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At least 127 records · Page 7Linked to original sources
USGS2007

Ground-Water Hydrology of the Upper Klamath Basin, Oregon and California

The upper Klamath Basin spans the California-Oregon border from the flank of the Cascade Range eastward to the Basin and Range Province, and encompasses the Klamath River drainage basin above Iron Gate Dam. Most of the basin is semiarid, but the Cascade Range and uplands in the interior and eastern parts of the basin receive on average more than 30 inches of precipitation per year. The basin has several perennial streams with mean annual discharges of hundreds of cubic feet per second, and the Klamath River at Iron Gate Dam, which represents drainage from the entire upper basin, has a mean annual discharge of about 2,100 cubic feet per second. The basin once contained three large lakes: Upper and Lower Klamath Lakes and Tule Lake, each of which covered areas of 100 to 150 square miles, including extensive marginal wetlands. Lower Klamath Lake and Tule Lake have been mostly drained, and the former lake beds are now cultivated. Upper Klamath Lake remains, and is an important source of irrigation water. Much of the wetland surrounding Upper Klamath Lake has been diked and drained, although efforts are underway to restore large areas. Upper Klamath Lake and the remaining parts of Lower Klamath and Tule Lakes provide important wildlife habitat, and parts of each are included in the Klamath Basin National Wildlife Refuges Complex. The upper Klamath Basin has a substantial regional ground-water flow system. The late Tertiary to Quaternary volcanic rocks that underlie the region are generally permeable, with transmissivity estimates ranging from 1,000 to 100,000 feet squared per day, and compose a system of variously interconnected aquifers. Interbedded with the volcanic rocks are late Tertiary sedimentary rocks composed primarily of fine-grained lake sediments and basin-filling deposits. These sedimentary deposits have generally low permeability, are not good aquifers, and probably restrict ground-water movement in some areas. The regional ground-water system is underlain and bounded on the east and west by older Tertiary volcanic and sedimentary rocks that have generally low permeability. Eight regional-scale hydrogeologic units are defined in the upper Klamath Basin on the basis of surficial geology and subsurface data. Ground water flows from recharge areas in the Cascade Range and upland areas in the basin interior and eastern margins toward stream valleys and interior subbasins. Ground water discharge to streams throughout the basin, and most streams have some component of ground water (baseflow). Some streams, however, are predominantly ground-water fed and have relatively constant flows throughout the year. Large amounts of ground water discharges in the Wood River subbasin, the lower Williamson River area, and along the margin of the Cascade Range. Much of the inflow to Upper Klamath Lake can be attributed to ground-water discharge to streams and major spring complexes within a dozen or so miles from the lake. This large component of ground water buffers the lake somewhat from climate cycles. There are also ground-water discharge areas in the eastern parts of the basin, for example in the upper Williamson and Sprague River subbasins and in the Lost River subbasin at Bonanza Springs. Irrigated agriculture is an integral part of the economy of the upper Klamath Basin. Although estimates vary somewhat, roughly 500,000 acres are irrigated in the upper Klamath Basin, about 190,000 acres of which are part of the Bureau of Reclamation Klamath Project. Most of this land is irrigated with surface water. Ground water has been used for many decades to irrigate areas where surface water is not available, for example outside of irrigation districts and stream valleys. Ground water has also been used as a supplemental source of water in areas where surface water supplies are limited and during droughts. Ground water use for irrigation has increased in recent years due to drought and shifts in surface-water allocation from irrigati

Scientific Investigations Report↗
USGS2008

Streamflow and Endangered Species Habitat in the Lower Isleta Reach of the Middle Rio Grande

San Acacia Dam is located in a reach of the Rio Grande that has been designated as critical habitat for two endangered species, the Rio Grande silvery minnow (Hybognathus amarus) and the southwestern willow flycatcher (Empidonax traillii extimus). Under present operations, the Rio Grande upstream from the dam is used to convey irrigation water to the Socorro main canal at San Acacia Dam. In order to increase operational flexibility and improve irrigation delivery efficiency, the 'Bernardo Siphon' has been proposed to intercept up to 150 cubic feet per second from the Lower San Juan Riverside Drain on the east side of the Rio Grande and transport it under the river into a drainage canal on the west side. Irrigation deliveries to the Socorro main canal would be conveyed by way of the drainage canal rather than the Rio Grande. The objective of this study was to provide the Bureau of Reclamation (BOR) and other stakeholders with a tool to evaluate the effects of different operational modes of the Bernardo siphon on habitat for H. amarus and E. t. extimus in this section of river. We used a two-dimensional hydraulic simulation model to simulate hydraulic conditions for a range of discharges at three study sites in the Rio Grande between the proposed siphon location and San Acacia Dam. Suitable habitat characteristics were defined for H. amarus by consensus of a panel of experts and for E. t. extimus on the basis of a study conducted in 2003 by BOR. Habitat suitability maps for each targeted life stage and simulated discharge were constructed using a Geographic Information System (ArcGIS) and the results compiled into tables relating discharge to areas of suitable habitat. A separate analysis was conducted to calculate an index of connectivity among habitat patches at low flows. A hydrologic model was constructed to synthesize flows, by reach, without the siphon, which was used as a baseline for comparison with similarly-synthesized discharges with the siphon under different operating rules. Results from the hydrologic time series were combined with the discharge-habitat relations to develop habitat time series models, statistics, and scoring metrics for comparisons of alternative rules of operation for the Bernardo siphon. Suitable habitat for H. amarus was defined as areas having suitable hydraulic conditions alone and as areas having suitable hydraulics in association with large woody debris. Suitable hydraulic habitat for adults was maximized at discharges between 40 and 80 cubic feet per second, and declined rapidly at discharges larger than 150 cubic feet per second. When large woody debris was included in the definition of suitable habitat, discharges between 40 and 200 cubic feet per second provided maximum suitable habitat for adults. Juvenile hydraulic habitat was maximized at discharges between 20 and 80 cubic feet per second, and hydraulic habitat associated with large woody debris was largest at flows between 40 and 150 cubic feet per second. Nesting habitat area for E. t. extimus increased monotonically at discharges larger than 5 ft3/s, but decreased rapidly below that flow.

