Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Ground Water”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 433 records · Page 24Linked to original sources
USGS2003

Tracing reclaimed water in the Menifee, Winchester, and Perris-South ground-water subbasins, Riverside County, California

As a component in the management of water resources in the Menifee, Winchester, and Perris-South subbasins in Riverside County, California, ponds are operated by the Eastern Municipal Water District for the temporary storage of reclaimed water that is produced by several regional water-reclamation facilities. A primary goal of this study was to evaluate the potential for using various ground-water constituents or characteristics as tracers of reclaimed water that has infiltrated from the storage ponds into the ground water in the three subbasins. A secondary goal was to estimate the degree to which the infiltrated reclaimed water has mixed with the native ground water. The evaluation of potential tracers and the estimation of mixing focused on data from wells located relatively close to the ponds. The most useful constituents and characteristics for evaluation of the fate and mixing of reclaimed water in the Menifee, Winchester, and Perris-South subbasins are major-ion composition, stable isotopes of hydrogen and oxygen, ultraviolet absorbance (UV-A), chloride concentration, and boron/chloride ratio plotted against chloride concentration. Emphasis in this study was placed on evaluating the utility of UV-A as a tracer and boron/chloride ratios in estimating the fraction of reclaimed water in ground water. In the Menifee subbasin, major-ion data, stable isotopes, chloride, UV-A, and boron/chloride ratio are all useful in identifying reclaimed water, and the results based on these indicators are consistent with each other. The results suggest that values of UV-A greater than or equal to 0.007 indicate the presence of reclaimed water in the Menifee subbasin. Ground-water samples with UV-A greater than 0.007 are estimated to consist of about 75 to 100 percent reclaimed water, on the basis of chloride-mixing calculations and boron/chloride-versus-chloride mixing calculations. In the Winchester subbasin, results based on the same factors used in the Menifee subbasin are less conclusive; nevertheless, UV-A can be used as a tracer. The results suggest that values of UV-A greater than 0.01 indicate the presence of reclaimed water. Values from 0.006 to 0.01 may indicate the presence of reclaimed water; however, water from wells not likely to have reclaimed water may also have UV-A values in this range. Ground-water samples with UV-A greater than 0.01 seem to contain about 25 percent reclaimed water (range 6 to 32 percent), on the basis of the consistency of the results of three types of mixing calculations--chloride alone, boron/chloride versus chloride, and UV-A. In the Perris-South subbasin, the potential tracers are not as conclusive in identifying reclaimed water in the subsurface as in the Menifee and Winchester subbasins. The less-conclusive results are a consequence of the multiple, spatially distributed sources of reclaimed water; the relative absence of wells close to the reclaimed-water pond; and the short period of operation (about 1 year) of the pond at the time of sampling. Mixing calculations suggest that ground-water samples with elevated UV-A values (greater than 0.01) in the Perris-South subbasin could contain as much as 40 to 65 percent reclaimed water.

Water-Resources Investigations Report↗
USGS1981

Ground-water hydrology of the Mormon Island Crane Meadows wildlife area near Grand Island, Hall County, Nebraska

The Platte River in south-central Nebraska flows generally eastward in a broad, flat valley. The river banks and many areas adjacent to the river support thick stands of cottonwood and willow trees. Brush, grass, pasture land, and cultivated fields occupy most of the remaining area. This is the habitat for many types of wildlife that live in the area or stop over in the area during annual migrations. Both sandhill cranes and whooping cranes are part of the annual migration. There is concern that water-management changes, such as surface-water diversions or ground-water withdrawals for irrigation, may alter the hydrologic environment of the wetland areas and be harmful to the wildlife habitat. In order to determine what affect changes in water management might have on ground-water levels in the wetland areas, detailed data were collected from Crane Meadows Wildlife Area, which is on an island in the Platte River near Grand Island, Nebr. Ground-water levels beneath the island respond to changes in river stage, to recharge from snowmelt and precipitation, and to evapotranspiration by riparian vegetation and from areas where the water table is close to the land surface. The data show that ground-water levels respond rapidly to changes in river stage-usually within 24 hours for distances up to 2,500 feet from the edge of the river. Thus changes in river stage due to changes in surface-water diversions will not have a long-term effect on ground-water levels. Changes in ground-water withdrawals will have the double effect of changing ground-water levels due to changes in drawdown and due to changes in river stage caused by the effects of pumping on river flow. These effects will develop slowly and be long lasting.

