Sustainable Groundwater Management Act

    Governor Jerry Brown signs the Sustainable Groundwater Management Act of 2014In September 2014, Governor Brown signed historic legislation requiring that California’s critical groundwater resources be sustainably managed by local agencies. The Sustainable Groundwater Management Act (SGMA) gives local agencies (cities, counties and water districts) the powers needed to sustainably manage groundwater over the long-term, and requires Groundwater Sustainability Plans (GSPs) be developed for medium- and high-priority groundwater basins. In Sonoma County, three of the county’s 14 basins and sub-basins are currently designated as medium-priority: Santa Rosa Plain, Sonoma Valley and Petaluma. No basins are currently designated as high-priority. The SGMA does not apply outside of mapped groundwater basins.

    The SGMA defines sustainable management as managing and using groundwater in a way that can be sustained over a long period of time. Specifically, sustainable yield is defined as the amount of groundwater that can be withdrawn annually without chronically lowering groundwater levels, causing seawater intrusion, degrading water quality, causing land subsidence or depleting interconnected surface water (for example, creeks, streams and rivers) in a manner that causes significant and adverse impacts.

    The SGMA provides local governments and stakeholders the time needed to implement the complex law. The chart below includes key milestones.



    June 30, 2017

    Formation of Groundwater Sustainability Agencies

    January 31, 2020

    Completion of plans in critically overdrafted basins (does not apply in any Sonoma County groundwater basins at this time)

    January 31, 2022

    Completion of plans in all other basins

    20 years after adoption of plan

    High- and medium-priority basins achieve sustainability


    Next Steps

    As a first step, in October 2014, County and Water Agency staff formed a workgroup to consider governance options and has been meeting with stakeholders to inform them of the new law’s requirements and to discuss collaborative approaches.

    On March 17, 2015, the work group presented information about SGMA and its implementation in Sonoma County to the Board of Supervisors. The Board provided direction to the work group, asking it to reach out collaboratively to GSA-eligible agencies and to solicit input from farmers, well-owners, economically disadvantaged communities, businesses, environmental groups and others.

    Sonoma County Sustainable Groundwater Management Website

    A new website has launched providing the most up-to-date information on the Sustainable Groundwater Management Act implementation in Sonoma County:

    More information

    For additional information about the SGMA and its impacts locally, please see the following:

    If you have questions about the SGMA, please contact Ann DuBay at or 707.524.8378.