It began with a light drizzle in mid-January, 1969. By late February, more than 20 inches of rain from a series of intense storms had saturated soil from the Santa Ana Mountains to the flatlands of central Orange County. Without warning, a towering wall of mud slammed into the Silverado Canyon fire station, killing five of the more than 60 homeless people who had sought shelter there.
Mass evacuations followed as water spilled over the Villa Park Dam and chocolate-colored rivers of boulders, cruddy foam and debris raged over the banks of normally bone-dry Santiago, Trabuco and San Juan creeks, turning roads into rivers.
When the clouds finally parted in early March, the grim toll for the Deluge of 1969 stood at 11 dead and more than $12 million in damage to public and private property.
Despite the devastation, H. G. Osborne, then chief of the county flood-control district, was encouraged that Prado Dam--perched at the head of Santa Ana Canyon near the Orange-Riverside county border--had held against what was widely considered one of the worst storms ever.
Eight months later, Osborne learned that the Deluge of 1969 was mere child's play in the history of the Santa Ana River. The U. S. Army Corps of Engineers, using new methods to compute the intensity of previous floods in the area, found that the river had brought a torrential flood in 1862 that was six times greater and had altered the river's course.
Suddenly Prado Dam was considered grievously inadequate. Based on these findings, the Santa Ana River was soon viewed as the greatest flood threat in the western United States, capable, in a worst-case scenario, of breaching Prado Dam, killing an estimated 3,000 people and causing $11 billion in damage as it inundated densely populated areas from Anaheim to Newport Beach and west to the Los Angeles County line.
Today, after 15 years of study and planning, a proposed $1.1-billion All-River plan to correct Prado Dam's design deficiency has yet to be approved by Congress, amid quarrels over the plan itself and who would pay how much.
Osborne and other flood-control experts repeat what they have been saying for so long: The question is not if a flood of the magnitude of 1862 will recur, but when.
Experts say that is impossible to predict.
"We more or less hold our breath," said Carl Nelson, head of the public works division of the county's Environmental Management Agency.
The Army Corps of Engineers considers the 1862 flood as roughly equivalent to a "standard project flood"--defined as a calamity with an expected recurrence of once every 200 years on the river, or one chance in 200.
But Dennis Majors, the corps' manager for the All-River project, said it is possible that such a flood could occur more frequently on the river that begins 90 miles from the ocean in the San Bernardino National Forest.
Meanwhile, the existing Prado Dam and system of levees along the river's course provide less than 70-year flood protection to the more than 1 million people living and working below it, according to a 1976 report by the corps' Los Angeles district office.
"Hundreds of thousands of homes, businesses and factories, and hundreds of schools would be inundated by the standard project flood under (existing) conditions," the report said.
"With only eight hours warning time, complete evacuation before the peak flow would be impossible. Untold numbers of lives could be lost in the floodwaters. . . .
"In addition . . . there is the possibility that during the maximum probable flood, the dam itself might be overtopped and perhaps even fail. The loss of life and property damage could be several times as severe as the standard project flood."
The proposed All-River plan would increase the storage capacity of Prado Dam by raising its height 30 feet, building a smaller upstream dam, and improving the lower Santa Ana River channel and its tributary, Santiago Creek. Together, these would give urban Orange County and parts of Riverside and San Bernardino protection from a 170-year flood at a cost of $1.1 billion in 1985 dollars.
Many of the local objections that previously have stymied the project's approval appear to have been resolved with a new proposal to build a $304-million dam in a steep, narrow canyon in the San Bernardino Mountains about two miles north of Redlands.
The Upper Santa Ana River Dam would replace the proposed Mentone Dam in the East Highlands area of San Bernardino. Residents and local officials had rejected the Mentone Dam as unsightly and too close to major earthquake faults to be safe.
If Congress were to authorize the plan as part of a massive water projects bill and if President Reagan withheld his threatened veto and signed it by 1986, construction could begin in 1989, Majors said. It would take from seven to 20 years or more to complete.
