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At least 991 records · Page 55Linked to original sources
USGS2003

Environmental controls on water quality: Case studies from Battle Mountain mining district, north-central Nevada

The environmental controls on water quality were the focus of our study in a portion of the Battle Mountain mining district, north-central Nevada. Samples representing areas outside known mineralized areas, in undisturbed mineralized areas, and in mined areas were chemically and isotopically analyzed. The results are related to geologic, hydrologic, and climatic data. Streams in background areas outside the mineralized zones reflect normal weathering of volcanically derived rocks. The waters are generally dilute, slightly alkaline in pH, and very low in metals. As these streams flow into mineralized zones, their character changes. In undisturbed mineralized areas, discharge into streams of ground water through hydrologically conductive fractures can be traced with chemistry and, even more effectively, with sulfur isotopic composition of dissolved sulfate. Generally, these tracers are much more subtle than in those areas where mining has produced adits and mine-waste piles. The influence of drainage from these mining relicts on water quality is often dramatic, especially in unusually wet conditions. In one heavily mined area, we were able to show that the unusually wet weather in the winter and spring greatly degraded water quality. Addition of calcite to the acid, metalrich mine drainage raised the stream pH and nearly quantitatively removed the metals through coprecipitation and (or) adsorption onto oxyhydroxides. This paper is divided into four case studies used to demonstrate our results. Each addresses the role of geology, hydrology, mining activity and (or) local climate on water quality. Collectively, they provide a comprehensive look at the important factors affecting water quality in this portion of the Battle Mountain mining district.

Nevada↗
USGS1997

Pesticides in surface and ground water of the San Joaquin-Tulare basins, California: Analysis of available data, 1966 Through 1992

Available pesticide data (1966-92) for surface and ground water were analyzed for the San Joaquin-Tulare Basins, California, one of 60 large hydrologic systems being studied as part of the National Water-Quality Assessment Program of the U.S. Geological Survey. Most of the pesticide data were for the San Joaquin Valley, one of the most intensively farmed and irrigated areas of the United States. Data were obtained from the Storage and Retrieval data base of the U.S. Environmental Protection Agency, the water-quality data base of the U.S. Geological Survey, and from data files of State agencies. Pesticides detected in surface water include organochlorine pesticides, organophosphate pesticides, carbamate pesticides, and triazine herbicides. Pesticides detected in ground water include triazine and other organonitrogen herbicides and soil fumi gants. Surface-water data indicate seasonal patterns for the detection of organophosphate and carbamate pesticides, which are attributed to their use on almond orchards and alfafa fields. Organochlorine pesticides were detected primarily in river-bed sediments. Concentrations detected in bed sediments of the San Joaquin River near Vernalis are among the highest of any major river system in the United States. Patterns and timing of pesticide use indicate that pesticides might be present in surface-water systems during most months of a year. The most commonly detected pesticide in ground water is the soil fumigant, dibromochloropropane. Dibromochloropropane, used primarily on vineyards and orchards, was detected in ground water near the city of Fresno. Triazine and other organonitrogen herbicides were detected near vineyards and orchards in the same general locations as the detections of dibromochloropropane. Pesticides were detected in ground water of the east side of the valley floor, where the soils are sandy or coarsegrained, and water-soluble pesticides with long environmental half-lives were used. In contrast, fewer pesticides were detected in ground water of the west side of the valley, where soils generally are finer grained.

California↗
USGS1984

Water resources of the Palau Islands

The Palau Islands are a group of 350 islands, ranging in size from a few hundred square feet to the 153-square-mile island of Babelthuap. Babelthuap is the second largest island in the Western Pacific and comprises more than 80 percent of the total land area of the Palau Islands. Most of the islands are uninhabited limestone ridges covered with dense vegetation. These islands have no freshwater resources and are not included in this report. The island of Koror with an area of 3.6 square miles is the administrative, commercial, and population center of Palau and has an annual average rainfall of 148 inches. Short-term rainfall records at other locations in the islands indicate little variation in annual rainfall throughout the Palau Islands. Runoff-to-rainfall ratios for streams on Babelthuap show that about 70 percent of the rain falling on the island runs off to the ocean. The uniformity of rainfall and basin characteristics is shown by the excellent correlation between mean annual rainfall on Koror and streamflow on Babelthuap and by the close correlations between discharge at gaging stations and partial-record sites. Surface water quality is generally very good as shown by 55 chemical analyses of water from 18 sources. The dissolved solids concentration of water samples did not exceed 66 milligrams per liter. This report summarizes in one volume hydrologic data collection in a 14-year period of study and provides interpretations of the data than can be used by planners and public works officials as a basis for making decisions on the development and management of the islands' water resources.

