According to the Municipal Water District of Orange County (MWDOC), together the State Water Project (SWP) and the Colorado River Aqueduct (CRA) supply about half of the water needed for Orange County. According to scpr.org, Oroville Lake, created by Oroville Dam, is the largest reservoir in the SWP. It stores water collected over the rainy season, then releases it gradually over the dry season. Over the course of more than four hundred miles, that water irrigates farms and provides drinking water before entering Lake Perris. MWDOC draws from Lake Perris to supply the needs of the County.