Search USGS⌕ Search

SEARCH · Search USGS

Results for “Irrigation Age”

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 217 records · Page 12Linked to original sources
USGS1968

Geology and ground-water resources of Fillmore County, Nebraska, with a section on chemical quality of the water

Fillmore County, an area 24 miles square, lies in the eastern part of the Nebraska loess plain. Although tributaries of the Big Blue River have eroded valleys into this plain, much of the original surface is intact. Broad flats and numerous shallow undrained depressions characterize the plain. The county is underlain by unconsolidated deposits of Quaternary age to depths ranging from about 80 to 450 feet. The upper part of this depositional sequence consists largely of wind-deposited clayey silt, and the lower part of stream-deposited sand and gravel. In part of the county, deposits of glacial till also are included. The Quaternary deposits mantle an eroded surface of marine-deposited strata of Cretaceous age. The lower deposits of Quaternary age are saturated and constitute a highly productive aquifer throughout much of the county. The saturated zone ranges from about 20 to 350 feet in thickness. Replenishment to this aquifer, derived principally from precipitation, is believed to average about 1.4 inches per year. Because the quantity of ground water pumped per year exceeds the average annual quantity of recharge, some of the water used for irrigation is from storage. Consequently, water levels in wells .are declining. This trend is likely to continue. The ground water is of the calcium bicarbonate type and is hard, but it is chemically suitable for irrigation use on most soils in the county.

Nebraska↗
USGS2026

Legacy of the fumigant 1,2-dibromo-3-chloropropane (DBCP) in California groundwater

The fumigant pesticide 1,2-dibromo-3-chloropropane (DBCP) was widely used in California agriculture during the 1960s and 1970s before being banned in 1979. Despite this ban, DBCP continues to contaminate groundwater due to its persistence and mobility. This study evaluates the distribution, historical trends, and projected persistence of DBCP in California using data from over 13,000 public supply wells and additional domestic, irrigation, and observation wells (1980-2022). Since 2010, DBCP has been detected in 9% of public supply wells statewide, with higher frequencies in the San Joaquin Valley (21%) and upper Santa Ana River watershed (13%), where DBCP use was most prevalent. Approximately 70% of wells had decreasing concentration trends, whereas increases were more common in deeper wells, indicating downward vertical migration of the DBCP front. Groundwater age estimates show that recharge timing aligns with the 1960s–1970s loading period, enabling reconstruction of peak inputs and providing a basis for age based modeling. To estimate future persistence, we applied a one dimensional advection–dispersion model that simulates long term declines in peak concentrations based on groundwater age, historical loading, and a 38 year degradation half life. Model projections suggest that concentrations above the maximum contaminant level may persist in a declining number of wells until approximately 2080 (range: 2048–2109), with longer persistence in the San Joaquin Valley. The simplified modeling framework, based on age distributions typical of wells capturing peak concentrations, can provide practical regional scale assessment of non-point source contaminants where long-term monitoring exists. This study highlights how the legacy of DBCP contamination will likely affect California's groundwater resources throughout the 21st century.

California↗
USGS2010

Processes affecting the distribution of selenium in shallow groundwater of agricultural areas, western San Joaquin Valley, California

A study was undertaken to evaluate the processes affecting the chemistry of shallow groundwater associated with agricultural drainage systems in the western San Joaquin Valley, California. The study was prompted by a need for an understanding of selenium mobility in areas having high selenium concentrations in shallow groundwater. Groundwater samples were collected along transects in three artificially drained fields where the age of the drainage system varied (15, 6, and 1.5 years). Selenium concentrations in the drain water also varied (430, 58, and 3700 μg/L, respectively). Isotopic enrichment and chemical composition of the groundwater samples indicate that saline- and selenium-enriched water has evolved as a result of evaporation or transpiration of groundwater. This evaporated, isotopically enriched water is being displaced by more recent, less saline irrigation water percolating through the root zone. This displacement seems to be a process whereby sodium chloride and sodium sulfate water is being replaced by more dilute calcium sulfate and calcium bicarbonate water.

California↗
USGS1979

Water in the Elizabethtown area: A study of a limestone terrane in north-central Kentucky

