Sacramento County Water Agency

Sustainable Groundwater Management Act (SGMA)


In 2014, the California Legislature passed the Sustainable Groundwater Management Act (SGMA) and the Governor signed it into law.  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 to provide governance over each sub-basin in the State.  A sub-basin can be governed by one GSA or by multiple smaller GSAs provided that all GSAs work collectively to sustainably manage the entire sub-basin. 

The deadline for GSA formation is June 30, 2017, or the State Water Resources Control Board can declare the sub-basin probationary and take over management of the sub-basin.  Once GSAs have been established, sub-basins have until 2022 to adopt Groundwater Sustainability Plans or GSPs, which describe the rules for groundwater management in the specific sub-basin.  After adoption of the GSP and approval by the State Department of Water Resources (DWR), GSAs have until 2042 to demonstrate that the basin is being sustainably managed and will be assessed according to 5-year goals.


Education and Outreach

SGMA mandates that all high and medium priority groundwater basins in California – including the Cosumnes Subbasin - must develop one or more groundwater sustainability plans by 2022 and be managed sustainably over a 20-year implementation period. 

In order for SGMA implementation to be responsive to local interest, public involvement and input is key to ensuring a thoughtful, locally driven plan for the Cosumnes Subbasin. Workshops provide the opportunity to learn more about local SGMA implementation, ask questions, and share what is important to you.


Upcoming community meetings


The Sub-basins

Sacramento County overlays all or part of five groundwater sub-basins

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


North American Sub-basin

This sub-basin is generally bounded by the American River on the south and extends into Sutter and Placer counties.  The Sacramento County portion of this sub-basin is being managed by the Sacramento Groundwater Authority (SGA).  For more information on this sub-basin, please visit

South American Sub-basin

This sub-basin 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 sub-basin has been managed by Sacramento Central Groundwater Authority (SCGA) since 2006, based on their Groundwater Management Plan.  SCGA submitted an Alternative to a GSP for the entire sub-basin during December 2016, as allowed by SGMA.  As part of a process to change the sub-basin boundary Sloughhouse Resource Conservation District and Omochumne Hartnell Water District submitted GSA applications that overlap the SCGA application, these overlap conditions will need to be resolved.  For additional information on SCGA, please go to

Cosumnes Sub-basin

This sub-basin is generally bounded by the Cosumnes River on the north, the San Joaquin County line on the south and extends into Amador County to the east.  Currently, seven GSAs have been formed in this sub-basin, including Sloughhouse Resource Conservation District, Omochumne Hartnell Water District, Clay Water District, City of Galt, Amador County, Galt Irrigation District and Sacramento County.  Planning and governance activities in this sub-basin are being facilitated through the Water Forum.  You can find more about this specific area on the Consumnes Sub-basin website.

Solano Sub-basin

This sub-basin is contained primarily in Solano County but includes the southernmost Delta portion of Sacramento County.  Sacramento County is currently coordinating with interested management entities in this sub-basin.

Tracy Sub-Basin

This sub-basin is contained primarily in Contra Costa County but includes a small portion of Sacramento County, less than 600 acres.  Sacramento County has discussed a boundary modification with DWR to move the 600 acres into the Solano Sub-basin.

Groundwater Sustainability Agencies

Current GSA boundaries in the Sacramento County region are shown on the map below.  The white spaces shown on the map represent areas in which no entity has submitted to become the GSA.  If these areas remain unmanaged on July 1, 2017, they will become part of the County’s GSA.

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 or would like to be included on the County’s groundwater distribution list, please e-mail your request to