Visiting The Site Of L.A.'s Most Deadly Disaster: The Collapse Of The St. Francis Dam
Investigators mill around the base of the collapsed dam. "The Tombstone" stood until 1929. It was demolished after a teenage boy who climbed the ruin fell to his death. (Photo via Los Angeles Public Library Photo Collection)
Nothing greets you when you arrive at the site of Southern California's single most deadly disaster. There are no signs, no memorials, nor even any recognizable ruins that mark the location where, on March 12, 1928, the St. Francis Dam suddenly and catastrophically collapsed. The collapse sent a 10-story wall of water barreling down San Francisquito Canyon. Over the next six hours, the wave would wash over several towns and settlements in its path on its 54 mile journey to the Pacific Ocean. Though the exact number of deaths is unknown, estimates range from 450 to 600 casualties. Thousands lost their home.
Today, San Francisquito Canyon is a tranquil place. The narrow and twisty canyon road up to the dam site is sporadically used, barring the occasional ranching resident or intrepid cyclist. Located in the northern rim of the Santa Clarita Valley, about a 40 minute drive north of Los Angeles, the canyon is nondescript—not particularly different than any one of the hundreds of other foothill canyons all over Southern California. The only indicator that something is different about this particular canyon is a moderately large Art Deco building dressed in Los Angeles Department of Water and Power regalia. This building, Power Plant #2, is one of two electrical generating stations in the canyon, that derives hydroelectric power from the Los Angeles aqueduct pipes buried underground in the canyon.
The abandoned portion of San Francisquito Canyon Road, passing over where the dam once stood. (Matt Tinoco/LAist)
A five minute drive past Power Plant #2 is a gravelly turnoff from where you may park. Though you stand just a five minute walk away from where the dam once stood, there are no reminders that tell you so. The exact location of the old dam is quick walk down from the turnoff along an eerie disused two lane highway, abandoned back in 2005 after severe storm damage. Plants grow through the cracks of the crumbling highway, a reminder that without human upkeep, nature is quick to reclaim what it considers its own. A modest pile of concrete, half buried by soil and vegetation on the canyon's floor, is all that remains of the once nearly 200-foot tall dam. A unknowing passerby could easily mistake the weathered and eroded concrete for natural geologic feature of San Francisquito Canyon.
Before it broke, the dam was a instrumental component of the long and windy chain of infrastructure that moved drinkable water from the Owens River Valley, in Inyo County, to the mushrooming city, 233 miles to the south, known as Los Angeles. Built over the course of two years, between 1924 and 1926, the dam was planned and engineered by William Mulholland, the General Manager and Chief Engineer of the Los Angeles Bureau of Water Works and Supply.
Saying that Mulholland "walked on water" in 1920s Los Angeles would be an understatement. Perhaps more so than any single actor, Mulholland is responsible for enabling Los Angeles to grow from large boomtown into the enormous megalopolis it is today. Born in Ireland in 1855, Mulholland arrived in Los Angeles when the humble pueblo had a population of just 9,000 people. In 1878, he started work for the Los Angeles City Water Company as a deputy zanjero, or water distributor. His work at the beginning consisted largely of digging ditches and laying down iron pipe to transport water from the Los Angeles River, to other neighborhoods around the city, but Mulholland's ingenuity and wry brilliance for water engineering meant he quickly became one of the city's lead watermen.
By the end of the 1890s, Mulholland had overseen the modernization of Los Angeles' water infrastructure from an ad hoc collection of rickety pipes and wells, into a modernized system that pumped its water from the vast underground flow of the Los Angeles River—and metered its customers.
Of course, rapidly expanding Los Angeles was becoming thirstier and thirstier. In 1900, about 100,000 people lived in the city. Four years later, in 1904, that number had doubled to 200,000. Mulholland understood that if the city's incredible rate of growth was to be sustained, Los Angeles needed more water. Though the Los Angeles River could provide enough water for hundreds of thousands of resident Angelenos, the millions that Mulholland envisioned living in the future metropolis would would quickly parch the local rivers and aquifers.