Nebraska↗
USGS2005

Questa baseline and pre-mining ground-water quality investigation. 10. Geologic influences on ground and surface waters in the lower Red River watershed, New Mexico

This report is one in a series that presents results of an interdisciplinary U.S. Geological Survey (USGS) study of ground-water quality in the lower Red River watershed prior to open-pit and underground molybdenite mining at Molycorp’s Questa mine. The stretch of the Red River watershed that extends from just upstream of the town of Red River, N. Mex., to just above the town of Questa includes several mineralized areas in addition to the one mined by Molycorp. Natural erosion and weathering of pyrite-rich rocks in the mineralized areas has created a series of erosional scars along this stretch of the Red River that contribute acidic waters, as well as mineralized alluvial material and sediments, to the river. The overall goal of the USGS study is to infer the premining ground-water quality at the Molycorp mine site. An integrated geologic, hydrologic, and geochemical model for ground water in the mineralized—but unmined—Straight Creek drainage (a tributary of the Red River) is being used as an analog for the geologic, geochemical, and hydrologic conditions that influenced ground-water quality and quantity in the Red River drainage prior to mining. This report provides an overall geologic framework for the Red River watershed between Red River and Questa, in northern New Mexico, and summarizes key geologic, mineralogic, structural and other characteristics of various mineralized areas (and their associated erosional scars and debris fans) that likely influence ground- and surface-water quality and hydrology. The premining nature of the Sulphur Gulch and Goat Hill Gulch scars on the Molycorp mine site can be inferred through geologic comparisons with other unmined scars in the Red River drainage.

New Mexico↗
USGS2006

Water resources of Monroe County, New York, water years 2000-02: Atmospheric deposition, ground water, streamflow, trends in water quality, and chemical loads in streams