Water-Resources Investigations Report↗
USGS1992

Geologic and hydrologic data collected at test holes NC-4 and NC-14, Manati and Vega Baja, Puerto Rico

Test holes NC-4 and NC-14 were drilled in the municipalities of Manati and Vega Baja, respectively, in northern Puerto Rico as part of a study of the ground-water resources in the Northern Coastal Province of Puerto Rico. This study was conducted from 1986 to 1988 by the U.S. Geological Survey in cooperation with the Puerto Rico Department of Natural Resources. Test holes NC-4 and NC-14 were drilled to depths of 1,898 and 1,837 feet below land surface, respectively. Geologic and hydrologic data collected during drilling included continuous core lithology, water-quality measurements, water levels, and estimates of aquifer yields from the water-bearing zones. Detailed petrological and microfaunal analyses of the cores were used to determine the mineralogical content, ages, and paleoenvironments of deposition. Analysis of the core recovered from test hole NC-4 indicated that four geologic formations of middle Tertiary age were penetrated, these were in descending order: the Aymam6n Limestone, the Los Puertos Limestone, the Cibao Formation, and the Lares Limestone. The Tertiary formations are capped by surficial deposits of Quaternary age. Test hole NC-14 penetrated rocks of middle Tertiary age that included three geologic formations, these were in descending order: the AymamOn Limestone, the Los Puertos Limestone, and the Cibao Formation. These formations are overlain by surficial deposits of Quaternary age. In both test holes the Cibao Formation consisted of the undifferentiated Quebrada Arenas and the Rio Indio Limestone Members of the Cibao Formation and an unnamed mudstone unit. Test hole NC-4 penetrated three water-bearing units: a water-table aquifer and two artesian aquifers. The specific conductance in the water-table aquifer ranged from 500 to 38,000 microsiemens per centimeter at 25 degrees Celsius. The specific conductance ranged from 740 to 800 microsiemens per centimeter at 25 degrees Celsius in the two artesian aquifers. The relative yield ranged from 120 to 195 gallons per minute in the water-table aquifer and from 60 to 195 gallons per minute in the artesian aquifers. The water level ranged from 81 to 89 feet below land surface in the water-table aquifer. In the artesian aquifers, water levels ranged from 22 feet below land surface to 88 feet above land surface. Test hole NC-14 penetrated four water-bearing units: a water-table aquifer and three artesian aquifers. The specific conductance in the water-table aquifer ranged from 590 microsiemens per centimeter at 25 degrees Celsius at a depth of 40 feet to 49,500 microsiemens per centimeter at 25 degrees Celsius at 1,010 feet below land surface. In the artesian aquifers specific conductance was about 700 microsiemens per centimeter at 25 degrees Celsius. The relative yield ranged from 58 to 370 gallons per minute in the water-table aquifer, and from 15 to 60 gallons per minute in the artesian aquifers. The water level in the water table aquifer ranged from 20 to 32 feet below land surface. In the artesian aquifers the water levels ranged from 18 feet below land surface to 19 feet above land surface.

Open-File Report↗
USGS2000

Comparison of water-quality samples collected by siphon samplers and automatic samplers in Wisconsin

In small streams, flow and water-quality concentrations often change quickly in response to meteorological events. Hydrologists, field technicians, or locally hired stream ob- servers involved in water-data collection are often unable to reach streams quickly enough to observe or measure these rapid changes. Therefore, in hydrologic studies designed to describe changes in water quality, a combination of manual and automated sampling methods have commonly been used manual methods when flow is relatively stable and automated methods when flow is rapidly changing. Auto- mated sampling, which makes use of equipment programmed to collect samples in response to changes in stage and flow of a stream, has been shown to be an effective method of sampling to describe the rapid changes in water quality (Graczyk and others, 1993). Because of the high cost of automated sampling, however, especially for studies examining a large number of sites, alternative methods have been considered for collecting samples during rapidly changing stream conditions. One such method employs the siphon sampler (fig. 1). also referred to as the "single-stage sampler." Siphon samplers are inexpensive to build (about $25- $50 per sampler), operate, and maintain, so they are cost effective to use at a large number of sites. Their ability to collect samples representing the average quality of water passing though the entire cross section of a stream, however, has not been fully demonstrated for many types of stream sites.