Open-File Report↗
USGS1992

Hydrology and digital simulation of the regional aquifer system, eastern Snake River Plain, Idaho

The occurrence and movement of water in the regional aquifer system that underlies the eastern Snake River Plain, Idaho, de- pend on the transmissivity and storage capacity of rocks that compose the geologic framework and on the distribution and amount of recharge and discharge of water within that frame- work. On a regional scale, most water moves horizontally through interflow zones in Quaternary basalt of the Snake River Group. In recharge and discharge areas, water also moves vertically along joints and interfingering edges of basalt flows. Aquifer thickness is largely unknown, but geophysical studies suggest that locally the Quaternary basalt may exceed several thousand feet. Along the margins of the plain, sand and gravel several hundred feet thick transmit large volumes of water. Regional ground-water movement is generally from northeast to southwest, from areas of recharge to areas of discharge. Re- charge is from seepage of surface water used for irrigation, stream and canal losses, underflow from tributary drainage ba- sins, and infiltration of precipitation. Aquifer discharge is largely spring flow to the Snake River and water pumped for irrigation. Major springs are near American Falls Reservoir and along the Snake River from Milner Dam to King Hill. Regional ground-water flow was simulated with numerical models. Initially, a two-dimensional steady-state model that in- cluded a nonlinear, least-squares regression technique was used to estimate aquifer properties. Later, a three-dimensional steady- state and transient model was used to replace the two-dimen- sional model. Three-dimensional model results indicated that average total transmissivity ranged from about 0.05 to 120 feet squared per second and vertical leakance ranged from about 3 x 10 -10 to 5 x 10 -6 feet per second per foot of aquifer thickness. The three-dimensional transient model was used to compare measured and estimated long-term changes in ground-water dis- charge and water levels with simulated values. Initial head con- ditions used in transient simulations were derived from a steady-state solution of estimated preirrigation hydrologic condi- tions. Transient simulations were 5-year stress periods beginning in 1891 and ending in 1980. Recharge for each stress period from 1926 to 1980 was estimated from surface-water irrigation, pre- cipitation, and streamflow records. Recharge for stress periods from 1891 to 1925 was based on the average value for stress peri- ods from 1926 to 1980 and was indexed to estimated irrigated acreages. Average annual tributary drainage-basin underflow for stress periods from 1891 to 1910 was calculated by using basin- yield equations. Underflow for stress periods from 1911 to 1980 was varied by use of streamflow records. Transient simulations reasonably approximated measured changes in aquifer head and ground-water discharge that re- sulted from use of surface water for irrigation. Irrigation with surface water peaked in about 1950; subsequent increases in irri- gation have been supplied largely by ground water. The three- dimensional model simulated water-level declines and reduced ground-water discharge caused in part by increases in ground- water pumping. The transient model was used to simulate aquifer changes from 1981 to 2010 in response to three hypothetical development alternatives: (1) Continuation of 1980 hydrologic conditions, (2) increased pumpage, and (3) increased recharge. Simulation of continued 1980 hydrologic conditions for 30 years indicated that head declines of 2 to 8 feet might be expected in the central part of the plain. The magnitude of simulated head declines was con- sistent with head declines measured during the 1980 water year. Larger declines were calculated along model boundaries, but these changes may have resulted from underestimation of tribu- tary drainage-basin underflow and inadequate aquifer definition. Simulation of increased ground-water pumpage (an additional 2,400 cubic feet per second) for 30 years indicated head declines of 10 to 50 feet in the central part of the plain. These relatively large head declines were accompanied by increased simulated river leakage of 50 percent and decreased spring discharge of 20 percent. The effect of increased recharge (800 cubic feet per sec- ond) for 30 years was a rise in simulated heads of 0 to 5 feet in the central part of the plain.

Idaho;Oregon↗
USGS1996

Ground Water Atlas of the United States: Segment 8, Montana, North Dakota, South Dakota, Wyoming