The Elizabethtown area of north-central Kentucky contains aquifers and streams that yield adequate quantities of water of suitable quality for most individual domestic needs as well as for industrial, public supply, and irrigation uses. The area consists of typical karst with numerous sinkholes and subsurface drainage. The bedrock structure controls, in part, the availability of ground water. Potentiometric and structure contours suggest that wells, springs, and streams on anticlines are more likely to have smaller yields or flows and possibly be more affected by droughts, than those on synclines. Water wells, tapping the St. Louis Limestone of Late Mississippian age, yield from less than 1 to about 540 gallons per minute. The average well is 93 feet deep and has a static water level of 40 feet. Well depths range from 43 to 335 feet. The low average discharges of springs during 7 consecutive days for a 10-year period range from 0.4 to 13.4 cubic feet per second. Stream discharges average from less than 0.002 cubic feet per second in the headlands, to 458 cubic feet per second for Nolin River at White Mills, just beyond the area of study. Low average discharges of streams during 7 consecutive days for a 10-year interval range from zero to 34 cubic feet per second. Along many intervals of Middle Creek and North Fork Nolin River, during periods of low flow, there may be no surface flow. Such losing streams are common in karstland which lacks surface drainage. The quality of water from wells and springs is typical of a limestone terrane. It is chiefly a calcium bicarbonate or calcium sulfate type of water. The water is moderately hard to very hard. The water quality of streams at baseflow is similar to that of the ground water. During periods of precipitation, water in streams is diluted by the overland runoff and contains fewer dissolved solids. Water in the basal gypsum-hearing part of the St. Louis Limestone is likely to have sulfate content in excess of 250 milligrams per liter. The water from this zone may also contain excessive dissolved solids. Water from rocks that have shale beds below the St. Louis Limestone is likely to be saline.

Kentucky↗
USGS2023

Arsenic, chromium, uranium, and vanadium in rock, alluvium, and groundwater, Mojave River and Morongo Areas, western Mojave Desert, southern California

Trace elements within groundwater that originate from aquifer materials and pose potential public-health hazards if consumed are known as geogenic contaminants. The geogenic contaminants arsenic, chromium, and vanadium can form negatively charged ions with oxygen known as oxyanions. Uranium complexes with bicarbonate and carbonate to form negatively charged ions having aqueous chemistry similar to oxyanions. The concentrations of arsenic, chromium, uranium, and vanadium in groundwater result from the combined effects of (1) geologic abundance within aquifer materials; (2) the fraction of these elements that have weathered from and sorbed to the surfaces of mineral grains and are potentially available to groundwater; and (3) the aqueous chemistry of dissolved oxyanions in groundwater during different redox conditions and pH, both of which are affected by hydrogeology, including the length of time groundwater has been in contact with aquifer materials. Concentrations of arsenic, chromium, uranium, and vanadium were measured in samples of (1) rock, surficial alluvium, and drill cuttings using portable (handheld) X-ray fluorescence (pXRF); (2) operationally defined fractions extractable from these materials; and (3) water from wells sampled between 2000 and 2018 within the 3,500 square mile Mojave River area and Morongo area of the western Mojave Desert, southern California. Regionally, rock and surficial alluvium in the Mojave River and Morongo areas are high in arsenic, low in chromium and uranium, and near the average bulk continental crust concentration for vanadium. Locally, high chromium concentrations are present in mafic rock within the San Gabriel Mountains; high uranium concentrations are present in felsic rock within the San Bernardino Mountains; and high arsenic, uranium, and vanadium concentrations are present in extrusive (volcanic) felsic rock within uplands surrounding groundwater basins along the Mojave River downstream from Barstow, California. Elemental assemblages identified using principal component analyses (PCA) of pXRF data were used to characterize felsic, mafic, and felsic volcanic source terranes in rock, surficial alluvium, and in geologic material penetrated by selected monitoring wells drilled between 1994 and 2018. Highly felsic alluvium associated with recent deposition from the Mojave River was identified along the 90-mile length of the floodplain aquifer along the river. The thickness of these highly felsic alluvial deposits ranged from 200 feet (ft) near Victorville and near Barstow to a thin veneer about 30 ft thick downstream from Victorville and downstream portions of the floodplain aquifer within the Mojave Valley. Groundwater in the Mojave River and Morongo areas was generally oxic and alkaline (pH≥7.5). Maximum concentrations of arsenic, hexavalent chromium [Cr(VI)], uranium, and vanadium in water from as many as 498 wells sampled between 2000 and 2018 were 360, 140, 1,470, and 690 micrograms per liter (μg/L), respectively. Water from 22 percent of sampled wells exceeded the U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) for arsenic of 10 μg/L, with arsenic concentrations commonly exceeding the MCL in water from wells east of Barstow, deep wells in the Victorville fan, and in suboxic or reduced groundwater within the floodplain aquifer. Water from about 1 percent of sampled wells had Cr(VI) concentrations greater than the California MCL for total chromium of 50 μg/L, whereas 13 percent of sampled wells had Cr(VI) concentrations greater than the former California MCL of 10 μg/L. Hexavalent chromium concentrations were highest in water from wells in the Sheep Creek alluvial fan, eroded from mafic rock in the San Gabriel Mountains, although Cr(VI) concentrations greater than the former California MCL also were present elsewhere in the study area where mafic materials or older groundwater were present. Water from about 9 percent of sampled wells exceeded the EPA MCL for uranium of 30 μg/L, with concentrations exceeding the MCL commonly associated with irrigation return from agricultural land overlying the floodplain aquifer. Water from about 7 percent of sampled wells had vanadium concentrations greater than the California notification level of 50 μg/L; most of these wells were in the Victorville fan within the Mojave River area. In general, arsenic concentrations were higher in suboxic or reduced water; chromium concentrations were higher in oxic, alkaline (pH≥7.5) water; uranium concentrations were higher in circumneutral to slightly alkaline water (pH≤7.4); and vanadium concentrations were higher in highly alkaline (pH≥8.0) water, independent of redox status. Concentrations within geologic source terranes are not the sole factor controlling the concentrations of geogenic elements in groundwater. Differences in mineral weathering, pH-dependent sorption to surface-exchange sites on mineral grains, and aqueous geochemistry (especially redox status and pH) affect geogenic element concentrations in groundwater. Consequently, the relative abundances of arsenic, Cr(VI), uranium, and vanadium in groundwater differ from their relative abundances in the average bulk continental crust and their regional abundances in rock and surficial alluvium within groundwater basins of the western Mojave Desert. Processes that control the concentrations of arsenic, chromium, uranium, and vanadium in groundwater operate at the mineral-grain and aquifer scale. At the mineral-grain scale, sequential chemical extraction data show arsenic and uranium are more available to groundwater (under specific geochemical conditions) than chromium or vanadium, which largely are unavailable within unweathered mineral grains. Additionally, chromium and vanadium form few aqueous complexes and bind tightly with iron minerals within surface coatings on mineral grains making them less available to groundwater, whereas complexation with other dissolved ions enhances the solubility of uranium and, to a lesser extent, arsenic. Complexation also increases the valence (less negative charge) and increases the size of dissolved oxyanions and uranium complexes with bicarbonate and carbonate making them less readily sorbed to aquifer materials. At the aquifer scale, hydrogeology (including isolation of water in aquifers from surface sources of recharge, older groundwater age, and long contact times between groundwater and aquifer materials) combined with geochemical processes (such as silicate weathering) to produce alkaline groundwater. Desorption from sorption sites on the surfaces of mineral grains with increasing pH increases arsenic, chromium, and vanadium concentrations in water from wells and increases Cr(VI) concentrations as long as water remains oxic. Aqueous geochemistry and concentrations of geogenic contaminants also are affected by anthropogenic activities including (1) discharge of treated municipal wastewater, which may change the redox status of groundwater; (2) return from irrigated agriculture, which may alter the chemistry of groundwater and increase the solubility of trace elements such as uranium; and (3) groundwater pumping and subsequent water-level declines, which may change the source of water yielded by wells. The quality of water imported from northern California and infiltrated from ponds for groundwater recharge may be altered by naturally present trace elements, especially uranium in areas of agricultural land use or chromium within mafic alluvium.

