of the natural waters of the area. The retort waters contain a greater concentration of dissolved solids and more organic carbon and nutrients. Without proper disposal or impoundment of retort and leachate waters, the salinity of downstream waters in the Colorado River Basin would be increased.

Colorado, Utah↗

USGS2005

Water withdrawals for irrigation, municipal, mining, thermoelectric-power, and drainage uses in Arizona outside of active management areas, 1991-2000

Economic development in Arizona is largely influenced by access to adequate water supplies owing to the State's predominantly semiarid to arid climate. Water demand is met by pumping ground water from aquifers or by conveying surface water through a system of reservoirs and canals. Water-withdrawal data provide important information on how water demand affects the State's water resources. Information on water withdrawals also can help planners and managers assess the effectiveness of water-management policies, regulations, and conservation activities. This report includes water-withdrawal data for irrigation, municipal, mining, thermoelectric-power, and drainage uses for 1991-2000, and describes the methods used to collect, compile, and estimate the data. Data are reported for the Arizona Department of Water Resources ground-water basins outside of Active Management Areas. Because of the climate, ground water and surface water are used to irrigate nearly all agricultural fields in Arizona. Irrigation accounted for the largest use of water in the study area during 1991-2000. The amount of water withdrawn for irrigation varies greatly from year to year for some of the basins, primarily because of differences in the consumptive water requirement for different crops and because of changes in irrigated acreage. The population of Arizona increased about 35 percent from 1991 to 2000-from about 3.79 million in 1991 to about 5.13 million in 2000. Correspondingly, water withdrawal for municipal use increased steadily in most of the basins during 1991-2000. Ground-water withdrawals for mining did not show any consistent trends during 1991-2000. Increases and decreases in withdrawals for mining were most likely due to variations in mineral production. Mineral prices and competition from mining in other States and foreign countries probably result in annual increases or decreases in mineral production in Arizona. Between 1991 and 2000, ground-water withdrawals for thermoelectric-power generation generally increased owing to an increase in production of electricity. Ground-water withdrawals for drainage of agricultural lands in the Lower Gila and Yuma Basins varied irregularly from year to year. Annual total water withdrawals are not presented in this report because for some years irrigation values for some of the basins are reported as "less than 1,000 acre-feet," and municipal and mining values for some of the basins are reported as "less than 300 acre-feet."

Arizona↗

USGS2005

Changes in the magnitude of annual and monthly streamflows in New England, 1902-2002

Selected annual and monthly streamflow statistics for 27 streamflow-gaging stations in New England were computed and tested for changes over time. These 27 stations were considered to be free of substantial human influences such as regulation, diversion, and land use-changes and have an average of 71 years of record. The longest streamflow record extended from 1902 to 2002. March mean streamflows increased significantly over time (Mann-Kendall test, p < 0.1) at 14 streamflow-gaging stations in northern New England, primarily in northern or mountainous sections of Maine, New Hampshire, and Vermont. March mean flows increased by 76 to 185 percent at the seven stations with the longest continuous records in areas of New England with the largest seasonal snowpack depths. These streamflow-gaging stations had continuous records from the late 1920's and the early 1930s through 2002. May mean streamflows significantly decreased at 10 stations in northern or mountainous sections of Maine and New Hampshire. May mean flows decreased by 9 to 46 percent at the seven stations with the longest continuous records. Despite the fact that March percentage increases were much larger than May percentage decreases, March streamflow increases (in cubic feet per second) were smaller than May decreases, except at one streamflow-gaging station. Increased March and April air temperatures over time may have caused earlier snowmelt and thus increased streamflows in March and decreased streamflows in May. There were no significant changes over time in annual mean streamflows at the 27 stations; however, there were significant increases over time in various annual percentile streamflows (minimum, 25th percentile, median, 75th percentile, or maximum flows) at 22 of the stations. This indicates that flows increased over time at many streams in New England, but the increase was not enough to have caused significant changes in annual mean flows. October mean streamflows increased significantly at five stations in western New England. December minimum streamflows increased significantly at 13 stations in northern and southern New England.