Wisconsin↗
USGS2010

Estimated Withdrawals and Use of Water in Colorado, 2005

The future health and economic welfare of the people and environment of Colorado depend on a continuous supply of fresh water. Detailed, comprehensive information on the use of water from Colorado's diverse surface-water and groundwater resources is important to water managers and planners by providing information they need to quantify current stresses and estimate and plan for future water needs. As part of the U.S. Geological Survey's (USGS) National Water Use Information Program (NWUIP), Statewide water withdrawal and water-use data have been collected or estimated and summarized in this report by county and by four-digit hydrologic unit code for the following seven water-use categories: irrigation (crop and golf course), public supply, self-supplied domestic, self-supplied industrial, livestock, mining, and thermoelectric power generation. A summary for instream water use for hydroelectric power generation also is included. This report is published in cooperation with the Colorado Water Conservation Board. In 2005, an estimated 13,581.22 million gallons per day (Mgal/d) was withdrawn from groundwater and surface-water sources in Colorado for the seven water-use categories. Withdrawals from surface water represented about 11,035 Mgal/d, or 81.3 percent of the total, whereas withdrawals from groundwater sources represented an estimated 2,546 Mgal/d or 18.7 percent of the total. Irrigation (combined crop and golf course) totaled 12,362.49 Mgal/d or 91 percent of the total water withdrawals in the State of Colorado. Crop irrigation accounted for 99.7 percent (12,321.85 Mgal/d) of the irrigation, whereas the 243 turf golf courses in Colorado accounted for 0.3 percent (40.64 Mgal/d) of the total irrigation water withdrawals. Total withdrawals for the other water-use categories were public supply, 864.17 Mgal/d; self-supplied domestic, 34.43 Mgal/d; self-supplied industrial, 142.44 Mgal/d; livestock, 33.06 Mgal/d; mining, 21.42 Mgal/d (includes both fresh and saline water); and thermoelectric, 123.21 Mgal/d. The counties with the largest total withdrawals (greater than 500 Mgal/d) were Mesa, Weld, Rio Grande, Montrose, Gunnison, and Saguache. Counties with the smallest total withdrawals (less than 5 Mgal/d) were Clear Creek, Gilpin, and San Juan. Four-digit hydrologic unit codes with the greatest withdrawals were 1019 (South Platte River Basin), 1301 (Rio Grande Basin), and 1102 (Arkansas River Basin); the high withdrawal rates were driven by crop irrigation withdrawals. Total instream water use for hydroelectric power generation was 5,253.60 Mgal/d. Groundwater withdrawals were estimated for 2004 for the bedrock and overlying alluvial aquifers in the Denver Basin for irrigation, public supply, commercial/industrial, household use only, and domestic/livestock water-use categories. Withdrawals were estimated for input into the USGS Denver Basin model by using the equations in the Senate Bill 96-074 groundwater model. The greatest withdrawals were for public supply. The smallest withdrawals were for household-use-only wells. Douglas County had the greatest groundwater withdrawals (183.98 Mgal/d), whereas Broomfield County had the smallest (3.09 Mgal/d). Of the seven Denver Basin aquifers, the Lower Arapahoe aquifer had the greatest total estimated withdrawals (287.11 Mgal/d), with Douglas County having the greatest public-supply withdrawal of any county (95.29 Mgal/d) from this aquifer. The Upper Dawson aquifer was the least used of the Denver Basin aquifers, based on estimated withdrawals of 17.64 Mgal/d. As part of the Colorado Statewide Water Supply Initiative (SWSI), forecasts of future water demand were made based on information such as population, climate, and then-current (2000) water-use information and did not include the effects of future water conservation. Categories compared between estimates in the SWSI baseline forecasted water demand and the USGS water-use compilation were limited to county population and w

Scientific Investigations Report↗
USGS1984

VERTICAL MOVEMENT OF GROUND WATER UNDER A LANDFILL, ANCHORAGE, ALASKA.

A thorough review of existing ground-water information may, in some cases, be adequate to estimate rates of migration of pollutants. Analysis of data from well-performance tests and from hydrologic-data stations near a landfill in Anchorage, Alaska, indicates that pollutants migrating downward toward a confined aquifer that supplies water to three municipal wells near the landfill do not pose an imminent threat to the water supply. The analysis helps alleviate some concerns that pollution of municipal wells is imminent. However, because the errors in estimating hydraulic conductivities may be as great as a factor of three, the analysis should not be used as justification to discontinue monitoring migration of the leachate.