This report, the fifth in a series that presents analyses of the hydrologic data collected in Monroe County since 1984, interprets data from four surface-water-monitoring sites in the Irondequoit Creek basin (Irondequoit Creek at Railroad Mills, East Branch Allen Creek at Pittsford, Allen Creek near Rochester, and Irondequoit Creek above Blossom Road); and from three sites on tributaries to the Genesee River (Oatka Creek at Garbutt, Honeoye Creek at Honeoye Falls, and Black Creek at Churchville) and from the Genesee River at Charlotte Docks. It also interprets data from a site on Northrup Creek, which provides information on nutrient loads delivered to Long Pond, a small eutrophic embayment of Lake Ontario. The report also includes water-level and water-quality data from nine observation wells in Ellison Park, and atmospheric-deposition data from a collection site at Mendon Ponds. Atmospheric Deposition : Average annual precipitation for 2000–02 was 33.11 in., 0.94 in. below normal. Average annual loads of some chemical constituents in atmospheric deposition for 2000–02 differed considerably from those for the previous period of record. Loads of all nutrients except ammonia decreased by amounts ranging from 28 percent (ammonia + organic nitrogen and phosphorus) to 2 percent (nitrite + nitrate), whereas ammonia loads an increased by 8 percent. Loads of dissolved sodium and total zinc in atmospheric deposition increased by 56 percent, and 54, percent respectively, over the previous period of record. Average annual loads of other constituents showed decreases ranging from 41 percent (dissolved magnesium) to 17 percent (dissolved chloride). Loads of all nutrients deposited in the Irondequoit Creek basin from atmospheric sources during 2000–02 greatly exceeded those transported by Irondequoit Creek. The ammonia load deposited in the basin was 165 times the load transported at Blossom Road (the most downstream site); the ammonia + organic nitrogen load was 2.8 times greater, orthophosphate 9.7 times greater, total phosphorus 1.2 times greater, and the nitrite + nitrate load was 1.6 times greater. Average yields of dissolved chloride and dissolved sulfate from atmosphoric sources were much less than those transported by streamflow at Blossom Road—chloride was about 1.5 percent and sulfate about 9.1 percent of the amount transported by Irondequoit Creek. Ground water : Ground-water-levels and water quality data were collected from 9 observation wells in Ellison Park in Monroe County. All wells except Mo 2 and Mo 659 are in the flood plain of Irondequoit Creek. Water levels indicate frequent reversals in direction of lateral flow toward or away from Irondequoit Creek, and all wells except Mo2 and Mo 659 respond to water level fluctuations in the Creek. Trend tests on water levels for the period of record indicate a slight upward trend in water levels at all nine wells, two of which (Mo 3 and Mo 667) were statistically significant. Concentrations of ammonia and ammonia + organic nitrogen showed a general decrease for the current period of record. Total phosphorus concentrations showed an increase at four wells and a decrease at four wells. Water quality data showed that the highest median concentrations of nutrients continues to occur in Mo 667 and the highest median concentrations of common ions was at Mo 664. Streamflow : Statistical analysis of long-term (greater than 15 years) streamflow records for unregulated streams in Monroe County indicated that annual mean flows for water years (A water year is the 12-month period from October 1 through September 30 of the following year.) 2000–02 generally were in the normal range (75th to 25th percentile), although Allen Creek continued to show a significant downward trend in mean monthly streamflow during the 1984–2002 water years. Chemical Concentration in Streams : Concentrations of several constituents in streams of the Irondequoit Creek basin showed statistically significant (α = 0.05) trends from the beginning of their period of record through 2002. Three of the four Irondequoit Creek sites (Allen Creek, Blossom Road, and Railroad Mills) showed downward trends in ammonia (4.6 to 12.0 percent per year) and ammonia + organic nitrogen (2.8 to 5.3 percent per year). Allen Creek showed downward trends in nitrite + nitrate and total phosphorus (both 1.2 percent per year), and Irondequoit Creek above Blossom Road showed an upward trend in orthophosphate (1.8 percent per year). Three Irondequoit Creek sites showed upward trends in dissolved chloride: Railroad Mills (4.8 percent per year), Allen Creek, and Blossom Road (both 1.9 percent per year). Allen Creek showed a downward trend in sulfate of 0.98 percent per year, whereas Blossom Road showed a downward trend in suspended solids of 4.0 percent per year. Volatile suspended solids showed an upward trend of 3.2 percent per year at Allen Creek and a downward trend of 2.2 percent per year at Blossom Road. Northrup Creek in western Monroe County, showed significant downward trends in concentrations of volatile suspended solids (2.5 percent per year), total phosphorus (5.3 percent per year), and orthophosphate (9.9 percent per year). The Genesee River at Charlotte Docks showed downward trends in volatile suspended solids (2.1 percent per year) and ammonia + organic nitrogen (4.5 percent per year). Oatka Creek at Garbutt showed an upward trend of 21.4 percent per year in turbidity. Chemical Loads in Streams : Mean annual yields (pounds or tons per square mile) of many constituents at the Irondequoit Creek sites were lower than those in previous reporting periods. Suspended solids and nitrite + nitrate yields were lower at three of the sites, and yields of volatile suspended solids, ammonia, and total phosphorus were lower at two of the sites. East Branch Allen Creek showed lower yields for five of the nine constituents for 2000–02, than for previous reporting periods. The decreased yields at East Branch Allen Creek are likely due to the Jefferson Road stormflow-detention basin and the much lower than normal runoff for the 2000–02 period.

New York↗
USGS1997

Hydrogeologic framework and simulation of ground-water flow and travel time in the shallow aquifer system in the area of Naval Support Activity Memphis, Millington, Tennessee