California↗
USGS1987

Processes affecting the distribution of selenium in shallow ground water of agricultural areas, western San Joaquin Valley, California

A study was undertaken to evaluate the processes affecting the chemistry of shallow ground water associated with agricultural drainage systems in the western San Joaquin Valley, California. The study was prompted by a need for an understanding of selenium mobility in areas having high selenium concentrations in shallow ground water. Groundwater samples were collected along transects in three artificially drained fields where the age of the drainage system varied (15, 6, and 1.5 years). Selenium concentrations in the drainage water also varied (0F30, 58, and 3700 micrograms per liter, respectively). Isotopic enrichment and chemical composition of the ground-water samples indicate that saline- and selenium-enriched water has evolved as a result of evaporation of ground water. This evaporated, isotopically enriched water is being displaced by more recent, less saline irrigation water percolating through the root zone. This displace-ment seems to be a process whereby sodium chloride and sodium sulfate water is being replaced by more dilute calcium sulfate and calcium bicarbonate water.

California↗
USGS1997

Digital data sets that describe aquifer characteristics of the Rush Springs Aquifer in western Oklahoma

This diskette contains digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Rush Spring aquifer in western Oklahoma. This area encompasses all or part of Blaine, Caddo, Canadian, Comanche, Custer, Dewey, Grady, Stephens, and Washita Counties. These digital data sets were developed by Mark F. Becker to use as input into a computer model that simulated ground-water flow in the Rush Springs aquifer (Mark F. Becker, U.S. Geological Survey, written commun., 1997). For the purposes of modeling the ground-water flow in the Rush Springs aquifer, Mark F. Becker (written commun., 1997) defined the Rush Springs aquifer to include the Rush Springs Formation, alluvial and terrace deposits along major streams, and parts of the Marlow Formations, particularly in the eastern part of the aquifer boundary area. The Permian-age Rush Springs Formation consists of highly cross-bedded sandstone with some interbedded dolomite and gypsum. The Rush Springs Formation is overlain by Quaternary-age alluvial and terrace deposits that consist of unconsolidated clay, silt, sand, and gravel. The Rush Springs Formation is underlain by the Permian-age Marlow Formation that consists of interbedded sandstones, siltstones, mudstones, gypsum-anhydrite, and dolomite beds (Mark F. Becker, written commun., 1997). The parts of the Marlow Formation that have high permeability and porosity are where the Marlow Formation is included as part of the Rush Springs aquifer. The Rush Springs aquifer underlies about 2,400 square miles of western Oklahoma and is an important source of water for irrigation, livestock, industrial, municipal, and domestic use. Irrigation wells are reported to have well yields greater than 1,000 gallons per minute (Mark F. Becker, written commun., 1997). Mark F. Becker created some of the aquifer boundaries, hydraulic conductivity, and recharge data sets by digitizing parts of previously published surficial geology maps. The hydraulic conductivity and recharge values are the input data to the ground-water flow model (Mark F. Becker, written commun., 1997). The water-level elevation data set was prepared at a scale of 1:250,000 by Mark F. Becker (written commun., 1997) from water levels measured in wells prior to the year 1950. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

