ABSTRACT
At 3 min before midnight, March 12, 1928, the St. Francis Dam—built to supply water to the growing city of Los Angeles—collapsed. During the early morning hours of March 13th, more than 38,000 acre-feet of water surged down from 1650 ft above sea level. The St. Francis was a curved gravity concrete dam, designed to be 62 m high. During construction, the height was increased by 7 m to allow more water to be stored in the reservoir. Investigations into the St. Francis Dam disaster have revealed that the ground on which it was built was indeed unstable. Even so, its design has been shown to be inadequate, and out of step with the contemporary understanding of concrete gravity dam requirements. In response to the disaster, the California legislature updated its dam safety program and eliminated the exemption of municipal engineering departments from regulations.
