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At least 163 records · Page 9Linked to original sources
USGS2022

Biophysical methods and data analysis for simulating overland flow in the Everglades

The Everglades in south Florida supply fresh drinking water for more than 7 million people, host a National Park, and are classified as a Ramsar wetland of international distinction. Predicting trajectories of water flow and water storage changes in the future is important to managing the Congressionally authorized restoration of the Everglades. Here we describe the needed data sources and analysis approaches to build the inputs for biophysically based modeling that can protect water and ecological resources in the face of changing water management and climate conditions. A biophysical approach to modeling overland flow in the Everglades can help predict future outcomes for ecological habitat, water storage during droughts, and water conveyance during floods. The needed data include measurements of vegetation stem architecture, microtopography, and landscape pattern metrics. Stem architecture measurements present the opportunity to estimate flow roughness of distinct vegetation communities based on hydraulic principles. At a larger scale, the microtopography and the connectivity of the sloughs between ridges offer a way to quantify the effects of flow blockage and tortuous flow paths on overland flow. Combined with theory these data provide the capacity to simulate overland flow in both the historical, pre-drainage Everglades as well as in the present-day managed Everglades. Also provided are the hydrologic data, e.g., water slopes, water depths and overland flow velocities, that can be used to verify a biophysical model. Ultimately, the purpose is to anticipate how changing flow and water depth will interact with evolving vegetation and landscape conditions to influence future water availability for society and for the ecosystem, both in the Everglades and in other low-gradient floodplains.

Florida↗
USGS2011

Hydrologic assessment of three drainage basins in the Pinelands of southern New Jersey, 2004-06

The New Jersey Pinelands is an ecologically diverse area in the southern New Jersey Coastal Plain, most of which overlies the Kirkwood-Cohansey aquifer system. The demand for groundwater from this aquifer system is increasing as local development increases. Because any increase in groundwater withdrawals has the potential to affect streamflows and wetland water levels, and ultimately threaten the ecological health and diversity of the Pinelands ecosystem, the U.S. Geological Survey, in cooperation with the New Jersey Pinelands Commission, began a multi-phase hydrologic investigation in 2004 to characterize the hydrologic system supporting the aquatic and wetland communities of the New Jersey Pinelands area (Pinelands). The current investigation of the hydrology of three representative drainage basins in the Pinelands (Albertson Brook, McDonalds Branch, and Morses Mill Stream basins) included a compilation of existing data; collection of water-level and streamflow data; mapping of the water-table altitude and depth to the water table; and analyses of water-level and streamflow variability, subsurface gradients and flow patterns, and water budgets. During 2004-06, a hydrologic database of existing and new data from wells and stream sites was compiled. Methods of data collection and analysis were defined, and data networks consisting of 471 wells and 106 surface-water sites were established. Hydrographs from 26 water-level-monitoring wells and four streamflow-gaging stations were analyzed to show the response of water levels and streamflow to precipitation and recharge with respect to the locations of these wells and streams within each basin. Water-level hydrographs show varying hydraulic gradients and flow potentials, and indicate that responses to recharge events vary with well depth and proximity to recharge and discharge areas. Results of the investigation provide a detailed characterization of hydrologic conditions, processes, and relations among the components of the hydrologic cycle in the Pinelands. In the Pinelands, recharge replenishes the aquifer system and contributes to groundwater flow, most of which moves to wetlands and surface water where natural discharge occurs. Some groundwater flow is intercepted by supply wells. Recharge rates generally are highest during the non-growing season and are inversely related to evapotranspiration. Analysis of subsurface hydraulic gradients, water-table fluctuations, and streamflow variability indicates a strong linkage between groundwater and wetlands, lakes and streams. Gradient analysis indicates that most wetlands are in groundwater discharge areas, but some wetlands are in groundwater recharge areas. The depth to the water table ranges from zero at surface-water features up to about 10 meters in topographically high areas. Depth to water fluctuates seasonally, and the magnitude of these fluctuations generally increases with distance from surface water. Variations in the permeability of the soils and sediments of the aquifer system strongly affect patterns of water movement through the subsurface and the interaction of groundwater with wetlands, lakes and streams. Mean annual streamflow during 2004-06 ranged from 83 to 106 percent of the long-term mean annual discharge, indicating that the data-collection period can be considered representative of average conditions. Measurements of groundwater levels, stream stage, and stream discharge and locations of start-of-flow are illustrated in basin-wide maps of water-table altitude, depth to the water table, and stream base flow during the period. Water-level data collected along 15 hydrologic transects that span the range of environments from uplands through wetlands to surface water were used to determine hydraulic gradients, potential flow directions, and areas of recharge and discharge. These data provide information about the localized interactions of groundwater with wetlands and surface water. Wetlands were categorized with r