Oklahoma↗
USGS1985

Generalized potentiometric surface of aquifers of Pleistocene age, Southern Louisiana, 1980

A map of potentiometric surface defines generalized water levels for 1980 in the Pleistocene aquifers of southern Louisiana. The map was prepared as part of the Western Gulf Coast Regional Aquifer-System Analysis study. The Pleistocene deposits in southern Louisiana consist of alternating beds of sand, gravel, silt, and clay deposited under fluvial, deltaic, and near-short marine conditions. The aquifers are mainly under artesian conditions and the regional flow direction is primarily southward. Areally definable cones of depression result from heavy pumpage in the Baton Rouge, Lake Charles, and New Orleans metropolitan areas and in the rice irrigation area of southwestern Louisiana. Where water levels differ vertically within the aquifer, the lowest water levels in the vertical section were used because these levels represented the thickest and most heavily pumped unit in the aquifer. The map represents regional water levels in the Pleistocene aquifers, and is not intended to show localized variations near pumping centers. (USGS)

Water-Resources Investigations Report↗
USGS1977

Selected water-level records for western Oklahoma, 1975-1976

A systematic program to collect water-level records in Oklahoma began in 1937. The objectives of this program are (1) to provide long-term records of water-level fluctuations in representative wells, (2) to facilitate the prediction of water-level trends and indicate future availability of ground-water supplies, and (3) to provide information for use in basic research. Water-level data in table 1 are from wells that are measured annually, prior to the irrigation season to achieve the most natural representation of the static water level. Water level measurements listed in the column under 1975 may have been made during December, 1974 or January or February, 1975. Measurements listed in the column 1976 may have been made during December 1975 or January or February 1976. Figure 1 shows the counties and number of wells therein, where data were obtained for this report. The stratigraphic nomenclature and age determinations used in this report are those accepted by the Oklahoma Geological Survey and do not necessarily agree with those at the U.S. Geological Survey. Records of water levels in Oklahoma are collected through a cooperative program by the U.S. Geological Survey and the Oklahoma Water Resources Board. The records are tabulated and published by the U.S. Geological Survey on an annual basis.

Oklahoma↗
USGS2014

Aquifers of Arkansas: protection, management, and hydrologic and geochemical characteristics of groundwater resources in Arkansas

