Big Santa Ana River Project Whets Appetite of Water Users : Resources: Army Corps of Engineers’ new flood control effort raises old questions.

If you ask the Army Corps of Engineers why the federal government and three Southern California counties are spending nearly $1.5 billion to build a new dam and enlarge an old one on the Santa Ana River, you’ll get a two-word answer: Flood control.

But others who eye the extensive work underway on dams, spillways and flood channels in Orange, San Bernardino and Riverside counties see something else: water--water to drink, water to replenish parched wells, water to fuel growth and development.

As the massive Santa Ana River flood control project moves into high gear, the perennial California questions are being asked: How much of the water to be trapped behind the new dams will be used to quench Orange County’s thirst for new homes and businesses? How much will be dumped into the sea? Who will get the water? How much will they pay?

The potential for capturing more water is significant. For example, raising the height of the Prado Dam by 29 feet, as contemplated, would increase the reservoir’s maximum capacity by 150,000 acre-feet--or nearly 50 billion gallons, although the water would reach that level only in the event of a major flood.

The answers to the water questions are to be worked out over the next few years by the Corps of Engineers, which is constructing the new dams and flood channels, the three county governments helping to pay for the project, and the Orange County Water District and other local agencies seeking new sources of water to replenish their wells.

But water won’t be the only subject under discussion.

Central to any plan to capture more water for the Orange County Water District’s vast underground reserves is an assessment of the health of a little bird, the least Bell’s vireo, that makes its home in the chaparral behind Prado Dam in Riverside County.

The negotiations could prove tortuous.

For example, a senior Army official suggested last week that rethinking the essential purpose of the Santa Ana River flood control project to provide more drinking, bathing and washing water to Orange and neighboring counties could lead to rethinking the way the enormous bill for the project should be carved up.

“The justification for building the new dam(s) is flood control,” said G. Edward Dickey, acting principal deputy assistant secretary of the Army for civil works.

“There was always some notion that (if) some of the costs of these new projects could be associated with water conservation . . . you would look to the people who get those benefits to make some contributions to the capital costs.”

That’s news to officials of the Orange County Water District, the agency that owns the rights to Santa Ana River water south of the Prado Dam, but is not now sharing the cost of the flood control project. Although Orange County will contribute substantially to the project’s cost, it is county government--not the water agency--that is footing the bill.

The water agency is in the last stages of negotiating a new deal with the Corps for the existing dam, and is interested in a working on another to cover the enlarged facility, scheduled for completion early in the next century.

But James Van Haun, a spokesman for the water agency, said no one has mentioned the possibility that the agency might get hit with a bill for part of the flood control work, just because the district wants more water for its underground reserves.

Meanwhile, there is still the question of whether the Army will again try to enforce a water-pricing policy that sparked a firestorm of controversy three years ago. At the time, the Corps told the Orange County Water District that it would store more water behind the existing Prado Dam and then slowly release it to the district’s recharging ponds if the district would pay all the associated costs--plus an additional fee roughly equal to half of the water’s market value.

After a full-court press by Orange County congressmen, the Army backed down. But several officials suggested that the issue could be raised again in the event that a new conservation deal is struck.

The Santa Ana River flood control program is the most costly water project underway in California, and one of the most expensive ongoing projects in the nation.

The Corps has identified the Santa Ana River as the greatest flood threat west of the Mississippi, and has estimated that a catastrophic flood could cost 3,000 lives and $18 billion in property damage.

To prevent that death and destruction, Congress authorized construction of the Santa Ana River flood control project, which has three major components--the new Seven Oaks Dam in San Bernardino County, an enlarged Prado Dam in Riverside County, and major channel improvements along the 31-mile stretch of the river from the Prado Dam through Orange County to the Pacific.

The bill for the entire project, to be finished in the early years of the 21st Century, is $1.45 billion. The federal government has agreed to spend roughly $975 million, while the remaining costs are to be divided among Orange, San Bernardino and Riverside counties.

Orange County, which stands to benefit the most in terms of flood protection, would pay 90% of the local government share, or about $427 million. Riverside County would pay $28 million and San Bernardino County $18 million.

But Dickey, the Army official, suggested that those costs could be lowered, if the Corps decided to charge the water district for a share of the construction costs.

“If . . . certain costs were to be allocated . . . water storage or water conservation, there could be some adjustments in the shares being paid by the flood control sponsors,” Dickey said.

Formed in 1933, the Orange County Water District in 1969 won exclusive rights to Santa Ana River water south of the Prado Dam. The lawsuit that finally settled the issue was in litigation for 36 years.

That means that any extra water stored for conservation purposes behind the Prado Dam would be sold to the district, said spokesman Van Haun. Water from the new Seven Oaks Dam upstream would go to other water districts in other counties, officials said.

The Orange County Water District is the only district in the county that does not sell water directly to household customers. Rather, it maintains a vast subterranean reserve in naturally occurring strata of sand and gravel. This underground “reservoir” can hold up to 10 million acre-feet of water--about 3.2 trillion gallons.

Forty or so other water districts throughout the county draw about 70% of their water from the subterranean reserve through a network of 500 wells, paying the countywide district $60 an acre-foot for the water they take.

The reserve is replenished both by rainfall and by the water district, which maintains recharging ponds along the length of the Santa Ana River. The district fills the ponds largely with water bought from the Metropolitan Water District, the massive Southern California water concern. But it also uses water released from the Prado Dam.

To be of use to the district, the dam water must be released slowly, so it can be diverted into the ponds before it rushes down the river channel to the sea. In addition, the Corps must keep more water in the dam for longer periods than it normally would for flood control purposes.

Under a 20-year water agreement about to be signed, the Corps has agreed to maintain the water level behind the Prado Dam at 505 feet above sea level, up from the 490-foot level at which water has been kept. The Corps would not allow the water level to rise until mid-March, after the end of the winter storms that might spawn serious floods.

In return, the water district has agreed to pay the additional costs associated with water conservation, and to make available 278 acres of new land to replace the bird and wildlife habitats that will be lost as the water level rises.

Most of that acreage will be devoted to nesting grounds for the least Bell’s vireo, an endangered bird whose potential loss raised serious concerns among environmentalists and the U.S. Fish and Wildlife Service.

At present, the Corps has agreed to make available 176,000 acre-feet--or 57.3 billion gallons--a year to the water district, said Corps planner Richard J. Schubel. That amount is expected to rise to 78.2 billion gallons by 2000, before the enlarged dam is finished.

Negotiations over future levels of water conservation--after the dam is enlarged--are certain to center on the future of the small bird, officials said.

The water district, for example, has suggested that ultimately it would like to see the Prado reservoir level rise to 512 feet above sea level. That seven-foot increase would nearly double the amount of water available for conservation at any given moment, from 27,000 to 48,000 acre-feet, Schubel said.