St. Francis Dam
|St. Francis Dam|
View of the dam looking north, with water in its reservoir (c.1926)
|Location||Los Angeles County, California, United States|
|Dam and spillways|
|Height||208 feet (63 m)|
|Length||main dam 700 feet (210 m)
wing dike 588 feet (179 m)
|Crest width||16 feet (4.9 m)|
|Base width||159 feet (48 m)|
|Curve radius||500 feet (150 m)|
|Volume||main dam 130,446 cu yd (99,733 m3)
wing dike 3,826 cu yd (2,925 m3)
|Crest elevation||parapet 1838 feet (560.2m)
spillway 1835 feet (559.3m)
|Impounds||Los Angeles Aqueduct
San Francisquito Creek
|Type of spillway||uncontrolled overflow|
|Capacity||38,168 acre·ft (47,080,000 m3)|
|Catchment area||37.5 sq mi (97 km2)|
|Max. water depth||185 ft (56 m)|
|Reservoir length||3 mi (4.8 km)|
|Hydraulic head||185 ft (56 m)|
|Official name: St. Francis Dam Disaster Site|
The St. Francis Dam was a curved concrete gravity dam, built to create a large regulating and storage reservoir as part of the Los Angeles Aqueduct. It was located in San Francisquito Canyon, about 40 miles (64 km) northwest of Los Angeles, California, approximately 10 miles (16 km) north of Santa Clarita.
The dam was designed and built between 1924 and 1926 by the Los Angeles Department of Water and Power, then named the Bureau of Water Works and Supply. The department was under the supervision of its General Manager and Chief Engineer, William Mulholland.
At two and a half minutes before midnight on March 12, 1928 the dam failed catastrophically and the resulting flood killed up to 600 people. The collapse of the St. Francis Dam is considered to be one of the worst American civil engineering disasters of the 20th century and remains the second-greatest loss of life in California's history, after the 1906 San Francisco Earthquake and fire. The disaster marked the end of Mulholland's career.
Planning and design
In the early years of Los Angeles, the city's water supply was obtained from the Los Angeles River. This was accomplished by diverting water from the river through a series of ditches called zanjas. At that time a private water company, the Los Angeles City Water Company, leased the city's waterworks and provided water to the city. Hired in 1878 as a zanjero (ditch tender), Willam Mulholland proved to be a brilliant employee who after doing his day's work would study textbooks on mathematics, hydraulics and geology, and taught himself engineering and geology. Mulholland quickly moved up the ranks of the Water Company and was promoted to Superintendent in 1886.
In 1902, the City of Los Angeles ended its lease with the private water company and took control over the city's water supply. The city council established the Water Department with Mulholland as its Superintendent and when the city charter was amended in 1911, the Water Department was renamed the Bureau of Water Works and Supply. Mulholland continued as Superintendent and named as its Chief Engineer.
Mulholland achieved great recognition among members of the engineering community when he supervised the design and construction of the Los Angeles Aqueduct, which at the time was the longest aqueduct in the world and uses gravity alone to bring the water 233 miles (375 kilometres) from the Owens Valley to Los Angeles. The project was completed in 1913, on time and under budget, despite several setbacks. Excluding the incidents of sabotage by Owens Valley residents in the early years, the aqueduct has continued to operate well throughout its history and remains in operation today.
It was during the process of designing and building the Los Angeles Aqueduct, that Mulholland first considered sections of San Francisquito Canyon as a potential dam site. He felt that there should be a reservoir of sufficient size to provide water for Los Angeles for an extended period in the event of a drought or if the aqueduct was damaged by an earthquake. In particular he favored the area between where Powerhouses No. 1 and No. 2 were to be built, with what he perceived as favorable topography, a natural narrowing of the canyon downstream of a wide, upstream platform which would allow the creation of a large reservoir area with a minimum possible dam. 
A large camp had been set up to house the workers near this area and Mulholland used his spare time becoming familiar with the areas geologic features. He found the western side of the site consisted of a reddish colored conglomerate or sandstone formation having small strings of gypsum interspersed within it. Below the red conglomerate, down the remaining portion of the western hillside, crossing the canyon floor and up the eastern wall, a drastically different rock composition prevailed. These areas were made up of mica schist that was severely laminated, cross-faulted in many areas and interspersed with talc. Although later, many geologists disagreed on the exact location of the area of contact between the two formations, a majority opinion placed it at the inactive San Francisquito Fault line.
