Valley of the Moon Water District serving the Valley since 1962


Water Sources – Where Does My Water Come From?

     One of the most important factors in water quality is its source: the purer the source, the better the water.  The Valley of the Moon Water District's customers are fortunate because they enjoy a reliable water supply from two sources.  The District's primary source is purchased water from the Sonoma County Water Agency (Water Agency).  In 2006, the Water Agency's water originated from five Ranney Collectors (or caissons), from seven production wells along the Russian River, and, to a minor degree, from three wells in the Santa Rosa plain.  One of the Water Agency's Ranney Collectors, referred to as Caisson 5, is the only source among these wells that is subject to surface water treatment regulations, and this is only when high flow conditions exist in the Russian River.

Russian River Mirabel

     The Russian River originates in central Mendocino County, approximately 15 miles north of the City of Ukiah.  The main channel of the Russian River is 110 miles long and flows southward from its headwaters near Potter Valley to the Pacific Ocean near Jenner, about 20 miles west of the City of Santa Rosa.  Three main reservoirs, Lake Sonoma, Lake Pillsbury, and Lake Mendocino, feed the Russian River, replenishing the aquifer.  Ranney Collectors withdraw water from about 40 to 60 feet below the Russian River streambed.  Streambeds beneath the Russian River provide the required filtration.  The Water Agency treats the water for bacterial disinfection with chlorine in the form of chlorine gas and to a lesser extent sodium hypochlorite and sodium hydroxide (also known as caustic soda), to adjust the PH before it is delivered to the District.  There is no additional treatment within the District's system.  In addition to the Valley of the Moon Water District, the Water Agency system supplies water to the cities of Santa Rosa, Cotati, Petaluma, Rohnert Park and Sonoma, as well as the North Marin, Forestville, and Marin Municipal Water Districts.