Conference Paper↗
USGS2006

Phosphorus Concentrations, Loads, and Yields in the Illinois River Basin, Arkansas and Oklahoma, 2000-2004

The Illinois River and tributaries, Flint Creek and Baron Fork, are designated scenic rivers in Oklahoma. Recent phosphorus levels in streams in the basin have resulted in the growth of excess algae, which have limited the aesthetic benefits of water bodies in the basin, especially the Illinois River and Lake Tenkiller. The Oklahoma Water Resources Board has established a standard for total phosphorus not to exceed the 30-day geometric mean concentration of 0.037 milligram per liter in Oklahoma Scenic Rivers. The U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, conducted an investigation to summarize phosphorus concentrations and provide estimates of phosphorus loads, yields, and flow-weighted concentrations in the Illinois River and tributaries from January 2000 through December 2004. Data from water-quality samples collected from 2000 to 2004 were used to summarize phosphorus concentrations and estimate phosphorus loads, yields, and mean flow-weighted concentrations in the Illinois River basin for three 3-year periods - 2000-2002, 2001-2003, and 2002-2004, to update a previous report that used data from water-quality samples from 1997 to 2001. This report provides information needed to advance knowledge of the regional hydrologic system and understanding of hydrologic processes, and provides hydrologic data and results useful to multiple parties for interstate compacts. Phosphorus concentrations in the Illinois River basin were significantly greater in runoff samples than in base-flow samples. Phosphorus concentrations generally decreased with increasing base flow, from dilution, and decreased in the downstream direction in the Illinois River from the Watts to Tahlequah stations. Phosphorus concentrations generally increased with runoff, possibly because of phosphorus resuspension, stream bank erosion, and the addition of phosphorus from nonpoint sources. Estimated mean annual phosphorus loads were greater at the Illinois River stations than at Flint Creek and Baron Fork. Annual total loads in the Illinois River from Watts to Tahlequah, increased slightly for the period 2000-2002 and decreased slightly for the periods 2001-2003 and 2002-2004. Estimated mean annual base-flow loads at stations on the Illinois River were about 11 to 20 times greater than base-flow loads at the station on Baron Fork and 4 to 10 times greater than base-flow loads at the station on Flint Creek. Estimated mean annual runoff loads ranged from 68 to 96 percent of the estimated mean annual total phosphorus loads from 2000-2004. Estimated mean seasonal base-flow loads were generally greatest in spring (March through May) and were least in fall (September through November). Estimated mean seasonal runoff loads generally were greatest in summer (June through August) for the period 2000-2002, but were greatest in winter (December through February) for the period 2001-2003, and greatest in spring for the period 2002-2004. Estimated mean total yields of phosphorus ranged from 192 to 811 pounds per year per square mile, with greatest yields being reported for Illinois River near Watts (576 to 811 pounds per year per square mile), and the least yields being reported for Baron Fork at Eldon for the periods 2000-2002 and 2001-2003 (501 and 192 pounds per year per square mile) and for Illinois River near Tahlequah for the period 2002-2004 (370 pounds per year per square mile). Estimated mean flow-weighted concentrations were more than 10 times greater than the median (0.022 milligram per liter) and were consistently greater than the 75th percentile of flow-weighted phosphorus concentrations in samples collected at relatively undeveloped basins of the United States (0.037 milligram per liter). In addition, flow-weighted phosphorus concentrations in 2000-2002 at all Illinois River stations and at Flint Creek near Kansas were equal to or greater than the 75th percentile of all National Water-Quality Assessment Program station

Scientific Investigations Report↗
USGS1992

Simulation of water-table response to management alternatives, central part of the western San Joaquin Valley, California