The House of Representatives voted overwhelmingly Nov. 13 to authorize the All-River Plan as one of nearly 400 water projects across the nation totaling nearly $20 billion, despite threats of a presidential veto. The Santa Ana River flood-control plan represents the largest single chunk.
The plan was approved last year by the House. But the smaller Senate version of the water projects bill never got out of committee. This year, project watchers like Orange County's Washington lobbyist, James McConnell, say "chances are good" that the Senate will vote on its $11-billion package before its winter break.
Veto Is Threatened
The biggest hurdle, McConnell said, will be averting a presidential veto. The Administration has insisted that local governments share 35% of the cost of flood-control projects and that the water projects package be held to $9 billion. Local governments used to pay 5% of the total costs.
"I have a feeling this (House) bill is too big for the Administration to support," McConnell said. "If you can get the total down to the neighborhood of $10 billion . . . he might just sign it."
But first, the All-River Plan would have to be in the compromise version of the House and Senate bills. In an election year, when congressional representatives are eager to bring projects and revenue to their districts, that could be difficult.
Even if the plan passes federal hurdles, local problems remain. There has been squabbling among San Bernardino, Riverside and Orange counties over how much of the cost each should bear. Since a corps' study determined that Orange County received 95% of the benefit of the All-River Plan, some have argued that it should pay 95% of the local portion.
That poses a problem for Orange County. Nelson, of the county's public works division, said the county Board of Supervisors has set aside a portion of its flood-control-district assessments for its share of the All-River Plan. Though the cumulative capital fund will have grown to $39 million by next June 30, according to county officials, Orange County's share could exceed $250 million.
Nelson said supervisors are looking at creating assessment districts and charging fees based upon the projected dollar damage a property would sustain in a standard project flood. He said state Sen. John Seymour (R-Anaheim) has introduced legislation that would make it possible to issue bonds to finance the project.
Meanwhile, the curtain has risen on another rainy season in Southern California, while the giant sleeps.
"The Santa Ana River is one of Orange County's best friends and one of its worst enemies," Osborne said. "It's a great friend because of the water supplies it yields . . . but a great enemy because of the flood threat."
Untamed, the Santa Ana River has been as fickle as it has been destructive. Historically, its course has ranged across most of Orange County's broad, fertile plain, from Seal Beach to Newport Beach.
The river is thought to have carved out present-day Newport Bay about 300,000 years ago. County officials say that old Spanish land grant maps show the river sweeping west to Buena Park, then bending south and emptying into the ocean near what is now the Seal Beach Naval Weapons Station.
In 1825, a flood on the Santa Ana River created present-day Balboa Island, according to county historian Jim Sleeper. During the disastrous floods of 1862 and 1884, most of the northern half of the county was under water. Settlers of the period reported that it was possible to row boats from Newport Beach to Santa Ana.
System of Levees
Farmers banded together before the turn of the century to divert the unpredictable river into a permanent channel through a system of levees that would prevent flooding and guard against drought. Productive farms soon dotted the canal banks.
But the river would not be harnessed. In 1914, all of Newport Beach was flooded. In 1916, the entire county was flooded and most of the bridges were washed out. In 1920, a new channel opening was dredged to divert the river to sea on the border of Newport Beach and Huntington Beach.
It took what has been called "the storm of the century" in early March of 1938 to spur action. Devastating storms lashed Southern California, leaving 119 people dead, 2,000 homeless and 68,400 acres under water, and bringing President Roosevelt west to survey the wreckage, according to newspaper accounts of the time.
Construction began the following year on Prado Dam, which was designed at the time to control a flood 2 1/2 times the size of the 1938 inundation.
Dam Tested in 1969
Although there were localized floods that led voters in 1956 to approve a $42-million bond issue to upgrade sorely strained control channels throughout the county, none put Prado Dam to the test until the Deluge of 1969--or so Osborne and county flood-control officials thought at the time.
