On March 14, 1928, the St. Francis Dam, responsible for transporting water to Los Angeles County, collapsed and was considered one of the greatest civil engineering disasters of the 20th century in the US.
Before the dam was built, Los Angeles County got its water from the Los Angeles River by diverting the river water through multiple ditches called zanjas. One of the Los Angeles City Water Company’s zanjeros (ditch tenders), William Mulholland, rose through the ranks of the company until he became superintendent in 1886.
The Los Angeles City Council established the Water Department in 1911, renaming it the Bureau of Water Works and Supply. Mulholland was its superintendent, and his position was also renamed to the Bureau’s chief engineer. He was recognized for the design and construction of the Los Angeles Aqueduct, bringing water from Owens Valley to Los Angeles.
While building the aqueduct, Mulholland considered sections of San Francisquito Canyon as potential dam sites. He wanted an ample-sized reservoir to provide water for Los Angeles in the case of a drought or if the aqueduct was damaged. The construction of the dam was completed on May 4, 1926, with a height of 185 ft above the canyon floor…