Delta-Mendota Subbasin exits state intervention, returns to DWR oversight

SACRAMENTO – The State Water Resources Control Board today took two major actions under the Sustainable Groundwater Management Act (SGMA): it ended the prospect of probation for the Delta-Mendota Subbasin and excluded about 3,000 groundwater pumpers in the Tule and Tulare Lake Subbasins from state reporting and fee requirements.

The Department of Water Resources (DWR) referred the Delta-Mendota Subbasin to the State Water Board in 2023 for state intervention because the sustainability plans of its 23 groundwater agencies were inconsistent in key areas and would not lead to sustainable management. In 2024, the subbasins successfully aligned their management activities to adopt one plan that board staff found made significant improvements, including a mitigation program for drinking water wells.

“Delta-Mendota is the fourth subbasin to exit state intervention after groundwater agencies came together and coalesced around the common goal of achieving sustainability,” said board Chair E. Joaquin Esquivel. “I congratulate the agencies on their cooperation and partnership, which will be key to managing the subbasin’s groundwater in the future.”

Following today’s board decision, the subbasin will return to DWR oversight.

In two separate decisions at the same meeting, the board elected to exclude groundwater pumpers in the Tule and Tulare Lake subbasins who extract 20 acre-feet or less annually from paying fees or reporting their usage to the state. Their extractions account for less than 2% of all groundwater pumped in these basins.

In 2024, the board designated the Tule and the Tulare Lake subbasins as probationary, which made all groundwater pumpers in these basins subject to state fees and reporting requirements.

“By excluding small farmers and other minor extractors from state fees and reporting, we are reducing hardship where we can while ensuring sustainability occurs,” said Chair Esquivel.

All other pumpers in these subbasins, totaling approximately 3,360 entities extracting over 98% of all groundwater pumped, are required to report pumping amounts by May 1, 2026, and pay associated fees.

Groundwater pumpers who are low-income residents, enrolled in income-based public assistance plans, public schools, or public water systems serving disadvantaged communities will have the option to request a fee waiver.

SGMA, enacted in 2014, established a new framework to ensure long-term groundwater sustainability in California. Under the law, local groundwater agencies must achieve long-term sustainable management of their subbasins within 20 years of implementing their sustainability plans. Initially, when DWR finds that plans to manage groundwater in a subbasin are inadequate to achieve sustainability within that period, it refers the subbasin to the board to initiate the state intervention process.

More information on the board’s role and implementation of SGMA can be found here.

The State Water Board’s mission is to preserve, enhance and restore the quality of California’s water resources and drinking water for the protection of the environment, public health, and all beneficial uses, and to ensure proper resource allocation and efficient use for present and future generations.