Cuyama Valley Groundwater Basin Joins Growing List of Post-SGMA Comprehensive Groundwater Adjudications

Facing depleting groundwater supplies, a group of landowners in the Cuyama Valley Groundwater Basin, which overlies parts of Ventura, Kern, San Luis Obispo, and Santa Barbara Counties, filed a complaint for a comprehensive adjudication of all the groundwater rights in the basin. In the wake of California’s Sustainable Groundwater Act (“SGMA”), which requires regulation of groundwater for long-term sustainability, and as drought affects water supplies throughout California, a growing number of adjudications are being filed under the Comprehensive Groundwater Adjudication Statute, California Code of Civil Procedure sections 830 et seq. This is the fifth such adjudication filed since 2015, when the California Legislature revised the process for comprehensive groundwater adjudications. These adjudications resolve all water rights in a given groundwater basin.

The Cuyama Valley relies on the Cuyama Groundwater Basin as its sole source of water, yet the basin is in critical overdraft. Critical overdraft occurs when groundwater extractions exceed the annual average replenishment of the basin, leading to adverse effects, such as seawater intrusion, subsidence, and chronic groundwater depletion. Despite being the driest agricultural region in the county, the Cuyama Valley is a major carrot-producing region, a valuable yet water-intensive crop.

The adjudications come in the wake of an overhaul of California’s approach to groundwater management and adjudications. The California Legislature in 2014 passed SGMA, which requires local agencies known as groundwater sustainability agencies (“GSAs”) to draft groundwater sustainability plans (“GSPs”) that will guide sustainable management over the coming decades. In 2015, the California Legislature passed AB 1390, which streamlined the processing of comprehensive groundwater basin adjudications. While GSAs do have the power to limit extractions and set groundwater allocations, a GSA does not have the authority to determine groundwater rights. If groundwater rightsholders believe a GSA’s pumping restrictions are inconsistent with groundwater rights under the common law, they may file an adjudication to seek judicial relief to harmonize the GSA’s regulations with groundwater rights. The Cuyama adjudication is just the most recent case where groundwater rightsholders have done so.

The effort to pass the Cuyama Valley groundwater plan highlights the differing goals among ranchers, carrot farmers, and the GSA. Small-scale farmers and conservationists challenged the region’s GSP last year, arguing that it did not do enough to conserve groundwater. In June 2021, California’s Department of Water Resources issued a letter identifying deficiencies in the GSP. 

The Cuyama adjudication joins a small but growing list of comprehensive groundwater adjudications filed under the new adjudication law. The adjudications showcase the unique issues facing California groundwater rightsholders. The adjudications often involve tensions between competing water uses, as well as differing views on the best strategies for sustainable management. Current ongoing adjudications include the Borrego Basin groundwater adjudication, the Ventura River adjudication, the Las Posas Valley Basin groundwater adjudication, and the recently filed Oxnard and Pleasant Valley adjudication, brought by O’Melveny on behalf of 50 landowners in Ventura County.

Although the Cuyama adjudication involves a relatively rural area, other adjudications involve major population centers and competing municipal, agricultural, and industrial uses. For example, the Oxnard and Pleasant Valley adjudication, filed in June 2021, encompasses the cities of Oxnard and Camarillo, as well as a U.S. Naval base.

Litigating a groundwater adjudication involves a unique skillset, as these cases are long-running, procedurally complex, and logistically difficult. These cases involve potentially thousands of parties, as anyone with a right to groundwater in the basin may bring a claim. Groundwater adjudications also involve complicated technical reports and expansive records. O’Melveny attorneys are actively litigating both the Las Posas adjudication, first filed in 2018, and the Oxnard and Pleasant Valley adjudication.

As climate change affects water supplies statewide and SGMA implementation progresses, it is likely that the number of groundwater adjudications will increase. One important site of potential future adjudications is the agriculturally rich San Joaquin Valley region, which will see significant forced pumping reductions in the coming years.

O’Melveny’s own groundwater expert, Russ McGlothlin, will be speaking at the Groundwater Resources Association’s Western Groundwater Congress on September 15 on groundwater adjudications and how they can be used constructively to implement sustainable and durable groundwater management.

This memorandum is a summary for general information and discussion only and may be considered an advertisement for certain purposes. It is not a full analysis of the matters presented, may not be relied upon as legal advice, and does not purport to represent the views of our clients or the Firm. Matt Kline, an O'Melveny partner licensed to practice law in California, Russel McGlothlin, an O'Melveny Counsel licensed to practice law in California, Heather Welles, an O'Melveny Counsel licensed to practice law in California, and Katie Sinclair, an O'Melveny associate licensed to practice law in California, contributed to the content of this newsletter. The views expressed in this newsletter are the views of the authors except as otherwise noted.

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