Marin Municipal Water DistrictEstablished in 1912, the Marin Municipal Water District provides high-quality drinking water to 191,300 customers in central and southern Marin County. Seventy-five percent of our water comes from more than 21,600 acres of protected watershed on Mt. Tamalpais and in the grassy hills of west Marin. Rainfall from these watersheds flows into one of MMWD’s seven reservoirs. This reservoir water is then treated at one of the district’s potable water treatment plants before traveling to customers’ homes and businesses.
Twenty-five percent of MMWD’s water is imported from the Sonoma County Water Agency (SCWA). SCWA water originates from rainfall that flows into Lake Sonoma and Lake Mendocino and is released into the Russian River. The Russian River water is filtered naturally through 80 feet of sand beds adjacent to the river. The Russian River water is blended with MMWD’s reservoir water in the distribution system.