Mulholland ordered exploratory tunnels and shafts excavated into the red conglomerate hillside to determine its characteristics. He also had water percolation tests performed. The results convinced him that the hill would make a satisfactory abutment for a dam should the need ever arise.
The surprising part to come from this early geologic exploration was that later, when the need for a dam arose, apparently Mulholland either misjudged or ignored the perilous nature of the schist on the eastern side of the canyon. He was well aware of it, as he wrote distinctly of its characteristics in his annual report to the Board of Public Works in 1911.
The population of Los Angeles was increasing rapidly. In 1900 the population was slightly over 100,000. By 1910, it had become more than three times that amount at 320,000 and by 1920, the figure reached 576,673. This unexpectedly rapid growth brought a demand for a larger water supply. Between 1920 and 1926, seven smaller reservoirs were built and modifications were made to raise the height of its largest of the time, the Lower San Fernando, by seven feet, but the need for a still larger reservoir was clear. Originally, the planned site of this new large reservoir was to be in Big Tujunga Canyon, above the city now known as Sunland, in the northeast portion of the San Fernando Valley, but the high value placed on the ranches and private land which would be needed were, in Mulholland's view, an attempted hold-up of the city. He ceased the attempts at purchasing those lands and, either forgetful of or disregarding his earlier acknowledgement of geological problems at the site, renewed his interest in the area he had explored twelve years earlier, the federally owned and far less expensive land in San Francisquito Canyon.
Construction and modification
The St. Francis, sometimes referred to as the San Francisquito, would be only the second concrete dam to be designed and built by the Bureau of Water Works and Supply. The first was the near identical, in size and shape, Mulholland Dam, on which construction had begun one year earlier.
Construction began without the usual fanfare for a municipal project of this nature. The Los Angeles Aqueduct had become the target of frequent sabotage by angry farmers and landowners in the Owens Valley and the city was eager to avoid any repeat of these expensive and time-consuming repairs.
In June 1923, the preliminary studies and surveys for the St. Francis dam and reservoir were completed. They called for a dam built to the elevation of 1,825 ft (556 m) above sea level, which is 175 ft (53 m) above the stream bed. These early calculations for the reservoir created by the dam revealed it would have a capacity of 30,000 acre·ft (37,000,000 m3)
On July 1, 1924, the same day Mulholland was to report to the Board of Public Service Commissioners, Office Engineer W. W. Hurlbut informed him that all of the preliminary work on the dam was completed. In his annual report presented the Board, Mulholland gave the capacity of the reservoir as 32,000 acre-feet (39,000,000 m3). Hurlbut also presented the Board with his annual report, Report of the Office Engineer. In it he wrote that
...at the St. Francis Reservoir the dam site has been cleared and the foundation trench started. All concrete placing equipment has been contracted for and it is expected actual work of pouring the concrete will start in approximately ninety days. Additional topographic surveys have been completed and disclose a storage capacity of 32,000 acre feet at elevation 1825 feet above sea level.
In March 1925, prior to Mulholland's yearly report to the Board of Public Service Commissioners, Hurlbut again reported to Mulholland on the progress of the St. Francis dam and reservoir. He stated the reservoir would have a capacity of 38,000 acre-feet (47,000,000 m3) and that the dam's height would be 185 ft (56 m) above stream bed level. Hurlbut wrote, in an explanation of these changes that was presented to the Board of Public Service Commissioners, that "Additional surveys and changes in the plans for this reservoir have disclosed the fact that at crest elevation of 1835 feet above sea level the reservoir will have a capacity of 38,000 acre-feet."
The 10-foot (3.0 m) increase in the dam's height over the original plan of 1923 necessitated the construction of a 588-foot (179 m) long wing dike along the top of the ridge adjacent to the western abutment in order to contain the enlarged reservoir.
A distinctive aspect of the St. Francis Dam was its stepped downstream face. While the height of each step was a constant 5 feet (1.5 m) the width of each step was unique to its respective elevation above sea level. This width varied between 5.5 feet (1.7 m) near the streambed level at 1,645 feet (501 m) and decreased to 1.45 feet (0.44 m) at 1,815 feet (553 m), the base of the spillways and upright panels.
Prelude to disaster
Water began to fill the reservoir on March 1, 1926. It rose steadily and uneventfully, other than several temperature and contraction cracks that appeared in the dam and some minor seepage under the abutments. The most notable of those were two vertical cracks that ran down through the dam from the top. One was approximately fifty eight feet west of the outlet gates and another about the same distance to the east. Mulholland, along with his Assistant Chief Engineer and General Manager Harvey Van Norman, inspected the cracks and leaks and judged them to be within expectation for a concrete dam the size of the St. Francis.
