The Los Angeles Department of Water and Power (LADWP) is the largest municipal utility in the United States with 8,100 megawatts of electric generating capacity (2021–2022) and delivering an average of 435 million gallons of water per day to more than four million residents and local businesses in the City of Los Angeles and several adjacent cities and communities in southwestern Los Angeles County, California.

The St. Francis Dam, or the San Francisquito Dam, was a concrete gravity dam located in San Francisquito Canyon in northern Los Angeles County, California, United States, that was built between 1924 and 1926. The dam failed catastrophically in 1928, killing at least 431 people in the subsequent flood, in what is considered to have been one of the worst American civil engineering disasters of the 20th century and the third-greatest loss of life in California history.