Focused groundwater recharge in the Amargosa Desert basin

U.S. Geological Survey (USGS) | July 1st, 2007

 The Amargosa River is an approximately 300-kilometer-long regional drainage connecting the northern highlands on the Nevada Test Site in Nye County, Nev., to the floor

 The Amargosa River is an approximately 300-kilometer-long regional drainage connecting the northern highlands on the Nevada Test Site in Nye County, Nev., to the floor of Death Valley in Inyo County, Calif. Streamflow analysis indicates that the Amargosa Desert portion of the river is dry more than 98 percent of the time. Infiltration losses during ephemeral flows of the Amargosa River and Fortymile Wash provide the main sources of ground-water recharge on the desert-basin floor. The primary use of ground water is for irrigated agriculture. The current study examined ground-water recharge from ephemeral flows in the Amargosa River by using streamflow data and environmental tracers. The USGS streamflow-gaging station at Beatty, Nev., provided high-frequency data on base flow and storm runoff entering the basin during water years 1998–2001. Discharge into the basin during the four-year period totaled 3.03 million cubic meters, three quarters of which was base flow. Streambed temperature anomalies indicated the distribution of ephemeral flows and infiltration losses within the basin. Major storms that produced regional flow during the four-year period occurred in February 1998, during a strong El Niño that more than doubled annual precipitation, and in July 1999. The study also quantified recharge beneath undisturbed native vegetation and irrigation return flow beneath irrigated fields. Vertical profiles of water potential and environmental tracers in the unsaturated zone provided estimates of recharge beneath the river channel (0.04–0.09 meter per year) and irrigated fields (0.1–0.5 meter per year). Chloride mass-balance estimates indicate that 12–15 percent of channel infiltration becomes ground-water recharge, together with 9–22 percent of infiltrated irrigation. Profiles of potential and chloride beneath the dominant desert-shrub vegetation suggest that ground-water recharge has been negligible throughout most of the basin since at least the early Holocene. Surface-based electrical-resistivity imaging provided areal extension of borehole information from sampled profiles. These images indicate narrowly focused recharge beneath the Amargosa River channel, flanked by large tracts of recharge-free basin floor.

Forebay Aquifer Subbasin Groundwater Sustainability Plan

Salinas Valley Basin Groundwater Sustainability Agency | January 13th, 2022

The 2014 California Sustainable Groundwater Management Act (SGMA) requires that medium- and high-priority groundwater basins and subbasins develop Groundwater Sustainabil

The 2014 California Sustainable Groundwater Management Act (SGMA) requires that medium- and high-priority groundwater basins and subbasins develop Groundwater Sustainability Plans (GSPs) that outline how groundwater sustainably will first be maintained for 50 years. This GSP fulfills that requirement for the Salinas Valley—Forebay Aquifer Subbasin (Subbasin, or Forebay Subbasin), which is designated by the DWR as a medium priority groundwater subbasin. Plan approved by DWR 4/27/23.

Fresh Submarine Groundwater Discharge to the Near‐Global Coast

American Geophysical Union (AGU) | April 24th, 2019

Abstract: The flow of fresh groundwater to the ocean through the coast (fresh submarine groundwater discharge or fresh SGD) plays an important role in global biogeochemic

Abstract: The flow of fresh groundwater to the ocean through the coast (fresh submarine groundwater discharge or fresh SGD) plays an important role in global biogeochemical cycles and coastal water quality. In addition to delivering dissolved elements from land to sea, fresh SGD forms a natural barrier against salinization of coastal aquifers. Here we estimate groundwater discharge rates through the near‐global coast (60°N to 60°S) at high resolution using a water budget approach. We find that tropical coasts export more than 56% of all fresh SGD, while midlatitude arid regions export only 10%. Fresh SGD rates from tectonically active margins (coastlines along tectonic plate boundaries) are also significantly greater than passive margins, where most field studies have been focused. Active margins combine rapid uplift and weathering with high rates of fresh SGD and may therefore host exceptionally large groundwater‐borne solute fluxes to the coast. Plain Language Summary: Fresh groundwater flows from land to sea through coastal rocks and sediment. While the amount of groundwater flow is small compared with rivers, it plays an important role in carrying dissolved chemicals like nutrients to sea, and it helps protect aquifers against salinization. We estimate groundwater flow through the near‐global coast. Tropical regions have more groundwater flow, while dry midlatitudes have less. Dry midlatitude regions are therefore more vulnerable to salinization, which is problematic because these regions are also more likely to depend on groundwater to meet their water needs. Additionally, mountainous coastlines along tectonic plate boundaries have relatively large rates of groundwater discharge and may be associated with higher dissolved chemical fluxes to the coast.