The States of Montana, North Dakota, South Dakota, and Wyoming compose the 392,764-square-mile area of Segment 8, which is in the north-central part of the continental United States. The area varies topographically from the high rugged mountain ranges of the Rocky Mountains in western Montana and Wyoming to the gently undulating surface of the Central Lowland in eastern North Dakota and South Dakota (fig. 1). The Black Hills in southwestern South Dakota and northeastern Wyoming interrupt the uniformity of the intervening Great Plains. Segment 8 spans the Continental Divide, which is the drainage divide that separates streams that generally flow westward from those that generally flow eastward. The area of Segment 8 is drained by the following major rivers or river systems: the Green River drains southward to join the Colorado River, which ultimately discharges to the Gulf of California; the Clark Fork and the Kootenai Rivers drain generally westward by way of the Columbia River to discharge to the Pacific Ocean; the Missouri River system and the North Platte River drain eastward and southeastward to the Mississippi River, which discharges to the Gulf of Mexico; and the Red River of the North and the Souris River drain northward through Lake Winnipeg to ultimately discharge to Hudson Bay in Canada. These rivers and their tributaries are an important source of water for public-supply, domestic and commercial, agricultural, and industrial uses. Much of the surface water has long been appropriated for agricultural use, primarily irrigation, and for compliance with downstream water pacts. Reservoirs store some of the surface water for flood control, irrigation, power generation, and recreational purposes. Surface water is not always available when and where it is needed, and ground water is the only other source of supply. Ground water is obtained primarily from wells completed in unconsolidated-deposit aquifers that consist mostly of sand and gravel, and from wells completed in semi-consolidated- and consolidated-rock aquifers, chiefly sandstone and limestone. Some wells withdraw water from volcanic rocks, igneous and metamorphic rocks, or fractured fine-grained sedimentary rocks, such as shale; however, wells completed in these types of rocks generally yield only small volumes of water. Most wells in the four-State area of Segment 8 are on privately owned land (fig. 2). Agriculture, primarily irrigation, is one of the largest uses of ground water. The irrigation generally is on lowlands close to streams (fig. 3). Lowlands within a few miles of major streams usually are irrigated with surface water that is diverted by gravity flow from the main stream or a reservoir and transported through a canal system. Surface water also is pumped to irrigate land that gravity systems cannot supply. In addition, ground water is pumped from large-capacity wells to supplement surface water during times of drought or during seasons of the year when surface water is in short supply. Ground water is the only source of water for irrigation in much of the segment. The thickness and permeability of aquifers in the area of Segment 8 vary considerably, as do yields of wells completed in the aquifers. Ground-water levels and artesian pressures (hydraulic head) have declined significantly in some places as a result of excessive withdrawals by wells. State governments have taken steps to control the declines by enacting programs that either limit the number of additional wells that can be completed in a particular aquifer or prevent further ground-water development altogether. The demand for water is directly related to the distribution of people. In 1990, Montana had a population of 799,065; North Dakota, 638,800; South Dakota, 696,004; and Wyoming, 453,588. The more densely populated areas are on lowlands near major streams. Many of the mountain, desert, and upland areas lack major population centers, particularly in Montana and Wyoming, where use of much of the land is controlled by the Federal Government and withdrawal of ground water is restricted. Average annual precipitation (1951-80) in Segment 8 ranges from less than 8 inches in parts of Montana and Wyoming to more than 40 inches in some of the mountainous areas (fig. 4). Most storms move eastward through Segment 8 and are particularly common during the winter months. Moisture that evaporates from the Pacific Ocean is absorbed by eastward- moving air. As the moisture-laden air masses move eastward, they rise and cool as they encounter mountain ranges and lose some of their moisture to condensation. Consequently, the western sides of mountain ranges receive the most precipitation, much of it as snow during the winter months. In contrast, the eastern sides of some of the higher mountain ranges are in rain shadows and receive little precipitation. East of the Continental Divide, precipitation that falls during many summer storms results from northward-moving, moisture-laden air masses from the Gulf of Mexico. These air masses move northward when the polar front recedes; accordingly, a major part of the annual precipitation falls on the plains during the growing season. Average annual precipitation minus the total of average annual runoff plus evapotranspiration (the combination of evaporation and transpiration by plants) is the amount of water potentially available for recharge to the aquifers. Average annual runoff (1951-80) in the area of Segment 8 varies greatly, and the distribution of runoff (fig. 5) generally parallels that of precipitation. In arid and semiarid areas of the segment, most precipitation replenishes soil moisture, evaporates, or is transpired by vegetation, and only a small part of the precipitation is left to maintain streamflow or recharge aquifers. In wetter areas of the segment, much of the precipitation runs off the land surface directly to perennial streams. Because a smaller percentage of precipitation in wet areas usually is lost to evapotranspiration than in dry areas, more water is, therefore, available to recharge aquifers where more precipitation falls. Precipitation that falls as snow generally does not become runoff until spring thaws begin. Runoff is affected in some areas by reservoirs that have been constructed on major streams to mitigate flooding and to store water for irrigation, electrical power generation, and recreation. Water stored in reservoirs during times when runoff is great is subsequently released during drier periods to maintain downstream flow.

Montana, North Dakota, South Dakota, Wyoming↗
USGS1978

Ground-water data for the Salt Basin, Eagle Flat, Red Light Draw, Green River Valley, and Presidio Bolson in westernmost Texas

From October 1971 through October 1974, the U.S. Geological Survey collected ground-water data in the basins in Texas west of the Pecos River drainage area and northwest of the Big Bend country. The basins included are, from east to west: The Presidio Bolson; the Salt Basin; Green River Valley, Eagle Flat, and Red Light Draw. These data, which were collected in cooperation with the Texas Department of Water Resources (formerly Texas Water Development Board), will provide information for a continuing assessment of water availability within the State. The data-collection program consisted of an inventory of all major irrigation, municipal-supply, and industrial wells; selected stock and domestic wells; and selected springs. Water samples were collected from representative wells and springs for chemical analyses. These data, together with data from geophysical surveys and test drilling, will be used to prepare a report on the availability of ground water in the basins of westernmost Texas. Data collected prior to this study are contained in the reports listed in the selected references. The well-numbering system is shown on figure 1, and the locations of the wells, test holes, and springs are shown on figures 2-8. The records of wells and springs are given in table 1, and the water levels in selected observation wells in the Salt Basin are given in table2. The chemical analyses of water samples from selected wells, test holes, and springs are given in table 3.

