It was just over a year ago that all of Sonoma County was experiencing severe drought or worse, with nearly 34 percent experiencing extreme drought, according to national drought monitors.

One year later, that scenario has dramatically changed, but the threats to groundwater due to climate change persist.

“Today our reservoirs are incredibly healthy due to the atmospheric rivers that came through in early 2023,” said Andrea Rodriguez, spokesperson for Sonoma County Water Agency. They are cautiously hoping for more rain this winter. “You’ve got a full reservoir. How do we make sure that lasts?”

The state Department of Water Resources is granting funds to make sure the county is prepared for the next dry spell. In a public event Monday, representatives from the county’s three groundwater basins ceremoniously received checks awarded through the state’s Sustainable Groundwater Management Grant Program.

“Today our reservoirs are incredibly healthy due to the atmospheric rivers that came through in early 2023. … How do we make sure that lasts?”

Andrea Rodriguez, Sonoma County Water Agency

Each of the agencies were required to create Groundwater Sustainability Plans, and this money is going for implementation. The plans are funded by fees paid by groundwater users, grants and support from local governments, including the County of Sonoma and the Sonoma County Water Agency.

Funded projects will include an assessment of available groundwater under current conditions and a detailed 20-year plan to ensure that groundwater is available to meet the region’s needs over the next 50 years.

Actions include environmental engineering projects, adding monitoring wells to fill data gaps, promoting rural water recycling systems and community education programs.

None of the county’s water comes from snowmelt. It’s all dependent on rain. Its reservoirs are Lake Mendocino and Lake Sonoma.

Recharging the groundwater

An example of an engineering solution is called Aquifer Storage and Recovery. The agency works with landowners, vineyards and farms to flood the land with winter water and then let the water soak back into the groundwater.

“We have a project in the Santa Rosa Plain where we were able to look at how to refill the aquifer with winter water,” Rodriguez said. “So, this pump has a two-way valve to take water off our aqueduct, put it into the ground and store it there. If we go through another few years of drought, that water could then be pulled from the ground.”

Each groundwater basin is unique and has different needs, Rodriguez said. Sonoma Valley basin has the Bay near it, and they are on the lookout for sea water intrusion. Santa Rosa Plain comes through Sebastopol. It is a little bit more urban, but it also has wells around it. Petaluma Valley contains some agricultural users, but it also butts up against the city and rural residents.

The county’s community engagement program focuses on rural residents that rely on wells for drinking water.

“They are our main audience for the groundwater sustainability plans. They’re the ones that use it, rely on it. So, how do we let them know about the plan, what was happening?” she said. The plan calls to incentivize rural residents to use gray water systems and low-flow water fixtures and adopt more water efficiency systems.

The groundwater sustainability agencies hold joint powers authority. Members are appointed to come together and work on governance of the agency. Each works with an advisory committee that includes businesses, environmental groups and other stakeholders who help the agency decide on projects.

Correction: This story previously said incorrectly that a check presentation was happening Monday, Nov. 6. The presentation happened this past Monday, Oct. 30.