Naval Support Activity (NSA) Memphis is a Department of the Navy facility located at the City of Millington, Tennessee, about 5 miles north of Memphis. Contaminants have been detected in surface-water, sediment, and ground-water samples collected at the facility. As part of the Installation Restoration Program, the Navy is considering remedial-action options to prevent or lessen the effect of ground-water contamination at the facility and to control the movement and discharge of contaminants. A numerical model of the ground-water-flow system in the area of NSA Memphis was constructed and calibrated so that quantifiable estimates could be made of ground-water-flow rates, direction, and time-of-travel. The sediments beneath NSA Memphis, to a depth of about 200 feet, form a shallow aquifer system. From youngest to oldest, the stratigraphic units that form the shallow aquifer system are alluvium, loess, fluvial deposits, and the Cockfield and Cook Mountain Formations. The shallow aquifer system is organized into five hydrogeologic units: (1) a confining unit composed of the relatively low permeability sediments of the upper alluvium and the loess; (2) the A1 aquifer comprising sand and gravel of the lower alluvium and the fluvial deposits, and sand lenses in the upper part of the preserved section of the Cockfield Formation; (3) a confining unit composed of clay and silt within the upper part of the Cockfield Formation; (4) the Cockfield aquifer comprising sand lenses within the lower part of the preserved section of the Cockfield Formation; and (5) a confining unit formed by low permeability sediments of the Cook Mountain Formation that composes the upper confining unit for the Memphis aquifer. Thicknesses of individual units vary considerably across the facility. Structural and depositional features that affect the occurrence of ground water in the shallow aquifer system include faulting, an erosional scarp, and 'windows' in the confining units. Underlying the shallow aquifer system is the Memphis aquifer, the primary source of water for NSA Memphis and the City of Memphis, Tennessee. Analyses of sediment cores, aquifer and well specific-capacity tests, and numerical modeling were used to estimate the hydraulic characteristics of units of the shallow aquifer system. The vertical hydraulic conductivity of core samples of the alluvium-loess confining unit ranged from about 8.5 x 10-5 to 1.6 x 10-2 feet per day, and the total porosity of the samples ranged from about 35 to 48 percent. The results of the aquifer test were used to estimate a horizontal hydraulic conductivity of about 5 feet per day for the alluvial-fluvial deposits aquifer. The total porosity of core samples of the alluvial-fluvial deposits aquifer ranged from about 22 to 39 percent. The vertical hydraulic conductivity of core samples of the Cockfield confining unit ranged from about 4.5 x 10-5 to 2.5 x 10-3 feet per day, and the total porosity ranged from about 41 to 55 percent. Well specific-capacity tests indicate that the horizontal hydraulic conductivity of sand units that compose the Cockfield aquifer range from about 0.5 to 3 feet per day. The vertical hydraulic conductivity of core samples of the Cook Mountain confining unit ranged from about 5.0 x 10-6 to 9.9 x 10-4 feet per day. Total porosity of core samples of the Cook Mountain confining unit ranged from about 30 to 42 percent. Ground-water flow and time-of-travel in the shallow aquifer system were simulated using the MODFLOW finite-difference model and the -particle-tracking program MODPATH. A three-layer, steady-state model of the shallow aquifer system was constructed and calibrated to the potentiometric surface of the A1 aquifer. Results of numerical modeling support the proposed conceptual hydrogeologic model of the shallow aquifer system. Ground-water time-of-travel in the A1 aquifer was simulated using an assumed effective porosity of 25 percent. Typical ground-water-flow velocities were on the order of 15 to 25 feet per year in the layer representing the Al aquifer in the model. The average residence time of particles seeded in this layer was about 800 years. Ground-water travel times were simulated at three sites within the Al aquifer: (1) the former N-6 hangar location, (2) the "grassy" area near Solid Waste Management Unit 7, and (3) at Solid Waste Management Unit 2. Results indicate close agreement between the particle-tracking simulations and the measured extent of contaminant plumes at the former N-6 hangar area and the grassy area near Solid Waste Management Unit 7. Based on the results of particle-tracking analyses of ground-water flow and the estimated locations of contaminant plumes at these two sites, the potential for contaminants to reach the Memphis aquifer in the next 100 years is negligible. However, particle-tracking analysis of ground-water flow at Solid Waste Management Unit 2 suggests that the time-of-travel of contaminants to Big Creek Drainage Canal could be less than 30 years.

