Like many water districts in south Orange County, nearly all of the District’s water supply is imported from Northern California via the State Water Project and from the Colorado River via the Colorado River Aqueduct.
As of February 15, 2017, approximately 90% of SMWD's potable (drinking) water supply is from Irvine Lake and 10% from the State Water Project. SMWD purchases 100% of it's potable drinking water from Metropolitan Water District of Southern California, a regional wholesaler and the largest supplier of treated water in the United States.
The State Water Project, also known as the California Aqueduct, is the longest aqueduct system in the world, featuring 23 dams and reservoirs, 22 pumping plants that lift water to heights of 3,500 feet, and six power plants. The aqueduct is comprised of 473 miles of canals, 175 miles of pipeline and 20 miles of tunnels. The project delivers water to two-thirds of California's population. It is maintained and operated by the California Department of Water Resources.
The Colorado River Aqueduct is a 242-mile water conveyance that brings water from the Colorado River to southern California. The aqueduct is composed of two reservoirs, five pumping stations, and 63 miles of canals and 92 miles of tunnels.
SMWD purchases this water from the Metropolitan Water District of Southern California, which delivers water to our region through an infrastructure network. Water from both sources is purified and tested at the Diemer Filtration Plant in Yorba Linda to ensure that it meets or exceeds state and federal drinking water standards. Then it is piped to SMWD, and then to you.
Our water quality staff monitors the water supply continuously and conducts 24,000 to 30,000 laboratory tests each year from 39 locations across the District, representing all sources, storage reservoirs and pressure zones. SMWD’s laboratory is certified by the California Environmental Laboratory Accreditation Program.
SMWD is committed to providing our customers with the highest quality drinking water.