Texas↗
USGS2018

Land subsidence

Land subsidence in the United States is inextricably linked to the development of groundwater—one of the Nation’s most valuable natural resources. More than 80 percent of the identified subsidence in the United States is a consequence of anthropogenic impact on water resources. Three processes account for most of the water-related subsidence—the compaction of aquifer systems, the drainage and subsequent oxidation of organic soils, and the collapse of subsurface cavities (sinkholes). The compaction of aquifer systems that are, at least in part, composed of unconsolidated fine-grained sediments and have undergone extensive groundwater development is the leading cause of subsidence in the United States. The withdrawal of subsurface fluids from alluvial aquifer systems has permanently lowered the elevation of more than 123,000 km2 of land and waterways in more than fifty areas in the conterminous United States—an area larger than Pennsylvania. Each of the affected aquifer systems in the fifty-four areas shown on figure 1 is comprised of a large thickness of unconsolidated deposits with a substantial aggregate thickness of fine-grained sediments. Not surprisingly, subsidence attributed to aquifer-system compaction in the United States generally is largest in magnitude in the arid and semi-arid West, where surface-water availability is limited, and groundwater is extensively used for irrigating agriculture and to support industries and growing populations. Subsidence is calculated by differencing the repeated elevation measurements derived from spirit-leveling surveys, or the repeated distance measurements between the ground and satellites or aircraft using campaign Global Positioning System (GPS), continuous GPS (CGPS), or Interferometric Synthetic Aperture Radar (InSAR) methods. The only method to directly measure aquifer-system compaction is by the use of a borehole extensometer. Aquifer-system compaction is tracked by repeated distance measurements between the extensometer element anchored at depth, and a reference point on or near the land surface. Data from co-located extensometers and CGPS stations can be combined to deduce depth intervals where aquifer-system compaction has occurred. The capability to determine the magnitudes of compaction that occur at specific depth intervals is critical for targeting mitigation measures and is important to track as pumping depths and volumes change.

Book chapter↗
USGS1984

Potential effects of surface coal mining on the hydrology of the West Otter area, Ashland and Birney-Broadus coal fields, southeastern Montana

Shallow aquifers exist primarily within the Tongue River Member of the Paleocene Fort Union Formation and within valley alluvium. Sandstone beds are the principal aquifers for domestic supply and livestock watering, with the Knobloch coal bed being a secondary source of supply. Surface-water resources consist principally of perennial flow in Otter Creek and intermittent flow in eight small drainage basins. The small streams are generally dry at their mouth, except after intense rainfall or sudden snowmelt. Otter Creek is used for livestock watering and, during spring floods, for irrigating alfalfa fields. The water supplied by wells generally is a sodium bicarbonate type. Dissolved-solids concentrations of water samples ranged from 480 to 3,460 milligrams per liter in sandstone beds and from 910 to 6,260 milligrams per liter in the Knobloch coal bed. Water in Otter Creek contains principally sodium, magnesium, and sulfate ions. The dissolved-solids concentration ranged from 2,050 to 2 ,950 milligrams per liter. Mining of the Knobloch coal bed would remove three private wells and adversely affect the yield of two other wells. After mining, water in the alluvium of Otter Creek might show long-term degradation in water quality as a result of waters leaching the soluble salts from the spoils material used to backfill the mine pits. Although mining would alter the existing hydrologic systems and remove several shallow wells, alternative ground-water supplies are available from deeper aquifers that could be developed to replace those lost by mining.

Montana↗
USGS1984

Restoration of freshwater in the Cano Tiburones area, Puerto Rico

Cano Tiburones on the north coast of Puerto Rico originally was a shallow, coastal lagoon, 9 square miles in area. It accumulated freshwater from adjacent rivers and springs and drained to the ocean through unobserved subterranean conduits. Forced drainage by pumping of Cano Tiburones for agriculture was begun in 1949, and resulted in lowering the water level to below sea level. The reversed hydraulic gradient permitted seawater to enter the Cano through the conduits forming seawater "springs". Seawater flooding caused widespread sodium chloride contamination in the canals and laterals and in the soils. Agricultural expectations of the area were not realized. The present investigation into the freshening potential of Cano Tiburones (1979-1982) determined that ground-water discharge does not contribute to salty conditions. On-site experiments were performed to segregate freshwater from seawater using differences in hydraulic head. Dams were constructed on canals and laterals, forcing accumulated saltwater to the ocean. Ring levees were placed around the discharging seawater conduits until sea level was reached and flow to the system stopped. These efforts have succeeded in reducing the amount of seawater in Cano Tiburones to one-third of its original concentration. Most of the water presently in Cano Tiburones is suitable for irrigation.