Tennessee↗
USGS2004

Hydrogeology and simulation of ground-water flow and land-surface subsidence in the northern part of the Gulf Coast aquifer system, Texas

As a part of the Texas Water Development Board Ground- Water Availability Modeling program, the U.S. Geological Survey developed and tested a numerical finite-difference (MODFLOW) model to simulate ground-water flow and land-surface subsidence in the northern part of the Gulf Coast aquifer system in Texas from predevelopment (before 1891) through 2000. The model is intended to be a tool that water-resource managers can use to address future ground-water-availability issues. From land surface downward, the Chicot aquifer, the Evangeline aquifer, the Burkeville confining unit, the Jasper aquifer, and the Catahoula confining unit are the hydrogeologic units of the Gulf Coast aquifer system. Withdrawals of large quantities of ground water have resulted in potentiometric surface (head) declines in the Chicot, Evangeline, and Jasper aquifers and land-surface subsidence (primarily in the Houston area) from depressurization and compaction of clay layers interbedded in the aquifer sediments. In a generalized conceptual model of the aquifer system, water enters the ground-waterflow system in topographically high outcrops of the hydrogeologic units in the northwestern part of the approximately 25,000-square-mile model area. Water that does not discharge to streams flows to intermediate and deep zones of the system southeastward of the outcrop areas where it is discharged by wells and by upward leakage in topographically low areas near the coast. The uppermost parts of the aquifer system, which include outcrop areas, are under water-table conditions. As depth increases in the aquifer system and as interbedded sand and clay accumulate, water-table conditions evolve into confined conditions. The model comprises four layers, one for each of the hydrogeologic units of the aquifer system except the Catahoula confining unit, the assumed no-flow base of the system. Each layer consists of 137 rows and 245 columns of uniformly spaced grid blocks, each block representing 1 square mile. Lateral no-flow boundaries were located on the basis of outcrop extent (northwestern), major streams (southwestern, northeastern), and downdip limit of freshwater (southeastern). The MODFLOW general-head boundary package was used to simulate recharge and discharge in the outcrops of the hydrogeologic units. Simulation of land-surface subsidence (actually, compaction of clays) and release of water from storage in the clays of the Chicot and Evangeline aquifers was accomplished using the Interbed-Storage Package designed for use with the MODFLOW model. The model was calibrated by trial-anderror adjustment of selected model input data in a series of transient simulations until the model output (potentiometric surfaces, land-surface subsidence, and selected water-budget components) reasonably reproduced field measured (or estimated) aquifer responses. Model calibration comprised four elements: The first was qualitative comparison of simulated and measured heads in the aquifers for 1977 and 2000; and quantitative comparison by computation and areal distribution of the root-mean-square error between simulated and measured heads. The second calibration element was comparison of simulated and measured hydrographs from wells in the aquifers in a number of counties throughout the modeled area. The third calibration element was comparison of simulated water-budget componentsprimarily recharge and dischargeto estimates of physically reasonable ranges of actual water-budget components. The fourth calibration element was comparison of simulated land-surface subsidence from predevelopment to 2000 to measured land surface subsidence from 1906 through 1995.

Texas↗
USGS2002

Water Resources Data, Wyoming, Water Year 2001, Volume 2. Ground Water

Water resources data for the 2001 water year for Wyoming consists of records of stage, discharge and water quality of streams; stage and contents of lakes and reservoirs, and water levels and water quality of ground water. Volume 1 of this report contains discharge records for 151 gaging stations, stage and contents for 12 lakes and reservoirs, and water quality for 33 gaging stations and 32 ungaged stations. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data together with the data in Volume 2 represent part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Wyoming.

Water Data Report↗
USGS2003

Wyoming Water Resources Data, Water Year 2002, Volume 2. Ground Water

Water resources data for the 2002 water year for Wyoming consists of records of stage, discharge and water quality of streams; stage and contents of lakes and reservoirs, and water levels and water quality of ground water. Volume 1 of this report contains discharge records for 156 gaging stations; water quality for 33 gaging stations and 34 ungaged stations, and stage and contents for one reservoir. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data together with the data in Volume 2 represent part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Wyoming.

Water Data Report↗
USGS2005

Water resources data, Wyoming, water year 2004; Volume 2. Ground water

Water resources data for the 2004 water year for Wyoming consist of records of stage, discharge and water quality of streams; stage and contents of lakes and reservoirs, and water levels and water quality of ground water. Volume 1 of this report contains discharge records for 164 gaging stations; water quality for 43 gaging stations and 45 ungaged stations, and stage and contents for one reservoir. Volume 2 of this report contains water levels records for 64 wells. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent part of the National Water Information System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Wyoming.

