Antelope Valley Groundwater Cases

Superior Court of California, County of Los Angeles | December 23rd, 2015

The complaints and cross-complaints in the Action frame many legal issues. The Action includes over 4,000 Parties, as well as the members of the Non-Pumper Class and the

The complaints and cross-complaints in the Action frame many legal issues. The Action includes over 4,000 Parties, as well as the members of the Non-Pumper Class and the members of the Small Pumper Class. The Basin’s entire Groundwater supply and Groundwater rights, extending over approximately 1390 square miles, have been brought to issue. The numerous Groundwater rights at issue in the case include, without limitation, overlying, appropriative, prescriptive, and federal reserved water rights to Groundwater, rights to return flows from Imported Water, rights to recycled water, rights to stored Imported Water subject to the Watermaster rules and regulations, and rights to utilize the storage space within the Basin. After several months of trial, the Court made findings regarding Basin characteristics and determined the Basin’s Safe Yield. The Court’s rulings and judgments in this case, including the Safe Yield determination, form the basis for this Judgment. For annual reports go to the Department of Water Resources Adjudicated Annual Reporting page.

Aquifer depletion exacerbates agricultural drought losses in the US High Plains

Nature Portfolio (Springer Nature) | January 15th, 2024

Aquifer depletion poses a major threat to the ability of farmers, food supply chains and rural economies globally to use groundwater as a means of adapting to climate var

Aquifer depletion poses a major threat to the ability of farmers, food supply chains and rural economies globally to use groundwater as a means of adapting to climate variability and change. Empirical research has demonstrated the large differences in drought risk exposure that exist between rainfed and irrigated croplands, but previous work commonly assumes water supply for the latter is unconstrained. Here we evaluate how aquifer depletion affects the resilience of irrigated crop production to drought risk using over 30 years of data on historical corn and soybean yields, production areas and aquifer conditions for the High Plains region in the United States. We show that aquifer depletion reduces the ability of farmers to sustain irrigated crop yields and production areas in years and locations with large growing-season water deficits. Our findings demonstrate that drought-related production losses on irrigated croplands increase non-linearly with aquifer depletion, highlighting the need for proactive aquifer conservation interventions to support adaptation and resilience to future increases in rainfall variability under climate change.

Aquifer-system compaction and land subsidence: Measurements, analyses, and simulations-the Holly Site, Edwards Air Force Base, Antelope Valley, California

U.S. Geological Survey (USGS) | July 1st, 2000

Assessing Natural Recharge in Indian Wells Valley, California: A Basin Characterization Model Case Study

U.S. Geological Survey (USGS) | March 18th, 2026

The communities in Indian Wells Valley (IWV), in the northern Mojave Desert in California, rely on groundwater for domestic and agricultural use. Mountain front recharge

The communities in Indian Wells Valley (IWV), in the northern Mojave Desert in California, rely on groundwater for domestic and agricultural use. Mountain front recharge from the surrounding Sierra Nevada is the main source of natural recharge to the valley. Increased urbanization, agricultural development, and groundwater pumping during recent decades put IWV in a state of critical overdraft. The U.S. Geological Survey Basin Characterization Model, version 8 (BCMv8) was used to evaluate historical and future climate and hydrologic conditions in IWV. The BCMv8 estimated natural recharge in IWV at 10.7 million cubic meters (Mm3) per year for the period from 1981 to 2010. Future patterns of water balance variables using three future climate scenarios, hot- wet, hot-dry, and warm-moderately wet, were calculated for mid-century (2040–69) and end-of-century (2070–99) periods. Results for both wet models projected an increase in recharge in both periods, whereas the hot-dry model projected a decrease in recharge in both periods. All models reported a large increase in seasonal variability in recharge, indicating more future availability and frequent occurrences of drought years. All climate scenarios projected an increase in climatic water deficit in both periods. These increases in irrigation demand and variability of water supply highlight the importance of strategic management planning for the sustainability of water resources in IWV.

At Risk: Public Supply Well Vulnerability Under California’s Sustainable Groundwater Management Act

Pacific Institute | June 1st, 2021

Base of fresh ground water (approximately 3,000 micromhos) in the San Joaquin Valley, California

U.S. Geological Survey (USGS) | June 30th, 1971

Widespread pumping of groundwater in the San Joaquin Valley began about 1900, and since 1940 pumpage has increased at an accelerated rate. In response to the heavy withdr

Widespread pumping of groundwater in the San Joaquin Valley began about 1900, and since 1940 pumpage has increased at an accelerated rate. In response to the heavy withdrawal of groundwater, water levels have declined rapidly beneath extensive areas of the valley. Consequently, it becomes necessary to delineate the base of fresh groundwater so that changes in thickness of the fresh-water zone can be monitored, and limited depths of water wells can be determined. In turn, those data will be useful in determining favorable areas for groundwater storage, and areas and depths for waste-water disposal wells. Because other agencies and the U.S. Geological Survey have collected a vast amount of well log and other data, most of the information in this report was assembled from existing files. However, for areas where data were scanty, a few hundred additional electrical logs were collected to supplement the available information.

Best Management Practices of the Sustainable Management of Groundwater Land Subsidence

California Department of Water Resources (DWR) | January 21st, 2026

The Subsidence Best Management Practices document (Subsidence BMP) provides a guide on the fundamentals of land surface subsidence (also called “land subsidence” or �

The Subsidence Best Management Practices document (Subsidence BMP) provides a guide on the fundamentals of land surface subsidence (also called “land subsidence” or “subsidence”), technical assistance related to subsidence, and best practices for managing subsidence. The Subsidence BMP also provides specific information about subsidence in California and how it must be considered within the structure of the Sustainable Groundwater Management Act (SGMA). Subsidence is one of the six sustainability indicators required to be managed under SGMA. The Subsidence BMP does not supersede or replace any existing local, state, or federal regulations. Rather, it is meant to help groundwater managers, especially Groundwater Sustainability Agencies and the public, better understand land subsidence and how it can be managed.

Borrego Water District v. All Persons Who Claim a Right to Extract Groundwater in the Borrego Valley Groundwater Subbasin No. 7-024-01

Superior Court of California, County of Orange | April 8th, 2021

Bulletin 39-A, South Coastal Basin Investigation, Records of Ground Water Levels at Wells for the Year 1932, Seasonal Precipitation Records to and including 1931-32

California Department of Water Resources (DWR) | January 2nd, 1933

Bulletin No. 39, South Coastal Basin Investigation, Records of Ground Water Levels at Wells

California Department of Water Resources (DWR) | December 1st, 1932