Cano Tiburones↗
USGS1999

Ground-water occurrence and contribution to streamflow, northeast Maui, Hawaii

The study area lies on the northern flank of theEast Maui Volcano (Haleakala) and covers about129 square miles between the drainage basins ofMaliko Gulch to the west and Makapipi Stream tothe east. About 989 million gallons per day of rain-fall and 176 million gallons per day of fog dripreaches the study area and about 529million gal-lons per day enters the ground-water system asrecharge. Average annual ground-water with-drawal from wells totals only about 3 million gal-lons per day; proposed (as of 1998) additionalwithdrawals total about 18 million gallons per day.Additionally, tunnels and ditches of an extensiveirrigation network directly intercept at least 10 mil-lion gallons per day of ground water.The total amount of average annual stream-flow in gaged stream subbasins upstream of 1,300feet altitude is about 255 million gallons per dayand the total amount of average annual base flow isabout 62 million gallons per day. Six major sur-face-water diversion systems in the study area havediverted an average of 163 million gallons per dayof streamflow (including nearly all base flow ofdiverted streams) for irrigation and domestic sup-ply in central Maui during 1925–97.Fresh ground water is found in two mainforms. West of Keanae Valley, ground-water flowappears to be dominated by a variably saturatedsystem. A saturated zone in the uppermost rockunit, the Kula Volcanics, is separated from a fresh-water lens near sea level by an unsaturated zone inthe underlying Honomanu Basalt. East of KeanaeValley, the ground-water system appears to befully saturated above sea level to altitudes greaterthan 2,000 feet. The total average annual streamflow of gagedstreams west of Keanae Valley is about 140 milliongallons per day at 1,200 feet to 1,300 feet altitude.It is not possible to estimate the total averageannual streamflow at the coast. All of the base flowmeasured in the study area west of Keanae Valleyrepresents ground-water discharge from the high-elevation saturated zone. Total average dailyground-water discharge from the high-elevationsaturated zone upstream of 1,200 feet altitude isgreater than 38 million gallons per day, all of whichis eventually removed from the streams by surface-water diversion systems. Perennial streamflow hasbeen measured at altitudes greater than 3,000 feetin several of the streams. Discharge from the high-elevation saturated zone is persistent even duringperiods of little rainfall. The total average annual streamflow of the gaged streams east of Keanae Valley is about 109million gallons per day at about 1,300 feet altitude. It is not possible to estimate the total average annual streamflow at the coast nor at higher altitudes. All of the base flow measured east of Keanae Valley represents ground-water discharge from the vertically extensive freshwater-lens system. Total average daily ground-water discharge to gaged streams upstream of 1,200 feet altitude is about 27million gallons per day. About 19 million gallons per day of ground water discharges through the Kula and Hana Volcanics between about 500 feet and 1,300 feet altitude in the gaged stream sub-basins. About 13 million gallons per day of this discharge is in Hanawi Stream. The total ground-water discharge above 500 feet altitude in this part of the study area is greater than 56 million gallons per day.

Hawaii↗
USGS1989

Preliminary assessment of sources, distribution, and mobility of selenium in the San Joaquin Valley, California

Selenium in tile drain water from parts of the western San Joaquin Valley, California, has adversely affected fish and waterfowl where drain water was impounded. Soils in these drained areas were derived from Coast Range marine sedimentary formations, were naturally saline and probably contained abundant soluble selenium. Decades of irrigation have redistributed the most soluble forms of selenium from the soil into groundwater and have caused the water table to rise 1 to 4 ft/year. Selenium in shallow groundwater has been further concentrated because of evapotranspiration. The rising water table has caused a large area of farmland to require artificial drainage of groundwater that contains high concentrations of selenium. The present areal distribution of selenium in shallow groundwater reflects the natural distribution of saline soils. The depth distribution of selenium in groundwater reflects the history of irrigation. The highest concentrations of selenium in groundwater (50 to more than 1,000 micrograms/L) are in a zone of variable thickness located between 20 and 150 ft below the water table. The toxic water in this zone was recharged during the first few decades of irrigation. The large volume of high selenium groundwater makes it desirable to leave this water where it is, rather than bring it to the land surface or allow it to move into parts of the aquifer that may be used for water supply. Selenium concentrations in the San Joaquin River depend on the magnitude of the selenium load from drain water and dilution by water with low concentrations of selenium from all other sources of streamflow. The San Joaquin Valley is a regional-scale example of how manipulation of the hydrologic system can cause water quality problems if naturally occurring toxic substances are mobilized. (USGS)

Water-Resources Investigations Report↗
USGS2012

Groundwater quality in the Antelope Valley, California

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Antelope Valley is one of the study areas being evaluated. The Antelope study area is approximately 1,600 square miles (4,144 square kilometers) and includes the Antelope Valley groundwater basin (California Department of Water Resources, 2003). Antelope Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lakebeds in the lower parts of the valley. Land use in the study area is approximately 68 percent (%) natural (mostly shrubland and grassland), 24% agricultural, and 8% urban. The primary crops are pasture and hay. The largest urban areas are the cities of Palmdale and Lancaster (2010 populations of 152,000 and 156,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Antelope Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Antelope Valley are completed to depths between 360 and 700 feet (110 to 213 meters), consist of solid casing from the land surface to a depth of 180 to 350 feet (55 to 107 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation and sewer and septic systems. The primary sources of discharge are pumping wells and evapotranspiration near the dry lakebeds.

California↗
USGS2001

National Irrigation Water Quality Program data-synthesis data base

Under the National Irrigation Water Quality Program (NIWQP) of the U.S. Department of the Interior, researchers investigated contamination caused by irrigation drainage in 26 areas in the Western United States from 1986 to 1993. From 1992 to 1995, a comprehensive relational data base was built to organize data collected during the 26-area investigations. The data base provided the basis for analysis and synthesis of these data to identify common features of contaminated areas and hence dominant biologic, geologic, climatic, chemical, and physiographic factors that have resulted in contamination of water and biota in irrigated areas in the Western United States. Included in the data base are geologic, hydrologic, climatological, chemical, and cultural data that describe the 26 study areas in 14 Western States. The data base contains information on 1,264 sites from which water and bottom sediment were collected. It also contains chemical data from 6,903 analyses of surface water, 914 analyses of ground water, 707 analyses of inorganic constituents in bottom sediments, 223 analyses of organochlorine pesticides in bottom sediments, 8,217 analyses of inorganic constituents in biota, and 1,088 analyses for organic constituents in biota. The data base is available to the public and can be obtained at the NIWQP homepage http://www.usbr.gov/niwqp as dBase III tables for personal-computer systems or as American Standard Code for Information Exchange structured query language (SQL) command and data files for SQL data bases.