At the beginning of April, the water level reached the area of the inactive San Francisquito Fault line in the western abutment. Some seepage began almost immediately as the water covered this area. Workers were ordered to seal off the leak, but they were not entirely successful and water continued to permeate through the face of the dam. A two-inch pipe was laid from the fault line down to the home of the dam keeper, Tony Harnischfeger, and the seepage it collected was used by him for domestic purposes. Water that collected in the drainage pipes under the dam to relieve the hydrostatic uplift pressure was carried off in this manner as well.
In April 1927 the reservoir level was brought to within ten feet of the spillway, and during most of May the water level was within three feet of overflowing. There were no large changes in the amount of the seepage that was collected and, month after month, the pipe flowed about one-third full. This is an insignificant amount for a dam the size of the St. Francis, and on this subject Mulholland said, "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." The seepage data recorded during the 1926–1927 period shows that the dam was an exceptionally dry structure.
On May 27 the problems in the Owens Valley escalated again with the dynamiting of a large section of the Los Angeles Aqueduct. A second incident a few days later destroyed another large section. The near-full reservoir behind the St. Francis dam was the only source of water from the north and withdrawals began immediately. The Daily Record of High Water Elevations of the St. Francis Dam shows that between May 27 and June 30, 7000 to 8000 acre-feet of water was used. Through June and July the Owens Valley fight continued, as did interruptions in the flow from the aqueduct. This in turn continued the withdrawals from the reservoir.
In early August, the Owens Valley conflict was at its height when suddenly the Inyo County Bank closed the doors of all their branches. An audit of the bank revealed the owners, Wilfred and Mark Watterson, who had not only been Inyo County’s financial leaders but also who had organized the valley residents into a unified opposition, were not only bankrupt themselves, there were large cash shortages from the vault and numerous inconsistencies found in the bank's accounting books. The two were indicted for embezzlement and later were tried and convicted on 36 counts. All of the local business had been transacted through their bank, and the closures had left merchants and customers with little more than what small amount of money they had on hand at the time. The attacks on the aqueduct ceased, and in the face of the collapse of both resistance and the Owens Valley economy, the city sponsored a series of repair and maintenance programs for aqueduct facilities that stimulated local employment.
Once again, the St. Francis reservoir level rose, although not without incident. Late in the year a fracture was noticed which began at the western abutment and ran diagonally upwards and toward the center section for a distance. As with others, Mulholland inspected it, judged it to be another contraction crack and ordered it sealed by filling it with oakum and grouting the surface to seal off any seepage. By coincidence, another fracture appeared in a corresponding position on the eastern portion of the dam. This fracture started at the crest, near the last spillway section and ran downward, at an angle, ending sixty-five feet below, where it reached the hillside. It too was sealed in the same manner. Both of these fractures were noted to be wider at their junction with the hillside abutments and narrowed as they angled toward the top of the dam. The reservoir continued to rise steadily until early February 1928, when the water level was brought to within one foot of the spillway. During this time though, several new cracks appeared in the wing dike and new areas of seepage began from under both abutments
Near the end of February, a notable leak began at the base of wing dike approximately 150 feet (46 m) west of the main dam. It was discharging about 0.60 cubic feet per second (4.5 U.S. gallons/17L) and was inspected by Mulholland who judged it to be another contraction or temperature crack and left it open to drain. During the first week of March, it was noticed that the leak had approximately doubled. Due in part to some erosion taking place, Mulholland ordered an eight inch (20.3 cm) concrete drain pipe to be installed. The pipe led the water along the dike wall, discharging it at the west abutment contact with the main dam.
Unfortunately, this gave the hillside a very saturated appearance and, with the water flowing down the steps of the dam where it abutted the hill, caused alarm among the canyon residents and others traveling on the road 700 feet (210 m) to the east, as at that distance it appeared the water was coming from the abutment. On March 7, 1928, the reservoir was three inches below the spillway crest and Mulholland ordered that no more water be turned into the St. Francis.