Connecticut, Maine, Massachusetts, New Hampshire, ↗

USGS2008

Variability in Lotic Communities in Three Contrasting Stream Environments in the Santa Ana River Basin, California, 1999-2001

Biotic communities and environmental conditions can be highly variable between natural ecosystems. The variability of natural assemblages should be considered in the interpretation of any ecological study when samples are either spatially or temporally distributed. Little is known about biotic variability in the Santa Ana River Basin. In this report, the lotic community and habitat assessment data from ecological studies done as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program are used for a preliminary assessment of variability in the Santa Ana Basin. Habitat was assessed, and benthic algae, benthic macroinvertebrate, and fish samples were collected at four sites during 1999-2001. Three of these sites were sampled all three years. One of these sites is located in the San Bernardino Mountains, and the other two sites are located in the alluvial basin. Analysis of variance determined that the three sites with multiyear data were significantly different for 41 benthic algae metrics and 65 macroinvertebrate metrics and fish communities. Coefficients of variation (CVs) were calculated for the habitat measurements, metrics of benthic algae, and macroinvertebrate data as measures of variability. Annual variability of habitat data was generally greater at the mountain site than at the basin sites. The mountain site had higher CVs for water temperature, depth, velocity, canopy angle, streambed substrate, and most water-quality variables. In general, CVs of most benthic algae metrics calculated from the richest-targeted habitat (RTH) samples were greater at the mountain site. In contrast, CVs of most benthic algae metrics calculated from depositional-targeted habitat (DTH) samples were lower at the mountain site. In general, CVs of macroinvertebrate metrics calculated from qualitative multihabitat (QMH) samples were lower at the mountain site. In contrast, CVs of many metrics calculated from RTH samples were greater at the mountain site than at one of the basin sites. Fish communities were more variable at the basin sites because more species were present at these sites. Annual variability of benthic algae metrics was related to annual variability in habitat variables. The CVs of benthic algae metrics related to the most CVs of habitat variables included QMH taxon richness, the RTH percentage richness, RTH abundance of tolerant taxa, RTH percentage richness of halophilic diatoms, RTH percentage abundance of sestonic diatoms, DTH percentage richness of nitrogen heterotrophic diatoms, and DTH pollution tolerance index. The CVs of macroinvertebrate metrics related to the most CVs of habitat variables included the RTH trichoptera, RTH EPT, RTH scraper richness, RTH nonchironomid dipteran abundance (in percent), and RTH EPA (U.S. Environmental Protection Agency) tolerance, which is based on abundance. Many of the CVs of habitat variables related to CVs of macroinvertebrate metrics were the same habitat variables that were related to the CVs of benthic algae metrics. On the basis of these results, annual variability may have a role in the relationship of benthic algae and macroinvertebrates assemblages with habitat and water quality in the Santa Ana Basin. This report provides valuable baseline data on the variability of biological communities in the Santa Ana Basin.

Scientific Investigations Report↗

USGS2010

Organic compounds and cadmium in the tributaries to the Elizabeth River in New Jersey, October 2008 to November 2008: Phase II of the New Jersey Toxics Reduction Workplan for New York-New Jersey Harbor

Samples of surface water and suspended sediment were collected from the two branches that make up the Elizabeth River in New Jersey - the West Branch and the Main Stem - from October to November 2008 to determine the concentrations of selected chlorinated organic and inorganic constituents. The sampling and analyses were conducted as part of Phase II of the New York-New Jersey Harbor Estuary Plan-Contaminant Assessment and Reduction Program (CARP), which is overseen by the New Jersey Department of Environmental Protection. Phase II of the New Jersey Workplan was conducted by the U.S. Geological Survey to define upstream tributary and point sources of contaminants in those rivers sampled during Phase I work, with special emphasis on the Passaic and Elizabeth Rivers. This portion of the Phase II study was conducted on the two branches of the Elizabeth River, which were previously sampled during July and August of 2003 at low-flow conditions. Samples were collected during 2008 from the West Branch and Main Stem of the Elizabeth River just upstream from their confluence at Hillside, N.J. Both tributaries were sampled once during low-flow discharge conditions and once during high-flow discharge conditions using the protocols and analytical methods that were used in the initial part of Phase II of the Workplan. Grab samples of streamwater also were collected at each site and were analyzed for cadmium, suspended sediment, and particulate organic carbon. The measured concentrations, along with available historical suspended-sediment and stream-discharge data were used to estimate average annual loads of suspended sediment and organic compounds in the two branches of the Elizabeth River. Total suspended-sediment loads for 1975 to 2000 were estimated using rating curves developed from historical U.S. Geological Survey suspended-sediment and discharge data, where available. Concentrations of suspended-sediment-bound polychlorinated biphenyls (PCBs) in the Main Stem and the West Branch of the Elizabeth River during low-flow conditions were 534 ng/g (nanograms per gram) and 1,120 ng/g, respectively, representing loads of 27 g/yr (grams per year) and 416 g/yr, respectively. These loads were estimated using contaminant concentrations during low flow, and the assumed 25-year average discharge, and 25-year average suspended-sediment concentration. Concentrations of suspended-sediment-bound PCBs in the Main Stem and the West Branch of the Elizabeth River during high-flow conditions were 3,530 ng/g and 623 ng/g, respectively, representing loads of 176 g/yr and 231 g/yr, respectively. These loads were estimated using contaminant concentrations during high-flow conditions, the assumed 25-year average discharge, and 25-year average suspended-sediment concentration. Concentrations of suspended-sediment-bound polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-difuran compounds (PCDD/PCDFs) during low-flow conditions were 2,880 pg/g (picograms per gram) and 5,910 pg/g in the Main Stem and West Branch, respectively, representing average annual loads of 0.14 g/yr and 2.2 g/yr, respectively. Concentrations of suspended-sediment-bound PCDD/PCDFs during high-flow conditions were 40,900 pg/g and 12,400 pg/g in the Main Stem and West Branch, respectively, representing average annual loads of 2.05 g/yr and 4.6 g/yr, respectively. Total toxic equivalency (TEQ) loads (sum of PCDD/PCDF and PCB TEQs) were 3.1 mg/yr (milligrams per year) (as 2, 3, 7, 8-TCDD) in the Main Stem and 28 mg/yr in the West Branch during low-flow conditions. Total TEQ loads (sum of PCDD/PCDFs and PCBs) were 27 mg/yr (as 2, 3, 7, 8-TCDD) in the Main Stem and 32 mg/yr in the West Branch during high-flow conditions. All of these load estimates, however, are directly related to the assumed annual discharge for the two branches. Long-term measurement of stream discharge and suspended-sediment concentrations would be needed to verify these loads. On the basis of the loads cal