San Francisquito Canyon is a quiet indistinct canyon on the northern edge of Santa Clarita. (Matt Tinoco/LAist)
In 1904, Mulholland made a formal proposal to build an aqueduct hundreds of miles long from the Owens River Valley to a spot just north of Los Angeles in the San Fernando Valley. It was totally possible, Mulholland assured, as the water would flow downhill the entire way. If built, Mulholland promised Los Angeles a virtually endless supply of drinkable water that would allow the city to grow and grow, seemingly without any boundary.
With his friend Fred Eaton sitting comfortably in the mayor's office, Mulholland received approval to begin a nationwide campaign to raise money for the aqueduct's construction. Though the bond campaign almost didn't make it, Mulholland managed to persuade investors to buy $1.5 million of municipal bonds. Construction began in 1908, with the approval of another $24.5 million bond paid for by Californian and Eastern investors, and finished ahead of schedule and under budget in 1913.
While the aqueduct's construction was a source of enormous controversy both locally and in Owens River Valley—see: the San Fernando Valley land grab and California Water Wars, both fictionalized in the film Chinatown—the aqueduct's completion ultimately ensured a reliable supply of water that the Angelenos could drink from for decades to come. Most of the water in the city of Los Angeles today still is sourced from the aqueduct that Mulholland designed and built.
While the aqueduct was under construction, Mulholland began investigating potential sites to build a large reservoir. Mulholland believed a large reservoir geographically close to Los Angeles would be necessary to maintain the city's water supply in the event of an extended drought in the Owens Valley, or an earthquake that rendered the aqueduct unable to move water from north to south. While the city maintained a store of water using smaller, more immediately local reservoirs after the aqueduct's opening, Mulholland saw the city's rapidly growing population as a sign that a large reservoir was still needed.
Mulholland's first choice was to build the reservoir in Big Tujunga Canyon. Unfortunately for him, a collage of private ranching interests owned much of the land Los Angeles would have needed to purchase. The landowners in what's now known as Sunland and Tujunga were willing to sell their land, but only for an artificially high price. Mulholland equated their price collusion to extortion. Instead of building dam in Big Tujunga Canyon, he chose instead to build one in San Francisquito Canyon. Unlike the privately held land in Big Tujunga, the land in San Francisquito Canyon was federally owned, and therefore easy to flood with a reservoir of water.
Initial surveys and studies to build the dam were completed in June of 1923, building on a knowledge base of the region's geology Mulholland had started back in 1911. While the canyon was noted to have some unique geologic features, notably the inactive San Francisquito fault line, Mulholland and his builders decided it was a suitable place to build a dam.
The completed dam in 1927. (Photo via Los Angeles Public Library Photo Collection)
The dam itself was the second concrete dam designed and built by Mulholland and his water department. The first is the Mulholland Dam in Hollywood Hills, responsible for Lake Hollywood, which supplied the basic design for St. Francis Dam. After a year or so of planning and engineering, the L.A. Bureau of Water Works and Supply began pouring concrete for dam in August of 1924. The dam was to be 185 feet tall, and would have a maximum capacity of 12.4 billion gallons, enough water to supply roughly 500,000 households for one year.
Construction proceeded uneventfully, and water began filling the dam in March of 1926. Though cracks in and leakage from the dam were reported as the water level began to rise, civil engineers—and Mulholland himself—inspected and signed off on the cracks and leaks as normal for a dam of the St. Francis' size and type. Even when the dam was filled almost to maximum capacity throughout 1927, the amount of water leaking from the dam was considered insignificant. Mulholland was even recorded saying at the coroner's inquest after the disaster, "of all the dams I have built and of all the dams I have ever seen, it was the driest dam of its size I ever saw."
Curiously, 1927 was the year the dam proved its apparent worth. Following a series of dynamite attacks on the aqueduct conducted purportedly by interests in the Owens River Valley, the dam's reservoir began acting as a replacement for the aqueduct flow. The summer of 1927 was ripe with conflict between Los Angeles and Owens Valley interests, prompting the withdrawal of about 2.5 billion gallons of water from the reservoir.