During the morning of March 12, while conducting his usual inspection of the dam, the dam keeper discovered a new leak in the west abutment. Concerned not only because other leaks had appeared in this same area in the past but more so that the muddy color of the runoff he observed could indicate the water was eroding the foundation of the dam, he immediately alerted Mulholland. After arriving, both Mulholland and Van Norman began inspecting the area of the leak. Van Norman found the source and by following the runoff determined that the muddy appearance of the water was not from the leak itself, but came from where the water contacted loose soil from a newly cut access road. The leak was discharging 2 to 3 cubic feet (15 to 22 U.S. gallons) per second of water by their approximation, and at times the volume being discharged was inconsistent, they later testified at the Coroner's Inquest.
Twice as they watched, an acceleration or surging of the flow was noticed by both men. Mulholland felt that some corrective measures were needed although this could be done at some time in the future. For the next two hours Mulholland, Van Norman and Harnischfeger inspected the dam and various leaks and seepages, finding nothing out of the ordinary or of concern for a large dam. With both Mulholland and Van Norman convinced that the new leak was not dangerous and that the dam was safe, they returned to Los Angeles.
Collapse and flood wave
Two and a half minutes before midnight on March 12, 1928, the St. Francis Dam catastrophically failed.
Although there were no eyewitnesses to the collapse, the time of 11:57:30 p.m. is the accepted time of the failure. This is due to the known facts that at this time, personnel of the Bureau of Water Works and Supply at both Receiving Stations in Los Angeles and at Powerhouse No. 1 noted a sharp drop in the voltage on their lines. At the same time a transformer at Southern California Edison's Saugus substation exploded. That transformer was connected to their Antelope Valley power line, which ran up the western hillside of the canyon near the dam to poles that were located about ninety feet above the east abutment. The prevailing theory of the investigators was that this line became severed as the eastern hillside and abutment gave way. The grounded lines caused a short, which in turn caused the transformer to explode.
It is known that at least five people passed the dam within an hour of the failure and none of them noticed any conditions that were out of the ordinary. A motorcyclist named Ace Hopewell, a carpenter at Powerhouse No. 1, had ridden past the dam by his estimate, ten minutes before midnight. In his testimony at the Coroner's Inquest, he stated that he had ridden up the canyon and had passed both Powerhouse No. 2 (a hydroelectric power plant) and the dam without seeing anything that caused him concern. He went on to state that at approximately one mile (1.6 km) upstream of the dam he heard, above the sound of his motorcycle, what to him was much like "rocks rolling down the mountain." He stopped and got off his motorcycle, leaving the engine idling, and smoked a cigarette while checking the hillside above him. He could still hear the sound that had caught his attention earlier though now fainter and behind him. Assuming it had possibly been a landslide as these were common to the area and satisfied that he was in no danger, continued on his way. It is believed that he was the last person to have seen the St. Francis Dam intact.
Within seconds after the collapse had begun little of the structure remained standing except for what had been the dam's center section, and 12.4 billion gallons (47 billion liters) of water began surging down San Francisquito Canyon  The dam keeper and his family were most likely among the first casualties caught in the flood wave, which was at about 140 feet (43 m) high when it hit their cottage, approximately ¼ mile (400 m) downstream from the dam. The body of Leona Johnson, the woman who lived with the Harnischfegers (often mistakenly reported later as Harnischfeger's wife) was found fully clothed and wedged between two blocks of concrete near the base of the dam. This led to the suggestion she and the dam keeper may have been inspecting the dam immediately before its failure. Neither Tony Harnischfeger's body nor that of his six-year-old son, Coder, were ever found.
Five minutes after the collapse, having traveled one and a half miles (2.4 km) at an average speed of 18 miles per hour (29 km/h), the now 120-foot-high (37 m) flood wave destroyed the heavy concrete Powerhouse No. 2 and took the lives of 64 of the 67 workmen and their families who lived nearby. The water traveled south down the canyon and began emptying into the Santa Clara riverbed. The amount of water was too great and caused it quickly to begin overflowing its banks, flooding parts of present-day Valencia and Newhall. The deluge, now 55 ft (17 m) high, was generally following the course of the river bed west. In doing so, it hit and demolished Southern California Edison Saugus substation, leaving the entire Santa Clara River Valley and part of the city of Ventura without power.
At this time, near 1:00 a.m., at least four miles of the state's main north-south highway (now Interstate 5) was under water and a short distance away, near what is presently the area around Six Flags Magic Mountain amusement park to State Route 126, the flood was washing away the town of Castaic Junction. At a speed of 12 mph (19 km/h) the water continued on and entered the valley. Approximately five miles downstream, near the Ventura and Los Angeles county line, on the flats of the river bank the Edison Company had set up a temporary construction camp for its 150 man crew. Due to miscommunication and confusion among the Edison personnel, no warning was sent and 84 of them died.
