Work Begins in County on Taming a Dangerous River : Flood control: The Santa Ana River, though mostly a trickle, can rage out of its banks. Officials welcome work on a project designed to bring the waterway to heel.

After more than two decades of planning the nation’s largest flood-control project, a crowd of local officials gathered on the windy bank of the dry Santa Ana River Thursday to witness the beginning of the long-awaited construction in Orange County.

Against a backdrop of banging and clanging from the riverbed below, representatives of several local governments and the Army Corps of Engineers celebrated progress by making speeches and turning a few, symbolic shovelfuls of soil on the bluffs overlooking the waterway at Victoria Street.

Costa Mesa City Councilman Peter F. Buffa praised the $1.4-billion project as a “story of cooperation” between local, county, state and federal officials and the business community. He said the unusual coalition had waged an uphill battle to gather support because the river itself, a trickle of water on most days, is hardly a convincing argument for flood control. But a whopping storm could force a wave of water over Prado Dam and flood a 100-square-mile area of Orange County to a depth of 4 feet, Buffa said.

A quick review of the river’s impressive flood history bolstered the case for the river project. The Agua Mansa flood of 1862 destroyed much of the agricultural region along the river, sending water up to 4 miles on either side of its banks, Buffa said. A 1938 flood killed 19 people and inundated 70,000 acres. Back-to-back storms in 1969 destroyed 22,000 homes and caused billions of dollars in damage.

The Santa Ana River project has been 25 years in the making and is expected to take at least another decade to complete. The river, which stretches 100 miles from Huntington Beach northeast into the San Bernardino Mountains, has been identified by the Corps of Engineers as the greatest flood threat west of the Mississippi River--one that could affect 3.3 million people and cause $15 billion in damage in a massive storm.

“The effects (of a major flood) would be monumental,” said Brig. Gen. Roger F. Yankoupe, commander of the corps’ South Pacific Division.

The project will include substantial work in Orange County: widening and deepening the riverbed and relining it with concrete, extending two bridges that straddle its path and restoring 92 acres of marshland that host several dwindling species of birds.

The first work locally began a few weeks ago on a 3-mile stretch of the river from the ocean inland to Adams Avenue, which slices east-west through Huntington Beach and Costa Mesa. The remaining 20 miles of river in Orange County will be improved in the coming years.

The first phase of the plan, stripping canyon land to bedrock to build the 550-foot-high Seven Oaks Dam in the San Bernardino National Forest, began last year.

Federal subsidies will account for 66.1% of the cost of the entire package. Orange County is providing 31.4%--with the state paying part of Orange County’s share--and Riverside and San Bernardino counties picking up the remaining 2.5%.

Robert Bein, chairman of the Santa Ana River Flood Control Project Education Committee, said completion of the project hangs on continuing congressional appropriations of as much as $75 million annually. A $20-million appropriation in fiscal 1990 made initial work on the Seven Oaks Dam possible, and another $65-million subsidy in 1991 enabled the current construction in Orange County, Bein said.

“It reminds us that this is really the beginning, not the end of the project,” Bein said.

Santa Ana River Flood Control Project After years of debate, the Orange County portionof the $1.4 billion public works project has begun. Without it, more than 3 million people are at risk from a devastating flood. A. Lower Santa Ana River Construction began a few weeks ago on the lower three miles of the riverbed from the Pacific Ocean to Adams Avenue. The channel will be deepened and widened and relined with concrete and bridges spanning its width will be extended. Similar work will be done along the 20 remaining miles in Orange County in the coming years, pending continuing federal appropriations. B. Seven Oaks Dam Work began last year to strip the land in preparation for building a 550-foot-high, 3,000-foot-long dam in the Upper Santa Ana River Canyon, inside San Bernardino National Forest. C. Prado Dam Estimates of the dam’s capacity indicate that it could not contain a major flood. The dam will be raised 28.4 feet and about 2,000 acres will be added to accommodate the reservoir behind it. Orange County is trying to acquire the land to make improvements. Source: U.S. Army Corps. of Engineers and Orange County flood control district supervisors for the project.