Department of Water Resources Releases 17 GSP Determinations – California Achieves Major Groundwater Sustainability Milestone

The California Department of Water Resources (DWR) today released seventeen assessments of groundwater sustainability plans (GSPs) developed by local agencies in non-critically overdrafted basins, to meet the requirements of the Sustainable Groundwater Management Act (SGMA). These determinations complete the initial GSP reviews for all high and medium priority groundwater basins that were required to submit plans under SGMA.

Today’s release includes the approval of ten GSPs for the following basins: Anderson and Enterprise Subbasins in Shasta County, San Antonio Creek Valley and Santa Ynez River Valley Basins in Santa Barbara County, Santa Clara River Valley East Subbasin in Los Angeles County, Solano Subbasin in Solano County, Temescal Subbasin in Riverside County, Tracy Subbasin in San Joaquin and Alameda Counties, Upper San Luis Rey Valley Subbasin in San Diego County, and Yucaipa Subbasin in San Bernardino and Riverside Counties. The assessments can be viewed on the SGMA Portal. These plans are approved with recommended corrective actions that the groundwater sustainability agencies (GSAs) will need to address in their next plan update, due in January 2027. DWR’s approval of a GSP identifies that the plan substantially complies with the GSP Regulations and SGMA law, relying upon the best available science and information, and whether implementation of the plan is likely to achieve the basin’s sustainability goal over the 20-year planning horizon of SGMA.

DWR has also found in its technical review that the GSPs in seven basins contain deficiencies that preclude approval and the plans are determined to be Incomplete. The seven basins include Butte Valley Subbasin in Siskiyou County; Fillmore Subbasin in Ventura County; Modesto Subbasin in Stanislaus and Tuolumne Counties; Pleasant Valley Subbasin (Basin No. 5-022.10) in Fresno County; Piru Subbasin in Ventura County; Tulelake Subbasin in Modoc and Siskiyou Counties, and Turlock Subbasin in Stanislaus and Merced Counties. The basins with GSPs that are determined Incomplete have 180 days from today’s release of DWR’s determination to address deficiencies and resubmit their corrected GSPs to the Department for review.

For additional information on these GSP assessments, DWR has prepared a press release providing an overview of these assessments and a GSP Evaluation fact sheet summarizing SGMA’s determination pathways for GSPs. SGMA lays out a process for continuous improvement, gathering information to fill data gaps, updating plans, carrying out projects and actions, and promoting science-based adaptation.

DWR encourages all SGMA interested parties to review the assessments, and related materials, accessible on our GSP webpage. For any SGMA-related questions, please email DWR at: sgmps@water.ca.gov.