The Sonoma County Groundwater Sustainability Agencies (GSAs) are pleased to announce the launch of the Well Aware Toolkit! This new interactive resource provides personalized water savings tips, programs, and rebates for groundwater users. The website has guidance for all property types including residential, commercial, vineyards, golf courses, specialty crops, and pasture. 

• Users can input their own address, and find specific solutions for their property including:
• Customized water-saving strategies for your property
• Financial assistance programs to support water conservation
• Guidance from trusted local experts who understand our region’s needs

Groundwater is a critical resource in Sonoma County, supporting families, farms, and ecosystems. About 43,000 people within the groundwater sustainability boundaries and many local jobs in Sonoma County solely rely on groundwater supplies. Preserving this resource is critical to the long-term health of our region.

 

Together, we can protect Sonoma County’s groundwater and build a sustainable future.

 

Start using the Toolkit today: 

The Sonoma County Groundwater Sustainability Agencies (GSAs) are inviting agricultural groundwater users to participate in a new survey aimed at shaping future groundwater policies and programs. 

 

Groundwater plays a critical role in supporting agriculture throughout Sonoma County. With three key subbasins—Petaluma Valley, Santa Rosa Plain, and Sonoma Valley—groundwater provides nearly half of the county’s total water supply. While levels remain stable in some areas, others, like the Sonoma Valley subbasin, are experiencing declines in deep aquifers.

 

To address these challenges, the agencies are considering a range of strategies. This survey is intended to capture feedback from agricultural property owners, farmers, processors, and other groundwater users and entities that support agricultural to inform potential changes to existing policies and programs, and/or the development of new policies and programs that support sustainable groundwater management practices. The survey seeks input from agricultural groundwater users to ensure these programs are practical, effective, and aligned with the needs of the agriculture community.

 

Survey closing soon!

The 22-question survey has been open for a couple of months, but will close November 26, so if you have not yet participated, please take time to do that now. If you rely on groundwater for your agricultural operations, your feedback is vital. Your participation will help shape policies that protect groundwater while supporting the agricultural economy.

Get Insights into Your Water Use: Last Call for Flow Smart Program Groundwater Sustainability Agencies (GSAs) launched the Flow Smart Program to deepen our understanding of groundwater use throughout the region. The program partners with volunteer well owners and installs professional-grade flow-metering devices, at no cost to participants (a $6,000 value), to track real-time groundwater pumping data.

A new groundwater technical assistance program from CA Dept. of Water Resources (URCTA) has launched to support Underrepresented Communities, California Native American Tribes (Federally and Non-Federally Recognized) and Small Farmers within Sustainable Groundwater Management Act (SGMA) regulated basins. The URCTA Program identifies eligible communities throughout California with water supply challenges such as dry groundwater wells, water shortages, or poor water quality with the assessment of water-related needs, risks, and vulnerabilities and to provide focused groundwater-related technical assistance to resolve them.

 

Services the URCTA program can provide include, but are not limited to:

• Analysis of groundwater conditions, interference, impact (for depletion, land subsidence, groundwater dependent ecosystem depletion, etc.), and water quality
• Analysis of long-term water supply demand, and assistance with facilitating water transfers, groundwater sustainability matters, water well and pump repairs
• Design of water systems (supply, production, distribution, treatment, and storage, including fire flow requirements)
• Preparation and submittals of relevant applications, project plans and specifications, equipment and system training

If you are a small farmer or a part of Tribe or an underrepresented community, this program could help you! Find out more about the program, and how to participate here: https://water.ca.gov/urctaprogram

Groundwater monitoring well construction is underway across all three Sonoma County groundwater basins as part of ongoing efforts to fill key data gaps, track long-term groundwater conditions, and improve understanding of interactions between groundwater, surface water, and potential areas of seawater intrusion.

 

Sonoma Valley Subbasin

Construction of two new multi-level groundwater-level monitoring wells began in late August 2025 and finished up in early November.

• A multi-level well off Millerick Road near Sonoma Creek and the Baylands boundary has been completed by Weeks Drilling & Pump. It includes two casings and three screened intervals (125–145 ft, 210–220 ft, and 250–260 ft) designed to monitor for potential seawater intrusion.
• A second multi-level well, off Fowler Creek Road within the El Verano Priority Area has also been completed with three screened intervals (115-135 ft, 310-320 ft and 445-465 ft).