New Jersey↗
USGS1983

Water-resources investigations of the U.S. Geological Survey in Kansas; fiscal years 1981 and 1982

One of the primary missions of the U.S. Geological Survey in Kansas is to investigate the occurrence, quantity, quality, distribution, and movement of surface and groundwater throughout the State. Primary activities include the systematic collection, analysis, and interpretation of hydrologic data, evaluation of water demands, and water-resources research. Hydrologic investigations are conducted through four basic types of projects: (1) data-collection programs, (2) local or areal investigations, (3) statewide or regional investigations, and (4) research projects. These projects are funded through cooperative agreements with State and local agencies, transfer of funds from other Federal agencies, and direct Federal funds. Forty-two water-related projects were funded during fiscal years 1981 and 1982 in Kansas. This report describes for each of these water-resources investigations the problem that initiated the study, the objectives of the project, and the approach designed to achieve this objective. Information on data-collection stations in Kansas is presented in maps and tables. A list of reports approved for publication by the U.S. Geological Survey, its cooperators, or technical and scientific organizations during fiscal years 1981 and 1982 is also provided. (USGS)

Open-File Report↗
USGS2007

Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Massachusetts, Drinking-Water Source Area, Water Year 2005

Records of water quantity, water quality, and meteorological parameters were continuously collected from three reservoirs, two primary streams, and four subbasin tributaries in the Cambridge, Massachusetts, drinking-water source area during water year 2005 (October 2004 through September 2005). Water samples were collected during base-flow conditions and storms in the subbasins of the Cambridge Reservoir and Stony Brook Reservoir drainage areas and analyzed for selected elements, organic constituents, suspended sediment, and Escherichia coli bacteria. These data were collected to assist watershed administrators in managing the drinking-water source area and to identify potential sources of contaminants and trends in contaminant loading to the water supply. Monthly reservoir capacities for the Cambridge Reservoir varied from about 59 to 98 percent during water year 2005, while monthly reservoir capacities for the Stony Brook Reservoir and the Fresh Pond Reservoir were maintained at capacities greater than 84 and 96 percent, respectively. Assuming a water demand of 15 million gallons per day by the city of Cambridge, the volume of water released from the Stony Brook Reservoir to the Charles River during the 2005 water year is equivalent to an annual water surplus of about 119 percent. Recorded precipitation in the source area for the 2005 water year was within 2 inches of the total annual precipitation for the previous 2 water years. The monthly mean specific conductances for the outflow of the Cambridge Reservoir were similar to historical monthly mean values. However, monthly mean specific conductances for Stony Brook near Route 20, in Waltham (U.S. Geological Survey station 01104460), which is the principal tributary feeding the Stony Brook Reservoir, were generally higher than the medians of the monthly mean specific conductances for the period of record. Similarly, monthly mean specific conductances for a small tributary to Stony Brook (U.S. Geological Survey station 01104455) were generally higher than the medians of the monthly mean specific conductances for the period of record. The annual mean specific conductance for Fresh Pond Reservoir increased from 514 microsiemens per centimeter (?S/cm) in the 2004 water year to 553 ?S/cm for the 2005 water year. Water samples were collected from four tributaries during base-flow and stormflow conditions in December 2004, and July, August, and September 2005 and analyzed for suspended sediment, 6 major dissolved ions, total nitrogen, total phosphorus, 8 total metals, 18 polyaromatic hydrocarbons (PAHs), 61 pesticides and metabolites, and Escherichia coli bacteria. Concentrations for most dissolved constituents in samples of stormwater were generally lower than the concentrations observed in samples collected during base flow; however, concentrations of total phosphorus, PAHs, suspended sediment, and some total recoverable metals were substantially greater in stormwater samples. Concentrations of dissolved chloride and total recoverable manganese in water samples collected during base-flow conditions from three tributaries exceeded the U.S. Environmental Protection Agency (USEPA) secondary drinking water standards of 250 and 0.05 milligrams per liter (mg/L), respectively. Concentrations of total recoverable manganese exceeded the secondary drinking water standard in samples of stormwater from each tributary. Concentrations of total recoverable iron in water samples exceeded the (USEPA) secondary drinking water standard of 0.3 mg/L periodically in water samples collected at (USEPA) stations 01104415, 01104455, and 01104475, and consistently in all water samples collected at USGS station 01104433. Concentrations of Escherichia coli bacteria in water samples collected during base flow ranged from 4 to 1,400 colony-forming units per 100 milliliters (col/100mL). Concentrations of Escherichia coli bacteria in composite samples of stormwater ranged between 1,700 to 43,000 c