Santa Clara River Valley telephone operator Louise Gipe was at her station located in Santa Paula when shortly before 1:30 a.m. she a received a message from the chief operator of the Pacific Long Distance Telephone Company that the St. Francis Dam had broken and a tremendous wall of water was sweeping down the valley. She was given orders to notify the authorities and then warn those who lived in the low lying areas. She immediately called California Highway Patrol officer Thornton Edwards, who lived in Santa Paula, and then began calling the homes of those in danger. Edwards, within a short time joined by another officer, Stanley Baker, used their motorcycles to awaken and warn residents by leaving their sirens running and criss-crossing the streets in the danger zone. The two policemen continued this until the rising floodwater forced their retreat.
The flood devastated much of the towns of Fillmore, Santa Paula and Bardsdale before emptying its victims and debris into the Pacific Ocean near Ventura at Montalvo at 5:30 a.m.. The flood had taken only 5 hours and 27 minutes to travel the 54 miles (87 km) from the dam site to the sea. At that time it was almost two miles (3 km) wide and traveling at a speed of 6 mph (9.7 km/h). Bodies of victims were recovered from the Pacific Ocean, some as far south as the Mexican border, while others were never found.
Newspapers across the country carried accounts of the disaster. The front page of the Los Angeles Times ran four stories, including aerial photos of the obliterated dam, the city of Santa Paula after its wake and a partial list of the dead. It also set up a Times Flood Relief Fund to receive donations from around the country. The Times also reported that Mullholland issued a statement saying, "I would not venture at this time to express a positive opinion as to the cause of the St. Francis Dam disaster... Mr. Van Norman and I arrived at the scene of the break around 2:30am this morning. We saw at once that the dam was completely out and that the torrential flood of water from the reservoir had left an appalling record of death and destruction in the valley below." In the article, Mullholland stated that it appeared that there had been major movement in the hills forming the western buttress of the dam. He added that three eminent geologists, Robert T. Hill, C. F. Tolman and D. W. Murphy, had been hired by the Board of Water and Power Commissioners to determine if this was the cause. It was noted that there were no tremors reported at seismograph stations and an earthquake could be ruled out as the cause of the break.
Investigation of the failure
The collapse of the dam prompted the creation of over a dozen separate investigations into the cause of failure. With unprecedented speed, eight of these had begun by the weekend following the collapse. Almost all of these involved investigative panels of prominent engineers and geologists. The more notable of these groups and committees were those sponsored by California governor C. C. Young, headed by A. J. Wiley, the renowned dam engineer and consultant to the U.S. Bureau of Reclamation's Boulder (Hoover) Dam Board; the Los Angeles City Council, which was chaired by the Chief of the Reclamation Service, Elwood Mead; the Los Angeles County coroner, Frank Nance and Los Angeles County District Attorney Asa Keyes. Others were convened: the Water and Power Commissioners started their own inquiry, as did the Los Angeles County Board of Supervisors who hired J. B. Lippincott. The Santa Clara River Protective Association employed the geologist and Stanford University professor emeritus, Dr. Bailey Willis, and eminent San Francisco Civil Engineer and past president of the American Society of Civil Engineers Carl E. Grunsky. There were others, such as the railroad commission and several political entities who only sent investigators or representatives.
Although they were not unanimous on all points, most very quickly reached their respective conclusions. The governor's commission met on March 19 and submitted their 79-page report to the governor five days later. Although this was sufficient time to correctly answer what they had been asked to determine, they had been deprived of the sworn testimony at the Coroner's Inquest, which was the only inquiry that took into consideration factors other than geology and engineering.
The need for immediate answers was understandable, having its roots in the Swing–Johnson Bill. This action which would provide the funding for constructing the Hoover Dam was before Congress at the time. Supporters and responsible leaders alike realized the jeopardy in which it now stood. Although the water and electricity from the project were needed, the idea of the construction of such a massive dam of similar design, which would create a reservoir seven hundred times larger than the St. Francis, did not sit well with many in light of the recent disaster and the devastation, all of which were fresh in their minds.
