Los Angeles Aqueduct, From Lee Vining Intake (Mammoth Lakes) to Van Norman Reservoir Complex (San Fernando Valley), Los Angeles, Los Angeles County, CA

Significance: The Los Angeles Aqueduct and its Mono Basin Extension delivers water to the City of Los Angeles from the Mono Basin in the Sierra Nevada Mountains through Owens Valley and across the Mojave Desert to the San Fernando Valley in Los Angeles. Built between 1907 and 1913, the First Los Angeles Aqueduct, together with the Mono Basin Extension completed in 1944, is significant as an engineering feat utilizing a gravity flow system that sends water from the east side of the Sierra Nevada Mountains to Los Angeles along a 338 mile line of conduit, inverted siphons, tunnels, dams and reservoirs. The Los Angeles Aqueduct is significant as a water conveying system that made possible the continuing growth and development of Los Angeles as it expanded from a small city to Pacific Coast metropolis. The Los Angeles Aqueduct gains significance for its association with its principal engineer-designer and superintendent of the City of Los Angeles Bureau of Water Supply, William Mulholland, who served and guided the Los Angeles water system for a half-century. Unprocessed Field note material exists for this structure: N859 Survey number: HAER CA-298 Building/structure dates: ca. 1907- ca. 1944 Initial Construction