Member Agencies
Under SGMA, Groundwater Sustainability Agencies (GSAs) are entities formed by local government agencies with land use authority or water supply or water management responsibilities. The Santa Rosa Plain GSA was created in 2017 when the participating agencies, listed below, entered into a Joint Exercise of Powers Agreement (JPA). The JPA spells out GSA Board membership, initial funding, voting and other governance issues. The GSA Board of Directors includes one representative from each member agency, plus one seat designated for a representative of independent water suppliers active in the groundwater basin (mutual water districts and those water districts that are regulated by the California Public Utilities Commission). Each member agency also has a representative on the Advisory Committee.
City of Cotati
The City of Cotati is a charming city of 7,000 residents located in Central Sonoma County near Sonoma State University and adjacent to US 101. Cotati is focused on continuing economic development while keeping our small town allure.
County of Sonoma
The County of Sonoma provide a full range of services to our community; the County plays a dual role to residents, providing municipal services such as law enforcement and fire protection to unincorporated areas and providing the day-to-day operation of state and federally mandated programs.
Gold Ridge Resource Conservation District
The Gold Ridge Resource Conservation District facilitates stewardship projects to address water quality, climate change, biodiversity, ecosystem health, and water quantity on private and public lands by providing technical assistance, outreach, education, and project implementation. The RCD provides non-regulatory, confidential, free assistance to our community.

Independent Water Systems
There are three California Public Utility Commission-regulated utilities and seven mutual water companies in the Santa Rosa Basin providing water service to approximately 3,600 customers collectively. Seven of those organizations currently participate in the GSA: Branger Mutual Water Company, California American Water, Willowside Mutual Water Company, Belmont Terrace Mutual Water Company, Fircrest Mutual Water Company, Kelly Mutual Water Company, and Penngrove Water Company.
City of Rohnert Park
The City of Rohnert Park is a thriving, family-friendly community that is a safe, enjoyable place to live, work, and play. The City cares for its 41,000 residents by working together to build a better community for today and tomorrow.
City of Santa Rosa
The City of Santa Rosa works to provide high-quality public services and cultivate a vibrant, resilient and livable City. Santa Rosa is home to more than 170,000 people, and is the county seat of Sonoma County.
Sonoma Resource Conservation District
The Sonoma Resource Conservation District (RCD) works to empower and partner with landowners and the community to address Sonoma County’s most pressing natural resource concerns. The RCD is organized to support natural resource management solutions through partnerships with individuals, organizations and agencies.
Sonoma Water
Sonoma Water manages Sonoma County’s water resources. The Water Agency provides an array of services including, but not limited to, naturally filtered drinking water, flood protection services, distribution of recycled water, recreational opportunities, and wastewater treatment.
Town of Windsor
The Town of Windsor is recognized as a family-oriented community with a diverse population and robust economy. Incorporated in 1992, Windsor is the newest city in the County. The Town and the Windsor Water District provide a high level of public service, including drinking water and recycled water, to its approximately 27,000 residents and to customers in the surrounding area.

City of Sebastopol
The City of Sebastopol is dedicated to the enhancement and protection of the immediate and long-term wellbeing of the City, its citizens, and its natural environment. Sebastopol, while a very small city, is at the forefront of nation-wide efforts to implement new technologies and address critical environmental policy issues. The population is 7,397, but its businesses also serve surrounding rural portions of Sonoma County, a region known as West County, which has a population of up to 50,000 residents.