Open-File Report↗
USGS1969

Availability of ground water for large-scale use in the Malad Valley-Bear River areas of southeastern Idaho: an initial assessment

Five areas within the Bear River drainage of southeastern Idaho offer potential for further development of ground water--the valley north of Bear Lake, north of Soda Springs, Gem Valley, Cache Valley in Idaho, and Malad Valley in Idaho. Saturated deposits north of Bear Lake are too fine-textured to yield large quantities to wells; the areas north of Soda Springs and in Gem Valley would provide large yields, but at the expense of current beneficial discharge. Northern Cache Valley has small areas of high yield in the northwestern part, but total annual yield would be only about 20,000 acre-feet and seasonal water-level fluctuation would be large. Malad Valley contains a large aquifer system within valley fill underlying about 75 square miles. The aquifer system is several hundred feet thick, and contains about 1.8 million acre-feet of water in storage in the top 300 feet of saturated thickness. Average annual recharge to the valley-fill aquifer is about 64,000 acre-feet. Lowering of the water level 100 feet uniformly over the valley area would theoretically yield about 300,000 acre-feet from storage and salvage a present-day large nonbeneficial discharge. Sufficient water to irrigate all lands in a planned project near Samaria could be pumped with a maximum 200-foot pumping lift and then delivered by gravity flow. Such pumping would cause water-level lowering of a few feet to a few tens of feet in present artesian areas, and would cause many present-day artesian wells to cease flowing at land surface. Chemical-quality problems in Malad Valley seem not to be sufficient to prohibit development and use of the ground-water resource.

Idaho↗
USGS2000

The importance of ground water in the Great Lakes Region

Ground water is a major natural resource in the Great Lakes Region because it indirectly contributes more than 50 percent of the stream discharge to the Great Lakes. In addition, ground water is the source of drinking water for millions of people in the region, is an important source of supply for agriculture and many industries, and provides a relatively uniform supply of water in some ecologically sensitive areas to sustain plant and animal species. Therefore, to improve our understanding of water-resources issues in the Great Lakes Region, it is important to have a better understanding of the role that ground water plays in the overall hydrologic system of the lakes. The main ground-water resources issues in the Great Lakes Region are related to the amount of ground water, the interaction of ground water and surface water, changes in ground-water quality as development expands, and ecosystem health related to quantity and quality of water. Issues related to the amount of ground water Although the amount of water in the Great Lakes Region is vast, issues related to relatively small quantities of water are being raised more and more often. For example, even though the amount of ground water pumped in the region is small compared to the total amount of water present, ground water is an important source of public-water supply as well as an important source of supply for industrial, agricultural, and domestic needs. Less clearly understood, however, is the relation between the amount of streamflow discharging to the Great Lakes and the large portion of that flow that originates as ground water. The implications of this understanding for water- and land-use practices and, in turn, their effects on water quantity and quality, have not been fully incorporated into a policy framework. To help include information about the implications of the role that ground water plays in addressing regional water issues, a comprehensive analysis of indirect ground-water discharge to the Great Lakes is needed. Direct ground-water discharge to the Great Lakes is not a large factor in water-budget analyses for the Great Lakes. Locally, however, direct ground-water discharge to the Great Lakes may be important, even though the rates and places of discharge are not well known. A long-term evaluation of direct ground-water discharge to the Great Lakes would help place this hydrologic process in proper perspective. Near-shore areas with high rates of direct ground-water discharge may provide valuable habitat for aquatic organisms. Issues related to the interaction of ground water and surface water Withdrawal of ground water removes that water from the watershed when it is consumptively used or when the return flow is discharged to another drainage basin. Under these circumstances, pumping ground water constitutes a diversion of Great Lakes water. Alternatively, ground-water withdrawal could have the opposite effect of diverting ground-water flow into the watershed by altering the ground-water divides. In particular, as withdrawals associated with urban expansion increase, more accurate data on the amount and effects of ground-water use need to be collected. Data on the amounts of ground water pumped both within the watershed and outside, but near the watershed boundaries needs to be collected and evaluated for potential diversion of water to or from the Great Lakes. It is currently thought that both irrigation and ground-water withdrawals near the watershed boundaries constitute relatively small amounts of water; however, both rapidly changing farming practices and rapidly expanding urban communities could alter these amounts in a relatively short timeframe, especially during drought periods. At present, the effects of ground-water withdrawals have been quantified in detail at only a few urban locations. In addition to quantifying the amount of water pumped out of aquifers, it is also important to improve our knowledge of the amount of water that is recharging them. Ground-water recharge rates estimated in earlier studies cover only a small part of the Great Lakes Region. A comprehensive study of ground-water recharge rates for the entire watershed is needed to more completely determine the role of ground water in the hydrologic budget of the Great Lakes. Issues related to changes in ground-water quality as development expands Ground-water quality is as important as quantity for most water uses. As ground-water development proceeds, the possibility of altering the quality of ground water increases. The quality of ground water can be altered when water levels are drawn below the layer that confines the aquifer or by inducing water of lesser quality into an aquifer. Many local studies of these problems have been conducted, but few regional-scale analyses of changes in ground-water quality as a result of ground-water development have been done. Issues related to ecosystem health and quantity and quality of ground water Ground water is essential to maintain wetlands and to provide healthy habitat for other aquatic systems. Wetland hydrology is widely recognized as the primary influence on wetland ecology, development, and persistence, and information about hydrology is essential to understanding and quantifying wetland functions and processes. Studies of the role of ground water in selected wetlands in a range of physiographic settings throughout the Great Lakes watershed are needed to more fully understand the role of wetlands in the Great Lakes Region.

