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Groundwater Sustainability Agencies

New!DWR has scheduled a GSA Formation Notification Tool Webinar. Submittal of new GSA Formation Notifications, and revision of posted notifications, will be required to use this online tool (currently under construction).
New!The GSA Interactive Map has been updated with the 2016 Bulletin 118 Groundwater Basin Boundary Modifications.

The Sustainable Groundwater Management Act (SGMA) established a new structure for managing California’s groundwater resources at a local level by local agencies. SGMA requires, by June 30, 2017, the formation of locally-controlled groundwater sustainability agencies (GSAs) in the State’s high- and medium-priority groundwater basins and subbasins (basins). A GSA is responsible for developing and implementing a groundwater sustainability plan (GSP) to meet the sustainability goal of the basin to ensure that it is operated within its sustainable yield, without causing undesirable results. The GSP Emergency Regulations for evaluating GSPs, the implementation of GSPs, and coordination agreements were adopted by DWR and approved by the California Water Commission on May 18, 2016.

A GSP may be any of the following (Water Code § 10727(b)):

  • A single plan covering the entire basin developed and implemented by one GSA.
  • A single plan covering the entire basin developed and implemented by multiple GSAs.
  • Subject to Water Code Section 10727.6, multiple plans implemented by multiple GSAs and coordinated pursuant to a single coordination agreement that covers the entire basin.
DWR’s Role in GSA Formation

Senate Bill (SB) 13 changed DWR’s role with respect to reviewing, posting, and tracking GSA formation notices. These changes relate to: notification completeness reviews; overlapping GSA boundaries; and service area boundaries. For more information see DWR’s GSA Frequently Asked Questions. Also, DWR developed and has revised its GSA Formation Notification Guidelines for Local Agencies which outlines the information that must be submitted by a local agency(s) after it decides to become or form a GSA(s). DWR will use these GSA guidelines to perform completeness reviews for all GSA notices filed after January 1, 2016. Only complete GSA formation notices will be posted on DWR’s GSA Formation Table and included on DWR’s GSA Interactive Map. The following summarizes DWR’s approach and responsibilities with respect to GSA formation:

  • DWR shall post all complete GSA formation notices received on its website within 15 days of receipt. (Water Code §10723.8(b))
  •  A complete GSA formation notice includes all of the following (Water Code §10723.8(a)):
    • Information that clearly shows the GSA formation notice was submitted to DWR within 30 days of the decision to become or form a GSA.
    • The service area boundaries, the boundaries of the basin or portion of the basin the agency intends to manage, and identification of any other agencies managing or proposing to manage groundwater within the basin.
    • A copy of the resolution or legal agreement forming the new agency.
    • A copy of any new bylaws, ordinances, or new authorities adopted by the local agency.
    • A list of interested parties developed pursuant to Water Code §10723.2 and an explanation of how their interests will be considered in the development and operation of the GSA and the development and implementation of the agency’s sustainability plan.
  • DWR will not post incomplete GSA formation notices.
  • If two or more local agencies separately decide to become GSAs in all or a portion of the same area of a basin and create overlap (within 90-days of the initial posted notice), then no exclusive GSA will be identified by DWR until the overlap is resolved. (Water Code §10723.8(c) and (d))
  • Only exclusive GSAs can coordinate to develop a GSP for a basin and submit that GSP to DWR for review.
  • DWR has a Facilitation Support Services program that helps local agencies work through challenging institutional and technical situations.
  • If you have questions about a specific entity’s GSA eligibility please contact the State Water Resources Control Board at

DWR hosted a 90-minute webinar in November 2015 to address the SB 13 amendments to SGMA as they pertain to the formation of a GSA. The following information is available for use by local agencies and the public:

Local Agency’s Role in GSA Formation

Local agencies are expected to collaborate and coordinate their GSA formations on a basin-wide scale to sustainably manage groundwater at a local level. A local agency that decides to become a GSA will be required to perform the duties, and exercise the necessary powers, of a GSA when developing, implementing, and enforcing a basin's groundwater sustainability program.