The occurrence of selenium in agricultural drainwater in the central pan of the western San Joaquin Valley, California, has focused concern on alternatives other than agricultural drains for managing shallow, poor-quality ground water. A transient, three-dimensional, finite-difference ground-water flow model was developed to assess the response of the water table to various management alternatives. The modeled area is 551 square miles and includes the semiconfined and confined zones above and below the Corcoran Clay Member of the Tulare Formation of Pleistocene age. The model was calibrated using hydrologic data from 1972 to 1988 and was able to reproduce the average change in water-table altitude to within 4 percent. The calibrated model was extended to forecast to the year 2040 for various management alternatives including maintenance of present practices, land retirement, reduced recharge, increased ground-water pumping, combinations of these alternatives, and five alternatives proposed by the U.S. Bureau of Reclamation. The model indicates that if current rates of recharge and pumping (as determined from an analysis of 1980 water-budget data) are maintained, the total area subject to bare-soil evaporation will increase by more than 50 percent and drainflow will increase by 20 percent. Model results indicate that retirement of land will result in a water-table decline beneath the area retired, but the effect on adjacent areas will be small to negligible. The effects of reducing recharge or increasing ground-water pumping vary with the magnitude of the change relative to average conditions and the size of the area managed. The area of land subject to bare-soil evaporation and the amount of drainflow in the model area can be reduced by more than 40 and 50 percent, respectively, if (1) recharge is reduced by 40 percent (about 0.3 foot per year) in areas that currently use only surface water, and by 15 percent (an average of about O. 1 foot per year) in the remainder of the model area; (2) pumping is increased by 0.5 foot per year in areas that currently use surface and ground water.

Water-Resources Investigations Report↗
USGS2016

The road to NHDPlus — Advancements in digital stream networks and associated catchments

A progression of advancements in Geographic Information Systems techniques for hydrologic network and associated catchment delineation has led to the production of the National Hydrography Dataset Plus (NHDPlus). NHDPlus is a digital stream network for hydrologic modeling with catchments and a suite of related geospatial data. Digital stream networks with associated catchments provide a geospatial framework for linking and integrating water-related data. Advancements in the development of NHDPlus are expected to continue to improve the capabilities of this national geospatial hydrologic framework. NHDPlus is built upon the medium-resolution NHD and, like NHD, was developed by the U.S. Environmental Protection Agency and U.S. Geological Survey to support the estimation of streamflow and stream velocity used in fate-and-transport modeling. Catchments included with NHDPlus were created by integrating vector information from the NHD and from the Watershed Boundary Dataset with the gridded land surface elevation as represented by the National Elevation Dataset. NHDPlus is an actively used and continually improved dataset. Users recognize the importance of a reliable stream network and associated catchments. The NHDPlus spatial features and associated data tables will continue to be improved to support regional water quality and streamflow models and other user-defined applications.

Journal of the American Water Resources Associatio↗
USGS2012

Passive thermal refugia provided warm water for Florida manatees during the severe winter of 2009-2010

Haloclines induced by freshwater inflow over tidal water have been identified as an important mechanism for maintaining warm water in passive thermal refugia (PTR) used by Florida manatees Trichechus manatus latirostris during winter in extreme southwestern Florida. Record-setting cold during winter 2009–2010 resulted in an unprecedented number of manatee deaths, adding to concerns that PTR may provide inadequate thermal protection during severe cold periods. Hydrological data from 2009–2010 indicate that 2 canal systems in the Ten Thousand Islands (TTI) region acted as PTR and maintained warm bottom-water temperatures, even during severe and prolonged cold periods. Aerial survey counts of live and dead manatees in TTI during the winter of 2009–2010 suggest that these PTR were effective at preventing mass mortality from hypothermia, in contrast to the nearby Everglades region, which lacks similar artificial PTR and showed high manatee carcass counts. Hydrological data from winter 2008–2009 confirmed earlier findings that without haloclines these artificial PTR may become ineffective as warm-water sites. Tidal pumping of groundwater appears to provide additional heat to bottom water during low tide cycles, but the associated thermal inversion is not observed unless salinity stratification is present. The finding that halocline-driven PTR can maintain warm water even under extreme winter conditions suggests that they may have significant potential as warm-water sites. However, availability and conflicting uses of freshwater and other management issues may make halocline-driven PTR unreliable or difficult to manage during winter.