Lake Erie, Lake Huron, Lake Michigan, Lake Ontario↗
USGS2015

Methods for estimating flow-duration curve and low-flow frequency statistics for ungaged locations on small streams in Minnesota

Knowledge of the magnitude and frequency of low flows in streams, which are flows in a stream during prolonged dry weather, is fundamental for water-supply planning and design; waste-load allocation; reservoir storage design; and maintenance of water quality and quantity for irrigation, recreation, and wildlife conservation. This report presents the results of a statewide study for which regional regression equations were developed for estimating 13 flow-duration curve statistics and 10 low-flow frequency statistics at ungaged stream locations in Minnesota. The 13 flow-duration curve statistics estimated by regression equations include the 0.0001, 0.001, 0.02, 0.05, 0.1, 0.25, 0.50, 0.75, 0.9, 0.95, 0.99, 0.999, and 0.9999 exceedance-probability quantiles. The low-flow frequency statistics include annual and seasonal (spring, summer, fall, winter) 7-day mean low flows, seasonal 30-day mean low flows, and summer 122-day mean low flows for a recurrence interval of 10 years. Estimates of the 13 flow-duration curve statistics and the 10 low-flow frequency statistics are provided for 196 U.S. Geological Survey continuous-record streamgages using streamflow data collected through September 30, 2012. The study area includes 196 streamgages located within Minnesota and 50 miles beyond the State’s borders in North Dakota, South Dakota, Iowa, and Wisconsin. The study area was divided into five regions that were developed in a previous study using the concept of hydrologic landscape units. Geographic information system software was used to calculate 18 characteristics investigated as potential explanatory variables in regression analyses for each streamgage drainage basin. Trend analyses indicated statistically significant trends in summer 7-day low flows that were not related to precipitation patterns for 19 streamgages. For 16 of these streamgages, the streamflow record was subset using structural change analysis to identify the most recent period of record without a significant trend. The three remaining streamgages with significant trends were excluded from the final analysis because the effective period of record without a significant trend was less than 10 years. Because several streams in this study have zero flow as their minimum reported flow, weighted left-censored regression was used to analyze the flow data in an unbiased manner, with weights based on the number of years of record. A total of 115 regression equations were developed in this study to calculate flow-duration curve and low-flow frequency statistics for ungaged locations in the study area. In addition, data from 25 pairs of streamgages were used to develop drainage-area ratio equations that can be used to estimate streamflow statistics at ungaged locations on streams that have a streamgage in another location. Streamflow statistics estimated using regional regression and drainage-area ratio equations were compared among regions. For regions A, D, and E, drainagearea ratio equations were more accurate than regional regression equations for flows, but regional regression equations were more accurate for high flows. For region F, regional regression equations were consistently more accurate than drainage-area ratio equations. For region BC, the pattern in accuracies of regional regression and drainage-area ratio equations between low flows and high flows was not consistent. Equations developed in this study apply only to stream locations where flows are not substantially affected by regulation, diversion, or urbanization. All equations presented in this study will be incorporated into StreamStats, a web-based geographic information system tool developed by the U.S. Geological Survey. StreamStats allows users to obtain streamflow statistics, basin characteristics, and other information for user-selected locations on streams through an interactive map.

Iowa, Minnesota, North Dakota, South Dakota, Wisco↗
USGS1998

Hydrogeology and simulation of the effects of reclaimed-water application in west Orange and southeast Lake counties, Florida

