Southern California’s St. Francis Dam Collapse Is One Of The Worst Disasters In This State’s History
In terms of loss of lives, it is the worst disaster in Southern California history, and the second worst in the entire state, after the
1906 San Francisco earthquake. And yet, this epic tragedy seems to have been long-forgotten, with most people being completely unaware that it ever even happened.
Construction of the St. Francis Dam was completed in 1926. The need for a new reservoir in the area arose due to the rapidly increasing population in Los Angeles which resulted in a demand for more water.
The dam towered 185 feet above the stream bed and was said to hold some 12.5 billion gallons of water.
The St. Francis Dam created a much-needed reservoir in San Francisquito Canyon in the center of two other reservoirs, Castaic Lake and Bouquet Reservoir, which still exist. When the dam broke, the water gushed southward into the canyon and toward Ventura County.
As water filled the dam in 1926, several cracks and leaks developed due to temperature and contraction, but they were inspected and determined to be in an acceptable range.
Larger cracks and leaks followed and were dealt with in various manners, from filling and grouting to installing small drain pipes, to simply letting them drain, all at the direction of the Los Angeles Department of Water and Power’s general manager and chief engineer, William Mulholland.
On March 12, 1928, exactly two years to the date from when the dam began to fill, the dam keeper discovered a new leak that caused concern due to the muddy water that leaked from it. However, as before, after being observed by both the dam keeper and William Mulholland, it was decided that the leak was not dangerous. Both men left the site for the night.
On that same night, March 12, 1928, at 11:57 p.m., The St. Francis Dam failed.
While there were no eyewitnesses to the actual break, it was determined that the entire dam collapsed suddenly. This was clear from the fact that at least five people had seen the dam within an hour beforehand, one having driven past at about 11:50 p.m., combined with the fact that the reservoir was nearly empty within a little over an hour. Only a small piece of the dam was left standing, appearing like a tombstone memorializing the disaster.
As seen on the map above. A power plant, Power-house No. 2 was located downstream from the dam.
The explosive wave of water completely destroyed the power plant building, leaving just two turbines behind. The lives of 64 workmen and their families were lost in the area around the plant.
Over 12 billion gallons of water surged from the reservoir, carrying with it thousands of tons of concrete chunks. The flood continued down the Santa Clarita River Valley, destroying a temporary construction camp belonging to the Edison Company, then parts of Fillmore, Bardsdale, and Santa Paula.
Around 5:30 a.m., the wave - which had reached nearly two miles in width and was still moving at close to 6 miles per hour - reached the Pacific Ocean just south of Ventura. The wave dumped debris and bodies that it had collected and carried over the 54 miles from the dam into the sea. Many victim’s bodies were never recovered, being either buried under wreckage and silt or washed out to sea.
The reported death toll has fluctuated due to reports of missing persons that were never settled, as well as the fact that many victims were farm workers without traceable family. A report in 2018, after continual efforts to investigate and figure out who all the victims were, stated the number of deaths to be 411.
The amount of water that was released was so powerful that huge pieces of the dam, weighing as much as 10,000 tons, were washed away. This concrete block, measuring over 60 feet high, over 50 feet wide, and 30 feet tall, was found about one-half mile from the original dam structure.
The “tombstone” section of the dam that remained after the collapse is now in ruins. In this 2009 photo, you can still see some of the stair-like ridges of the dam face which have become mostly buried over the years.
Chunks of concrete rubble and shorn-off rebar are all that remain of this once-massive dam and are strewn through the area around and downstream from their original location.
Though the old dam can hardly be recognized now, it is still an interesting place to discover and the abandoned highway known as Old San Francisquito Canyon Road has become a sort of official hiking trail. It is also a sobering monument to those who know the story of the St. Francis Dam Disaster.
This catastrophe, seemingly faded from memory, is considered one of the worst 20th Century civil engineering disasters in the U.S. Had you ever heard of the St. Francis Dam collapse? If you would like to see the site and learn more about the fateful event, a
guided historical hiking tour is available.
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Address: Santa Clarita, CA, USA