Los Angeles flood of 1938

Los Angeles Flood of 1938

The Los Angeles River overflowing its banks near Griffith Park
Date	February–March 1938
Location	Los Angeles, Orange, Riverside, San Bernardino and Ventura counties, California
Deaths	113-115
Property damage	About US$40 million ($627 million in 2011 dollars) 5,601 buildings destroyed 1,500 buildings damaged several small towns completely destroyed Large portions of Riverside and Orange counties completely inundated

The Los Angeles flood of 1938 was responsible for inundating much of Los Angeles, Orange, and Riverside counties, California during February and March 1938. The flood was caused by a pair of Pacific storms that swept inland across the Los Angeles Basin, causing abnormally high rainfall across much of coastal Southern California. Between 113 to 115 people were killed in what ultimately became one of the most catastrophic natural disasters in Southern California history. The flood caused the Santa Ana, Los Angeles, and San Gabriel Rivers to burst their banks, washing away roads, bridges, and buildings, and stranding hundreds of people. Damage in some parts of Los Angeles County was mitigated by dams in the San Gabriel Mountains, while Orange and Riverside Counties experienced more damage because of the lack of flood-control works in the Santa Ana River system.

The flooding event of 1938 is considered a 50-year flood. It resulted in $40 million of damages, and the Red Cross deemed it the "fifth largest flood in history". In response to the floods, the U.S. Army Corps of Engineers began channelizing local streams and building more flood control dams. Dams built in the aftermath of the flood include Sepulveda Dam, Hansen Dam, Prado Dam, and Whittier Narrows Dam, which hydrologically connects the San Gabriel River to the Rio Hondo. These works have been instrumental in protecting coastal Southern California from subsequent flooding events, although the storms of 1969 and 2005, which had larger volume than the 1938 flood, still caused major damage and forced the evacuation of low-lying areas.