Wastewater reclamation and reuse has become increasingly popular as water agencies search for alternative water-supply and wastewater-disposal options. Several governmental agencies in central Florida currently use the land-based application of reclaimed water (wastewater that has been treated beyond secondary treatment) as a management alternative to surface-water disposal of wastewater. Water Conserv II, a water reuse project developed jointly by Orange County and the City of Orlando, began operation in December 1986. In 1995, the Water Conserv II facility distributed approximately 28 Mgal/d of reclaimed water for discharge to rapid-infiltration basins (RIBs) and for use as agricultural irrigation. The Reedy Creek Improvement District (RCID) began operation of RIBs in September 1990, and in 1995 these RIBs received approximately 6.7 Mgal/d of reclaimed water. Analyses of existing data and data collected during the course of this study were combined with ground-water flow modeling and particle-tracking analyses to develop a process-oriented evaluation of the regional effects of reclaimed water applied by Water Conserv II and the RCID RIBs on the hydrology of west Orange and southeast Lake Counties. The ground-water flow system beneath the study area is a multi-aquifer system that consists of a thick sequence of highly permeable carbonate rocks overlain by unconsolidated sediments. The hydrogeologic units are the unconfined surficial aquifer system, the intermediate confining unit, and the confined Floridan aquifer system, which consists of two major permeable zones, the Upper and Lower Floridan aquifers, separated by the less permeable middle semiconfining unit. Flow in the surficial aquifer system is dominated regionally by diffuse downward leakage to the Floridan aquifer system and is affected locally by lateral flow systems produced by streams, lakes, and spatial variations in recharge. Ground water generally flows laterally through the Upper Floridan aquifer aquifer to the north and east. Many of the lakes in the study area are landlocked because the mantled karst environment precludes a well developed network of surface-water drainage. The USGS three-dimensional ground-water flow model MODFLOW was used to simulate ground-water flow in the surficial and Floridan aquifer systems. A steady-state calibration to average 1995 conditions was performed by using a parameter estimation program to vary values of surficial aquifer system hydraulic conductivity, intermediate confining unit leakance, and Upper Floridan aquifer transmissivity. The calibrated model generally produced simulated water levels in close agreement with measured water levels and was used to simulate the hydrologic effects of reclaimed-water application under current (1995) and proposed future conditions. In 1995, increases of up to about 40 ft in the water table and less than 5 ft in the Upper Floridan aquifer potentiometric surface had occurred as a result of reclaimed-water application. The largest increases were under RIB sites. An average traveltime of 10 years at Water Conserv II and 7 years at the RCID RIBs was required for reclaimed water to move from the water table to the top of the Upper Floridan aquifer. Approximately 67 percent of the reclaimed water applied at the RCID RIB site recharged the Floridan aquifer system, whereas 33 percent discharged from the surficial aquifer system to surface-water features; 99 percent of the reclaimed water applied at Water Conserv II recharged the Floridan aquifer system, whereas only 1 percent discharged from the surficial aquifer system to surface-water features. The majority of reclaimed water applied at both facilities probably will ultimately discharge from the Floridan aquifer system outside the model boundaries. Proposed future conditions were assumed to consist of an additional 11.7 Mgal/d of reclaimed water distributed by the Water Conserv II and RCID facilities. Increases of up to about 20 ft in the water table and 2 ft in the potentiometric surface of the Upper Floridan aquifer were simulated. The directions of reclaimed water movement through the ground-water system generally were similar to those under 1995 conditions. However, the greater reclaimed-water application rate at the RCID RIBs caused approximately half of the RCID reclaimed water to discharge to surface-water features and half to recharge the Floridan aquifer system.

Florida↗
USGS1980

Ground water in the Thousand Oaks area, Ventura County, California

The ground-water basin beneath the city of Thousand Oaks, Calif. , corresponds closely in area with the surface-water drainage basin of Conejo Valley. Before World War II there was little ground-water development. After World War II, urban development put a stress on the ground-water basin; many wells were drilled and water levels in wells were drawn down as much as 300 feet in places. Beginning in 1963, imported water replaced domestic and municipal ground-water systems, and water levels rapidly recovered to predevelopment levels or nearly so. Most of the ground water in the Thousand Oaks area is stored in fractured basalt of the middle Miocene Conejo Volcanics. Depending on the degree of occurrence of open fractures and cavities in the basalt, recoverable ground water in the upper 300 to 500 feet of aquifer is estimated to be between 400,000 and 600,000 acre-feet. The yield of water from wells in the area ranges from 17 to 1,080 gallons per minute. Most of the ground-water in the eastern part of the valley is high insulfate and has a dissolved-solids concentration greater than 1,000 milligrams per liter. In the western part of the valley the ground-water is mostly of a bicarbonate type, and the dissolved-solids concentration is less than 800 milligrams per liter. In most areas of Conejo Valley, ground-water is a viable resource for irrigation of public lands and recreation areas. (USGS)

California↗
USGS1987

Possible changes in ground-water flow to the Pecos River caused by Santa Rosa Lake, Guadalupe County, New Mexico

In 1980 Santa Rosa Dam began impounding water on the Pecos River about 7 miles north of Santa Rosa, New Mexico, to provide flood control, sediment control, and storage for irrigation. Santa Rosa Lake has caused changes in the groundwater flow system, which may cause changes in the streamflow of the Pecos River that cannot be detected at the present streamflow gaging stations. Data collected at these stations are used to measure the amount of water available for downstream users. A three-dimensional groundwater flow model for a 950 sq mi area between Anton Chico and Puerto de Luna was used to simulate the effects of Santa Rosa Lake on groundwater flow to a gaining reach of the Pecos River for lake levels of 4,675, 4,715, 4,725, 4,750, 4,776, and 4,797 feet above sea level and durations of impoundment of 30, 90, 182, and 365 days for all levels except 4 ,797 feet. These simulations indicated that streamflow in the Pecos River could increase by as much as 2 cu ft/sec between the dam and Puerto de Luna if the lake level were maintained at 4 ,797 feet for 90 days or 4,776 feet for 1 year. About 90% of this increased streamflow would occur < 0.5 mi downstream from the dam, some of which would be measured at the streamflow gaging station located 0.2 mile downstream from the dam. Simulations also indicated that the lake will affect groundwater flow such that inflow to the study area may be decreased by as much as 1.9 cu ft/sec. This water may leave the Pecos River drainage basin or be diverted back to the Pecos River downstream from the gaging station near Puerto de Luna. In either case, this quantity represents a net loss of water upstream from Puerto de Luna. Most simulations indicated that the decrease in groundwater flow into the study area would be of about the same quantity as the simulated increase in streamflow downstream from the dam. Therefore, the net effect of the lake on the flow of the Pecos River in the study area appears to be negligible. Model simulations indicated that effect of lake levels below 4 ,750 feet on water levels in observation wells completed in the San Andres Limestone could not be distinguished from the effects of other hydrologic stresses. (Author 's abstract)

Water-Resources Investigations Report↗