Chowchilla Subbasin Staff Assessment

California State Water Resources Control Board (SWRCB) | April 1st, 2025

The state intervention process for the Chowchilla Subbasin was triggered in March 2023 when DWR determined the subbasin’s 2022 GSP was inadequate and identified multipl

The state intervention process for the Chowchilla Subbasin was triggered in March 2023 when DWR determined the subbasin’s 2022 GSP was inadequate and identified multiple deficiencies in the GSP. DWR identified issues regarding the local agencies’ plans for managing for the chronic lowering of groundwater levels and land subsidence (land sinking due to groundwater pumping). State Water Board staff reviewed the 2022 GSP and determined that implementing the 2022 GSP would result in additional groundwater level declines, potential impacts to drinking water wells, and damage to subbasin infrastructure, such as canals and levees, through continued land subsidence. The GSAs released a revised draft GSP in August 2024, which they adopted with slight revisions in March 2025 (2025 GSP). State Water Board staff evaluated the 2025 GSP to determine if identified deficiencies were addressed. The GSAs made significant progress through the 2025 GSP and adequately addressed deficiencies. Through the 2025 GSP, the GSAs show a greater commitment to protecting drinking water users and improved groundwater management. State Water Board staff concludes the GSAs amended the GSP such that a probationary designation of the Chowchilla Subbasin is unnecessary and recommends the Board return the Subbasin to DWR’s jurisdiction for continued evaluation of local management under SGMA.

Chowchilla Subbasin Sustainable Groundwater Management Act (SGMA) Groundwater Sustainability Plan (3rd Revision)

Madera County | January 3rd, 2025

In 2024-2025, the GSAs revised the Subbasin GSP to:  Amend the Domestic Well Mitigation Program Refine the Groundwater Level Representative Monitoring Sites (RMS

In 2024-2025, the GSAs revised the Subbasin GSP to:  Amend the Domestic Well Mitigation Program Refine the Groundwater Level Representative Monitoring Sites (RMS) Network Refine Groundwater Level Sustainable Management Criteria (SMC)  Backstop Projects and Management Actions Refine Subsidence SMC and Provide for Subsidence Mitigation

Chowchilla Subbasin Sustainable Groundwater Management Act (SGMA) Groundwater Sustainability Plan (Revised)

Chowchilla Subbasin GSP Advisory Committee | July 27th, 2022

Due to file size, this document has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13, Part 14, Par

Due to file size, this document has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13, Part 14, Part 15, Part 16, Part 17  

Chowchilla Subbasin Sustainable Groundwater Management Act (SGMA) Groundwater Sustainablity Plan

Chowchilla Subbasin GSP Advisory Committee | January 1st, 2020

Chromium, chromium isotopes and selected trace elements, western Mojave Desert, USA

Elsevier | February 6th, 2008

The purpose of this study was to evaluate the geologic, hydrologic and geochemical processes that control natural Cr concentrations and Cr isotopic compositions in ground

The purpose of this study was to evaluate the geologic, hydrologic and geochemical processes that control natural Cr concentrations and Cr isotopic compositions in ground-water.

Chronic, low concentration pesticide exposure alters reproduction and behavior in the intertidal sea anemone, Anthopleura elegantissima

Elsevier | December 10th, 2025

Widespread pesticide and herbicide use paired with frequent transport away from application sites has led to pesticide presence in nearly all terrestrial and aquatic envi

