The St. Francis Dam Disaster

The St. Francis Dam disaster of 1928 was the failure of a large concrete gravity dam due to unmitigated geologic hazards, causing over 55 miles of violent flooding, and over 400 deaths. It is said to be California’s worst engineering catastrophe to date. Updated April 11, 2024.

Unmitigated geologic hazards (unknown at the time) are what caused the St. Francis Dam to collapse.
Geologic hazards are the root cause of the St. Francis Dam collapsing. Photos Credits: United States Geological Service (USGS); Santa Clarita Valley Public Television (SCVTV), Google Earth. Preparation by: Geo Forward.

Saint Francis Dam Facts

What was the St. Francis Dam Disaster?

The St. Francis Dam was a Los Angeles Water and Power (LADWP) project from 1924 to 1928. The dam officially opened in May of 1926 and stored roughly 3,800 acre-feet of drinking water. The purpose of the dam was to provide a secondary drinking water reserve for the growing City of Los Angeles. In fact, it was an accessory to the Los Angeles Aqueduct project, which pipes water from Owens Valley.

A Violent Flood Due to the Saint Francis Dam Failure

In the near midnight hours of March 12, 1928, the Saint Francis Dam collapsed. The dam’s failure caused a violent flood that destroyed acres of land and farms over 55 miles downstream. The floodwater terminus was the Pacific Ocean at Ventura Beach, California. Over 400 lives were lost due to the flooding. And thousands of acres of land, houses, bridges, roads, farms, and orchards were impacted. The image below shows the general flood path, from the site of the dam and into to the ocean.

Map of St. Francis Dam Disaster Flood Path by Geo Forward 2021
Map of St. Francis Dam disaster flood path. Preparation by: Geo Forward.

Worst Disaster in California History

Historians believe the Saint Francis Dam disaster is the worst engineering catastrophe in the history of California. Casualties were swept from their homes during the midnight hours and discharged miles downstream. In fact, bodies and debris deposited into the ocean were later found as far as Santa Catalina Island. 

Archived Footage of the St. Francis Dam

There is no actual footage of the St. Francis Dam failing because motion picture technology was very new at the time. It was a sudden and unexpected collapse, during the darkness of the midnight hours. Consequently, it left local videographers no opportunity to set up equipment to capture footage. However, there is footage covering the dam before failure, as well as after it.

Movies That Used Actual Footage of the Saint Francis Dam Construction

The following video is a clip from the 1926 film “The Temptress.” This clip contains actual footage of the St. Francis Dam being built, sometime between 1924 and 1926. This motion picture was released in 1926, before the San Francisquito Dam disaster.

All production credits for this clip belong to Metro-Goldwyn-Mayer (MGM) & Cosmopolitan Productions. The organization of the footage is courtesy of Santa Clarita Valley Public Television Programing (SCVTV).

Video Coverage of Santa Paula and Fillmore After the Saint Francis Dam Collapse

Hundreds of human and animal lives were lost from this catastrophe. Additionally, the flood leveled acres of land, as far as 55 miles downstream. The cities of Santa Paula and Fillmore are roughly 25 to 40 miles downstream from the St. Francis Dam disaster site. The following video is a compilation of footage of these areas after the flood. Geo Forward estimates these shots are from March 13 to 15 of 1928. This video captures damage to homes, farms, and orchards. It also covers roads and brides with severe damage.

Credits are not available pertaining to the producers of the footage above. Geo Forward presumes the footage was captured for newsreel purposes. Alternatively, there is a presumption the video has an affiliation with the American Red Cross for record-keeping purposes. Regardless, this video is currently available to the public via the Santa Clarita Valley Public Television Program (SCVTV).

Footage of Dynamiting the St. Francis Dam Remains

The next video captures the leftover center block of the Saint Francis Dam disaster, as well as the remaining western wing dike. The clip also shows workers dynamiting the remains into the rubble that exists today. Additionally, large fragments of the dam that were deposited downstream after the flood were also dynamited. These demolition events took place around April 17, 1929. And this is about one year after the St. Francis Dam disaster took place.

The reel starts by showing Water and Power employees carving cavities at the base of the leftover center block. These caves would be filled later with dynamite for demolition. Unfortunately, the actual explosion and take-down of the center block are not in this film. However, it does show workers coring the wing dike to insert dynamite sticks, as well as the dynamite explosions.