Like the Los Angeles Aqueduct, this too was the brainchild of William Mulholland.
Running a total of 242 miles from the Colorado River to Southern California, the Colorado River Aqueduct was completed in 1941 and is held in San Bernardino County at Parker Dam near the town of Needles. It is owned and operated by the Metropolitan Water District that serves most of the Los Angeles area. However, most of the water from the aqueduct goes to Arizona, the result of a U.S. Supreme Court ruling in 1964.