The storm pushed Prado to its limit. Marines were called to sandbag the upper reaches of the river and flood-control crews furiously pumped water from gravel pits west of the river to prevent its banks from collapsing.
In January, 1970, the corps disclosed that new hydrological information revealed that the 1862 flood flowed at an unheard-of volume of more than 300,000 cubic feet per second, three times greater than the maximum volume recorded for the 1938 so-called "flood of the century."
Prado Dam, which was not built to contain such storm runoff, joined the ranks of 60 other corps flood projects across the nation found to be seriously flawed.
Corps' Work Criticized
Many have criticized the corps for failing to design a sufficient dam. County officials in the past have argued that the corps was obligated to bear the full cost of improvements to Prado Dam and the river channel.
But the corps has argued that Prado was the state of the art in design and construction in 1939. "It's their position that they were working with the best information available at the time, that no one else could have done any better; and that is true," said Osborne, himself an engineer.
In a standard project flood, corps' officials project that the Santa Ana River would break its banks in many locations, inundating a 16-square-mile area of San Bernardino and Riverside and causing heavy damage to bridges. Water as much as three feet deep would cover 800 acres of homes and businesses in north Riverside and along historic Mission Boulevard.
Below Prado Dam, the picture is grim. A 160-square-mile area would be flooded, and water ranging from depths of one to five feet would saturate hundreds of thousands of homes and businesses. Utility lines could be broken, water supplies contaminated, roads and rail lines and even freeways cut off, isolating entire communities from vital services.
Originally, the solution was to improve the lower river channel and raise the height of Prado Dam by 45 feet. That plan was scrapped because of the furor raised in Riverside, where the larger reservoir would have claimed 6,000 more acres of productive dairylands and several hundred homes.
Some Flood Proofing
Now, the plan for raising Prado Dam to 136 feet would mean acquiring 1,461 acres of mostly dairy farms and about 125 homes. Majors said it may be possible to provide flood-proofing to some of those residents.
Osborne, who has watched the ebb and flood of the Santa Ana River since he came to Orange County in 1920 at the age of 5, said he thinks he will see the start of construction in his lifetime, "barring accidents, jealous husbands and so on."
Until the project gets started, Osborne said, people may as well continue to pay the flood insurance that is required of those living in the broad flood plain, and "just go about (their) business as usual, just as people do--disregarding the possibility of war, famine, pestilence, earthquakes, fire and floods."
PROTECTING AGAINST FLOODS
Congress is considering a $1.1 billion All-River plan to protect Orange County from an anticipated flooding disaster. The House has approved such a plan, but quarrels remain over some of the details and over who would pay how much. If it is passed, and if President Reagan withholds a threatened veto, construction could begin in 1989. It would take from seven to 20 years or more to complete.
UPPER SANTA ANA RIVER DAM A new dam costing $304 million will be built two miles north of Redlands in San Bernardino National Forest. It will be 550-feet high and 40 feet wide, with a maxium reservoir pool of 780,000 acres. Because it is near the San Andreas fault, it must be built to withstand a major earthquake. The new dam had been planned farther downstream in earlier proposals.
PRADO DAM AND RESERVOIR At a cost of $318 million, Prado Dam would be raised by 30 feet to 136 feet, to withstand a 170-year-flood. The dam was erected after a devastating 1938 flood. Because it was built, it is estimated that the dam prevented $525 million in damages from a 1969 flood. Raising the dam by 30 feet would increase its holding capacity of 195,000 acre-feet of water by 86% to 363,000 acre-feet.
FLOOD CHANNE IMPROVEMENTS Flood channels along the Santa Ana River and Santiago Creek would be upgraded. Included in the project are major improvements to the Talbert Channel, the failure of which led to widespread damage in the 1983 floods. Some channels will be lined with concrete, others graded and widened. Total project cost is approximately $451 million.