Sacramento County Groundwater Sustainability Agency


In 2014, the California Legislature passed the Sustainable Groundwater Management Act (SGMA), becoming effective January 2015. SGMA provides a framework for sustainable management of groundwater by local water supply, water management and land use agencies.

SGMA required the formation of Groundwater Sustainability Agencies, or GSAs, for providing governance over each groundwater subbasin in the State by June 2017. Unmanaged areas, areas where no GSA formed for groundwater management, are susceptible to State Water ​Resources Control Board (State Board) intervention. The State Board could declare subbasins with unmanaged areas as probationary, thereby requiring reports of groundwater extractions and charge fees for developing an interim plan for sustainably managing groundwater.

Because Sacramento County became the GSA for unmanaged areas in the South American, Cosumnes, and Solano subbasins, GSAs cover all areas of subbasins that the County overlies, avoiding State Water Board intervention. A public notice for Sacramento County GSA combining with Sacramento County Water Agency forming the Sacramento County GSA over unmanaged areas in the Cosumnes and Solano Subbasins was prepared for the August 10, 2021 County Board of Supervisors and SCWA Board of Directors meeting.  Sacramento County supports local groundwater management, continuing compliance with SGMA as a Groundwater Sustainability Agency in unmanaged areas in all subbasins the County overlies.

SGMA mandates that all high and medium priority groundwater basins1 develop one or more Groundwater Sustainability Plans, or GSPs, by 2022. Using GSPs as a roadmap SGMA requires subbasins meet a sustainability goal over a 20-year implementation timeframe by avoiding undesirable results and mitigating any overdraft, reaching long-term sustainability. Sacramento County GSA participates in GSP development in the South American, Cosumnes, and Solano subbasins. Following is Sacramento County GSA subbasin specific information.

1. The State Department Water Resources (DWR) defines the boundaries and describe the hydrologic characteristics of California’s groundwater basins and subbasins in Bulletin 118.

South America​n Subbasin​

This high priority subbasin is located entirely within Sacramento County. Because of its central location in the County, historically references of the “Central basin” exist. Sacramento Central Groundwater Authority (SCGA) manages the majority of this subbasin. SCGA has a sixteen-member board with representation from local municipalities, water purveyors, agricultural, agricultural-residential, and conservation stakeholder groups. Sacramento County has a seat on the Board as a land use authority and is a signatory to the JPA.

Sacramento County is one of five GSAs in this subbasin. Omochumne-Hartnell Water District, Northern Delta, SCGA, and Sloughhouse Resource Conservation District are also GSAs that are collaboratively working together developing a GSP.  Sacramento County GSA covers approximately 1,500 acres in this subbasin and in 2021, SCGA and Sacramento County GSA entered into a Memorandum of Understanding: item 27 for guiding incorporation of this small area into the SCGA GSA. See the map below for the Sacramento County GSA area in the South American subbasin.


Cosumnes Subba​sin​

This medium priority subbasin is bounded by the Cosumnes River on the north, the Sacramento County boundary on the south and extends into Amador County to the east.  Seven GSAs in this subbasin are working collaboratively under a Framework Agreement, calling themselves the Cosumnes Working Group.  The seven GSAs are: Amador County Groundwater Management Authority, City of Galt, Clay Water District, Galt Irrigation District, Omochumne-Hartnell Water District, Sacramento County, and Sloughhouse Resource Conservation District. The Water Forum has facilitated planning and governance activities in this subbasin until 2021. The State DWR awarded the Cosumnes Subbasin $1.75 million in State DWR grants for G​SP development and Sacramento County is the administrator of these grants.

All GSAs in the Cosumnes subbasin have adopted a fee for groundwater management for GSP implementation.  A subbasin wide Fee Study is what all GSAs in the subbasin are using for determining the fee, supporting the first year of GSP implementation. Sacramento County GSA adopted a groundwater management fee at a public hearing on July 27, 2021 Board of Supervisors meeting. For more information on the fee program go to the Cosumne​s Subbasin website​.
See the map below for the Sacramento County GSA portion of this subbasin.


Solano Subbasin

This medium priority subbasin is primarily in Solano County though the southernmost Delta portion of Sacramento County is included in the Solano Subbasin.  There are multiple GSAs in the Solano subbasin and five entered into a Memorandum of Understanding forming the Solano Collaborative that are developing the GSP.  The five GSAs in the Collaborative are; City of Vacaville, Northern Delta (representing 17 Reclamation Districts in the Delta), Sacramento County, Solano Irrigation District, and the Solano Subbasin. The Solano Subbasin GSA is the Grant Administrator of a $1.5 million State DWR grant for GSP development. See the map below for the Sacramento County GSA portion of the Solano Subbasin.


Public Notices

December 21, 2021
Public hearing to consider adoption of Groundwater Sustainability Plan

Sacramento County Board of Supervisors Chambers
700 H Street
​Sacramento, CA 95814​