Monday, April 2, 2012

Catastrophic Failure: Ventura County & The St. Francis Dam Collapse

The St. Francis Dam shortly after completion

At five minutes to midnight, on Thursday, March 12th, 1928, the towns of Santa Paula, Newhall, Piru and Fillmore in Ventura County, spread out along a river valley, were undoubtedly peaceful, sequestered from harm, residents asleep in their warm beds. Less than three minutes later, all hell would break loose and 600 people would be dead. The event was the single worst engineering disaster of the 20th Century in the United States, and the second worst disaster in California history. Though it has become a footnote in Ventura’s history, the St. Francis Dam Disaster is a tragedy of unparalleled proportions. Why the dam was built and why it failed is a complex story of greed, vision, money, and dreams of the future. Fundamentally however, it’s about an essential human resource - water.

The dry riverbed of the St. Francis today
Southern California is a semi-arid environment. Water, we assume, has always been plentiful. Everyday we observe people washing their cars, shopkeepers hosing down concrete sidewalks; we see lush lawns and gardens, and it streams effortlessly from our faucet as we brush our teeth. But water comes at a price, even the price of death. When Los Angeles began to grow exponentially, William Mullholland, the chief engineer of the Bureau of Water Works and Supply, the precursor to the Department of Water and Power (DWP), envisioned Los Angeles as a utopia for millions of people, who dwelt on the banks of the Pacific Ocean as carefree sojourners, however Los Angeles would soon run out of the one thing that made its existence possible - water. The Owens Valley was a rural farming community, 250 miles north of L.A. and it held massive amounts of water, fresh from the snow packs of the Sierra Nevada’s, which could provide the burgeoning metropolis with every drop it needed.
Los Angeles began to surreptitiously buy water and land rights in the Owens Valley. But getting the water to Southern California was a problem. In 1910 Mulholland built an aqueduct 230 miles long, using gravity flow over mountains and across deserts, which is still recognized as one of the great engineering achievements of the early 20th Century. As water levels in the Owens Valley decreased, anger increased. Mulholland’s aqueduct was repeatedly dynamited ten times. But Los Angeles continued to grow faster than anyone anticipated. When the Owens Valley ran dry, L.A secured water from Mono Lake, north of Owens Valley; then the Colorado River in Nevada; then the Feather River near Sacramento. That Los Angles was unable to secure a dam site in the Owens Valley, known as Long Valley, in order to build a vast reservoir, proved a terrible and costly oversight. Mulholland believed that a series of dams and reservoirs, closer to L.A., away from the politically unstable Owens Valley, would be the safe bet in case emergency water was needed. He decided on a narrow canyon, north of Santa Clarita, known as San Fransicquito Canyon.

The day after the collapse - notice the two persons in the lower right
Construction of the St. Francis Dam began in April, 1924. In July of that year, the original dam height of 184 feet was extended 10 vertical feet in order to expand its holding capacity. One year later another ten vertical feet was added. Raising the dam 20 feet allowed more storage capacity, but what was overlooked was widening its base to be commensurate with its new height. Known as “hydraulic uplift,” the base of the dam actually raised up slightly prior to its demise due to its inherent instability. It short, it became top-heavy. Additionally, the rock the dam was anchored to, known as schist, a flaky metamorphic rock, was not fully understood by the engineers at the time, nor did they know that the mountain the dam was adhered to was part of an ancient landslide and was also inherently unstable. Simply put, the technology did not exist to know unequivocally that the rock was solid.  It wasn’t. The dubious rock was becoming saturated with water. Ironically, on March 11th, the day before the failure, William Mullholland himself inspected the dam about 10:30 a.m. and pronounced it secure.