The governor's commission was the first to release its findings, titled Report of the Commission appointed by Governor C. C. Young to investigate the causes leading to the failure of the St. Francis dam near Saugus, California, which became the most widely distributed report. As did most of the other investigators, they perceived the new leak as the key to understanding the collapse. Although, the commission believed that "the foundation under the entire dam left very much to be desired." In their report was written, "With such a formation, the ultimate failure of this dam was inevitable, unless water could have been kept from reaching the foundation. Inspection galleries, pressure grouting, drainage wells and deep cut-off walls are commonly used to prevent or remove percolation, but it is improbable that any or all of these devices would have been adequately effective, though they would have ameliorated the conditions and postponed the final failure." They placed the cause of the failure on the western hillside. "The west end," the commission stated, "was founded upon a reddish conglomerate which, even when dry, was of decidedly inferior strength and which, when wet, became so soft that most of it lost almost all rock characteristics." The softening of the "reddish conglomerate" undermined the west side. "The rush of water released by failure of the west end caused a heavy scour against the easterly canyon wall ... and caused the failure of that part of the structure." There then "quickly followed ... the collapse of large sections of the dam."
The committee appointed by the Los Angeles City Council, for the most part, concurred in blaming the collapse on "defective foundations" and wrote, "The manner of failure was that the first leak, however started, began under the concrete at that part of the dam which stood on the red conglomerate; this leak increased in volume as it scoured away the foundation material already greatly softened by infiltrated water from the reservoir which removed the support of the dam at this point and since no arch action could occur by reason of the yielding conglomerate abutment, made failure of the dam inevitable." Likewise, they concluded the failure most likely followed a pattern similar to that which was proposed by the governor's commission, although they did acknowledge that "the sequence of failure is uncertain."
The committee ended their report with, "...having examined all of the evidence which it has been able to obtain to date reports its conclusions as follows:
- The type and dimensions of the dam were amply sufficient if based on suitable foundation.
- The concrete of which the dam was built was of ample strength to resist the stresses to which it would normally be subjected.
- The failure cannot be laid to movement of the earth's crust.
- The dam failed as a result of defective foundations.
- This failure reflects in no way the stability of a well designed gravity dam properly founded on suitable bedrock."
The consensus of most of the investigators was that the initial break took place at or near the fault line, which had been a problem area since water first covered the area, on the western abutment.
The only theory to vary greatly from the others was that of Bailey Willis and Carl Grunsky. They believed that the portion of the east abutment below the dam was the first to give way, clearing the way for the collapse to take place.
The center section of the dam, later nicknamed "The Tombstone", remained standing. The rest of the dam broke into numerous smaller and several large pieces, most of which were washed downstream. The largest piece, weighing 10,000 tons, was found about three-quarters of a mile (1200 m) below the dam site.
A few months after the collapse, a young man fell to his death from the standing section after his friend had thrown a dead rattlesnake at him as a joke. In May 1929, the upright section was toppled with dynamite and the remaining blocks were demolished with bulldozers and jackhammers to discourage sightseers and souvenir hunters from exploring the ruins. The wing dike, which had also remained intact, was used by Los Angeles firemen to gain experience in using explosives on building structures. The St. Francis Dam was not rebuilt, though Bouquet Reservoir in nearby Bouquet Canyon was subsequently built in 1934, as a replacement.
To this day, the exact number of victims remains unknown. The official death toll in August 1928 was 385, but the remains of victims continued to be discovered every few years until the mid-1950s. Many victims were swept out to sea when the flood reached the Pacific Ocean and were never recovered while others were washed ashore, some as far south as the Mexican border. The remains of a victim were found deep underground near Newhall in 1992 and another believed a victim of the disaster was found in 1994. The current death toll is estimated to be more than 600 victims, excluding the itinerant farm workers camped in San Francisquito Canyon, whose exact number will never be known.
At the Coroner's Inquest, the leak that Tony Harnischfeger had spotted was cited as evidence that the dam was leaking on the day of the break and that both the Bureau of Water Works and Supply and Mulholland were aware of it. Mulholland told the jury he had been at the dam not only on the day of the break, due to the dam keeper's call, but also on the day before, on a routine inspection. He testified that he had observed nothing of concern on either day, nor any dangerous conditions. Mulholland further testified that leaks in dams, especially of the type and size of the St. Francis, were common. During the Inquest Mulholland said, "the only people I envy in this whole thing are the dead." As the inquest was nearing a close, he said, "Don't blame anyone else, you just fasten it on me. If there was an error in human judgment, I was the human, and I won't try to fasten it on anyone else."