Friant Water Authority vs. Eastern Tule Groundwater Sustainibilty Agency

Superior Court of California, County of Tulare | February 15th, 2024

Geochemistry and isotope hydrology of representative aquifers in the Great Basin region of Nevada, Utah, and adjacent States

U.S. Geological Survey (USGS) | July 1st, 1996

Geohydrologic and Water-Quality Data in the Vicinity of the Rialto-Colton Fault, San Bernardino, California

U.S. Geological Survey (USGS) | July 7th, 2014

The Rialto-Colton Basin is in western San Bernardino County, about 60 miles east of Los Angeles, California. The basin is bounded by faults on the northeast and southwest

The Rialto-Colton Basin is in western San Bernardino County, about 60 miles east of Los Angeles, California. The basin is bounded by faults on the northeast and southwest sides and contains multiple barriers to groundwater flow. The structural geology of the basin leads to complex hydrology. Between 2001 and 2008, in an effort to better understand the complex hydrologic system of the Rialto-Colton Basin, seven multiple-well monitoring sites were constructed. Two to six observation wells were installed in the borehole at each site; a total of 32 observation wells were installed. This report presents geologic, hydrologic, and water-quality data collected from these seven multiple-well monitoring sites. Descriptions of the collected drill cuttings were compiled into lithologic logs for each monitoring site. The lithologic logs are summarized along with the geophysical logs, including gamma-ray, spontaneous potential, resistivity, and electromagnetic induction tool logs. At selected sites, sonic tool logs also were recorded. Periodic water-level measurements are reported, and water-level data are displayed on hydrographs. Water levels at multiple-well monitoring sites in the northern part of the study area differed between the shallow and deep observation wells; in the remaining multiple-well monitoring sites, water levels differed little with depth. Along the southern trace of the Rialto-Colton Fault, water levels are slightly higher east of the fault than west of the fault. Selected water-quality data for 21 of the observation wells show water from wells in the northern and central parts of the study area is calcium-carbonate water. In the southern part of the study area, water from wells screened above 400 feet below land surface is of mixed type or is calcium-carbonate water. Water from wells screened greater than 400 feet below land surface in the southern part of the study area is sodium-carbonate or sodium-mixed anion water. Water from most wells in the study area plots above the Global Meteoric Water Line along an apparent local meteoric water line, indicating the water has not experienced substantial evaporation before infiltration. A few samples from shallow wells in the study area plot slightly to the right of the Global Meteoric Water Line, possibly indicating the water experienced some evaporation before recharge.

Geohydrological Characterization, Water-Chemistry, and Ground-Water Flow Simulation Model of the Sonoma Valley Area, Sonoma County, California

U.S. Geological Survey (USGS) | December 14th, 2006

Sonoma County is in the northern part of the greater San Francisco Bay region, an area of Northern California that has experienced rapid population growth and accelerated

Sonoma County is in the northern part of the greater San Francisco Bay region, an area of Northern California that has experienced rapid population growth and accelerated urbanization in response to economic expansion over the past few decades. The large increase in population and concomitant changes in land use within Sonoma County require reassessment of the water resources and how best to manage them for optimal utilization over the next few decades. Most basins in the county currently rely on a combination of Russian River water and native ground water to meet demand. Recycled water is used on a limited basis. In addition, water conservation programs have been implemented and are being expanded. The Sonoma Valley is a well-defined hydrologic basin in southeastern Sonoma County. The basin has some areas of declining ground-water levels, potential water-quality problems from seawater intrusion and upwelling of geothermal waters, and ground-water/surface-water interaction. Location of the Study Area The study area is located approximately 30 miles (mi) northeast of San Francisco and includes the entire Sonoma Creek watershed in southeastern Sonoma County, California (fig. 1). The study focused on the area of the valley floor and the adjacent hills where most of the urban development and irrigated agriculture have been occurring. The watershed includes approximately 166 square miles (mi2) of land that drains by way of Sonoma Creek and its tributaries to San Pablo Bay (fig. 2), which is the northern arm of the San Francisco Bay. The Sonoma Mountains form the southwestern side of the watershed and the Mayacmas Mountains form the northeastern side. Between these two mountain ranges lies the northwest trending elongate depression of Sonoma Valley, which extends roughly 20 mi from the shore of San Pablo Bay to near Kenwood (fig. 2). Purpose and Scope: The U.S. Geological Survey (USGS), in cooperation with the Sonoma County Water Agency (SCWA), undertook this study to evaluate the ground-water resources of Sonoma Valley and to develop a tool to better understand and manage the ground-water system. The goals of the study were to update the geohydrologic characterization of the study area; to provide a current assessment of hydrologic conditions, including a description of historical ground-water level and waterquality changes; and to provide water-supply agencies with a ground-water flow model that can be used as a planning tool for water-resources assessment and management. To meet the objectives of this study, four principal tasks were identified: (1) evaluation of existing geohydrologic, geophysical, and geochemical data; (2) collection and analysis of new geohydrologic data, including subsurface lithologic data, gravity measurements, ground-water levels, and streamflow gains and losses; (3) collection and analysis of new water chemistry, temperature, and isotopic data; and (4) development a ground-water flow model. This report provides a geologic and hydrologic description of the area, presents selected hydrologic data collected from the 1970s to 2004, quantifies historical changes in the ground-water system, documents a ground-water flow simulation model, and presents an interpretation of surface geophysical data that help define the geometry of the ground-water reservoir.