  • Before deciding to become a GSA, and after publication of notice pursuant to Section 6066 of the Government Code, the local agency or agencies shall hold a public hearing in the county or counties overlying the basin. (Water Code §10723(b))
  • The decision of a local agency or combination of agencies to become a GSA shall take effect as provided in §10723.8. (Water Code §10723(d))
  • One local agency can decide to become a GSA or a combination of local agencies can decide to form a GSA by using a joint powers agreement, a memorandum of agreement, or other legal agreement. (Water Code §10723.6)
  • Within 30 days of deciding to become or form a GSA, the local agency or combination of local agencies shall inform DWR of its decision and its intent to undertake sustainable groundwater management. (Water Code §10723.8(a))
  • The GSA formation notice shall include all the information in Water Code §10723.8(a), as applicable.
  • The decision to become an exclusive GSA shall take effect pursuant to Water Code §10723.8(c) and (d) – an exclusive GSA will not be identified by DWR until any GSA overlap is resolved.
  • Only exclusive GSAs can coordinate to develop a GSP for a basin and submit that GSP to DWR for review.
  • A GSA may withdraw from managing a basin by notifying DWR in writing of its intent to withdraw. (Water Code §10723.8(e))
  • A list of local agencies and GSAs that have withdrawn their posted notices is located here.
County’s Role in GSA Formation

The legislative intent of SGMA is to recognize and preserve the authority of cities and counties to manage groundwater pursuant to their existing powers. As such, local governments play an important land use and water management role in California and should be involved in GSA formation and GSP implementation. A GSP shall take into account the most recent planning assumptions stated in local general plans of jurisdictions overlying the basin. (Water Code §10726.9)

  • In the event that there is an area within a high- or medium-priority basin that is not within the management area of a GSA, the county within which that unmanaged area lies will be presumed to be the GSA for that area. (Water Code § 10724(a))
  • A county shall provide notification to DWR of its intent to manage the unmanaged area pursuant to Water Code §10723.8 unless the county notifies DWR in writing that it will not be the GSA for the area. (Water Code § 10724(b))
  • An “unmanaged area” as used in Water Code §10724(a) is an area of a basin that has not yet had (or will not have) a local agency file a GSA formation notice with DWR.
  • Water Code §10724 does not give the county exclusive authority to be the GSA in a basin if other local agencies have also declared their intent to manage groundwater, but have not yet resolved their service area overlap.
  • A list of counties that have decided not to be the GSA for unmanaged areas in a basin is located here.
Where Do I Submit My GSA Information?

Please email your GSA formation notification and GIS shape file, and/or send via postal mail a hardcopy, to the following DWR staff:

  • Mark Nordberg, GSA Project Manager
    Sustainable Groundwater Management Program
    California Department of Water Resources
    901 P Street, Room 213-B
    P.O. Box 942836
    Sacramento, CA 94236
  • DWR Region Office Groundwater Contact
State Intervention

The State Water Resources Control Board's (SWRCB) Groundwater Management Program, after notice and a public hearing, may designate a basin as a probationary basin if it finds that after June 30, 2017, none of the following has occurred (Water Code § 10735.2(a)):

  • A local agency has decided to become a GSA that intends to develop a GSP for the entire basin.
  • A collection of local agencies has formed a GSA or prepared agreements to develop one or more GSPs that will collectively serve as a GSP for the entire basin.
  • A local agency has submitted an alternative that has been approved or is pending approval pursuant to Section 10733.6.

If unmanaged areas of a basin exist on July 1, 2017, those areas shall be subject to groundwater extraction reporting in accordance with Part 5.2 (commencing with §5200) of Division 2 of the Water Code and could be subject to fees listed in §1529.5. If you have questions about a specific entity’s GSA eligibility please contact SWRCB at

More GSA Information

Click here to sign up to receive email updates on DWR's SGMA activities.

For additional information regarding GSAs and DWR's role in their formation, please contact Mark Nordberg at or 916-651-9673.