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Remembering the St. Francis Dam - 80 years later

Disaster viewed as worst civil engineering failure of 20th century.

Posted: March 7, 2008 12:59 a.m.
Updated: May 8, 2008 5:02 a.m.
BEFORE: The St. Francis Dam is shown shortly after it was constructed across San Francisquito Canyon in 1926. BEFORE: The St. Francis Dam is shown shortly after it was constructed across San Francisquito Canyon in 1926.
BEFORE: The St. Francis Dam is shown shortly after it was constructed across San Francisquito Canyon in 1926.
AFTER: On March 12, 1928, the St. Francis Dam broke, killing at least 450 people. The center portion of the dam remained standing, as shown in this photo, taken a day after the disaster. AFTER: On March 12, 1928, the St. Francis Dam broke, killing at least 450 people. The center portion of the dam remained standing, as shown in this photo, taken a day after the disaster.
AFTER: On March 12, 1928, the St. Francis Dam broke, killing at least 450 people. The center portion of the dam remained standing, as shown in this photo, taken a day after the disaster.
Nestled in the peaceful, rolling hills of San Francisquito Canyon is a power plant owned by the Department of Water and Power. There is little evidence of a day that once was anything but peaceful, as a historic disaster roughly one mile away from the power plant claimed approximately 450 lives in 1928.

On Wednesday, the Santa Clarita Valley will remember those who fell victim to what is considered the greatest civil engineering disaster in the 20th century. On March 12, 1928, the St. Francis Dam in the San Francisquito Canyon collapsed.

The concrete gravity-arch dam was built under the supervision of William Mulholland. The dam's collapse, failure and subsequent flood killed approximately 450 people as waters rushed from the dam, through the Santa Clarita Valley and into Ventura County before connecting with the Pacific Ocean 54 miles away. The loss of life was the second worst in California history; the 1906 San Francisco earthquake and fire claimed more lives.

For Mulholland, who at the time was the chief engineer and general manager of the Bureau of Water Works and Supply (now the Department of Water & Power), the dam's collapse ended his storied architectural career.

Mulholland built the dam as part of the Los Angeles Aqueduct, which he designed and built in 1913. At the time, the 233-mile waterway was the longest aqueduct in the world, bringing water from the Owens Valley in Central California to the city of Los Angeles.

Mulholland chose the dam site at San Francisquito Canyon in 1911. The St. Francis Dam, the anglicized version of the canyon it was built in, was constructed in 1926 by William Mulholland as a reservoir for the Los Angeles Aqueduct. The Los Angeles Aqueduct ran alongside the canyon with two generating stations nearby. It was an ideal location for Mulholland to build the dam, as he believed it provided enough water for Los Angeles in the event of a drought, earthquake or other damage to the aqueduct.

Building the dam
In March 1923, a site study was completed and approved. Approximately one year later, work began on the dam, with the first portion of concrete set in August 1924. Two years into the construction, in March 1926, water was diverted into the reservoir from the Los Angeles Aqueduct.

The reservoir's capacity was set at 38,168 acre-feet. Construction was complete shortly thereafter, as water continued to fill the reservoir.

There were several modifications along the way.

In 1924, the dam's height was increased by 10 feet, and the capacity was adjusted from 30,000 acre-feet to 32,000 acre-feet. In 1925, with the damn roughly half constructed, Mulholland added an additional 10 feet to the dam's height and increased the capacity to 38,168 acre-feet.

It was not until March 7, 1928 - five days before the collapse - that warning signs began to surface.

On March 7, 1928, water in the dam reached its maximum height at 1,834.75 feet - approximately three feet below the spillway. It was the first time that the reservoir was filled to capacity.

The damkeeper spotted the leaks and apparently reported them to Mulholland, who allegedly dismissed them as normal.

Over the next few days, there were reports by passers-by that the roadbed adjacent to the dam began to sag. On March 12, 1928, the same damkeeper who noticed leaks five days earlier contacted Mulholland again as he apparently saw more leaks.

Mulholland visited the St. Francis Dam with his assistant, Harvey van Norman. After they both inspected the dam site, Mulholland remained convinced that the leaks were normal for a concrete dam and determined there was no reason for alarm. The inspection occurred at noon on March 12.

Less than 12 hours later, at 11:57 p.m., the dam collapsed and a floodwave stormed through the Santa Clarita Valley, into Ventura County and into the Pacific Ocean. Twelve billion gallons of water emptied from the reservoir into the SCV.

