The Sonoma County Water Agency (SCWA) is the controlling agency for the Water Supply System of Sonoma County.  The system supplies water for the cities of Forestville, Guerneville, Santa Rosa, Sebastopol, Rohnert Park, Cotati, Sonoma, Petaluma, and Novato.

The central area of the City of Santa Rosa uses approximately 70 to 75 percent of the total water volume supplied by the Sonoma County Water Agency to the City of Santa Rosa.  The system includes pressure reducing valves (PRV) off of the aqueduct (lower elevation areas). The rest of Santa Rosa’s water, due to higher elevations, is boosted to 21 reservoirs that are supplied by booster pump stations.