Florida↗
USGS1986

Selected geohydrologic data for the Mesilla Basin, Dona Ana County, New Mexico, and El Paso County, Texas

In 1983, the U.S. Geological Survey began a multiphase study to help define the hydrologic system of the Mesilla Basin in Dona Ana County, New Mexico, and El Paso County, Texas. This report is a compilation of selected geohydrologic data collected through July 1985. The report describes the groundwater monitoring network of 143 wells, including 3 hydrologic sections constructed across the Mesilla Valley. Geohydrologic data presented in the report include: well records and water levels from 143 wells, chemical analyses of water samples from 34 observation wells, borehole-geophysical logs of 10 observation wells, and river stage at 3 hydrologic sections. (USGS)

Open-File Report↗
USGS2011

Groundwater conditions and studies in Georgia, 2008-2009

The U.S. Geological Survey collects groundwater data and conducts studies to monitor hydrologic conditions, better define groundwater resources, and address problems related to water supply, water use, and water quality. In Georgia, water levels were monitored continuously at 179 wells during 2008 and 181 wells during 2009. Because of missing data or short periods of record (less than 3 years) for several of these wells, a total of 161 wells are discussed in this report. These wells include 17 in the surficial aquifer system, 19 in the Brunswick aquifer and equivalent sediments, 66 in the Upper Floridan aquifer, 16 in the Lower Floridan aquifer and underlying units, 10 in the Claiborne aquifer, 1 in the Gordon aquifer, 11 in the Clayton aquifer, 12 in the Cretaceous aquifer system, 2 in Paleozoic-rock aquifers, and 7 in crystalline-rock aquifers. Data from the well network indicate that water levels generally rose during the 2008-2009 period, with water levels rising in 135 wells and declining in 26. In contrast, water levels declined over the period of record at 100 wells, increased at 56 wells, and remained relatively constant at 5 wells. In addition to continuous water-level data, periodic water-level measurements were collected and used to construct potentiometric-surface maps for the Upper Floridan aquifer in Camden, Charlton, and Ware Counties, Georgia, and adjacent counties in Florida during September 2008 and May 2009; in the Brunswick, Georgia area during July 2008 and July-August 2009; and in the City of Albany-Dougherty County, Georgia area during November 2008 and November 2009. In general, water levels in these areas were higher during 2009 than during 2008; however, the configuration of the potentiometric surfaces in each of the areas showed little change. Groundwater quality in the Floridan aquifer system is monitored in the Albany, Savannah, Brunswick, and Camden County areas of Georgia. In the Albany area, nitrate as nitrogen concentrations in the Upper Floridan aquifer during 2008-2009 generally increased, with concentrations in two wells above the U.S. Environmental Protection Agency (USEPA) 10-milligrams-per-liter (mg/L) drinking-water standard. In the Savannah area, measurement of specific conductance and chloride concentration in water samples from discrete depths in three wells completed in the Upper Floridan aquifer indicate that chloride concentrations in the Upper Floridan aquifer showed little change and remained below the 250 mg/L USEPA secondary drinking-water standard. Chloride concentrations in the Lower Floridan aquifer increased slightly at Tybee Island and Skidaway Island, remaining above the drinking-water standard. In the Brunswick area, maps showing the chloride concentration of water in the Upper Floridan aquifer were constructed using data collected from 28 wells during July 2008 and from 29 wells during July-August 2009, indicate that chloride concentrations remained above the USEPA secondary drinking-water standard in an approximately 2-square-mile area. During 2008-2009, chloride concentrations decreased, with a maximum decrease of 160 mg/L, in a well located in the northern part of the Brunswick area. In the Camden County area, chloride concentration during 2008-2009 was analyzed in water samples collected from eight wells, six of which were completed in the Upper Floridan aquifer and two in the Lower Floridan aquifer. In most of the wells sampled during this period, chloride concentrations did not appreciably change; however, since the closure of the Durango Paper Company in October 2002, chloride concentrations in the Upper Floridan aquifer near the paper mill decreased from a high of 184 mg/L in May 2002 to 41 mg/L in September 2009. Groundwater studies conducted in Georgia during 2008-2009 include the following: * evaluation of groundwater flow, water-quality, and water-level monitoring in the Augusta-Richmond County area; * evaluation of groundwater flow, water-quality, and water

Georgia↗
USGS2024

Small forested watershed weathers effects of climate change better than a nearby urban watershed in Northern Virginia, USA

