East Valley Water District uses State Water Project water, which is imported from Northern California, only when necessary. Water from the State Water Project is available through the San Bernardino Valley Municipal Water District, which provides backup water supply to the district and other water agencies throughout the San Bernardino Valley. Imported water is available and used on an as-needed basis.
The State Water Project consists of 22 dams and reservoirs. The largest storage reservoir, with a capacity of 3.5 million acre-feet, is the Oroville Dam in Northern California. From there, water flows south to the Bay-Delta where the North and South Bay aqueducts serve San Francisco Bay area communities. The 444-mile long California Aqueduct begins at the Delta Pumping Plant and parallels Interstate 5 south to the Tehachapi Mountains. To cross the Tehachapi's into southern California, water is lifted by 2,000 feet at the Robert D. Edmonston Pumping Plant.