Sixteen aquifers in Arkansas that currently serve or have served as sources of water supply are described with respect to existing groundwater protection and management programs, geology, hydrologic characteristics, water use, water levels, deductive analysis, projections of hydrologic conditions, and water quality. State and Federal protection and management programs are described according to regulatory oversight, management strategies, and ambient groundwater-monitoring programs that currently (2013) are in place for assessing and protecting groundwater resources throughout the State. Physical attributes, groundwater geochemistry, and groundwater quality are described for each of the 16 aquifers of the State. Information in regard to the hydrology and geochemistry of each of the aquifers is summarized from about 550 historical and recent publications. Additionally, more than 8,000 sites with groundwater-quality data were obtained from the U.S. Geological Survey National Water Information System and the Arkansas Department of Environmental Quality databases and entered into a spatial database to investigate distribution and trends in chemical constituents for each of the aquifers. The 16 aquifers of the State were divided into two major physiographic regions of the State: the Coastal Plain Province (referred to as Coastal Plain) of eastern and southern Arkansas, which includes 11 of the 16 aquifers, and the Interior Highlands Division (referred to as Interior Highlands) of western Arkansas, which includes the remaining 5 aquifers. The 11 aquifers in the Coastal Plain consist of various geologic units that are Cenozoic in age and consist primarily of Cretaceous, Tertiary, and Quaternary sands, gravels, silts, and clays. Groundwater in the Coastal Plain represents one of the most valuable natural resources in the State, driving the economic engines of agriculture, while also supplying abundant water for commercial, industrial, and public-supply use. In terms of age from youngest to oldest, the aquifers of the Coastal Plain include Quaternary alluvial aquifers, including the Mississippi River Valley alluvial aquifer (the most important aquifer in Arkansas in terms of volume of use and economic benefits), the Jackson Group (a regional confining unit that served for decades as an important source of domestic supply), and the Cockfield, Sparta, Cane River, Carrizo, Wilcox, Nacatoch, Ozan, Tokio, and Trinity aquifers. The Mississippi River Valley alluvial aquifer accounts for approximately 94 percent of all groundwater used in the State, and the aquifer is used primarily for irrigation purposes. The Sparta aquifer is the second most important aquifer in terms of use, and the aquifer was used in the past dominantly as a source of public and industrial supply, although increasing irrigation use is occurring because of critically declining water levels in the Mississippi River Valley alluvial aquifer. Other aquifers of the Coastal Plain generally are used as important local sources of domestic, industrial, and public supply, in addition to other minor uses. Water quality generally is good for all aquifers of the Coastal Plain, except for elevated iron concentrations and localized areas of high salinity. The high salinity results from intrusion from underlying formations, evapotranspiration processes in areas of low recharge, and inadequate flushing in downgradient areas of residual salinity from deposition in marine environments. Trends in the spatial distribution of individual chemical constituents are related to position along the flow path for most aquifers of the Coastal Plain. These trends include elevated iron and nitrate concentrations with lower pH values and dissolved solids in groundwater from the outcrop areas, transitioning to lower iron and nitrate (related to changes in redox) and higher pH and dissolved solids (dominantly from the dissolution of carbonate minerals) in groundwater downgradient from outcrop areas. Groundwater generally trended from a calcium- to a sodium-bicarbonate water type with increasing cation exchange along the flow path. The Interior Highlands of western Arkansas has less reported groundwater use than other areas of the State, reflecting a combination of factors. These factors include prevalent and increasing use of surface water, less intensive agricultural uses, lower population and industry densities, lesser potential yield of the resource, and lack of detailed reporting. The overall low yields of aquifers of the Interior Highlands result in domestic supply as the dominant use, with minor industrial, public, and commercial-supply use. Where greater volumes are required for growth of population and industry, surface water is the greatest supplier of water needs in the Interior Highlands. The various aquifers of the Interior Highlands generally occur in shallow, fractured, well-indurated, structurally modified bedrock of this mountainous region of the State, as compared to the relatively flat-lying, unconsolidated sediments of the Coastal Plain. In terms of age from youngest to oldest, the aquifers of the Interior Highlands include: the Arkansas River Valley alluvial aquifer, the Ouachita Mountains aquifer, the Western Interior Plains confining system, the Springfield Plateau aquifer, and the Ozark aquifer. Spatial trends in groundwater geochemistry in the Interior Highlands differ greatly from trends noted for aquifers of the Coastal Plain. In the Coastal Plain, the prevalence of long regional flow paths results in regionally predictable and mappable geochemical changes along the flow paths. In the Interior Highlands, short, topographically controlled flow paths (from hilltops to valleys) within small watersheds represent the predominant groundwater-flow system. As such, dense data coverage from numerous wells would be required to effectively characterize these groundwater basins and define small-scale geochemical changes along any given flow path for aquifers of the Interior Highlands. Changes in geochemistry generally were related to rock type and residence time along individual flow paths. Dominant changes in geochemistry for the Ouachita Mountains aquifer and the Western Interior Plains confining system are attributed to rock/water interaction and changes in redox zonation along the flow path. In these areas, groundwater evolves along flow paths from a calcium- to a sodium-bicarbonate water type with increasing reducing conditions resulting in denitrification, elevated iron and manganese concentrations, and production of methane in the more geochemically evolved and strongest reducing conditions. In the Ozark and Springfield Plateau aquifers, rapid influx of surface-derived contaminants, especially nitrogen, coupled with few to no attenuation processes was attributed to the karst landscape developed on Mississippian- and Ordovician-age carbonate rocks of the Ozark Plateaus. Increasing nitrate concentrations are related to increasing agricultural land use, and areas of mature karst development result in higher nitrate concentrations than areas with less karst features.

Arkasas↗
USGS1959

Ground-water conditions and storage capacity in the San Joaquin Valley, California

