About the Sustainable Groundwater Management Act (SGMA)

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) powers to sustainably manage groundwater over the long-term, and requires Groundwater Sustainability Plans (GSPs) be developed for medium- and high-priority groundwater basins.

The first step implementing the new law is the creation of local Groundwater Sustainability Agencies (GSAs). Three GSAs are in the process of formation in Sonoma County:  Santa Rosa Plain, Sonoma Valley and Petaluma Valley. The GSAs must be formed by June 30, 2017.

New! Update on GSA Creation

Are You In An Affected Groundwater Basin?

There is a tool on the California Department of Water Resources website that can help you determine the basin where your property is located.

Go to

Some basic instructions:

  1. On the right side of the page, check the box that reads “Bulletin 118 Groundwater Basins.”
  2. Type the property address into the search bar on the map.
  3. A dot will appear that identifies the property location.
  4. The name of the basin will also be in the map.

Groundwater Basins

The three basins immediately affected by SGMA are below. Clicking each link will provide additional information about each groundwater basin:

Sonoma County Groundwater Basins

What’s Happening in Sonoma County?

In Sonoma County, the State has designated three of the county’s 14 basins and sub-basins as medium-priority: Santa Rosa Plain, Sonoma Valley, and Petaluma. These three basins are required to comply with the Act.

To start the process of creating GSAs, in March 2015, the Sonoma County Board of Supervisors asked staff to reach out collaboratively to GSA-eligible agencies and to solicit input from farmers, well-owners, economically disadvantaged communities, businesses, environmental groups and other interested stakeholders.

Santa Rosa Groundwater Meeting

As a follow-up to Board direction, a facilitator conducted a stakeholder assessment and issued a report in September 2015. Working groups comprised of staff from the agencies that are eligible to serve as GSAs in the three basins have been meeting since 2015 to develop recommendations for forming GSAs. Public meetings were held in Fall 2015, Summer 2016, and Spring 2017 to inform people about SGMA, present GSA formation options, and make recommendations. The boards and councils of the GSA-eligible agencies have heard presentations and received public comment on staff recommendations.

The boards and councils of GSA-eligible agencies are considering the legal agreements for forming GSAs in April and May. A public hearing will be held in each basin in June.

SGMA Implementation Timeline

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

SGMA timeline

General Information About SGMA