In an emergency move to save billions of gallons of storm water that was flowing into the ocean, federal and local officials on Monday reached an agreement to store more water behind Prado Dam while at the same time protecting an endangered bird that nests there.
Despite the worst water shortage in California history, federal officials since Thursday night had opened the gates of Prado Dam and released about 6 billion gallons of storm runoff into the Santa Ana River, which empties into the ocean.
The water--produced by a powerful, 48-hour storm last week--was released primarily because federal officials were trying to avoid soaking the nesting grounds of the least Bell's vireo, a small bird protected by federal endangered-species law.
Beginning at 4:44 p.m. Monday, the water releases were cut by more than 80% after officials of the Orange County Water District, the U.S. Fish and Wildlife Service and the Army Corps of Engineers agreed on measures to protect the bird. The agreement came just hours before a new storm was expected to bring even more rain to the region.
Now, all the water is being held and released very slowly so that 100% of it can be captured in the county's reservoirs downstream in Anaheim instead of flowing unused into the ocean off Huntington Beach.
"We'll be draining (the water behind the dam) very slowly for the full benefit of water conservation," said Greg Grigorian, who is in charge of opening Prado Dam's gates as chief of reservoir regulations at the Corps of Engineers.
Dick Zembal, a federal wildlife biologist based in Laguna Niguel, said Monday that all sides were happy with the agreement.
"We have now accommodated long-term goals for the vireo to such a great extent that they will be very well taken care of," Zembal said. "The water district has come to the rescue, and so has the Corps."
Only about 400 breeding pairs of the least Bell's vireos exist, and about 40 of those pairs nest behind Prado Dam, located on the Santa Ana River in Riverside County just across the Orange County line. It is the bird's largest breeding area north of San Diego County.
In return for the dam storage, the Orange County Water District agreed to set aside and enhance 122 nearby acres of willows behind the dam as a new nesting area for the vireos. The district also promised to donate $450,000 to a fund to manage and monitor the rare birds.
Also, more acres will be protected in the future and the water district is arranging with a national environmental group, the Nature Conservancy, to manage the area and protect the bird nests from predators, Zembal said.
William R. Mills Jr., the water district's general manager, emphasized that the district had long offered to make those same concessions in return for more dam storage.
Orange County officials covet the storm water because it is a cost-free way to replenish the underground water basin, which provides 75% of the water consumed by residents of north Orange County.
The storm runoff, however, is not a solution for the area's severe water shortage. Major storms are rare, and the water is not immediately of drinkable quality. The storm water is valuable in that it sinks into the county's ground-water basin, which is being depleted by the drought.
But using the dam to store water has been a contentious issue for longer than a decade, and negotiations between local and federal agencies have dragged on for several years.
Federal rules require the Army Corps of Engineers to release water when it reaches a certain elevation to protect not only the birds' nesting grounds but to avoid flooding Orange County downstream. Grigorian, however, said the flood threat is small this time of year, so protecting the bird habitat was the major reason for opening the gates.
The water was being released into the river at a rate of 2,500 cubic feet per second. On Monday evening, after the agreement, the water was slowed by 84%, which means that it can be captured by Orange County and none will be wasted, Grigorian said.
By this afternoon, the water district will rebuild some levees so the water can be released at a faster rate and still be captured, Grigorian said. About 5 billion gallons was behind the dam Monday evening, enough to serve about 50,000 families for a year.
"Sometimes, it takes an emergency before all of us realize the necessity of coming to grips with the issues," Zembal said. "You can't ignore the water needs in Southern California. But you also cannot ignore the fact that in making the water available to people, it can also impact habitat and endangered species."
The least Bell's vireo, a small, 5-inch-long bird, nests only in Southern California's streamside thickets and willows, which are disappearing rapidly because most rivers in the region have been drained or paved. The grayish bird arrives from Baja California to nest in mid-March.
The birds may not have many places to nest this season behind Prado Dam, but in the future they will have more--and better--places than ever as a result of the agreement, Zembal said. He added that the new location is preferred to the existing one because it is on higher ground.
Wildlife officials must be cautious with the plan to save the vireo because trying to force the birds into a new habitat is an uncertain science. "We can create a new habitat, but whether or not the birds go there is another story," Grigorian said.