Open-File Report↗
USGS2008

Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Massachusetts, Drinking-Water Source Area, Water Year 2006

Records of water quantity, water quality, and meteorological parameters were continuously collected from three reservoirs, two primary streams, and four subbasin tributaries in the Cambridge, Massachusetts, drinking-water source area during water year 2006 (October 2005 through September 2006). Water samples were collected during base-flow conditions and storms in the subbasins of the Cambridge Reservoir and Stony Brook Reservoir drainage areas and analyzed for dissolved calcium, sodium, chloride, and sulfate; total nitrogen and phosphorus; and polar pesticides and metabolites. These data were collected to assist watershed administrators in managing the drinking-water source area and to identify potential sources of contaminants and trends in contaminant loading to the water supply. Monthly reservoir contents for the Cambridge Reservoir varied from about 59 to 98 percent of capacity during water year 2006, while monthly reservoir contents for the Stony Brook Reservoir and the Fresh Pond Reservoir was maintained at greater than 83 and 94 percent of capacity, respectively. If water demand is assumed to be 15 million gallons per day by the city of Cambridge, the volume of water released from the Stony Brook Reservoir to the Charles River during the 2006 water year is equivalent to an annual water surplus of about 127 percent. Recorded precipitation in the source area was about 16 percent greater for the 2006 water year than for the previous water year and was between 12 and 73 percent greater than for any recorded amount since water year 2002. The monthly mean specific-conductance values for all continuously monitored stations within the drinking-water source area were generally within the range of historical data collected since water year 1997, and in many cases were less than the historical medians. The annual mean specific conductance of 738 uS/cm (microsiemens per centimeter) for water discharged from the Cambridge Reservoir was nearly identical to the annual mean specific conductance for water year 2005 which was 737 uS/cm. However, the annual mean specific conductance at Stony Brook near Route 20 in Waltham (U.S. Geological Survey (USGS) station 01104460), on the principal tributary to the Stony Brook Reservoir, and at USGS station 01104475 on a smaller tributary to the Stony Brook Reservoir were about 15 and 13 percent lower, respectively, than the previous annual mean specific conductances of 538 and 284 uS/cm, respectively for water year 2005. The annual mean specific conductance for Fresh Pond Reservoir decreased from 553 uS/cm in the 2005 water year to 514 uS/cm in the 2006 water year. Water samples were collected in nearly all of the subbasins in the Cambridge drinking-water source area and from Fresh Pond during water year 2006. Discrete water samples were collected during base-flow conditions with an antecedent dry period of at least 4 days. Composite samples, consisting of as many as 100 subsamples, were collected by automatic samplers during storms. Concentrations of most dissolved constituents were generally lower in samples of stormwater than in samples collected during base flow; however, the average concentration of total phosphorus in samples of stormwater were from 160 to 1,109 percent greater than the average concentration in water samples collected during base-flow conditions. Concentrations of total nitrogen in water samples collected during base-flow conditions and composite samples of stormwater at USGS stations 01104415, 01104460, and 01104475 were similar, but mean concentrations of total nitrogen in samples of stormwater differed by about 0.5 mg/L (milligrams per liter) from those in water samples collected during base-flow conditions at U.S. Geological Survey stations 01104433 and 01104455. In six water samples, measurements of pH were lower than the U.S. Environmental Protection Agency (USEPA) national recommended freshwater quality criteria and the USEPA secondary drinking water-standa

Open-File Report↗
USGS1988

Chemical and hydrologic data for selected thermal-water wells and nonthermal springs in the Boise Area, southwesten Idaho

Data were collected during January to July 1988 from 37 thermal-water wells and 3 nonthermal springs in the Boise area, southwestern Idaho. Included are well and spring locations; well-construction, water-level, and water-use information; hydrographs of water levels in 3 wells; chemical and isotopic analyses of water from 18 thermal-water wells and 3 nonthermal springs; and drillers ' logs from 23 wells. The purpose of the report is to make these data conveniently available to the public. (USGS)

