Characterizing Nitrates in Central Coast Groundwater

Central Coast Groundwater Coalition (CCGC) | April 1st, 2016

The Central Coast Groundwater Coalition (CCGC) is a third-party cooperative groundwater monitoring program that was established for landowners/operators in the Ce

The Central Coast Groundwater Coalition (CCGC) is a third-party cooperative groundwater monitoring program that was established for landowners/operators in the Central Coast region as an alternative to the individual groundwater monitoring program. The cooperative program collects and synthesizes groundwater monitoring data on behalf of its members to fulfill requirements of the Irrigated Lands Regulatory Program. The Central Coast Regional Water Quality Control Board required that the CCGC characterize groundwater quality in the uppermost aquifer and identify and evaluate groundwater used for drinking water purposes. Specifically, the focus was on evaluating the spatial distribution of nitrate concentrations in ground- water basins used for drinking water and provide statistically-based estimates of where groundwater nitrate concentrations are likely to be above the maximum contaminant level (MCL) for nitrate.

Chino Basin Municipal Water District v. City of Chino et al

Superior Court of California, County of San Bernardino | August 25th, 2014

From "An Evaluation of California's Adjudicated Groundwater Basins" by Langridge et al: "Chino Basin is one of the largest groundwater basins in Southern California. It a

From "An Evaluation of California's Adjudicated Groundwater Basins" by Langridge et al: "Chino Basin is one of the largest groundwater basins in Southern California. It abuts Los Angeles County, Orange County, and Riverside County. Over the past few decades, the basin has experienced rapid growth. The southern area was once notable for containing the heaviest concentration of dairy farms in the United States. There is significant subsidence in areas of the basin due to overpumping. While it is often described as a basin with ongoing conflict, there were also significant collaborative efforts to address basin problems during and after the adjudication process. Three different stakeholder groups—overlying agricultural, overlying non-agricultural, and appropriators—negotiated a management plan prior to adjudication, and it was adopted in a 1978 stipulated judgment. Stakeholders agreed on water rights for each group of users. There were multiple additional amendments over the last twenty years adopted in a 2012 restated judgment." Click here for the Chino basin Department of Water Resources Adjudicated Basin Reporting page.

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

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."

City of San Bernardino vs. Fontana Water Co. et al.

Superior Court of California, County of San Bernardino | January 28th, 1924

Climate Change and Water Supply Security: Reconfiguring Groundwater Management to Reduce Drought Vulnerability

California Energy Commission (CEC) | July 31st, 2012

Periodic droughts, projected to become more frequent and severe with climate change, present a significant planning challenge for California’s water agencies. This r

Periodic droughts, projected to become more frequent and severe with climate change, present a significant planning challenge for California’s water agencies. This research examined approaches to reducing drought vulnerability, focusing on five water agencies on California’s north and central coast that rely on local and regional sources of water. Curtailing water use is the principal response to drought. In contrast, this project highlights an important but underutilized proactive adaptation to improve water supply security during drought: the development of locally based groundwater drought reserves. While this approach represents an obvious solution in principle, it is uncommon to find it in practice, and this research provides insight into (1) motivating factors, (2) legal barriers and opportunities, (3) tools, and (4) policy options to support increased drought resilience and the development of drought reserves.

Climate Warming and Water Management Adaptation for California

Climatic Change (Springer) | June 10th, 2010

The ability of California’s water supply system to adapt to long-term climatic and demographic changes is examined. Two climate warming and a historical climate

The ability of California’s water supply system to adapt to long-term climatic and demographic changes is examined. Two climate warming and a historical climate scenario are examined with population and land use estimates for the year 2100 using a statewide economic-engineering optimization model of water supply management. Methodologically, the results of this analysis indicate that for long-term climate change studies of complex systems, there is considerable value in including other major changes expected during a long-term time-frame (such as population changes), allowing the system to adapt to changes in conditions (a common feature of human societies), and representing the system in sufficient hydrologic and operational detail and breadth to allow significant adaptation. While the policy results of this study are preliminary, they point to a considerable engineering and economic ability of complex, diverse, and intertied systems to adapt to significant changes in climate and population. More specifically, California’s water supply system appears physically capable of adapting to significant changes in climate and population, albeit at a significant cost. Such adaptation would entail large changes in the operation of California’s large groundwater storage capacity, significant transfers of water among water users, and some adoption of new technologies.