Widespread pesticide and herbicide use paired with frequent transport away from application sites has led to pesticide presence in nearly all terrestrial and aquatic environments globally. Pesticides have unintentional toxic effects on non-target organisms by interfering with cellular processes, behavior, feeding, reproduction, and disrupting endocrine processes. The aggregating anemone, Anthopleura elegantissima, is an important species along the North American Pacific coast due to its symbiotic relationships that contribute to high productivity, and its clonal abundance that structures the rocky intertidal habitat. Commonly used pesticides, atrazine, diuron, and carbendazim were previously detected in coastal waters of Oregon, U.S.A. This study examined the potential effects of these pesticides at environmentally relevant concentrations on reproduction, symbionts, and behavior of A. elegantissima over an eight-week period. Pesticides significantly decreased gonad development in all treatments, having the most significant effect in individual treatments of atrazine (p = 0.003), carbendazim (p = 0.003), and the mixture of all three pesticides (p = 0.008).All pesticide treatments significantly increased cloning behavior compared to the control, suggesting that cloning could be a stress response. Pesticide exposure also significantly increased tentacle retraction movement, suggesting possible metabolic or energy impairments. While other studies have previously found behavioral changes in anemones due to pollutants, our study is the first to document behavioral changes in anemones from pesticide exposure. All three pesticides significantly impacted a non-target marine invertebrate at environmentally relevant concentrations, which underscores the value of studies that focus on effects on marine invertebrates, paired with comprehensive pesticide monitoring in coastal areas.

Chronology of major litigation involving the Central Valley Project and the State Water Project

California Department of Water Resources (DWR) | January 1st, 2013

A chronology of major litigation involving the Central Valley Project and the State Water Project from 1950 to 2007.

A chronology of major litigation involving the Central Valley Project and the State Water Project from 1950 to 2007.

Citizen's Guide to Working with the California Water Boards

California State Water Resources Control Board (SWRCB) | July 8th, 2011

The Guide provides an overview of the Water Boards and the many opportunities that all Californians have to participate with the Water Boards in decisions and activities

The Guide provides an overview of the Water Boards and the many opportunities that all Californians have to participate with the Water Boards in decisions and activities that affect the state’s water resources. While some of the public participation opportunities are formal, e.g., at a Water Board hearing, others are less formal, but just as important, e.g., a stakeholder process implemented by a Regional Board. Although the Guide doesn’t contain information about specific water quality decisions that are before the Boards, it will direct you where you can find that information. We look forward to updating this Guide periodically to assure its continuing usefulness to you, the public.

City and County of San Francisco v. United States Environmental Protection Agency

Supreme Court of the United States | January 8th, 2024

For a plain language summary from Scotusblog, click here.

For a plain language summary from Scotusblog, click here.

City of Barstow, et al v. City of Adelanto, el al (Mojave Basin Area cases)

Superior Court of California, County of Riverside | December 5th, 2002

From An Evaluation of California’s Adjudicated Groundwater Basins, Langridge et al, UC Davis (2016): "The Mojave Basin adjudication was initiated by a lawsuit filed

From An Evaluation of California’s Adjudicated Groundwater Basins, Langridge et al, UC Davis (2016): "The Mojave Basin adjudication was initiated by a lawsuit filed May 30, 1990, by the City of Barstow and the Southern California Water Company. The complaint alleged that the cumulative increase in water use in the upper part of the Mojave Basin caused or threatened to cause a reduction in the natural flow of water to the central part of the Mojave Basin. Water users included downstream agriculture (many alfalfa farms), aquaculture, recreational lakes, homeowner associations, and upstream burgeoning municipalities. In the center of the basin is the smaller, low-income town of Barstow, which was concerned about its water supply. A 1993 Stipulated Judgment set forth a proposed physical solution that did not apportion production rights on the basis of preexisting legal water rights, and parties representing over 80 percent of verified water production in the basin agreed to its terms. However, some farmers with overlying rights chose not to stipulate to the judgment. On appeal, the court stated that in considering a stipulated physical solution involving equitable apportionment, the water rights of parties that did not join the stipulation must also be considered. The adjudication set out a complex system to reduce production a producer’s free production allowance (FPA) over time, but withdrawals remain significant in three out of the five subareas. The judgment also contained unique provisions for assuring that the water needs of endangered and other species and their habitat would be protected. One outcome of the adjudication was that many farmers in the western Alto Subarea sold or leased their base annual production (BAP) rights or leased their FPA to municipalities, and population in the Alto Subarea almost doubled. The Barstow Marine Corps Logistics Base east of Barstow is a federal Superfund site."