Open-File Report↗
USGS2001

Hydrologic data and a proposed water-quality monitoring network for the Kobuk River basin, Gates of the Arctic National Park and Preserve, and Kobuk Valley National Park, Alaska

Located in northwestern Alaska, the Kobuk River drains a watershed of approximately 12,300 square miles. Two national parks are located in the basin: the entire Kobuk Valley National Park and and a portion of Gates of the Arctic National Park and Preserve. Reconnaissance-type water-quality data collected on the Kobuk River and some of its tributaries indicate that the water is of a calcium to calcium-magnesium-bicarbonate type. To design a representative water-quality monitoring network, a geographical information system (GIS) of the Kobuk River Basin was created. The GIS was used with a statistical technique, cluster analysis, to stratify the Kobuk River Basin into different regions. Potential water-quality monitoring sites were then selected from these regions.

Alaska↗
USGS1979

Hydrologic and related data for water-supply planning in an intensive-study area, northeastern Wichita County, Kansas

Data are presented that result from an intensive geohydrologic study for water-supply planning in a 12-square-mile area in northeastern Wichita County, Kansas. These data include records of wells, test drilling, chemical analyses, ground-water levels, rainfall, soilmoisture, well yield, solar radiation, crop yield, and crop acreage. Data indicate that water levels in the unconsolidated aquifer are declining at an average annual rate of about 1 to 2 feet per year (1950-78). This decline is the aquifer's response to pumping by irrigation wells for watering corn, wheat, grain sorghum, and other crops.

Kansas↗
USGS2017

Estimating discharge and nonpoint source nitrate loading to streams from three end‐member pathways using high‐frequency water quality data

The myriad hydrologic and biogeochemical processes taking place in watersheds occurring across space and time are integrated and reflected in the quantity and quality of water in streams and rivers. Collection of high‐frequency water quality data with sensors in surface waters provides new opportunities to disentangle these processes and quantify sources and transport of water and solutes in the coupled groundwater‐surface water system. A new approach for separating the streamflow hydrograph into three components was developed and coupled with high‐frequency nitrate data to estimate time‐variable nitrate loads from chemically dilute quick flow, chemically concentrated quick flow, and slowflow groundwater end‐member pathways for periods of up to 2 years in a groundwater‐dominated and a quick‐flow‐dominated stream in central Wisconsin, using only streamflow and in‐stream water quality data. The dilute and concentrated quick flow end‐members were distinguished using high‐frequency specific conductance data. Results indicate that dilute quick flow contributed less than 5% of the nitrate load at both sites, whereas 89 ± 8% of the nitrate load at the groundwater‐dominated stream was from slowflow groundwater, and 84 ± 25% of the nitrate load at the quick‐flow‐dominated stream was from concentrated quick flow. Concentrated quick flow nitrate concentrations varied seasonally at both sites, with peak concentrations in the winter that were 2–3 times greater than minimum concentrations during the growing season. Application of this approach provides an opportunity to assess stream vulnerability to nonpoint source nitrate loading and expected stream responses to current or changing conditions and practices in watersheds.

Water Resources Research↗
USGS2014

Land-margin ecosystem hydrologic data for the coastal Everglades, Florida, water years 1996-2012

