History & Background

Western was formed by the voters in 1954 to bring supplemental water to growing western Riverside County. Today, the District serves roughly 24,000 retail and eight wholesale customers with water from both the Colorado River and the State Water Project, as well as groundwater within our Murrieta Division.

As a member agency of the Metropolitan Water District of Southern California (MWD), Western provides supplemental water to the cities of Corona, Norco, and Riverside and the water agencies of Box Springs Mutual, Eagle Valley Mutual, Elsinore Valley, Lee Lake and Rancho California. Western serves customers in the unincorporated areas of El Sobrante, Eagle Valley, Temescal Creek, Woodcrest, Lake Mathews, and March Air Reserve Base.

Western operates and maintains domestic and industrial wastewater collection and conveyance systems for retail and contract services customers in Lake Hills, March Air Reserve Base, Home Gardens, and Norco.

Western is one of five of the member agencies of the Santa Ana Watershed Project Authority (SAWPA), a regional water resources planning and project implementation organization. Western's general manager is a court-appointed Watermaster, responsible for reporting compliance with water quality and quantity provisions of court orders regarding water rights issues in the Santa Ana watershed.

Western's general district consists of a 527-square mile area of western Riverside County... an assessed valuation of $88 billion... and a population of more than 825,000 people. Western currently sells approximately 125,000 acre-feet of water annually. This is equal to about 34 billion gallons of water. (One acre foot is enough water to cover a football field one foot deep.)

About two-thirds of the water Western sells is treated; the balance is untreated or raw water. About one-quarter of water sales are for agricultural uses; the balance is for domestic purposes. One-quarter of Western's sales are to retail customers; the rest wholesale. Nearly all water sold by the District for agricultural purposes is used to irrigate citrus and avocados planted since the 1950s.

About one-fifth of the water Western purchases from the MWD comes from the Colorado River Aqueduct. Most of the imported water supply comes from the State Water Project, which transports water from Northern California via the California Aqueduct. Western also imports a very small quantity of water from the San Bernardino basin. Western also has several wells for pumping groundwater in its Murrieta Division.