At the Coroner's Inquest, the jury determined that a portion of responsibility for the disaster lay with the Bureau of Water Works and Supply and the department's General Manager and Chief Engineer, William Mulholland, for an "error in engineering judgment". They cleared Mulholland of any criminal charges since neither he nor anyone else at the time could have known of the instability of the rock formations on which the dam was built. The hearings also recommended that "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 from the Bureau of Water Works and Supply in March 1929. His assistant, Harvey Van Norman, succeeded him as chief engineer and general manager. Mulholland was retained as Chief Consulting Engineer, with an office, and received a salary of $500.00 a month. In later years, he retreated into a life of self-imposed semi-isolation. He died in 1935, at the age of 79.
Dam safety legislation
In response to the St. Francis Dam disaster, the California legislature created an updated dam safety program and eliminated the municipal exemption. Before this was added, a municipality having their own engineering department was completely exempt from regulation.
On August 14, 1929, the Department of Public Works, under the administrative oversight of the State Engineer, which was later assumed by the Division of Safety of Dams, was given authority to review all non-federal dams over 25 feet high or which would hold more than 50 acre-feet of water. The new legislation also allowed the State to employ consultants, as they deemed necessary.
Additionally, the State was given full authority to supervise the maintenance and operation of all non federal dams.
The failure of the dam is now believed to have begun when the eastern abutment of the dam gave way due to a landslide. The material on which the eastern abutment of the dam had been built was itself part of an ancient landslide, but this would have been impossible for almost any geologists of the 1920s to detect. Indeed, the site was inspected, at different times, by two of the leading geologists and civil engineers of the day, John C. Branner of Stanford University and Carl E. Grunsky, neither found fault with the San Francisquito rock.
J. David Rogers published a comprehensive scenario of possible geologic actions which could have led to the dam's failure. He attributed the failure to three major factors: the instability of the ancient landslide material on which the dam was built, the failure to compensate for the additional height added to the dam's design, and the design and construction being overseen by only one person.
A critique of Rogers's historical analysis of the dam's collapse was published in the journal California History in 2004 by historians Norris Hundley Jr. (Professor Emeritus, UCLA) and Donald C. Jackson (Professor, Lafayette College). While accepting most of his geological analysis of the failure, the article makes more clear the differences and deficiencies of the structure built in San Francisquito Canyon and how it fell short of the standards for large-scale concrete gravity dams as practiced by other prominent dam engineers in the 1920s.
Mulholland Dam reinforced
Shortly after the disaster, many living below Mulholland Dam, which creates the Hollywood Reservoir, petitioned the City of Los Angeles to reinforce it. The dam, almost identical in shape and design to the St. Francis Dam, was reinforced by piling tons of earth and rock on its face.
The only visible remains of the St. Francis Dam are weathered, broken chunks of gray concrete and the rusted remnants of the handrails that lined the top of the dam and the wing dike. The ruins and the scar from the ancient landslide can be seen from San Francisquito Canyon Road.
The road sustained heavy storm damage in 2005 and when rebuilt, it was routed away from both the remains of the dam and the damaged portion of the roadway.
A mass grave for victims of the disaster is at Ivy Lawn Memorial Park in nearby Ventura.
In popular culture
- Robert Towne made numerous references to Mulholland, the California Water Wars, the aqueduct, and the St. Francis Dam disaster in his screenplay for the 1974 Neo-noir movie Chinatown. Mulholland is split between the characters of Noah Cross and the city's chief engineer Hollis Mulwray.
- Rock musician Frank Black has made several references to the St. Francis Dam disaster in his songs, including the tracks "St. Francis Dam Disaster" and "Olé Mulholland".
- Baldwin Hills Reservoir
- Dam failure
- List of dams and reservoirs in California
- Malpasset Dam
- Teton Dam
- Vajont Dam
- "St. Francis Dam disaster". Office of Historical Preservation, California State Parks. Retrieved 2012-10-08.
- Rogers, David J. "Impacts of the 1928 St. Francis Dam Failure on Geology, Civil Engineering, and America"
- Transcript of Testimony and Verdict of the Coroner's Jury In the Inquest Over Victims of St. Francis Dam Disaster
- Pollack, Alan (March–April 2010). "President's Message". The Heritage Junction Dispatch (Santa Clara Valley Historical Society).
- Mulholland, Catherine, William Mulholland and the St. Francis Dam ; St. Francis Dam Disaster Revisited, Nunis Jr., Doyce B. (Ed.) Historical Society of Southern California. 1995. ISBN 0-914421-13-1
- Water and Power Associates Inc. "William Mulholland Biography"
- Water and Power Associates Inc. "DWP - Name Change Chronology"
- American Society of Civil Engineers "First Owens River - Los Angeles Aqueduct"
- "Los Angeles City Council Declares 2013: Year of the L.A. Aqueduct". LADWP. 18 January 2013. Retrieved 11 March 2013.