Tensions died down into winter, and the dam was refilled to within one foot of its spillway levels by February of 1928. Around this time though, dam inspectors begin to find more cracks and more leaks. Mulholland inspected the dam, ordered some patchwork fixes to be built, and signed off on the dam's structural sanctity. Water to continue to flow into the reservoir until it was within three-inches of the dams spillway. On March 7, Mulholland ordered no more water enter the reservoir.
Five days later, on March 12, 1928, dam keeper Tony Harnischfeger discovered a newer, larger leak with muddy and murky water. Worried that the new leak's dirty qualities could indicate the dam's foundation was eroding, Harnischfeger phoned immediately for Mulholland. Mulholland, as well as his number two engineer Harvey Van Norman, inspected the dam and determined that though the new leak should be remedied quickly, it did not pose a threat to the safety of the thousands living in the dam's hypothetical flood path should it fail.
A silent film ca. 1928 titled 'Destruction of a Dam', depicting the dam break via miniatures and also showing footage of the aftermath and rescue operations.
Nobody who survived the flood saw the dam break. A city electric employee, Ace Hopewell, rode his motorcycle past the dam about 10 minutes before it collapsed. After riding for a few minutes, Hopewell reported hearing an enormous roar. At the time, Hopewell figured he was heard a landslide. He didn't.
Two minutes before midnight on March 12, the dam failed catastrophically, sending a tsunami down into San Francisquito Canyon. Dam keeper Harnischfeger, along with his son and girlfriend, were likely the first causalities of the 10-story wall of water.
Onlookers watch the swollen Santa Clara River sweep debris towards the Pacific Ocean. (Photo via Los Angeles Public Library Photo Collection)
On its way to the ocean, a full 54 miles away from where the dam once stood, the wave devastated the towns of Castaic, Saugus, Bardsdale, Saticoy, Santa Paula, Piru and Fillmore. The flood also washed over an Edison Power Company worker's camp, taking with it 84 workers, and carved a mile-wide gash across the Oxnard Plain where countless migrant agricultural workers slept. By the time the water reached the Pacific Ocean at 5:30 a.m., the watery froth of earth, debris and victims was nearly 2 miles wide.
While the total number of dead is unknown, estimates place the number somewhere between 450 and 600 people. The dam's collapse was immediately recognized as a catastrophic failure of civil engineering, and more than a dozen independent investigations were launched in the days immediately after. Most of these declared bluntly that the dam's design was defective, and the collapse was the consequence building on a weak foundation, though geologists of the time found no fault in the San Francisquito Canyon rock. Later investigations, during the 1960s, revealed the dam was built on the site of an ancient landslide, undetectable to geologists with tools and equipment of the 1920s. Though the rock appeared stable, it was ultimately not strong enough to hold back 12.4 billion gallons of water.
The empty reservoir after the dam's collapse. (Photo via Los Angeles Public Library Photo Collection)
Mulholland took immediate responsibility for the disaster, saying, famously, how "Whether it is good or bad, don't blame anyone else, you just fasten it on me. If there is an error in human judgement, I was that human." Mulholland resigned his position of Chief Engineer in late 1929 as inquiries into the dam's collapse concluded. During his late years, his family reported that he was consistently haunted by the disaster, never regaining the spunk and vigor he had during his time as the chief waterman.
As for the dam, the only vague indicator of what once transpired in the sleepy canyon is a commemorative plaque at the rebuilt Powerhouse #2. Hidden behind a chain-link fence, the California Historic Landmark plaque compresses the history of the dam to a couple rusty paragraphs. A congressional bill to establish a St. Francis Dam National Memorial is working its way through the machinery of government. Though the U.S. House of representatives passed the bill back in July, the U.S. Senate is yet to.
The concrete ruins of the dam are nearly buried. (Matt Tinoco/LAist)