Sustainable Groundwater Management Act (SGMA)


In 2014, the California Legislature passed the Sustainable Groundwater Management Act (SGMA) and the Governor signed it into law, becoming effective January 2015.  SGMA provides a framework for sustainable management of groundwater by local water supply, water management and land use agencies.  SGMA requires the formation of Groundwater Sustainability Agencies, or GSAs, for providing governance over each basin in the State.  The State Department Water Resources (DWR) defines the boundaries and describes the hydrologic characteristics of California’s groundwater basins and subbasins in Bulletin 118. A basin, and subbasins, can be governed by one GSA, or multiple GSAs, provided that all GSAs work collectively and collaboratively to sustainably manage groundwater in the entire subbasin.

The deadline for GSA formation was June 30, 2017. Areas where no GSA formed were susceptible to State Water Resources Control Board intervention, declaring the subbasin probationary and taking over management of the subbasin.  Sacramento County is currently located within four groundwater subbasins, and GSAs cover all areas within these subbasins, as Sacramento County accepted GSA responsibility for areas where a local agency did not, known asunmanaged areas, and areas where GSA’s overlap.

SGMA mandates that all high and medium priority groundwater basins develop one or more Groundwater Sustainability Plans, or GSPs, by 2022 and be managed sustainably over a 20-year implementation period. The GSPs will be evaluated every 5 years, with annual reporting, to assess the effectiveness of implementation of the plans toward meeting the goal of sustainably managing groundwater by 2042. 

Stakeholder Engagement, Education, and Outreach

In order for SGMA implementation to be responsive to stakeholder and local interests, public involvement and input is a key component to the process.  The State DWR has published guidelines and provides assistance for communication with stakeholders as part of the GSP development process. Ensuring a thoughtful, locally driven plan for the subbasins requires outreach to those who would be affected by the plan. Workshops provide opportunities for learning more about local SGMA implementation, asking questions, and sharing what is important to you. Workshops will be held periodically by each subbasin during GSP development.

The Sacramento County Board of Supervisors (BOS) is another forum for education and engagement by the public.  The BOS has taken several actions in support of local groundwater management, and will continue to be engaged in the process as GSAs work to comply with SGMA.  A principle adopted by the BOS supports existing and new groundwater management actions and planning efforts in the County, providing these efforts include broad representation of all interested stakeholders, management based on sound science, conjunctive use of groundwater and surface water supplies and promotion of Countywide cooperation in groundwater management.

If you’d like more information, please e-mail your request to

Upcoming pu​blic meetings

The Sub-​basins

Sacramento County overlays all or part of four groundwater sub-basins listed abov​e. 

These sub-basins are described below and shown on the image below.​


North American Sub-basin

This high priority subbasin is bounded by the American River on the south, the Sacramento River on the west, and extends northward into Sutter and Placer counties. The Sacramento County portion of this subbasin is being managed by the Sacramento Groundwater Authority (SGA), a Joint Powers Authority.  SGA is governed by a joint powers agreement (JPA), created in 1998, managing the groundwater in Sacramento County, north of the American River to the County boundary.

SGA is considered essential for implementing the groundwater management element of the historic 2000 Water Forum Agreement. A centerpiece of the agreement is a regional program to manage and conjunctively use groundwater and surface water to help meet water needs through the year 2030, while reducing diversions from the lower American River during environmentally sensitive times.

In January 2016, SGA became the exclusive Groundwater Sustainability Agency (GSA) for its portion of the North American Subbasin. There are five GSAs in the North American Subbasin who are collaboratively developing a GSP by January 30, 2022 for sustainably managing groundwater. SGA is the CA DWR grant administrator in the subbasin for a $1 million Groundwater Sustainability Plan (GSP) development grant.

GSP development is underway and SGA is leading a regional modeling effort, known as CoSANA, for use in the North American, South American, and Cosumnes Subbasins.

South American Sub-basin

This high priority subbasin is located entirely within Sacramento County and is generally bounded by the American River, the Sacramento River, the Cosumnes River and the eastern Sacramento County line.  The majority of this subbasin has been managed by Sacramento Central Groundwater Authority (SCGA), a Joint Powers Authority governed by a JPA, since 2006, based on the 2006 Groundwater Management Plan (GMP). SCGA has a sixteen member board with representation from local municipalities, water purveyors, agricultural, agricultural-residential, and conservation stakeholder groups.

In July 2016 SCGA became a GSA for the majority of the subbasin. Sloughhouse Resource Conservation District and Omochumne-Hartnell Water District also submitted GSA applications in June 2016 that overlap the SCGA application, these overlap conditions need to be resolved. Sacramento County is the GSA in these areas until the overlap is resolved.  Several reclamation districts located in the Delta became GSAs during 2016 and are primarily represented by the Northern Delta GSA, through a JPA.  Sacramento County is responsible for a small area within the Delta region.

SCGA submitted an Alternative to a GSP for the subbasin in December 2016, based on their 2006 GMP.  In July 2019, the State DWR disapproved the Alternative. Relatively few basins in the state successfully demonstrated to have been operating in a functionally-equivalent manner to SGMA for the prior ten years, sufficient to demonstrate operation within the sustainable yield as defined in SGMA.  Since the Alternative was not approved, SCGA has entered into an agreement with State DWR to administer a $1 million grant for GSP development.

Cosumnes Sub-basin

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 have formed in this subbasin and are working collaboratively under a Framework Agreement, calling themselves the Cosumnes Working Group.  The seven GSAs include: Amador County Groundwater Management Authority GSA, City of Galt GSA, Clay Water District GSA, Galt Irrigation District GSA, Omochumne-Hartnell Water District GSA, Sacramento County GSA, and Sloughhouse Resource Conservation District GSA. Planning and governance activities in this sub-basin are being facilitated by the Water Forum

The Cosumnes Subbasin was awarded a $1 million State DWR grant for GSP development and Sacramento County is the administrator of this grant. A consultant was selected by the Cosumnes Working Group in August 2018 for GSP development, which is well underway.

Solano Sub-basin

This medium priority subbasin is contained primarily in Solano County and includes the southernmost Delta portion of Sacramento County.  There are multiple GSAs in the Solano subbasin; City of Vacaville, Solano Irrigation District, Northern Delta (representing 17 Reclamation Districts in the Delta), Sacramento County, Reclamation District 150, Reclamation District 999, and the Solano Subbasin GSA.

A Collaboration Agreement exists among the GSAs, identifying the Solano Subbasin GSA as the Grant Administrator of a $1 million State DWR grant for GSP development.  A GSA Coordination Committee, also known as the Solano Collaborative, will make recommendations for MOU implementation that will be forwarded to each GSA Governing Board for final decision-making.

GSP development is well underway.

Groundwater Sustainability Agenci​​​es

Cu​​rrent GSA boundaries in the Sacramento County region are shown on the map below. 


The Sacramento County Board of Supervisors has taken several actions in support of local groundwater management, and will continue to be engaged in the process as the GSAs work to comply with SGMA in the future.  If you’d like more information, please e-mail your request to​​