13 Dec

Map of the Week: Flood Path following St. Francis Dam collapse

By Thomas Jang

A significant part of urban history, and particularly Los Angeles history, the tragedy of the Saint Francis Dam disaster remains largely forgotten. It is a moment in history at the forefront of water rights in a time when the United States was at its height of industrialization and commerce. As a way to stockpile water, the story of the St. Francis Dam was one of workers’ rights, monumental alterations to the local environment, and a tragic loss of life. 

As the population of Los Angeles shot from 102,749 in 1900 to 1,238,048 by 1930, its demand for water also grew exponentially. Ultimately, an aqueduct system—the Los Angeles Aqueduct—was constructed from 1908 to 1913 to satisfy this thirst. At the time of its completion, the aqueduct was considered the largest engineering project, only slightly smaller compared to the Panama Canal. The dam stood near the Owens Valley at the San Francisquito Canyon and held back 12.5 billion gallons of water—or 3,861.10 acre-feet. 

The surveying process for the construction of the dam commenced in December 1922. Built with concrete, it became the second dam built in such material to be created by the Bureau of Water Works and Supply. The first concrete dam was the Mulholland Dam, located in the Hollywood Hills in Los Angeles. At the time of the construction of the St. Francis Dam, major outrage was directed towards the Los Angeles Aqueduct, which was frequently targeted by bombs planted by angry landowners and farmers from which the water was redirected from. The dam was made in the shape of a curve, which is now considered to be an arched-gravity design by current engineering standards. Disaster struck on March 12, 1928, two minutes before midnight. 

Read more here: St. Francis Dam Disaster | Fillmore Historical (fillmorehistoricalmuseum.org)