Sustainable Groundwater Management Act

    Governor Jerry Brown signs the Sustainable Groundwater Management Act of 2014

    In 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 Valley.

    In May 2018, the California Department of Water Resources (DWR) announced its recommendations for basin re-prioritization under SGMA. Under the proposed recommendations, Santa Rosa Plain, Sonoma Valley and Petaluma Valley would each be elevated to high priority, and three additional Sonoma County basins would be identified as medium priority and subject to SGMA: Alexander Valley, Wilson Grove Highlands and Dry Creek. Public comment is open for two months (until August 20th, 2018) with final prioritization in mid-October. View a map of these groundwater basins on the Department of Water Resources website.

    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 Specifically, sustainable yield is defined as the amount of groundwater that can be withdrawn annually without chronically lowering groundwater levels, causing seawater intrusion, degrading water quality, causing land subsidence or depleting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


    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.