The San Joaquin Valley includes roughly the southern two-thirds of the Great Central Valley of California. It is a broad structural trough surrounded by mountains. The northern part of the valley drains through the San Joaquin River northward to San Francisco Bay ; the southern part of the valley normally is a basin of interior drainage tributary to evaporation sumps in the trough of the valley, chiefly Tulare and Buena Vista Lake beds. In years of normal discharge most of the streamflow in the southern part of the valley not diverted for irrigation finds its way to Tulare and Buena Vista Lake beds. In the historic past, however, during years of heavy floods the low divide between Buena Vista and Tulare Lakes and the low divide between Tulare Lake and the San Joaquin River were overtopped and through-flowing drainage occurred over the full length of the valley. Because the Tulare Lake bed is the lowest point and also the largest sump, this whole basin of interior drainage is commonly referred to as the Tulare Lake drainage basin. Average annual precipitation ranges from more than 15 inches in the north- eastern part of the valley to less than 4 inches in the southwestern part. The precipitation decreases from north to south and from east to west across the valley. Streamflow, the critical quantity in the water supply, depends almost wholly on the amount and distribution of precipitation in the Sierra Nevada to the east. Much of this precipitation falls as snow, and the snowpack acts as a natural reservoir retaining much of the annual runoff until late spring and early summer. The mean seasonal runoff to the San Joaquin Valley is nearly 10 million acre- feet, of which about two-thirds is tributary to the San Joaquin River; the remaining third is tributary to Tulare Lake drainage basin. In 1952 about 8.5 million acre-feet of surface water was diverted for irrigation. Withdrawals of ground water for irrigation in 1952 approximated 7.5 million acre-feet. The surface of the San Joaquin Valley is not a featureless plain but is characterized by various types of physiography such as dissected uplands, low alluvial plains and fans, river flood plains and channels, and overflow lands and lake bottoms. The dissected uplands fringe the valley along its mountain borders. They are underlain by unconsolidated to semiconsolidated continental deposits of late Tertiary and early Quaternary age which have been moderately tilted and folded. The topography of these uplands ranges from deeply dissected hill land having a relief of several hundred feet to gently rolling land whose relief Is only a few feet. The low plains and fans border the dissected uplands along their valley- ward margins. They are generally fiat to gently undulating and featureless and are underlain by undeformed to slightly deformed alluvial deposits of Quaternary age. The river flood plains and channels lie along the San Joaquia and Kings Rivers in the axial part of the valley and along the major east-side streams. Where the rivers are incised below the general land surface, the flood plains are well defined; but in the axial trough of the valley, where the rivers are flanked by low-lying overflow lands, the flood-plain and channel deposits are confined to the stream channel and to the natural levees that slope away from the river. Overflow lands and lake bottoms include the historic beds of Tulare, Buena Vista, and Kern Lakes in the southern part of the valley, and the low-lying lands in the axial trough between the low alluvial plains and fans and the natural levees of the San Joaquin River and its major tributaries. They are level and featureless and are underlain by lake and swamp deposits of Recent age. The San Joaquin Valley is a great structural downwarp between the tilted block of the Sierra Nevada on the east and the complexly folded and faulted Coast Ranges on the we

Water Supply Paper↗
USGS1993

Water resources of Taos County, New Mexico

In Taos County, ground water generally is unconfined and moves toward the Rio Grande or perennial streams. Water quality is good except in some areas where water has high values of specific conductance and hardness and contains high concentrations of dissolved solids and fluoride. Most wells are completed in alluvial sediments of Quaternary and Tertiary age in the Costilla Plains. A few wells are completed in basalt of the Taos Plateau and in alluvium of stream channels in the Sangre de Cristo Mountains. Depths to water in wells range from less than 1 to 1,080 feet below land surface. Well yields range from 1 to 3,000 gallons per minute. Water levels in wells in Sunshine Valley dropped 5 to 50 feet between 1955 and 1970. Ground-water irrigation has since declined and water levels have risen. Surface-water records show the county is a net producer of water. The average discharge gained in the Rio Grande as it flows through the county was 271,700 acre-feet per year for water years 1931-89. The highest mean monthly discharge occurs in May or June due to snowmelt runoff. Water quality ranges from good in upstream reaches to fair in lower reaches. Surface water was the source for 93 percent of water withdrawn in 1990, but ground water was used for all public supply, domestic, and industrial purposes. The largest water use is irrigation. About 28,500 acres were irrigated in 1990; alfalfa, native pasture, and planted pasture accounted for 91 percent of this acreage.

New Mexico↗
USGS2005

Hydrogeology and quality of ground water in the upper Arkansas River basin from Buena Vista to Salida, Colorado, 2000-2003