Geohydrology and ground-water-flow simulation of the Surprise Spring Basin aquifer system, San Bernardino, California

U.S. Geological Survey (USGS) | May 24th, 1991

Geohydrology and Numerical Model Analysis of Ground-Water Flow in the Goose Lake Basin, Oregon and California

U.S. Geological Survey (USGS) | December 15th, 1988

From the early 1970s until 1981, ground-water development in the Goose Lake basin underwent rapid growth. The number of new wells constructed and total State-perm

From the early 1970s until 1981, ground-water development in the Goose Lake basin underwent rapid growth. The number of new wells constructed and total State-permitted ground-water withdrawals for irrigation reflect the increase in ground-water development that occurred during this period. A strong agricultural economy spurred much of the development by providing incentives to expand irrigated acreage and modernize irrigation methods (from gravity to sprinkler systems). The drought of 1976-77 also encouraged farmers to develop ground water as a supplemental source to less reliable surface-water supplies used in the past. A preliminary assessment of the basin by OWRD staff (R. B. Almy, Oregon Department of Water Resources, written commun., 1981) concluded that, based on rates of water-level decline and increases in withdrawals, further and more detailed study of the basin was warranted. Between 1975 and 1982, water-level declines in some OWRD observation wells ranged from 0.5 to 3 feet per year, while permitted ground- water withdrawals increased at an average rate of 4,000acre-feetperyear(acre-ft/yr). Similarwater-level declines and increases in withdrawals occurred near Davis Creek on the California side of the basin during this period. This prompted a 1982 assessment of ground-water conditions by the California Department of Water Resources (California Department of Water Resources, 1982). At the time of OWRD's assessment it was felt that too little information on the actual rates of ground-water use, recharge, and the geohydrology of the aquifer system was available to allow proper management of the resource. If the rates of water-level decline and ground-water withdrawal that existed prior to 1981 had continued, issuance of new permits for ground-water use potentially could have been halted in order to determine if the Goose Lake basin should be designated as a "criticalground-water area." Sucha designation would allow the State of Oregon to limit the use of ground-water resources in the area. However, overdraft of the ground-water resource became a less urgent issue after 1982, when a downturn in the agricultural economy, combined with rising costs of electrical power (and thus pumping), resulted in a widespread reversion to dryland farming and low-water-use crops. Adverse agricultural market conditions halted the growth of ground-water development in the basin; these trends could conceivably reverse in the future to spur growth again. In recognition of this potential and the need to build an understanding of the basin in order to properly manage future ground-water development, OWRD entered into a joint program of study with the U.S.Geological Survey. The first of a proposed series of ground-water basin assessments, this 1-year study was started in 1986 with the goals of characterizing the nature, extent, and properties of water-bearing rocks within the basin and describing and quantifying the components of recharge to, and discharge from, the basin. Additionally, this study was designed toe valuate the adequacy of available and readily collectable information to quantitatively describe the geohydrology of the basin. If this information was found to be inadequate, the study would also identify the data needed to better describe, understand, and manage the ground-water resource.

Geohydrology and Simulated Response to Ground-Water Pumpage in Carson Valley, A River-Dominated Basin in Douglas County, Nevada, and Alpine County, California

U.S. Geological Survey (USGS) | May 2nd, 1986

This investigation of the ground-water hydrology in Carson Valley was conducted from 1980 through 1985 by the U.S. Geological Survey, in cooperation with Douglas County.

This investigation of the ground-water hydrology in Carson Valley was conducted from 1980 through 1985 by the U.S. Geological Survey, in cooperation with Douglas County. The purpose of the study was to: (1) collect, compile, and analyze hydrologic data to quantify the hydrology of the valley and to enhance the understanding of the valley's geohydrologic system; and (2) develop a ground-water model that would simulate the response of the hydrologic system to applied stresses and that could be used to estimate the probable hydrologic effects of various development alternatives. This report presents the results of the investigation. Work began with a gravity survey in 1980 to determine the depth to bedrock in Carson Valley; the results are discussed in detail in a separate publication (Maurer, 1986). From 1981 to 1983, work included: (1) measurement of water-level fluctuations and surface-water runoff, (2) drilling of additional observation wells, (3) collection of ground-water pumpage data and measurement of pump efficiencies, and (4) compilation of existing data reports and drillers 1 logs to obtain estimates of geohydrologic characteristics of the ground-water reservoir. Development of a water budget and initial estimates of hydraulic conductivities and specific yield were accomplished in 1983. From 1983 to 1985, the ground-water model was developed and calibrated, and simulations of possible ground-water development were made. The model, which represents a compilation of all available data, was used to (1) test estimates of the geohydrologic characteristics of the ground-water reservoir, (2) evaluate the components of the water budget for the basin, (3) enhance the understanding of the hydrologic flow system in the basin, and (4) simulate the effect of various possible developmental alternatives on Carson River outflow, evapotranspiration, ground-water levels, and ground-water storage in the valley.