Mangrove forests and salt marshes dominate the landscape of the coastal Everglades (Odum and McIvor, 1990). However, the ecological effects from potential sea-level rise and increased water flows from planned freshwater Everglades restoration on these coastal systems are poorly understood. The National Park Service (NPS) proposed the South Florida Global Climate Change Project (SOFL-GCC) in 1990 to evaluate climate change and the effect from rising sea levels on the coastal Everglades, particularly at the marsh/mangrove interface or ecotone (Soukup and others, 1990). A primary objective of SOFL-GCC project was to monitor and synthesize the hydrodynamics of the coastal Everglades from the upstream freshwater marsh to the downstream estuary mangrove. Two related hypotheses were set forward (Nuttle and Cosby, 1993): 1. There exists hydrologic conditions (tide, local rainfall, and upstream water deliveries), which characterize the location of the marsh/mangrove ecotone along the marine and terrestrial hydrologic gradient; and 2. The marsh/mangrove ecotone is sensitive to fluctuations in sea level and freshwater inflow from inland areas. Hydrologic monitoring of the SOFL-GCC network began in 1995 after startup delays from Hurricane Andrew (August 1992) and organizational transfers from the NPS to the National Biological Survey (October 1993) and the merger with the U.S. Geological Survey (USGS) Biological Research Division in 1996 (Smith, 2004). As the SOFL-GCC project progressed, concern by environmental scientists and land managers over how the diversion of water from Everglades National Park would affect the restoration of the greater Everglades ecosystem. Everglades restoration scenarios were based on hydrodynamic models, none of which included the coastal zone (Fennema and others, 1994). Modeling efforts were expanded to include the Everglades coastal zone (Schaffranek and others, 2001) with SOFL-GCC hydrologic data assisting the ecological modeling needs. In 2002, as a response for a more interdisciplinary science approach to understanding the coastal Everglades ecological system, the SOFL-GCC hydrology project was integrated into the “Dynamics of Land-Margin Ecosystems: Historical Change, Hydrology, Vegetation, Sediment, and Climate” study (Smith and others, 2002). Data from the ongoing study has been useful in providing an empirical hydrologic baseline for the greater Everglades ecosystem restoration science and management needs. The hydrology network consisted of 13 hydrologic gaging stations installed in the southwestern coastal region of Everglades National Park along three transects: Shark River (Shark or SH) transect, Lostmans River (Lostmans or LO) transect, and Chatham River (Chatham or CH) transect (fig. 1). There were five paired surface-water/groundwater gaging stations on the Shark transect (SH1, SH2, SH3, SH4, and SH5) and one stage gaging station (BSC) in the Big Sable Creek; four paired surface-water/groundwater gaging stations on the Lostmans transect (LO1, LO2, LO3, and LO4); and three paired surface-water/groundwater gaging stations on the Chatham transect (CH1, CH2, and CH3). Both surface-water and groundwater levels, salinities, and temperatures were monitored at the paired gaging stations. Rainfall was recorded at marsh and open canopy gaging stations. This report details the study introduction, method, and description of data collected, which are accessible through the final instantaneous hydrologic dataset stored in the USGS South Florida Information Access (SOFIA) South Florida Hydrology Database website, http://sofia.usgs.gov/exchange/sfl_hydro_data/location.html#brdlandmargin .

Florida↗
USGS1993

Hydrologic data and hydrologic budget for Summit Lake Reservoir, Henry County, East-Central Indiana, water years 1989 and 1990

Hydrologic data were collected near Summit Lake Reservoir for 2 years beginning October 1, 1988, and ending September 30, 1990. The data-collection network consisted of 1 reservoir-stage gage, 2 precipitation gages, 1 evaporation pan, 2 streamflow gages, and 13 observation wells. Stage-area and stage-storage relations for the reservoir were used in combination with the hydrologic data to determine the reservoir's annual hydrologic budgets for water years 1989 and 1990. Components of the hydrologic budget are considered either as inflow or outflow. Differences between inflow and outflow result in a change in reservoir storage. Components of inflow are direct precipitation, surface-water flow, and ground-water flow. Components of outflow are evaporation and ground-water flow. There was no surface-water outflow during the study. The hydrologic budget was calculated by use of daily, monthly, and yearly values of precipitation and surface-water flow, monthly values of ground-water flow, and yearly values of evaporation and reservoir storage. Comparison of results from different time intervals indicates there is little difference between annual volumes for components calculated from daily and monthly values. Annual volumes calculated from yearly values differ by less than 5 percent from those calculated from daily and monthly values. The total inflow to Summit Lake Reservoir was nearly identical for water years 1989 and 1990-about 10,360 acre-feet per year. Surface water was about 72 percent of the total inflow in water year 1989 and about 70 percent in water year 1990. Direct precipitation was about 18 percent of the total inflow in water year 1989 and about 23 percent in water year 1990. Ground-water inflow was about 10 percent of the total inflow in water year 1989 and about 7 percent in water year 1990. The total outflow from evaporation and ground-water flow was 5,700 acre-feet in water year 1989 and 7,710 acre-feet in water year 1990--about 19 percent evaporation and 81 percent ground-water outflow for both water years. Reservoir storage increased during both years; the change in storage was about 4,330 acre-feet in water year 1989 and about 2,890 acre-feet in water year 1990. Discrepancies between inflow, outflow, and reservoir storage reflect errors in the budget resulting from regionalization or interpretation of hydrologic data and from errors inherent in all hydrologic measurements.