These wells expand the long-term monitoring network and support more accurate evaluation of aquifer conditions.

 

Santa Rosa Plain Subbasin

In the Santa Rosa Plain, construction of five new monitoring wells is anticipated to begin in early November and continue through early 2026.

Weeks Drilling & Pump will construct three multi-level wells in late 2025 and early 2026 in priority data-gap areas to monitor both shallow and deep aquifer conditions.

 

GSA staff and GEI Consultants are working closely with drilling teams to coordinate permitting, scheduling, and field oversight.

 

Petaluma Valley Basin

Construction of six new monitoring wells is now in progress and will continue through the end of 2025.

 

In late July and early August, Gregg Drilling constructed three shallow wells to monitor interconnected surface water at Wiggins Creek (Rainsville Road), Lynch Creek (Petaluma Community Center), and Adobe Creek (Del Oro Park).

• Multi-level wells were also installed at Del Oro Park and Petaluma Hill Road near Railroad Avenue, providing monitoring across both shallow and deep aquifer zones.
• Two additional multi-level wells—located at the Ellis Creek Treatment Plant and along Lakeville Highway—are under construction to monitor potential seawater intrusion in identified data-gap areas.

GSA staff and Todd Groundwater continue coordinating with drilling contractors to schedule and oversee this work.

 

Across all basins, these new monitoring wells will significantly strengthen the region’s ability to track groundwater trends, protect sensitive areas, and support long-term sustainable groundwater management.

Aquifer Storage and Recovery (ASR) is an innovative and cost-effective water management strategy that stores treated drinking water in underground aquifers during wet years, then recovers it for use when water is scarce. It improves supply reliability, reduces pressure on other water sources, and supports long-term groundwater sustainability, all while using existing infrastructure.

 

There are several pilots testing ASR here in Sonoma County with a goal to learn whether storing drinking water underground is a safe and effective strategy for additional water supply and groundwater conservation. Each of these projects involve multiple recharge and recovery cycles, in which high quality potable water from Sonoma Water is injected into a well, and after a period of time, the water is pumped back out through the same well, simulating what might happen when that water is needed during a time of drought. Technical staff measure the quantity and quality of the water throughout the pilot.

ASR Pilot Status in Santa Rosa Plain
GSA staff and GEI have compiled, updated, and evaluated existing data and coordinated with member agency staff to identify municipal wells that could be candidates for focused characterization or pilot testing. GEI prepared a technical report for conducting an ASR pilot test at the City of Santa Rosa’s Martha Way test well, which was submitted to the California Regional Water Quality Control Board (RWQCB). The RWQCB approved the report and issued a Notice of Applicability. ASR pilot testing began on September 18 and has completed the second of three cycles, each involving the recharge, storage, and recovery of approximately 10 acre-feet of treated drinking water.

ASR Pilot Status in Sonoma Valley
In November 2024, the Valley of the Moon Water District launched ASR pilot studies at two municipal wells, one within the Subbasin and one just outside it: the Park Well, which was new construction, and the Verano Well which already had a production well that just needed to be converted for ASR), in November 2024. Each pilot test has involved recharging, storing, and recovering roughly 15 acre-feet of treated drinking water. Their pilot study results showed ASR was a feasible strategy for alternative water supply management.

ASR Pilot Status Petaluma Valley
In Petaluma Valley, an ASR pilot is underway near Del Oro Park. GSA staff, the City of Petaluma, and GEI Consultants submitted a technical report and Notice of Intent for an ASR pilot test at the City’s Del Oro wellsite. The RWQCB approved the submittal, and the pilot test began in August 2025, with testing planned through November 2025. For this pilot, a deep monitoring well is tracking aquifer behavior and water quality changes at depth, while a shallow well is monitoring for any interaction between the aquifer and nearby Adobe Creek.

 

Next Steps
Results from all three basins—along with additional ASR pilot studies by Sonoma Water and the Town of Windsor—will help GSAs and regional partners better understand the costs, feasibility, and performance of ASR across a range of hydrogeologic and geochemical conditions.

Message sent by Sonoma County Groundwater Sustainability Agencies at 2235 Mercury Way, Suite 105, Santa Rosa, CA, United States.

 

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