Your Drinking Water Is About to Cost More

Sonoma Water board has approved wholesale water rate adjustment for fiscal year 2026-27. Sonoma Aqueduct customers (Valley of the Moon and City of Sonoma) will pay 8.72 percent more for water.

The Board of Directors of Sonoma Water on Tuesday approved a wholesale water rate adjustment for the 2026-27 fiscal year to address aging infrastructure, rising operational costs and continued investment in system reliability.

The approved rates result in increases of 8.21 percent for Santa Rosa Aqueduct customers, 8.97 percent for Petaluma Aqueduct customers and 8.72 percent for Sonoma Aqueduct customers. Additional increases include 9.42 percent for North Marin Water District and 7.68 percent for Marin Municipal Water District.

The cost of water delivered by Sonoma Water costs roughly a half cent per gallon. Wholesale rates are only one component of customers’ total water bills. Actual impacts to households will depend on how local water retailers incorporate the increase and on individual water use.

Revenue from the rate adjustment will support essential operations and maintenance, continued implementation of projects required by federal biological opinions, construction of hazard mitigation and reliability projects and maintenance of prudent financial reserves.

Sonoma Water, like agencies across California, continues to face increasing costs for labor, materials, utilities and regulatory compliance. At the same time, lower water demand in recent years has reduced revenues under the agency’s volumetric rate structure, contributing to declines in reserve balances.

Over the past decade, Sonoma Water has secured more than $23 million in grant funding to help offset costs, including $12.6 million in Federal Emergency Management Agency funding for hazard mitigation projects. Additional funding strategies, including use of reserves and financing, are incorporated into the adopted budget to help reduce the impact on ratepayers.

The 2026-27 budget includes funding for ongoing maintenance and rehabilitation of critical infrastructure, including the multiyear tank rehabilitation program, system upgrades and construction of multiple hazard mitigation and resiliency projects.

Under the Restructured Agreement for Water Supply, rates are set annually based on projected costs and expected deliveries. Sonoma Water estimates deliveries of 41,776 acre-feet for fiscal year 2026-27, slightly lower than the prior year.