A Brief Introduction
St. Francis Dam was built by the Bureau of Water Works and Supply of the City of Los Angeles in 1925-26 as a curved concrete gravity dam in San Francisquito Canyon, about 5 miles northeast of what is now Santa Clarita, California. The purpose of the dam was to provide an additional 38,000 acre-feet of storage for Los Angeles-Owens River Aqueduct water close to Los Angeles.

The dam failed catastrophically upon its first filing, near midnight on March 12, 1928, killing at least 450 people. It was the greatest American civil engineering failure in the Twentieth Century.

The St. Francis Dam was a massive concave-faced concrete structure 185 feet high that backed up an artificial lake 2.8 miles long. About 38,000 acre-feet of water was impounded behind the dam. The water weighed almost 52 million tons. The dam was built on a giant ancient landslide, which reactivated, with no evidence of seismic activity. The mass of land that moved weighed 877,500 tons, more than three times the weight of the dam itself, which weighed 250,000 tons.
The original reservoir capacity was to be 30,000 acre-feet of water. This was increased 39% by adding 10 feet and then later another 10 feet to the dam's height without increasing the dam's base width. This 11% increase in height necessitated the building of the wing dike. For a gravity dam that derives its stability from its weight this was a potentially dangerous action. The wall of water that scoured this canyon was 135 feet high and its speed was 18 miles per hour.


As The Story Goes

Minutes before midnight on the chilly evening of March 12, 1928, the St. Francis Dam failed. The dam's 185-foot high concrete wall crumpled and collapsed, sending billions of gallons of raging flood waters down San Francisquito Canyon, about five miles northwest of Magic Mountain in what is now Santa Clarita. As the flood picked up debris it became a giant thick snake of mud and water and houses and bodies crawling at about 12 miles per hour down the Santa Clara River valley and eating everything in its 54 mile path to the Pacific Ocean. 

Built by the Los Angeles Bureau of Water Works and Supply, the St. Francis Dam Disaster was the greatest American Civil Engineering failure of the 20th century when it collapsed on its first filling. As a result of the dam's failure 1,200 homes were damaged, 909 were totally destroyed, 10 bridges were washed out, power was knocked out over a wide area and the communities of Castaic, Piru, Fillmore, Bardsdale, Santa Paula and Saticoy were paralyzed. An exact death toll is impossible because the bodies of many victims were washed out to sea with the floodwaters, but more than 450 people perished that night. It is California's second largest disaster; only the San Francisco Earthquake and Fire of 1906 claimed more lives.


This Site Focuses On...

  In this site the focus is on the aftermath of the flood downstream and the impact on the lives of everyday people who lived and worked in the rural valley below the dam. Histories of the disaster have been written that cover the building, engineering, geology and politics of the St. Francis Dam. The intention here is to introduce photographs of the downstream aftermath and weave in the stories direct from the heroes and survivors. (see stories and photo pages).

As our guides, researcher of Santa Paula history Charles Outland - who wrote Man-Made Disaster (see bibliography page) and the technical expertise of J. David Rogers whom contributed to the Ventura County Museum of History and Art's The St. Francis Dam Disaster Revisited (see bibliography page).

DamDisaster.com is intended to be an introduction to the St. Francis Dam Disaster; however, there may never be a complete telling of this story. DamDisaster.com gathers the facts as we find them and those facts will be distributed downstream in random patterns just like the pieces of the collapsed dam.

Please bookmark this site and check it often as there are many more pictures and stories to be told. DamDisaster.com is a continually working site. Each page designed to guide you through the disaster with pictorial overviews and disaster stories. Along with information DamDisaster.com intends to provide you with not only intangible items of the disaster but also tangible items which you may purchase (see merchandise page). If you have been affected by the St. Francis Dam Disaster or someone you know has please encourage them to write to us (see contact page) and tell us their story. Each month DamDisaster.com will feature a new survivor or heroic story with a featured photo of the month. The story and photo you send may be featured.

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