Indiana↗
USGS1989

Selected ground-water data, Chester County, Pennsylvania

Hydrologic data for Chester County, Pennsylvania are given for 3,010 wells and 32 springs. Water levels are given for 48 observation wells measured monthly during 1936-86. Chemical analyses of ground water are given for major ions, physical properties, nutrients, metals and other trace constituents, volatile organic compounds, acid organic compounds, base-neutral organic compounds, organochlorine insecticides, polychlorinated biphenyls, polychlorinated napthalenes, organophosphorous insecticides, organic acid herbicides, triazine herbicides, other organic compounds, and radionuclides.

Pennsylvania↗
USGS2005

Water resources data, Iowa, water year 2005

This volume of the annual hydrologic data report of Iowa is one of a series of annual reports that document hydrologic data gathered from the U.S. Geological Survey’s surface- and ground-water data-collection networks in each State, Puerto Rico, and the Trust Territories. These records of streamflow, ground-water levels, and quality of water provide the hydrologic information needed by local, State, and Federal agencies, and the public for developing and managing our Nation’s land and water resources. This report is the culmination of a concerted effort by dedicated personnel of the U.S. Geological Survey who collected, compiled, analyzed, verified, and organized the data, and who typed, edited, and assembled the report. The authors had primary responsibility for assuring that the information contained herein is accurate, complete, and adheres to U. S. Geological Survey policy and established guidelines.

Iowa↗
USGS1986

Limnological characteristics of selected lakes in the Nebraska sandhills, U.S.A., and their relation to chemical characteristics of adjacent ground water

Limnological characteristics of Crane, Hackberry, Island and Roundup Lakes, and chemical characteristics of shallow ground water, within the Crescent Lake National Wildlife Refuge, western Nebraska, were determined during a preliminary investigation of the interaction between lakes and ground water in this study area between 1980 and 1984. When ice cover was absent, the lakes were well-mixed vertically, regardless of season. Depth to which 1% of surface illumination penetrated was commonly less than 1m. Variability in light penetration, as measured by Secchidisk transparency, appeared to be unrelated to changes in algal biomass, even though algal biomass, measured as chlorophyll a, varied seasonally within a two-order-of-magnitude range. Blue-green algae were the most abundant phytoplankton; this condition occurred most often when the ratio of total nitrogen to total phosphorus in the lakes' water was less than 29. Although rotifers and copepod naupli commonly were the most abundant zooplankton in the lakes, cladocerans were dominant occasionally. Either sodium or calcium was the most abundant cation, and bicarbonate was the most abundant anion, in water from water-table wells and lakes sampled during the study. The second most abundant cation in the ground water was related to the location of the sampled well within the ground-water system. The lakes were a source of dissolved organic carbon seeping to ground water. Chemical and hydrologic data indicate there is interaction between lakes and ground water in the study area.

Nebraska↗
USGS1986

Maps showing altitude of the potentiometric surface and changes in water levels in the aquifer in the Sparta and Memphis Sands in eastern Arkansas, spring 1985

Aquifers in the Tertiary Sparta and Memphis Sands are a major source of water supply for much of eastern and south-central Arkansas. Major withdrawals occur from the aquifer for industrial and public supply, with generally lesser but locally significant amounts withdrawn for agricultural uses. Water level data from wells tapping the artesian aquifer in the Sparta and Memphis Sands indicate steadily declining water levels in some areas where relatively large withdrawals occur. In addition, a simulation of water levels using projected withdrawals to the year 1990 indicated increasing water level declines in the aquifer. Because of the potential quantity and quality problems, the continual monitoring of water levels in the aquifer in the Sparta and Memphis Sands is essential for proper aquifer management and the continuation of the use of the aquifer as a major source of water for much of eastern and south-central Arkansas. The U.S. Geological Survey with the cooperation of the Arkansas Geological Commission has been monitoring water levels in the aquifer in the Sparta and Memphis Sands annually throughout the aquifer 's extent within the State of Arkansas. This report, prepared in cooperation with the Arkansas Geological Commission and the Arkansas Soil and Water Conservation Commission interprets water level data through hydrologic maps of the potentiometric surface and water level changes. The potentiometric surface map is based on water levels collected in the spring of 1985. The water level change map is based on a comparison of water levels collected in the spring of 1980 and 1985. This report includes the Sparta Sand and most of the Memphis Sand aquifer within the State of Arkansas. Little or no data are available in the northeastern part of the State where limited withdrawals from the aquifer occur. (Lantz-PTT)

Water-Resources Investigations Report↗