Water Data Report↗
USGS1979

Ground water in Myrtle Creek - Glendale area, Douglas County, Oregon

The Myrtle Creek-Glendale area covers about 400 mi 2 (1,000 km 2 in Douglas County in southwestern Oregon. Although the geologic formations of the area have low permeabilities and generally yield small amounts of water to wells, ground water is the chief source of water for domestic usse in rural parts of the area not served by public supplies. A well capable of yielding 5 to 10 gal/min (0.3 to 0.6 L/s) can supply household needs. In most places in the area, the quantities of water obtainable from wells are inadequate or would be only marginally adequate for irrigation, municipal, of large industrial use. The purpose of this report is to describe briefly the occurrence of ground water and to present ground-water information that will help water users, public officials, and planners to determine the probability of obtaining adequate quanitities of good-quality ground water in the Myrtle Creek-Glendale area.

Oregon↗
USGS2007

Elements in cottonwood trees as an indicator of ground water contaminated by landfill leachate

Ground water at the Norman Landfill Research Site is contaminated by a leachate plume emanating from a closed, unlined landfill formerly operated by the city of Norman, Oklahoma, Ground water contaminated by the leachate plume is known to be elevated in the concentration of many, organic and inorganic constituents. Specific conductance, alkalinity, chloride, dissolved organic carbon, boron, sodium, strontium, and deuterium in ground water are considered to be indicators of the leachate plume at this site. Leaf samples of broad-leafed cottonwood, Populus deltoides, were collected from 57 sites around the closed landfill. Cottonwood, a phreatophyte or “well plant,” functions as a & surrogate well and serves as a ground water quality sampler. The leaf samples were combusted to ash and analyzed by instrumental neutron activation for 35 elements and by prompt-gamma instrumental neutron activation, for boron. A monitoring well was located within a few meters of a sampled cottonwood tree at 15 of the 57 sites, and ground water samples were collected from these monitoring wells simultaneously with a leaf sample. The chemical analyses of the ground water and leaf samples from these 15 sites indicated that boron, bromine, sodium, and strontium concentrations in leaves were significantly correlated with leachate indicator constituents in ground water. A point-plot map of selected percentiles indicated high concentrations of boron, bromine, and sodium in leaf ash from sites downgradient of the most recent landfill and from older landfills nearby. Data from leaf analysis greatly extended the known areal extent of the leachate plume previously determined from a network of monitoring wells and geophysical surveys. This phytosgeochemical study provided a cost-effective method for assessing the extent of a leachate plume from an old landfill. Such a method may be useful as a preliminary sampling tool to guide the design of hydrogeochemical and geophysical studies.

Oklahoma↗
USGS2008

Analysis of Streamflow Trends, Ground-Water and Surface-Water Interactions, and Water Quality in the Upper Carson River Basin, Nevada and California