Scientific Investigations Report↗

USGS2025

Fluvial sediment dynamics in the Shoshone River and tributaries around Willwood Dam, Park County, Wyoming

Sedimentation affects many of the aging reservoirs in the United States. Dams and water diversions from rivers have been central elements of infrastructure supporting agricultural irrigation in the arid and semiarid regions of the Western United States for more than a century. The Willwood Irrigation District diversion dam (hereafter referred to as “Willwood Dam”) in Park County, Wyoming, is approximately 12 miles northeast of Cody, Wyo.; has a structural height of 70 feet; and impounds the Shoshone River for diversion into the Willwood Canal. Willwood Dam is part of a larger irrigation scheme supported by water storage in the much larger Buffalo Bill Dam, which is approximately 20 miles upstream. In October 2016, renovation construction activities at Willwood Dam and the Willwood Canal caused an unplanned evacuation of nearly 96,000 cubic yards of fine sediment. The fine sediment release in 2016 raised concerns that ongoing sediment management at Willwood Dam could impose limits on the long-term health of the aquatic ecosystem and fish populations. The U.S. Geological Survey, in cooperation with Wyoming Department of Environmental Quality and Willwood Work Groups 2 and 3, initiated an investigation of the dynamics of sediment transport in the Shoshone River and selected tributaries between Buffalo Bill Dam and Willwood Dam. The goal of the study was to quantify sediment transport into and out of Willwood Dam on an annual, seasonal, and event basis to better understand the relative quantities of sediment coming from natural sources and human activities on the landscape. The study ran from March 2019 through October 2021 and used observations of streamflow, turbidity, and acoustic backscatter collected at streamgages upstream and downstream from Willwood Dam to quantify suspended-sediment loads into and out of the dam during irrigation and fallow seasons, precipitation-runoff events, and deliberate sediment releases. Each tributary’s relative contribution to the sediment load upstream from Willwood Dam was examined using discrete measurements of suspended-sediment concentration and bedload during irrigation and fallow seasons, precipitation events, and stable conditions. Analysis of daily precipitation and temperature data indicated that conditions in the study area during the 2019 agricultural year were wetter and colder than period of record normal, and drier and near normal temperatures for the 2020 and 2021 agricultural years. Not all sediment load records between 2019 and 2021 are complete because of rejected observations (outliers), instrument failures or fouling, and instrument removal for calibrations. Statistical modeling of suspended-sediment concentration using paired values of turbidity and acoustic backscatter produced four models that, after refinement, had coefficients of determination indicating that more than 84 percent of the variance was explained by either turbidity or acoustic backscatter. A system of rules was developed to select the model predictions based on the seasonal operations of Willwood Dam, assumptions about the grain sizes mobilized during these operations, and assumed accuracy of the models at the downstream streamgage (Shoshone River below Willwood Dam, near Ralston, Wyo. [streamgage 06284010]) under different operational conditions. The sediment budget between upstream and downstream estimates of loads was interpreted using the mean predicted values bound by their respective model prediction intervals. When mean predicted loads of one streamgage were contained in the prediction intervals of the other streamgage, and vice-versa, difference in the sediment budget were interpreted as “indeterminate.” Modeled sediment load balances demonstrated the depositional and erosional behaviors expected from the conceptual model of dam operations whereby sediment tends to accumulate during irrigation seasons when the dam is spilling over the top, and sediment tends to evacuate during the fallow seasons when it is flowing through the sluice gates at the base of the dam. The sediment load calculations using the rules-based model criteria indicated that between 14,200 and 380,000 tons of suspended sediment moved through the Shoshone River around Willwood Dam during the irrigation seasons of 2019, 2020, and 2021; 380,000 tons of suspended sediment were transported during the cool, wet year of 2019, and 14,200 tons of suspended sediment were transported in 2020, which was relatively dry. During fallow seasons 2019, 2020, and 2021, which had fewer complete records, between 1,140 and 106,000 tons of suspended sediment was estimated to have moved through the river. For all seasons except fallow season 2022, the models estimated that more sediment was released from the dam than entered the dam, but the modeled mean