South Fork Quantico Creek (SFQ; 19.8 square kilometre (km 2 ), forested) and Fourmile Run (4MR; 32.4-km 2 , urban) are small watersheds in northern Virginia, United States. Precipitation and streamflow data for both watersheds were examined from water year (WY) 1952 through 2022. Temporal changes in hydrologic metrics were identified by calculating trends in annual precipitation, annual peak flow, mean daily flow, minimum daily flow, stream flashiness, and the runoff ratio. The impact of climate and urbanization on watershed hydrology was assessed by computing trends on both raw and precipitation-adjusted data. Despite increasing precipitation in both watersheds, increasing monotonic trends in most hydrologic metrics were observed only in 4MR. At 4MR, the long-term trend in annual peak flow was non-linear, thus trends were calculated on separate periods. Annual peak flow increased from WY 1952 through 1968, coinciding with a period of rapid urbanization. During WY 1969 through 1981, annual peak flows decreased, coinciding with construction of a flood channelization project. Trends for both periods were robust to precipitation adjustment. From WY 1982 through 2022, no change in the precipitation-adjusted annual peak flows occurred, suggesting annual peak flows increased due to climate factors during this period. Comparison of area-normalized hydrologic metrics between the two watersheds revealed higher flows in 4MR than SFQ across all flows, not just high flows. Runoff ratio and stream flashiness also were higher in 4MR. Differences in hydrologic metrics between the two watersheds were driven primarily by differences in land use, land cover, and modifications to the water balance related to urbanization. Climate change has altered watershed hydrology at both sites, but extensive urbanization in 4MR has altered the hydrology more than that of SFQ. We conclude that urban watersheds are likely at greater risk of increased flooding than less developed areas as the climate intensifies.

Virginia↗
USGS1984

Water resources of Ponape, Caroline Islands

Ponape is the third largest island in the western Pacific, with a land area of 129 square miles. The island is volcanic, nearly circular in shape, and covered with lush tropical vegetation. The mountainous interior has the highest peaks in the western Pacific. Annual rainfall at Kolonia and other coastal areas is 191 inches. Inland at higher elevations, the rainfall is considerably higher. The upper Nanpil River basin averages about 340 inches annually. Runoff-to-rainfall ratios for Ponapean streams show that about two thirds of the rain falling on the island runs off. Flow-duration curves show the similarity of the geology, vegetation, and rainfall of the drainage basins and indicate little ground-water contribution to surface runoff. Surface-water quality is excellent as shown by 53 chemical anlyses of water from 19 streams. Water of the Nanpil River, the source of water for the central water system, is especially low in dissolved elements and solids. This report summarizes in one volume all the hydrologic data collected and provides analyses that may be used by planning and public works officials as a basis for making decisions on the development and management of their water resources. (USGS)

Water-Resources Investigations Report↗
USGS2005

Surface water-quality and water-quantity data from selected urban runoff-monitoring sites at the Rocky Mountain Arsenal, Commerce City, Colorado, water years 1988-2004

The U.S. Geological Survey has monitored the quality and quantity of streamflow at the Rocky Mountain Arsenal (RMA) northeast of Denver, Colorado, since the early 1990s in cooperation with the U.S. Army. This report, prepared in cooperation with the U.S. Fish and Wildlife Service, documents existing surface-water-quality conditions on the RMA. All RMA water-quality data for the Irondale Gulch and First Creek Basins adjacent to and on the RMA were reviewed. Where applicable, water-quality data were compared to State standards established by the Colorado Department of Public Health and Environment. At both the Havana Interceptor below 56th Avenue gaging station and the Uvalda Interceptor below 56th Avenue gaging station, all of the dissolved-oxygen concentrations met the State standard requiring at least 5.0 milligrams per liter (mg/L) of dissolved oxygen for the protection of aquatic life. In contrast, the dissolved-oxygen concentrations at the Peoria Interceptor below 56th Avenue gage commonly were less than 5.0 mg/L. Excluding one suspect concentration of 1.6 mg/L, the dissolved-oxygen concentrations for the First Creek Basin ranged from 4.2 to 12.6 mg/L. Excluding the one suspect value, three dissolved-oxygen concentrations failed to meet the State standard of 5.0 mg/L at the First Creek below Buckley Road site. At the Peoria Interceptor below 56th Avenue site, all pH values were within the range specified by the State standard (6.50-8.99). Results of seven sampling events at the Havana Interceptor below 56th Avenue gaging station indicated a pH greater than or equal to 9 (pH values of 9 or greater exceed the upper limit of the standard). No sampling events indicated a pH less than 6.50. Results from one sampling event at the Uvalda Interceptor below 56th Avenue indicated pH values outside the range specified by the State standard. The concentrations obtained for chloride, magnesium, and sodium generally were below 200 mg/L at all three Irondale Gulch monitoring stations for the entire period of record, but there were a few sampling events at each of these sites where much higher concentrations for these analytes were obtained. The median concentrations for calcium, magnesium, and sodium generally were higher at the First Creek below Buckley Road site than in the three Irondale Gulch sites, while the 90th percentile and maximum concentrations for magnesium and sodium generally were higher at the three Irondale Gulch sites than at the First Creek below Buckley Road site. The urban runoff flowing onto the RMA had low concentrations and few, if any, detections for most organic contaminants. Part of the reason for low detections of organic contaminants may be in how the samples are collected. The existing surface-water sampling program was not designed specifically to target storm runoff and therefore does not characterize water quality for all hydrologic regimes, most notably storm runoff. As a result, the existing data may not adequately represent potential contaminant transport onto the RMA. In addition, during stormwater-runoff events, the sites examined for this report frequently are subject to sharp increases in discharge, and just as quickly the discharge rapidly recedes. These types of transient flow events make water-quality sampling difficult, and none of the sites have a safe place to sample the higher flows that occur in any given year. As a result, most of the surface-water-quality samples were collected after the flow had decreased substantially from the peak flow, which may have transported much of the chemical contaminant load through the system. Thus, little is known about the water quality during the critical initial stormwater-runoff period when contaminants are most likely to be mobilized and transported through the stormwater conveyances past the locations where gaging stations are located.

