The Mendocino County Water Agency (Water Agency) is a special district that encompasses all of Mendocino County and is governed by the Board of Supervisors sitting as the Board of Directors.  The Water Agency is administered by the Department of Transportation.  The Agency’s roles include:

• The National Pollution Discharge Elimination System (NPDES) - municipal separate storm sewer system (MS4) Phase II permit, for the control of storm water runoff.
• The California State Groundwater Elevation Monitoring program (CASGEM) – statewide effort to track seasonal and long-term trends in groundwater elevations.
• Represent the County in the implementation of the Sustainable Groundwater Management Act by being a member of the Ukiah Valley Basin Groundwater Sustainability Agency and collaboratively develop a Groundwater Sustainability Plan for the Ukiah Valley Basin.
• Providing the public with information regarding water resources in Mendocino County, actively communicate with federal, state, and local water agencies with regards to water related legislation and policy.
• Protect County-managed reservoirs from invasive species through implementation of the Mill Creek Ponds Mussel Prevention Plan.

More information on the Water Agency is available in the following reports:

• 2015 Water Agency Action Plan
• 2022 Water Agency Implementation Plan
• 2023 Mendocino County Water Resources Team Technical Memo

340 Lake Mendocino Drive
Ukiah, CA 95482

Phone: 707-463-4363
Fax: 707-463-5474
Email: mcwa@mendocinocounty.gov

Hours of Operation
Monday – Friday from 8:00 am – 4:30pm