Sustainable Groundwater Management Act (SGMA)


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 mandates that all high and medium priority groundwater basins  develop one or more Groundwater Sustainability Plans, or GSPs, by 2022 and that subbasins achieve a sustainability goal over a 20-year implementation timeframe by being sustainability managed.

SGMA required the formation of Groundwater Sustainability Agencies, or GSAs, for providing governance over each groundwater subbasin in the State by June 2017. One GSA can govern a groundwater subbasin or multiple GSAs can govern a subbasin, if all GSAs work collectively and collaboratively to sustainably manage groundwater in the entire subbasin. Sacramento County accepted GSA responsibility for unmanaged areas (areas where no GSA formed) in three of the four subbasins (North American, South American, Cosumnes, and Solano) that the County overlies. Take a look at the Sacramento County GSA page  for more information about the South American, Cosumnes, and Solano subbasins.

Unmanaged areas are susceptible to State Water Resources Control Board (State 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. 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. 

SGMA tasked the State Department of Water Resources with implementing GSPs and coordination agreements; identifying basins subject to critical conditions of overdraft; identifying water available for groundwater replenishment; and publishing best management practices for the sustainable management of groundwater. DWR is the regulatory agency that evaluates GSPs for adequacy. DWR will evaluate updated GSPs every 5 years, along with annual reporting, to assess the effectiveness of implementation of the plans toward meeting the goal of sustainably managing groundwater by 2042.

The figure below shows how local GSAs, the State Board, and the State DWR interact under SGMA.


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 facilitation services provide 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 affected by the plan. Workshops provide opportunities for learning more about local SGMA implementation, asking questions, and sharing what is important to you. The links below provide access to workshops held periodically by each subbasin during GSP development. Each subbasin, and GSAs within that subbasin, will determine the type and frequency of public outreach for GSP implementation.

The Sacramento County Board of Supervisors (BOS) is another forum for education and engagement by the public. BOS actions supporting groundwater management, include adopting principles of groundwater management efforts inclusive of 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. The Sacramento County BOS and Sacramento County Water Agency Board of Directors will continue engagement in SGMA implementation as the County GSA for unmanaged areas as we work to comply with SGMA.

If you’d like more information on SGMA in Sacramento County, please e-mail your request to SacCo_​  For information on public engagement opportunities in each of the subbasins that Sacramento County overlies please click the links below.

Groundwater Subbasins In Sacramento County

Sacramento County overlays all or part of four groundwater subbasins listed below. 

You can find general information about the subbasins and maps showing the GSAs within the subbasins below.  For detailed information, please visit the subbasin and GSA websites. 

 North American Subbasin

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 manages groundwater through the Sacramento Groundwater Authority (SGA), a Joint Powers Authority (JPA), created in 1998.  ​


In January 2016, SGA became the exclusive Groundwater Sustainability Agency (GSA) for its portion of the North American Subbasin.  SGA is 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.​​  SGA also leads a regional modeling effort, know as CoSANA, for use in the Cosumnes, South American, and North American Subbasins.

The five GSAs in the North American Subbasin collaboratively developed a GSP to guide the sustainable management of groundwater in the North American subbasin and submitted the final GSP to the California Department of Water Resources (CA DWR) in January 2022. Now in the initial years of GSP implementation, the five GSA continue to work collaboratively. The subbasin has been awarded more than $4.5 million in funding from the state’s Sustainable Groundwater Management Grant Program to help develop and implement the GSP. Visit​ for more information.

In July 2023 the CA DWR issued an initial approval of the North American GSP. This indicates that the North American Subbasin is in compliance with the Sustainable Groundwater Management Act. SGMA requires that each subbasin submit Annual Reports to CA DWR by April 1st of each year and a 5-year Periodic Review will be due by January 2027. Showing success toward implementing the GSPs through these two processes will be key factors in staying in compliance.​​

South American ​Subbasin​

This high priority s​ubbasin 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.  Sacramento Central Groundwater Authority (SCGA), a Joint Powers Authority (JPA), formed in 2006, based on the 2006 Groundwater Management Plan (GMP), and 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.

In July 2016, SCGA became a GSA for the majority of the subbasin. Omochumne-Hartnell Water District, Northern Delta, and Sloughhouse Resource Conservation District are also GSAs in the South American Subbasin 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 GSAs in the South American subbasin.

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, requiring GSP development for the subbasin. ​ Following this determination, the GSAs within the subbasin entered into a series of Memorandum of Understanding (MOUs) to develop a collaborative GSP for the subbasin. This effort, administered by SCGA, received over $1 million in grant funds to develop the GSP which was submitted to the CA DWR in January 2022. Similar to the North American Subbasin, the GSAs have begun implementing the GSP which received approval from the CA DWR in July 2023. Visit for more information.​

Cosumnes Subbasin

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 worked collaboratively through a Framework Agreement to develop the Cosumnes GSP. With facilitation support from the Water Forum and over $2.5 million in state grant funds administered by the Sacramento County Department of Water Resources, the GSP was submitted in January 2022 to CA DWR.  The seven GSAs are: Amador County Ground​water Management Authority, City of ​Galt, Clay Water District, Galt Irrigation District, Omochumne-Hartnell Water District GSA, Sacramento County, and Sloughhouse Resource Conservation District. The GSAs in the Cosumnes subbasin formed the Cosumnes Groundwater Authority, a joint powers authority, in November 2021 to better collaborate on implementation of the GSP. The Cosumnes GSP received CA DWR approval in October 2023. Learn more at​.​​


Solano Subbasin

This medium priority subbasin is primarily in Solano County including the southernmost Delta portion of Sacramento County.  There are multiple GSAs in the Solano Subbasin. Five GSAs worked together as the Solano Collaborative in developing, and now implementing, the GSP: City of Vacaville, Northern Delta (representing several of the Reclamation Districts in the Delta), Sacramento County, Solano Irrigation District, and the Solano Subbasin. The Solano Subbasin GSA served as the Grant Administrator for the $1.5 million state grant for GSP development and now serves as the Grant Administrator for a $4.4 million implementation grant. The Solano GSP received CA DWR approval in January 2024. Visit for more information.



Public Notices and Contact Information:

The Sacramento County Board of Supervisors serve as the Board of Directors of the Sacramento County Groundwater Sustainability Agency and meet on various Tuesdays and Wednesdays through the month. Visit the Sacramento County Clerk of the Board of Supervisors website.

Public Notices:

Contact Us:

If you’d like more information about sustainable groundwater management act in Sacramento County, please e-mail us at​​. ​