Changes in land and water use and increasing development of water resources in the Carson River basin may affect flow of the river and, in turn, affect downstream water users dependent on sustained river flows to Lahontan Reservoir. To address these concerns, the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, Churchill County, and the Truckee-Carson Irrigation District, began a study in April 2006 to compile data on changes in land and water use, ground-water levels and pumping, streamflow, and water quality, and to make preliminary analyses of ground-water and surface-water interactions in the Carson River basin upstream of Lahontan Reservoir. The part of the basin upstream of Lahontan Reservoir is called the upper Carson River basin in this report. In 2005, irrigated agricultural land covered about 39,000 acres in Carson Valley, 3,100 acres in Dayton Valley, and 1,200 acres in Churchill Valley. Changes in land use in Carson Valley from the 1970s to 2005 included the development of about 2,700 acres of native phreatophytes, the development of 2,200 acres of irrigated land, 900 acres of land irrigated in the 1970s that appeared fallow in 2005, and the irrigation of about 2,100 acres of new agricultural land. In Dayton and Churchill Valleys, about 1,000 acres of phreatophytes and 900 acres of irrigated land were developed, about 140 acres of phreatophytes were replaced by irrigation, and about 600 acres of land irrigated in the 1970s were not irrigated in 2006. Ground-water pumping in the upper Carson River basin increases during dry years to supplement surface-water irrigation. Total annual pumping exceeded 20,000 acre-ft in the dry year of 1976, exceeded 30,000 acre-ft in the dry years from 1987 to 1992, and increased rapidly during the dry years from 1999 to 2004, and exceeded 50,000 acre-ft in 2004. As many as 67 public supply wells and 46 irrigation wells have been drilled within 0.5 mile of the Carson River. Pumping from these wells has the potential to affect streamflow of the Carson River. It is not certain, however, if all these wells are used currently. Annual streamflow of the Carson River is extremely variable, ranging from a low of about 26,000 acre-ft in 1977 to slightly more than 800,000 acre-ft in 1983 near Fort Churchill. Graphs of the cumulative annual streamflow and differences in the cumulative annual streamflow at Carson River gaging stations upstream and downstream of Carson and Dayton Valleys show an annual decrease in streamflow. The annual decrease in Carson River streamflow averaged about 47,000 acre-ft through Carson Valley, and about 11,000 acre-ft through Dayton Valley for water years 1940-2006. The decrease in streamflow through Carson and Dayton Valleys is a result of evapotranspiration on irrigated lands and losses to ground-water storage, with greater losses in Carson Valley than in Dayton Valley because of the greater area of irrigated land in Carson Valley.

Scientific Investigations Report↗
USGS1964

Records of wells and springs, water levels, and chemical quality of ground water in the East Portland area, Oregon

Data are presented on more than 300 wells , including many new ones whose records will not be a part of a forthcoming interpretative report on the occurrence of ground water in this area . A brief description of the geomorphic features is given, and the characteristics of the rock units are summarized in a table. Principal aquifers are beds of loose sand and gravel in the early Pliocene Troutdale Formation, late Pleistocene fluviolacustrine deposits, and Recent alluvium. Locally, Columbia River Basalt (Miocene) and the Boring Lava (late Pliocene to Pleistocene) yield substantial amounts of wate.. In addition to well records there are 124 driller's logs and a table of chemical analyses of the ground water .

Oregon↗
USGS2002

Water withdrawals and trends in ground-water levels and stream discharge in Louisiana

In 2000, approximately 10,400 mgal/ d (million gallons per day) of water was withdrawn from ground - and surface- water sources in Louisiana , an increase of 10 percent from 1990. In 2000, about 16 percent (1,600 Mgal/ d ) of the water withdrawn was ground water . Approximately 93 percent of the ground water withdrawn was from four aquifers or aquifer systems: the Chicot aquifer system (49 percent), the Mississippi River alluvial aquifer (22 percent), the Sparta aquifer (4 percent), and the Southern Hills aquifer system (18 percent). Three of these, the Chicot aquifer system, the Sparta aquifer, and the Southern Hills aquifer system, contain areas where declines in ground - water levels from 1990-2000 are 1 ft/yr (foot per year) or greater. The Chicot aquifer system in southwestern Louisiana is the most heavily pumped aquifer or aquifer system in the State. By 2000, water levels in areas of Calcasieu, Jefferson Davis, and Acadia Parishes had declined to 50 feet or more below sea level. Water levels in areas of largest withdrawals declined as much as 1.7 ft/yr during the period 1990-2000. The Sparta aquifer in north-central Louisiana is the fourth most heavily pumped aquifer in the State. Approximately 68.2 Mgal/d was withdrawn in 2000. Water levels in the aquifer declined to more than 200 feet below sea level in the Monroe area by 1997. During 1990-2000, water level declines ranged from 0.1 to 5.2 ft/yr at monitor wells screened in the aquifer. The Southern Hills aquifer system of southeastern Louisiana is composed of numerous freshwater aquifers. This aquifer system is the third most heavily pumped aquifer or aquifer system in the State (291 Mgal/d in 2000). By the 1970's saltwater encroachment had been documented in major aquifers in the Baton Rouge area. Water levels in deep aquifers having largest withdrawals declined about 0.2 to 3.5 ft/yr or more during the period 1990-2000. In 2000, about 84 percent (8,700 Mgal/d) of the water withdrawn in Louisiana was surface water. Stream discharge data were analyzed for 59 continuous discharge stations. Eleven stations on nine streams had decreasing mean annual discharge during the period 1990-2000.

