William Mulholland
William Mulholland (September 11, 1855 – July 22, 1935) was an Irish American self-taught civil engineer who was responsible for building the infrastructure to provide a water supply that allowed Los Angeles to grow into the largest city in California. As the head of a predecessor to the Los Angeles Department of Water and Power, Mulholland designed and supervised the building of the Los Angeles Aqueduct, a 233-mile-long (375 km) system to move water from Owens Valley to the San Fernando Valley.