- Rogers, J. David A Man, A Dam and A Disaster" in Nunis, Doyce B. Jr. (ed.), The St. Francis Dam Disaster Revisited. Historical Society of Southern California, 1995. ISBN 0-914421-13-1
- Outland, Charles F. Man-Made Disaster: The Story of St Francis Dam. A.H. Clark Co. 1977 ISBN 0-87062-322-2
- Sixth Annual Report of the Bureau of the Los Angeles Aqueduct to the Board of Public Works, 1911
- "Historical Resident Population City & County of Los Angeles, 1850 to 2000". LA Almanac. Retrieved November 20, 2013.
- Kahrl, William L. Water and Power: The Conflict Over Los Angeles' Water Supply in the Owens Valley. Berkeley, California: University of California Press, 1982. p.312 ISBN 0-520-05068-1
- Official Action Taken by the Board of Public Service Commissioners and Board of Water and Power Commissioners of the City of Los Angeles, Relative to the St. Francis Reservoir
- Annual Reports of the Board of Public Service Commissioners 1924-1925
- 24th Annual Report of the Board of Public Service Commissioners, Report of the Office Engineer
- Nadeau, Remi A. The Water Seekers. New York: Doubleday, 1950. ISBN 0962710458
- Los Angeles Department of Water and Power "Whoever Brings the Water Brings the People"
- Rogers, J. David. Reassessment of the St. Francis Dam Failure Rogers/Pacific, 1992
- Pollack, Alan (March–April 2008). "St. Francis Dam Disaster: Victims and Heroes". The Heritage Junction Dispatch (Santa Clara Valley Historical Society).
- Chanson, H. (2009). Application of the Method of Characteristics to the Dam Break Wave Problem. Journal of Hydraulic Research, IAHR, Vol. 47, No. 1, pp. 41–49 doi:10.3826/jhr.2009.2865 (ISSN 0022-1686).
- Charles H. Lee collection, Water Resources Collections and Archives, University of California, Riverside
- "Report of the Commission appointed by Governor C. C. Young to investigate the causes leading to the failure of the St. Francis dam near Saugus California".
- Jackson, Donald C. and Hundley, Norris. "Privilege and Responsibility: William Mulholland and the St. Francis Dam Disaster." California History (Fall 2004) pp. 8–47
- Report of Committee appointed by the City Council of Los Angeles to investigate and report the cause of the failure of the St. Francis Dam
- SCV Historical Society "Construction of the St. Francis Dam"
- "Statutes and Regulations pertaining to Supervision of Dams and Reservoirs". State of Ccalifornia. Retrieved 10-04-2013.
- Rogers is Ph.D., P.E., R.G., Karl F. Hasselmann Missouri Chair in Geological Engineering, Department of Geological Sciences & Engineering and professor at Missouri University of Science and Technology
- "Earth Guards Dam from Quakes." Popular Science, April 1934
- "Roads Closed for Months, San Francisquito, Bouquet Routes Heavily Damaged" Daily News (Los Angeles, California) (January 20, 2005)
- Horton, Pony R. "A Test of Integrity: The Original Story Upon Which The Docu-Drama is Based".
- A popular article detailing the St. Francis Dam disaster. Based on Horton's 25 years of research into the story. Informational sources include Horton's interviews with Catherine Mulholland, Dr. J. David Rogers, and Robert V. Phillips, former Chief Engineer & General Manager, LADWP. A slightly lengthened version of the article was published in 2009 in The Raven and The Writing Desk; The 6th Antelope Valley Anthology by MousePrints Publishing, Lancaster, California. ISBN 0-9702112-7-9
|Wikimedia Commons has media related to St. Francis Dam.|
- "San Francisquito Canyon and the St. Francis Dam". Santa Clarita Valley Historical Society. Retrieved March 29, 2003.. Several photographs of the dam under construction, completed, its ruins, and a list of the victims.
- St. Francis Dam Disaster 30-minute television program available online.
- Remembering the St. Francis Dam Disaster, by Michele E. Buttelman, The Signal March 11, 2001.
- Google Earth image of the St. Francis Dam ruins
- "Application of the Method of Characteristics to the Dam Break Wave Problem", Journal of Hydraulic Research, 47 (1), pp. 41–49.
- St Francis Dam Flood, image gallery at USGS
- Partial list of victims