The upper Arkansas River Basin between Buena Vista and Salida, Colorado, is a downfaulted basin, the Buena Vista-Salida structural basin, located between the Sawatch and Mosquito Ranges. The primary aquifers in the Buena Vista-Salida structural basin consist of poorly consolidated to unconsolidated Quaternary-age alluvial and glacial deposits and Tertiary-age basin-fill deposits. Maximum thickness of the alluvial, glacial, and basin-fill deposits is about 5,000 feet, but 95 percent of the water-supply wells in Chaffee County are no more than 300 feet deep. Hydrologic conditions in the 149-square mile study area are described on the basis of hydrologic and geologic data compiled and collected during September 2000 through September 2003. The principal aquifers described in this report are the alluvial-outwash and basin-fill aquifers. An estimated 3,443 wells pumped about 690 to 1,240 acre-feet for domestic and household use in Chaffee County during 2003. By 2030, projected increases in the population of Chaffee County, Colorado, may require use of an additional 4,000 to 5,000 wells to supply an additional 800 to 1,800 acre-feet per year of ground water for domestic and household supply. The estimated specific yield of the upper 300 feet of the alluvial-outwash and basin-fill aquifers ranged from about 0.02 to 0.2. Current (2003) and projected (2030) ground-water withdrawals by domestic and household wells are less than 1 percent of the estimated 472,000 acre-feet of drainable ground water in the upper 300 feet of the subsurface. Locally, little water is available in the upper 300 feet. In densely populated areas, well interference could result in decreased water levels and well yields, which may require deepening or replacement of wells. Infiltration of surface water diverted for irrigation and from losing streams is the primary source of ground-water recharge in the semiarid basin. Ground-water levels in the alluvial-outwash and basin-fill aquifers vary seasonally with maximum water levels occurring in the early summer after snowmelt runoff peaks. Because of the drought during 2002, relatively large declines in ground-water levels occurred in about one-half of the monitored wells. Differences in water-level altitudes in shallow and deep wells indicate the potential for downward flow in upland areas and support results of preliminary cross-sectional models of ground-water flow. The apparent mean age of ground-water recharge ranged from about 1 to more than 48 years before 2001. The older (pre-1953) water was from wells that were located in ground-water discharge areas. Ground-water flow in the Buena Vista-Salida structural basin drains eastward toward the Arkansas River and, locally, toward the South Arkansas River. Ground water in the alluvial-outwash and basin-fill aquifers generally is calcium-bicarbonate water type with less than 250 milligrams per liter dissolved solids. Nitrate concentrations generally were less than 1 to 2 milligrams per liter and do not indicate widespread contamination of ground water from surface sources.

Scientific Investigations Report↗
USGS1992

Geohydrologic framework of the Snake River plain regional aquifer system, Idaho and eastern Oregon

The Snake River Plain in southern Idaho is a major geologic structure of uncertain origin. Surface geology is generally well defined, but subsurface geology is poorly defined below about 500 feet. Rocks that underlie the plain form the framework for a regional ground-water system that supplies large quantities of water for irrigation and makes the plain nationally important in terms of agricultural production. The 15,600-square-mile Snake River Plain is a grabenlike structure that formed in middle Miocene time. The graben may have been formed by oblique extensional forces resulting from interactions between the North American and Pacific tectonic plates. The oldest known rocks underlying the plain, penetrated in a 14,007-foot-deep test hole northwest of Boise, are of middle Miocene age. Miocene volcanic rocks at the plain's margin that dip toward and underlie the plain were highly faulted and se- verely eroded before the plain was formed. Faults along the margins of the eastern part of the plain are not visible at land surface and have been defined chiefly by geo- physical methods. However, well-defined fault systems bound the western part of the plain. The eastern plain is underlain predominantly by Quaternary basalt of the Snake River Group, which is intercalated with sedimentary rocks along the margins. Basalt crops out or is less than 10 feet below land surface in the central part of the east- ern plain and is usually less than 100 feet below land surface elsewhere. Geophysical data and drillers' logs indicate that Quaternary basalt in the central part of the eastern plain is as much as 5,000 feet thick. A test hole about 10 miles northeast of the Snake River near Wendell provided the first information about deep subsurface stratigraphic relations in that part of the plain. The stratigraphic sequence penetrated in the test hole is similar to that in the north wall of the Snake River canyon be- tween Milner and King Hill. In that area, basalt of the Snake River Group thins toward the river and is underlain by sedi- mentary rocks and basalt of the Tertiary and Quaternary Idaho Group. The western plain is underlain mainly by unconsolidated and weakly consolidated Tertiary and Quaternary sedimentary rocks as much as 5,000 feet thick. Basalt also is present in the west- ern plain and is most extensive near Mountain Home. Quaternary basalt of the Snake River Group, which composes much of the Snake River Plain regional aquifer system, is highly transmissive. In the eastern plain, a thick sequence of thin- layered basalt flows yields large volumes of water to wells. Wells open to less than 100 feet of the aquifer yield as much as 7,000 gallons per minute; yields of 2,000 to 3,000 gallons per minute with only a few feet of drawdown are common. Transmissivity commonly exceeds 100,000 feet squared per day and, in places, 1 million feet squared per day. Large springs in the Snake River canyon between Milner and King Hill issue at the contact between highly transmissive pil- low lava and less transmissive underlying rocks. In 1980, ground-water discharge between Milner and King Hill, largely spring flow, averaged about 6,000 cubic feet per second. In the western plain, coarse-grained sedimentary deposits are thickest and transmissivity is highest along the northern mar- gins. The percentage of coarse-grained sedimentary deposits de- creases to the southwest, where lacustrine sedimentary deposits predominate. In most of the eastern plain, the upper part of the ground- water system is unconfined. At depth and in much of the west- ern plain, aquifers are confined. Across most of the plain, Quaternary basalt aquifers overlie aquifers in the Tertiary Idavada Volcanics and Banbury Basalt of the Idaho Group. The older volcanic rocks are typically much less transmissive than the Quaternary basalt. Faults and frac- tures are permeable zones for water storage and conduits for water movement. In places near the margins of the plain, the Idavada Volcanics contains important geothermal aquifers.

