Utilities in Sonoma, Marin counties ask customers to reduce water use by 20 percent By Eli Walsh Phoenix Lake in Marin County (photo: Mark Tamayo) MARIN COUNTY, Calif. - Eight public water utilities in Sonoma and Marin counties have called on customers to voluntarily reduce their water usage by 20 percent as the region faces worsening drought conditions. The Water Advisory Committee to the Sonoma County Water Agency passed a resolution Monday asking residents to do so as water supply in the Russian River watershed and both Lake Mendocino and Lake Sonoma are at historic lows. The committee includes representatives from water utilities under the Sonoma-Marin Saving Water Partnership, which includes the cities of Santa Rosa, Rohnert Park, Petaluma, Sonoma, Cotati, Healdsburg; the North Marin, Valley of the Moon and Marin Municipal Water Districts; the town of Windsor; California American Water - Larkfield District and Sonoma County Water Agency.