loads at each streamgage were nearly always within the prediction intervals of each other, making the sediment balance indeterminant. Examination of suspended-sediment loads during irrigation seasons indicated that between 65 and 85 percent of fine sediment was transported during annual high flows and storm events, with the remainder transported during steady, lower streamflows. Examination of suspended loads during fallow seasons indicated that deliberate sediment releases through Willwood Dam accounted for between 39 and 67 percent of the total sediment moved during the fallow seasons. Deliberate sediment releases from Willwood Dam had estimated net exports of between 1,360 and 22,400 tons. Between August 2017 and July 2023, suspended-sediment concentration and bedload sediment samples were collected from 9 tributaries to the Shoshone River during 137 sampling events, including stable and precipitation-runoff conditions. During irrigation season precipitation events, the mean total sediment yields ranged from 0.33 to 9.51 tons per day per square mile; during fallow season precipitation events, the mean total yields ranged from 0.04 to 0.95 ton per day per square mile. The mean total sediment yield per unit area across all samples at each tributary site ranged from 0.26 to 3.08 tons per day per square mile. Bedload was a minor fraction of the total load, constituting a mean of 4 percent across all samples; 3 and 6 percent for events and nonevents, respectively, during irrigation season; and 3 and 1 percent for events and nonevents, respectively, during the fallow season. With the exception of one tributary, Dry Creek, these mean yield values were within the range of watershed-scale background sediment yield values estimated from reservoir surveys and previous suspended-sediment studies. Imagery from irrigation seasons 2012, 2015, 2017, 2019, and 2022 was used to determine the planimetric backwater extent of the pool area in the Shoshone River behind Willwood Dam to identify any changes in sediment storage. Active river channel widths in the Shoshone River upstream from Willwood Dam were all similar between years except 2015, which was determined to be statistically different from all other years. Bathymetric data taken in the pool behind Willwood Dam during three different surveys between November 2017 and April 2022 indicated no statistically significant differences in bed elevations between the years. Results from the planimetric and bathymetric survey data provide multiple lines of evidence indicating that sediment did not accumulate behind the dam within the error of the methods used. Examination of how precipitation affects sediment transport in the Shoshone River upstream from Willwood Dam indicated that accumulated rainfall from the natural runoff events captured during the study period varied from a trace to as much as 4.26 inches, with associated predicted suspended-sediment loads varying from 112 to 232,000 tons of suspended sediment. The behavior of the sediment loads relative to accumulated precipitation did not appear to change depending on irrigation or fallow season. A model of suspended-sediment concentrations relative to the 2-day accumulated precipitation indicated that suspended-sediment concentrations in the Shoshone River upstream from Willwood Dam increased exponentially for accumulations of 0.3 inch or more; such storms accounted for 10 percent or less of precipitation events observed during the 1981 to 2018 period of record. The gaps in records, precision of the instrumentation, and large variation in grain sizes in suspended-sediment mixtures downstream from the dam made closing the sediment budgets for most seasons unattainable. The biggest recent change in sediment storage measured using the planimetric area of deposits behind Willwood Dam took place between 2015 and 2017. The main event between these two measurements was the installation of new Willwood Canal gates in October 2016, which resulted in the large unplanned sediment release. Because the sediment budgets were nearly always indeterminate and the planimetric and bathymetric data indicated little change in the bed and bank material, it is likely that the change in sediment storage behind the dam during the study period was small relative to the precision of the statistical models and other uncertainties. This body of evidence suggests that, averaged during the 3-year study period, no major changes in storage took place, and that the current operations may be keeping storage at near-equilibrium. This condition could have been initiated because the middle sluice gate has now been operational since 2014, and the sediment release in October 2016 evacuated a large amount of legacy sediment from storage. Although the uncertainties are large, sluicing events allow for controlled releases of sediment that contributed to the near equilibrium conditions observed over an annual basis during this study.

