Extreme hydrological changes in the southwestern US drive reductions in water supply to Southern California by mid century

Environmental Research Letters (IOP) | September 21st, 2016

The Southwestern United States has a greater vulnerability to climate change impacts on water security due to a reliance on snowmelt driven imported water. The State of C

The Southwestern United States has a greater vulnerability to climate change impacts on water security due to a reliance on snowmelt driven imported water. The State of California, which is the most populous and agriculturally productive in the United States, depends on an extensive arti cial water storage and conveyance system primarily for irrigated agriculture, municipal and industrial supply and hydropower generation. Here we take an integrative high-resolution ensemble modeling approach to examine near term climate change impacts on all imported and local sources of water supply to Southern California. While annual precipitation is projected to remain the same or slightly increase, rising temperatures result in a shift towards more rainfall, reduced cold season snowpack and earlier snowmelt. Associated with these hydrological changes are substantial increases in the frequency and the intensity of both drier conditions and ooding events. The 50 year extreme daily maximum precipitation and runoff events are 1.5–6 times more likely to occur depending on the water supply basin. Simultaneously, a clear de cit in total annual runoff over mountainous snow generating regions like the Sierra Nevada is projected. On one hand, the greater probability of drought decreases imported water supply availability. On the other hand, earlier snowmelt and signicantly stronger winter precipitation events pose increased flood risk requiring water releases from control reservoirs, which may potentially decrease water availability outside of the wet season. Lack of timely local water resource expansion coupled with projected climate changes and population increases may leave the area in extended periods of shortages.

From Climate Traces to Climate Insights: Future Scenarios Analysis for the California Central Valley

California Department of Water Resources (DWR) | October 2nd, 2023

California Water Code Section 10004.6 requires the California Department of Water Resources (DWR) to quantify current and future water conditions in the state. This infor

California Water Code Section 10004.6 requires the California Department of Water Resources (DWR) to quantify current and future water conditions in the state. This information is published in the California Water Plan (Water Plan), which is updated every five years. Water managers and planners constantly face the challenges of planning for an uncertain future where the only constant is change. To address the potential future changes and mitigate the probable risks, water managers must consider and quantify uncertainties and their impacts on water system vulnerability. Although it is not possible to know for certain how population growth, land use decisions, climate, and other factors change over time, water planners must consider these system stressors in long-term planning to evaluate future risks and uncertainty. The Water Plan evaluates many alternative future scenarios as an integral part of its analytical approach to quantify system vulnerability under a range of population and urban growth scenarios, land use, and climate uncertainties.

Geohydrology of the Parker-Blythe-Cibola Area, Arizona and California

U.S. Geological Survey (USGS) | July 16th, 1973

The Parker-Blythe-Cibola area, as defined in this report, extends from the bedrock narrows north of Parker, Ariz., southward for about 85 miles along the valley of the Co

The Parker-Blythe-Cibola area, as defined in this report, extends from the bedrock narrows north of Parker, Ariz., southward for about 85 miles along the valley of the Colorado River to the bedrock narrows below Cibola, Ariz. The area is about midway between Hoover Dam and the Gulf of California. It includes parts of Yuma County, Ariz., and Imperial, Riverside, and San Bernardino Counties, Calif.

Geologic Setting, Geohydrology, and Ground-Water Quality near the Helendale Fault in the Mojave River Basin, San Bernardino County, California

U.S. Geological Survey (USGS) | July 15th, 2003

The proximity of the Moja ve River groundwater basin to the highly urbanized Los Angeles region has resulted in rapid population growth and, consequently, an increase in

The proximity of the Moja ve River groundwater basin to the highly urbanized Los Angeles region has resulted in rapid population growth and, consequently, an increase in the demand for water. The Mojave River, the primary source of surface water for the region, normally is dry—except for periods of flow after intense storms; therefore, the region relies almost entirely on ground water to meet its agricultural and municipal needs. The area where the Helendale Fault intersects the Mojave River is of particular hydrogeologic interest because of its importance as a boundary between two water-management subareas of the Mojave Water Agency. The fault is the boundary between the upper Mojave River Basin (Oeste, Alto, and Este subareas) and the lower Mojave River Basin (Centro and Baja subareas); specifically, the fault is the boundary between the Alto and the Centro subareas. To obtain the information necessary to help better understand the hydrogeology of the area near the fault, multiple-well monitoring sites were installed, the surface geology was mapped in detail, and water-level and water-quality data were collected from wells in the study area.

Ground-Water Hydrology of the Hollister and San Juan Valleys San Benito County, California, 1913-68

U.S. Geological Survey (USGS) | August 31st, 1972

The Hollister and San Juan Valleys are within the Gilroy-Hollister ground-water basin. That part of the ground-water basin underlying the valleys consists of three subbas

The Hollister and San Juan Valleys are within the Gilroy-Hollister ground-water basin. That part of the ground-water basin underlying the valleys consists of three subbasins each of which contains two or more ground-water subunits. The subbasin and subunit boundaries are formed by known or postulated faults, folded sedimentary rocks, and igneous rocks.

Groundwater Conditions Report Water Year 2021

California Department of Water Resources (DWR) | March 15th, 2022

Groundwater Hydraulics

American Geophysical Union (AGU) | January 1st, 1984

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 9. John Ferris's research has covered a broad range of hydrologic p

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 9. John Ferris's research has covered a broad range of hydrologic problems in groundwater, including pollution, storage, recharge, and pumping of groundwater; drainage design; hydraulics of aquifer systems; saltwater encroachment; and application of geophysics to groundwater development. These contributions have been made as a researcher and teacher of national and international renown during a career that has lasted more than four decades. During these four decades, the methodologies for application of hydraulics to solving groundwater problems have continued to evolve and improve. The development of aquifer test techniques and analytical solutions been coemonplace in the 1950's, 1960's, and early 1970's have increasingly been supplemented by the use of numerical methods and automated parameter estimation techniques.

Groundwater in California

Public Policy Institute of California (PPIC) | June 6th, 2024

Groundwater Management: The Use of Numerical Models

American Geophysical Union (AGU) | February 1st, 1980

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 5. The first proposal for an assessment of groundwater models follo

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 5. The first proposal for an assessment of groundwater models followed the 1973 meeting of the Scientific Committee on Problems of the Environment (SCOPE), part of the International Council of Scientific Unions (ICSU), in Kiel, Federal Republic of Germany. SCOPE invited the Holcomb Research Institute (HRI) of Butler University, Indianapolis, Indiana to undertake the assessment since it had just completed a critical evaluation of the roles of mathematical models in environmental decision?]making in the United States (HRI, 1976). An international steering committee, chaired by John Bredehoeft of the U.S. Geological Survey, was assembled for the proposed study. Yehuda Bachmat was the on?]site head of the project, having come to the Institute on a year's leave from his position as Director of Research, Hydrological Service of Israel.

Groundwater microbiomes balance resilience and vulnerability to hydroclimatic extremes

Nature Portfolio (Springer Nature) | August 20th, 2025