Three Sonoma County groundwater agencies propose changes to their own rules

By The Downspout · Posted Nov 11, 2026 · 3 min read

County and Sonoma Water staff recommend that the Board of Supervisors approve updated agreements for the three local groundwater agencies on November 17, 2026. The changes cover how the agency boards are run and how they vote. The staff report lists no change to pumping limits or fees. Nothing is decided yet.

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What these agencies are

Sonoma County has three groundwater agencies. Each one is a Groundwater Sustainability Agency, or GSA. They cover the Petaluma Valley, Santa Rosa Plain and Sonoma Valley. A GSA manages the underground water supply in its area, as a 2014 state law requires.

Each GSA was formed in 2017 and is shared by several public agencies. Each has a board of directors and an advisory committee that advises it.

The County of Sonoma, Sonoma Water and the Sonoma Resource Conservation District are members of all three. Sonoma Water is the county's water agency, officially the Sonoma County Water Agency. Cities and other local agencies are members of the GSA for their area.

The contract that sets up each GSA is called a joint powers agreement. It sets how the board is made up, how it votes and how it changes its own rules. Today, every member agency's governing board must say yes to change it.

What happened

Three updated agreements are on the Board of Supervisors' agenda for Tuesday, November 17, 2026. Staff recommend approval. The Board of Supervisors and the Sonoma Water Board of Directors would each need to approve. The Supervisors need a majority vote. This is a proposal. Nothing is decided yet.

All three GSA boards approved their updated agreements in June 2026. Santa Rosa Plain voted June 11, Sonoma Valley June 22 and Petaluma Valley June 25. The updates take effect only if every member agency's governing board approves too.

Staff say the changes are meant to clarify governance and improve efficiency. The main changes in all three are these.

Each member could name a second backup director. The second backup could fill in only if both the main director and the first backup are absent or sitting out a vote. That could happen at no more than two board meetings a year.
The yearly budget could be approved any time before the new budget year starts.
Some future changes to the agreement would pass with a two-thirds vote of the GSA board in Petaluma Valley and Sonoma Valley. In Santa Rosa Plain it would take three-fourths. Today every member agency must agree.
Changing how many seats the advisory committee has would need a bigger vote. Filling one member's seat would not.

Two more changes apply to some of the agencies.

Petaluma Valley and Sonoma Valley would elect board officers every two years instead of every year.
In Santa Rosa Plain, contracts with member agencies for technical and outreach work would no longer need a supermajority vote. A supermajority is a vote above a simple majority.

Some changes would still need every member agency's governing board to agree. They include changes to these.

The agency's powers.
How the board is made up.
Voting rules.
Liability.
Ending the agency, or a member leaving it.
Removing the advisory committee.
Other matters the agreement names.

What it means for you

This changes how the agencies are run. The staff report lists no change to any pumping limit, fee or well rule. It lists no cost to the county.

If your well sits over one of the three basins, that basin's GSA is the agency that manages groundwater there. Not sure which one covers you? Use our water map. Our guide to who manages groundwater in Sonoma County explains what each agency does.

What happens next

The Board of Supervisors takes up the item on November 17, 2026. The report does not say when the Sonoma Water board or the member agencies will vote. All of them must approve before the changes take effect.

For recent groundwater agency news, see our posts on the Petaluma Valley plan review and the Sonoma Valley pumping plan.

Where this came from

The Sonoma County staff report "Amendments to Joint Powers Agreements for Groundwater Sustainability Agencies" and the November 17, 2026 Board of Supervisors agenda, both on the county's meeting-records website.

Sources

Checked 2026-11-11. Rules and programs change. If something here is out of date, the source above wins. Spot an error? See our corrections policy.