Wyoming↗

USGS2002

Estimation of nitrogen yields and loads from basins draining to Long Island Sound, 1988–98

Monitoring data on total nitrogen concentrations and streamflow were used to estimate annual nonpoint nitrogen loads for 1988?98 at 28 monitoring sites and 26 unmonitored basins that drain to Long Island Sound. The estimated total nitrogen yields at monitoring sites were used with basin characteristics and ancillary data to develop a multiple-linear regression equation to estimate nonpoint nitrogen yields from monitored and unmonitored basins. The estimated nonpoint nitrogen load to Long Island Sound from the basins studied ranged from 21 million pounds in water year 1995 to 50 million pounds in water year 1990. Statistically significant regression variables include time, population density, annual mean runoff (minus wastewater return flow), pointsource nitrogen yields, percentage of basin area classified as urban/recreational grasses, percentage of the basin classified as agricultural land, and the ratio of deciduous to total forest area. Nonpoint nitrogen loads from monitored and unmonitored basins were computed using the regression equation by setting the point-source nitrogen yields and wastewater return variables to zero, and incorporating streamflow information from index stations in or near unmonitored basins. Nonpoint nitrogen load information obtained through use of this equation was summarized by six Long Island Sound management zones. Estimates of nonpoint nitrogen loads from these basins can be improved by additional sampling, and by developing data on nitrogen loads from municipal wastewater-treatment facilities outside of Connecticut, compiling information on annual interbasin diversions of flow, studying instream losses of nitrogen, and analyzing the processing and storage of atmospheric nitrogen in different forest types.

New York↗

USGS1979

Floods in Puerto Rico, magnitude and frequency

Annual-peak discharge records at 50 sites in Puerto Rico with five or more years of record were used to determine individual site log-Pearson type III frequency curves. The frequency curve values for 2-, 10-, 25-, 50-, and 100-year recurrence intervals at 37 sites with 10 or more years of record were regressed against basin characteristics. Drainage area and mean annual rainfall proved to be the only independent variables significant at the 95 percent confidence level in these regression equations. (Woodard-USGS)

Water-Resources Investigations Report↗

USGS2000

Quality of wet deposition in the Grand Calumet River Watershed, northwestern Indiana, April 29, 1997–April 28, 1998

The Grand Calumet River, in northwestern Indiana, drains a heavily industrialized area along the southern shore of Lake Michigan. Steel production and petroleum refining are two of the area’s predominant industries. High-temperature processes, such as fossil fuel combustion and steel production, release contaminants to the atmosphere that may result in wet deposition being a major contributor to major-ion and trace-metal loadings in northwestern Indiana and Lake Michigan. A wet-deposition collection site was established at the Gary (Indiana) Regional Airport to monitor the quantity and chemical quality of wet deposition. During a first phase of sampling, 48 wet-deposition samples were collected weekly between June 30, 1992, and August 31, 1993. During a second phase of sampling, 40 wet-deposition samples were collected between October 17, 1995, and November 12, 1996. Forty-two wet-deposition samples were collected during a third phase of sampling, which began April 29, 1997, and was completed April 28, 1998. Wet- deposition samples were analyzed for pH, specific conductance, and selected major ions and trace metals. This report describes the quantity and quality of wet-deposition samples collected during the third sampling phase and compares these findings to the results of the first and second sampling phases. All of the samples collected during the third phase of sampling were of sufficient volumes for at least some of the analyses to be performed. Constituent concentrations from the third sampling phase were not significantly different (at the 5-percent significance level) from those for the second sampling phase. Significant increases, however, were observed in the concentrations of potassium, iron, lead, and zinc when compared to the concentrations observed in the first sampling phase. Weekly loadings were estimated for each constituent measured during the third sampling phase. If constituent concentrations were reported less than the method reporting limit, a range for the weekly loading was computed. The estimated annual loadings of chloride, silica, bromide, copper, and zinc during the third sampling phase were greater than those estimated for the first two sampling phases. The only estimated annual loading in the third sampling phase that was less than the estimated annual loadings observed during the first two sampling phases was sulfate. The estimated annual loadings of calcium, magnesium, nitrate, potassium, barium, lead, iron, and manganese observed during the third sampling phase were greater than the loadings observed during the first sampling phase but less than those observed during the second sampling phase. No significant differences were observed between the quantity of wet deposition collected during the three sampling phases.

Indiana↗