Orange County was settled around areas of surface water. San Juan Creek supplied the mission at San Juan Capistrano. Santa Ana River supplied the early cities of Anaheim and Santa Ana. The Santa Ana River also provided water to a large aquifer underlying the northern half of the county, enabling settlers to move away from the river's edge and still obtain water by drilling wells.
By the early 1900s, Orange County residents understood that their water supply was limited: the rivers and creeks didn't flow all year long, and the aquifer would eventually be degraded or even dry up if the water wasn't replenished on a regular basis.
That's why in 1928 the cities of Anaheim, Santa Ana, and Fullerton joined with 10 other Southern California cities to form the Metropolitan Water District of Southern California (MET). Their objective was to build an aqueduct to the Colorado River to provide the additional water necessary to sustain the growing Southern California economy and its enviable lifestyle.
The Orange County Water District was formed in 1933 to protect the County's water rights on the Santa Ana River. Later that mission was expanded to manage the underground aquifer, making optimum use of local supplies and augmenting those with imported supplies provided through the County's Metropolitan Water District member agencies.
It wasn't long before other parts of Orange County also saw the need for supplemental supplies. A severe drought in the late 1940s further emphasized the need for coastal communities from Newport Beach to San Clemente. In 1948, coastal communities from Newport Beach south to the San Diego county line formed the Coastal Municipal Water District as a way to join in the benefits provided by the Metropolitan Water District.
The Municipal Water District of Orange County (MWDOC) was formed by Orange County voters in 1951 under the Municipal Water District Act of 1911. Today, MWDOC is MET’s third largest member agency, providing and managing the imported water supplies used in Orange County.
The Coastal Municipal Water District became a part of MWDOC in January 2001, a move that streamlined local government and allowed MWDOC to more efficiently provide wholesale water services at a reduced cost for the benefit of residents living throughout the service area.