Idaho;Oregon↗
USGS1977

Hydrologic evaluation of the Arikaree Formation near Lusk, Niobrara and Goshen counties, Wyoming

The Arikaree Formation of early Miocene age is an aquifer of large areal extent and is composed of very fine grained, poorly bedded, loosely to moderately cemented sandstone and interbedded silt, limestone, and many concretionary layers. The area studied is about 800 square miles in southern Niobrara and northern Goshen Counties of Wyoming. Long-term average annual recharge to the aquifer from streams and precipitation is estimated to total about 24,270 acre-feet. Pumpage from public-supply and irrigation wells is estimated to have totaled about 48,000 acre-feet from 1938 through 1972. This pumpage did not cause any noticeable decrease in natural discharge and it is assumed there has been no significant change in ground-water storage. Pumpage is estimated to total about 39,500 acre-feet for the 3-year period 1973 through 1975. A digital model was developed to simulate the ground-water system in the Arikaree Formation. The model can be used to indicate the general effect of applying hydraulic stresses to the aquifer. (Woodard-USGS)

Water-Resources Investigations Report↗
USGS1963

Ground-water geology of Karnes County, Texas

The exposed rocks and those underlying Karnes County dip toward the Gulf of Mexico at average rates ranging from 20 to more than 200 feet per mile. The oil fields are on structures associated with faulting; the effect of faulting on the occurrence of ground water has not been determined. The principal water-bearing formations, from oldest to youngest, underlying the county are the Carrizo sand, Yegua formation, Jackson group, Catahoula tuff, Oakville sandstone, and Lagarto clay. They range in age from Eocene to Miocene and all are of sedimentary origin. About 40 million acre-feet of usable water (water containing less than 3,000 ppm) is stored more then 2,500 feet below land surface in the Carrizo sand; 30 million acre-feet is stored in the younger formations at depths less than 1,000 feet. Ground-water withdrawals for municipal, industrial, and domestic use averaged about 1.7 million gpd in 1957. Irrigation and stock supplies were derived from both ground- and surface-water sources. In general, water levels from 1936 through 1957 were not affected appreciably by withdrawals. Recharge to the ground-water reservoir from precipitation, although only a small percentage of total precipitation, exceeded withdrawals of ground water by wells in 1957. Most of the usable ground water in Karnes County is of substandard quality; whereas water from the San Antonio River, although hard, is of excellent quality. Wells tapping the Carrizo may yield as much as 1,000 gpm in the northwestern part of the county; wells in the shallower formations may yield as much as 600 gpm in the most favorable areas, but in some places may yield only a few gallons per minute of water suitable only for stock.

Water Supply Paper↗
USGS1967

Availability of water in eastern Saunders County, Nebraska

The sand and gravel deposits of Quaternary age constitute the most important ground-water reservoir and are the source of nearly all the water pumped from wells in the area. An estimated 3.5 million acre-feet for good quality water is stored in these deposits and an additional 1.5 million acre-feet is stored in the underlying Dakota Sandstone. Even larger quantities are stored at greater depths in the Paleozoic dolomites and sandstones, but the water is of poorer quality. Pumpage for irrigation since 1956 is estimated to have ranged from about 2,500 acre-feet (1962) to about 6,000 acre-feet (1957). The town of Wahoo annually pumps about 460 acre-feet, and other towns pump an estimated total of 180 acre-feet. In 1963 the City of Lincoln pumped 27,000 acre-feet from its well field alongside the Platte River in the southeast corner of the area; since then pumpage has increased and probably is likely to continue to do so. Pumping at Lincoln city well field induces recharge from Platte River. The quantity of ground water pumped to date is very small compared to the amount of water stored in the rocks. Furthermore, most of the ground water withdrawn has been replaced by infiltrating precipitation and by influent seepage from the Platte River. The large quantity of ground water in storage in addition to the flow of the Platte River indicates that the water resources of the area, if managed properly, can be developed much more extensively without appreciably depleting the supply.

Nebraska↗
USGS1982

Dissolved-solids concentrations of ground water in the Sacramento Valley, California

The general quality of the ground water in the Sacramento Valley , Calif., in terms of dissolved-solids concentration is considered good for irrigation, domestic, and most other uses. This map shows the distribution of dissolved-solids concentrations and is based on about 1,330 chemical analyses collected from about 900 wells between 1974 and 1978. On the west side of the valley some of the smaller streams contribute water of higher dissolved-solids concentrations to the ground water. The sources of these waters are thought to be the upper Cretaceous Chico Formation or marine deposits of Early Cretaceous age that are exposed in the Coast Ranges. (USGS)

Hydrologic Atlas↗