Louisiana↗
USGS2008

Ground-water availability in the United States

Ground water is among the Nation's most important natural resources. It provides half our drinking water and is essential to the vitality of agriculture and industry, as well as to the health of rivers, wetlands, and estuaries throughout the country. Large-scale development of ground-water resources with accompanying declines in ground-water levels and other effects of pumping has led to concerns about the future availability of ground water to meet domestic, agricultural, industrial, and environmental needs. The challenges in determining ground-water availability are many. This report examines what is known about the Nation's ground-water availability and outlines a program of study by the U.S. Geological Survey Ground-Water Resources Program to improve our understanding of ground-water availability in major aquifers across the Nation. The approach is designed to provide useful regional information for State and local agencies who manage ground-water resources, while providing the building blocks for a national assessment. The report is written for a wide audience interested or involved in the management, protection, and sustainable use of the Nation's water resources.

Circular↗
USGS1988

Water resources data for Florida, water year 1988. Volume 1B. Northeast Florida - ground water

Water-resources data for the 1988 water year in Florida consist of continuous or daily discharge for 338 streams, periodic discharge for 34 streams, miscellaneous discharge for 28 streams, continuous or daily stage for 152 streams, periodic stage for 29 streams, peak discharge for 71 streams, continuous daily tide stage 8, and peak stage for 84 streams; continuous or daily elevations for 73 lakes, periodic elevations for 72 lakes; continuous ground-water levels for 490 wells, periodic. ground-water levels for 1,620 wells, and miscellaneous water-level measurements for 2,678 wells; quality-of-water data for 158 surface-water sites and 884 wells. The data for northeast Florida include continuous or daily discharge for 132 streams, periodic discharge for 15 streams, miscellaneous discharge for 14 streams, continuous or daily stage for 45 streams, periodic stage for 27 streams, peak discharge for 26 streams, and peak stage for 27 streams; continuous or daily elevations for 39 lakes, periodic elevations for 53 lakes; continuous ground-water levels for 81 wells, periodic groundwater levels for 150 wells, and miscellaneous water-level measurements for 970 wells; quality-of-water data for 59 surface-water sites and 100 wells. These data represent the National Water Data System records collected by the U.S. Geological Survey and cooperating local, state and federal agencies in Florida.

Florida↗
USGS1995

Analysis of nutrient and ancillary water-quality data for surface and ground water of the Willamette Basin, Oregon, 1980-90

An analysis of historical water-quality data for surface and ground water collected in the Willamette and Sandy River Basins during the 1980-90 water years was performed. For surface water, most data were concentrated at sites on the main stem Willamette River or near the mouths of major tributaries. All seasons were represented. Data for nitrogen and phosphorus species were readily available, but simultaneously collected discharge measurements frequently were not. Seven primary sites were used for a quantitative analysis of nutrient data in surface water. At six of the seven primary sites, median concentrations of nitrite plus nitrate and total phosphorus were less than 0.5 milligrams per liter (mg/L) as nitrogen (N) and 0.1 mg/L as phosphorus (P), respectively. These concen- trations were lower than national median concen- trations for basins with similar land uses. At the Pudding River site, which received significant point-source and agricultural nonpoint-source inputs, median values for nitrite plus nitrate and total phosphorus were 1.4 mg/L as N and 0.2 mg/L as P, respectively. Nitrite-plus-nitrate concentrations at this site were seasonally dependent, with the highest concentrations occurring during winter. Forested sites had significantly lower water temperatures and nutrient concentrations than urban or agricultural sites. Evidence of diel variations in dissolved oxygen concentrations and pH values suggest that, at some sites, low dissolved oxygen concentrations may be a problem during early morning hours in the summer. Historical nutrient data for ground water were limited primarily to nitrate and nitrite-plus-nitrate determinations for wells completed in the basin-fill and alluvial aquifer. Nitrate and nitrite-plus-nitrate concentrations in this aquifer showed a weak inverse relationship with depth.

Water-Resources Investigations Report↗