Colorado↗
USGS2020

Estimating late 19th century hydrology in the Greater Everglades Ecosystem: An integration of paleoecologic data and models

Determining hydrologic conditions prior to instrumental records is a challenge for restoration of freshwater ecosystems worldwide. Paleoecologic data provide this information on past conditions and when these data are used to adjust hydrologic models, allow conditions to be hindcast that may not be directly estimated from the paleo-data alone. In this context, the paleo-data provide real-world estimates as input to the models. Restoration of the Greater Everglades Ecosystem requires this understanding of the hydrology of the natural system prior to significant alterations due to water management and land use. Large scale models such as the Natural Systems Model (NSM 4.6.2) have been used by the South Florida Water Management District and other agencies responsible for restoration to estimate past hydrologic conditions; however, these models typically portray a drier natural system for the beginning of the 20th century than what is indicated by paleoecologic analyses and historical data. The purpose of this study is to estimate pre-20th century water levels, hydroperiods and flow in the freshwater wetlands of the Everglades by using pollen assemblage data in three sediment cores to adjust the Natural Systems Model. This study is designed to further test estimates of flow through the Everglades derived from analysis of sediment cores collected in Florida Bay. The results demonstrate that the NSM 4.6.2 underestimates water levels and hydroperiods in the Everglades compared to the paleo-adjusted NSM 4.6.2 model outputs. Flow models that use the paleo-adjusted water levels as input indicate flow through Shark River Slough in the late 19th century was approximately two times flow between 1990 and 2000, and flow through Taylor Slough was approximately three times flow between 1990 and 2000. The flow estimates derived from this study agree with the estimates derived from earlier studies using estuarine cores. This integration of paleoecologic information and hydrologic models provides resource managers with the best available estimates of past conditions and allows them to set realistic targets for restoration of freshwater ecosystems.

Florida↗
USGS2018

Streamflow contributions from tribal lands to major river basins of the United States

While many studies on tribal water resources of individual tribal lands in the United States (US) have been conducted, the importance of tribal water resources at a national scale has largely gone unrecognized because their combined totals have not been quantified. Thus, we sought to provide a numerical estimate of major water budget components on tribal lands within the conterminous US and on USGS hydrologic unit codes (HUC2) regions. Using existing national-scale data and models, we estimated mean annual precipitation, evapotranspiration, excess precipitation, streamflow, and water use for the period 1971–2000. Tribal lands represent about 3.4 percent of the total land area of the conterminous US and on average account for 1.9 percent of precipitation, 2.4 percent of actual evapotranspiration, 0.95 percent of excess precipitation, 1.6 percent of water use, and 0.43 percent of streamflow origination. Additionally, approximately 9.5 and 11.3 percent of US streamflow flows through or adjacent as boundaries to tribal lands, respectively. Streamflow through or adjacent to tribal lands accounts for 42 and 48 percent of streamflow in the Missouri region, respectively; and for 86 and 88 percent in the Lower Colorado region, respectively. On average, 5,600 million cubic meters of streamflow per year was produced on tribal lands in the Pacific Northwest region, nearly five times greater than tribal lands in any other region. Tribal lands in the Great Lakes, Missouri, Arkansas-White-Red, and California regions all produced between 1,000 and 1,400 million cubic meters per year.

PLoS ONE↗