Sixty square miles
In a report compiled on March 24, 1928, by George Newhall Jr., the then-president of Newhall Land & Farming Company, the amount of water at the St. Francis Dam was put into perspective. Newhall described the amount of water in his report: "In other words, sufficient to cover 38,000 acres or approximately 60 square miles with water one foot deep. To picture this amount of water, think of a river or body of water 10 feet deep, 1 mile wide and 6 miles long; or 20 feet deep, 1Ž2 mile wide and 6 miles long.

"Apparently this tremendous volume was almost instantaneously released into a canyon which for the first 3 or 4 miles was probably 200 to 300 feet wide and by the time it has reached our property line had only widened out to about 2500 feet."

Later in his report, Newhall estimated that the amount of property damage due to the St. Francis Dam's collapse would exceed $25,000,000.

With 12 billion gallons of water, several communities were hit hard by the disaster. As the waters filled the Santa Clara River, towns such as Castaic Junction, Fillmore, Bardsdale and Santa Paula were hit within hours after the dam's collapse. The floodwave ultimately reached the Pacific Ocean in Montalvo, a small town in Ventura County 54 miles away from the St. Francis Dam.

'The Tombstone'
It took over five and a half hours for the waters to reach the Pacific Ocean. As the wave approached Montalvo, flood waters hit speeds of five miles per hour. Bodies were recovered in the Pacific Ocean - as far south as the Mexican border.

In the wake of the dam's collapse, the center section of it remained standing and was nicknamed "The Tombstone." Two months later, the section of dam was demolished by dynamite, with the remaining pieces destroyed by bulldozer and jackhammer in order to prevent harm and to discourage souvenir hunters.

Other portions of the dam - which were found as far as a half mile away from the dam site -were also destroyed.

The dam was never rebuilt, though there were two replacement dams built - Bouquet Reservoir (built in 1934) and Castaic Dam (built in 1973).

It was determined by the Los Angeles Coroner that a paleomegalandslide caused the collapse of the St. Francis Dam. The rock formations were determined to be too unstable for a dam site, according to Stanford University geologists.

The Coroner conducted an inquest, where it determined that it would have been impossible for geologists of the 1920s, with the available technology, to detect the instability of the rock formations.

For Gladys Laney, 97, it was difficult to fathom that a flood struck the SCV. A Newhall resident who attended UCLA at the time of the disaster, the 17-year-old Laney was asleep at the time the dam burst. Moments later, she heard yells of the local newsboys (similar to a town crier), who claimed that the was a flood in Saugus.

"I thought, how can that be so," Laney said.

"There was no water in Saugus." After hearing the newsboy, she went back to sleep, only to wake up the next day to find muddy streets and a town crowded with crew workers, sheriff's deputies and plenty of "looky-loos."

"It was such a strange scene for a small town," she said. "The streets were muddy, the poor workers were muddy, it was very strange."

'Just fasten it to me'
Immediately after the disaster, Mulholland was reported to take full responsibility. He admitted to inspecting the dam the day of the collapse, saying he noticed nothing out of the ordinary and there was no need for alarm. Mulholland added that, in his opinion, the leaks he observed were normal for dams the size of St. Francis.

"Don't blame anyone else, you just fasten it on me," Mulholland told reporters. "If there was an error in human judgment, I was the human, and I won't try to fasten it on anyone else. I envied those who were killed."

While responsibility of the accident was placed upon Mulholland and the government entities that over saw the construction, Mulholland himself was cleared of all charges, as they claimed that there was no way he could have been aware of the rock formation's instability.

The Coroner's inquest also recommended that Mulholland should bear no blame for the incident, saying "the construction and operation of a great dam should never be left to the sole judgment of one man, no matter how eminent."

Mulholland retired shortly after the inquest, and went into self-imposed isolation before dying at the age of 79 in 1935.

Eighty years later
Wednesday will mark the 80-year anniversary of the St. Francis Dam collapse. A pleasant drive up San Francisquito Canyon Road shows little to no evidence of the historic dam break and flood, save for a commemorative rock and sign about one mile south of the dam, which marks the area surrounding the dam as a historical landmark. The exact death toll was never determined, with the official report at 450 deaths.

But there were unofficial reports of the death toll reaching almost 600.

Though a disastrous event, Laney pointed out that the Santa Clarita Valley recovered rather quickly.


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