A colored rendition of the dam showing only the center section
At 11:57 p.m., the St. Francis Dam collapsed. The left side of the dam gave way first, unable to support the weight of nearly 13 billion gallons of water. What was once a life-giving force turned into death itself and merged with the Santa Clara River. The initial wall of water was 200 feet high. Of the 70 people that lived just below the dam, only three survived. By the time the water hit Castaic Junction, near present day Magic Mountain, it was 75 feet high and Santa Paula faced a torrent still 25 feet high with trees and broken houses acting like battering rams obliterating everything. The path of destruction was 54 miles long. In Newhall, a makeshift morgue was set up in the dance hall, which was still festooned with decorations from the dance held there the night before. “Bodies found by the river were so heavily encrusted with mud they had to be hosed off when they got to the mortuary to see if they were breathing,” recalled survivor Elizabeth Blanchard. Five and a half hours after the dam collapsed it lapped the Pacific Ocean near Ventura Harbor. If you drive highway 126 today, it’s possible to retrace the nearly exact route the water took through the Santa Clara River.

Mulholland (L) inspects the dam the day after the collapse
The “official” death toll was 450 people. Many historians believe that with the number of migrant Mexican farm workers living at Camulos, the death toll was closer to 600. “There were a lot of Hispanics living by the river and a lot got killed,” recalled survivor Eva Griffiths of Santa Paula. “The police tried to warn them, but they didn’t understand English. It was terrible,” she said. Poor immigrant workers don’t land on the front page of major newspapers, not in 1928 and certainly not today. But they died. By the hundreds.  Cattle too; livestock, cars, roads, power lines, bridges, rail track, farms, all washed to the ocean or covered in a blanket of mud, debris and wreckage nearly 30 feet thick. Bodies were recovered as far south as San Diego. Some bodies were found weeks later in the isolated canyons along the Santa Clara River. And some bodies have never been found.  Men, women and children were obliterated in the middle of the night, in their beds.  Some fought the torrent of water, only to drown or be crushed by the fast moving debris.  Perhaps mercifully so, some families died instantaneously, family pets being the only survivors; mute witnesses to the unthinkable. 

The numbers are staggering: 1,200 homes demolished, 24,000 acres of fertile land destroyed, almost 11,000 acres of crops laid waste, 140,000 trees uprooted or badly damaged. Nearly 3,000 volunteers searched for bodies. The reality is that the St. Francis Dam should never have been built where it was. Had Los Angeles secured the necessary property rights for the Long Valley reservoir, the St. Francis would not have been constructed. But politics and myopic thinking prevented a logical solution. The fact remains that the St. Francis Dam killed scores of people, bankrupt farmers in the Owens Valley, and brought riches to Los Angeles. If history means anything, L.A’s success was purchased on the backs of dead and dying people.

Just some of the hundreds of bodies recovered
After multiple inquires and reports, dam safety legislation changed. Prior to the St. Francis, there was little dam construction oversight. Two days after the St. Francis fell, the federal government required all dams to be inspected (similar to the widespread concern of bridges after the I-35 Mississippi River Bridge collapsed in Minnesota killing 13 people). California mandated professional registration for engineers, and the DWP established soil compaction tests and acquired a greater understanding of hydraulic uplift.

There were a multitude of design deficiencies of the St. Francis. It’s now understood that the dam was built into an ancient landslide, something Mulholland could not have known at the time, and in fact 254 dams worldwide have been identified as having been built against such unstable rock, though currently they are still standing. But probably the greatest single factor was the decision to heighten the dam a second time. The resulting hydrostatic pressure on the dam and its left abutment created an untenable situation. In fact, around 8 p.m., four hours before the failure, on a road that ran above the dam, one witness recalled seeing a 12-inch high mound of dirt across the roadway. The landslide had actually begun hours before the collapse.
Looking downstream today with the remnants of the dam in the foreground

Today the dam site is tangible history. There are discarded beer cans, soda bottles and spent shell casings lining the old flood path, a disturbing reminder that tragedy means nothing if it is forgotten, and that respect for the loss of life is little more than a trash heap. Parts of the dam are still visible, though malformed and eroding. What is eerily noticeable is the landslide, clearly cut from the mountain even over 80 years later. There are few remaining survivors to the tragedy but in 2007, writing an article for the Ventura County Reporter on this subject, I sat down with Catherine Mulholland, granddaughter of William Mulholland - who passed away in July, 2011. “By now we know that Homo sapiens have plundered the earth,” she told me. “We’ve dislodged, displaced and removed forests and oceans. We’ve flourished and also suffered. When you move water, things get destroyed in the process.”
Catherine Mulholland during my four hour interview with her - 2007

No comments:

Post a Comment