A Rebuilt Dam Emerges From Clamor

LAKE CASITAS —  The bulldozers have been stilled and enough dirt to fill the Rose Bowl to overflowing has been packed onto Casitas Dam.

After 14 months and $42 million, workers have finished bringing the 40-year-old dam in line with earthquake safety standards. The top of the massive earthwork is nearly triple its old width of 40 feet, and a squat, 10-acre buttress braces the front--heavy enough, officials say, that no dirt behind it will move. Ever.

Rebuilding the 335-foot-high, 2,000-foot-long dam became a priority for federal officials after a 1995 study showed it to be more vulnerable to strong ground motion and liquefaction--in which soil can shake like pudding--than previously believed.

Now, as the heavy machinery has moved away, residents near the dam, which blocks Coyote Creek two miles above the junction with the Ventura River, can get their lives back to normal.

“It made a pretty major dent in improving it,” said Stephen Kally, who lives just below the dam, which creates Lake Casitas. Kally spent the past 1 1/2 years listening to the behemoth grow noisily just beyond his backyard.

“Oddly enough, as close as we live, the construction was not a particular problem,” he said.

Many of his neighbors disagree, but all are glad to be rid of the daily rumble of trucks. Crews have moved to more pastoral work two miles southeast of the dam, as they plant purple sage, buckwheat and coyote bush on a remote 50-acre excavation site, from which the dirt for the additions came.

But nothing came easily for the project.

Controversy first arose when clamor from a gigantic boulder-sorting machine--called a grizzly--reverberated day and night in homes near the dam.

Ventura County lawmakers and emergency response personnel also complained the emergency siren system along the Ventura River was not fully functional before work had begun, though officials from the U.S. Bureau of Reclamation, a division of the Department of the Interior, said eight sirens were in place and would have worked if needed. Eleven sirens were eventually installed along an eight-mile stretch, from the dam to the fairgrounds in Ventura.

Then in January 1999, entire neighborhoods panicked when a test of the dam’s emergency siren system went awry, squawking 15 minutes of garbled warnings that sent frightened residents fleeing.

There was more. Early last year the Environmental Defense Center of Ventura County, representing environmental groups Friends of the Ventura River and the California Native Plant Society, threatened to sue to halt the project until concerns on the loss of wetlands and mature oaks were addressed. Legal action was averted with the start of compromise discussions, which John Buse, an attorney with the EDC, said are still in the works.

All is quiet now. But the dam, its new crest temporarily bald of vegetation and starkly visible from California 33 a few miles away, looms over the valley below. For some people living in its flood plain, it’s a grim reminder of latent fears.

“The bottom line is, do we ever really know?” said Margaret Merryman, president of Ventura’s Westside Community Council.

“They’re saying that it is safe, so we have to believe that it’s safe,” she said.

But Merryman, who spent months working with U.S. Bureau of Reclamation officials to keep residents updated on the project, said the bureau’s public relations efforts to allay concerns have impressed her.

Public Relations Campaign Launched

Indeed, from the project’s start, bureau officials mounted an unprecedentedly large public relations effort, continually visiting neighborhoods below the dam. They spoke at block meetings, city councils, to any residents’ group that asked them to speak. They passed out fliers about the siren system and on how to prepare for emergencies, printed T-shirts proclaiming, “I survived the Great Grizzly Attack of 1999,” led tours, created a Casitas Dam newsletter and Web site, and hired a local public relations firm to help.

They tried to put a human face on an agency as seemingly monolithic as the dams it builds.

“We’re usually seen as very remote and inaccessible,” said Marian Echeverria, spokeswoman for the Bureau of Reclamation. “What we tried to do from the very beginning was get the affected public involved.”

They had to, Echeverria said, because 14,000 people live below the dam. Most dams are farther removed from populated areas.

Meetings will continue, she said, because the replanting just began and worries could resurface each time the siren tests sound, which is four times a year.

Bureau of Reclamation officials began working on the project in 1995, when they studied dams in the 17 western states for safety. Casitas Dam had been examined earlier, but seismic information gathered after the 1994 Northridge earthquake showed it was in more danger of liquefying than was previously known.

Strengthening it required digging out part of the dam’s foundation, replacing it with firmer dirt and rocks, then building the massive berm to ensure nothing moves.

Effort Begins to Reintroduce Wildlife

“Even if there was water in the foundation after construction, then the material is dense enough that it can’t liquefy,” said Gary Egan, project manager for Casitas Dam.

Twelve wells were sunk into the dam during construction to suck water from the soil and keep the dam fortified. The wells were removed once the berm was built.

With construction over, now it’s time to coax the deer back.

The bureau wants the excavation area pristine enough so that deer, raccoons and the occasional mountain lion and bear that once walked the area will return.

Echeverria called the replanting a modification, not a restoration, because the contours of the land have been changed. And it is the bureau’s largest yet, officials said.

“Every job we’ve done in the past five years, the amount of restoration has increased,” said Albert Penna, a special projects officer with the bureau. “It’s really in response to the times. The requirements that we’re working under continually evolve.”

For instance, removing the dirt for the project involved digging in patches--instead of strip-mining--to preserve clusters of trees. While the excavation site covered 50 acres, only half of that was actually excavated.

Workers must replant not just because the action is mandated by law, but to make sure native plants take hold and keep out nonnative species, said Mary Marshall, an environmental specialist with the bureau.

The bureau hired URS Corp., an international environmental consulting firm with offices in Santa Barbara, to oversee the replanting. John Gray of URS said his firm began gathering permits, preparing environmental studies and determining what to plant a few years ago, and his involvement may continue for years. Once the grass and bushes take hold, more than 2,000 oak and walnut saplings plus Christmas berry shrubs will be planted. Those will have to be watched for five years to make sure they thrive, Gray said.

A related project will also take time. Construction of a two-mile road from the excavation area to the dam destroyed marshes where four streams meet the lake. To compensate, crews will breach an old diversion dam near the visitors’ entrance to Lake Casitas and create a new six-acre wetlands, Gray said.

The Environmental Defense Center still has concerns on the plantings and wetlands projects. Buse, with the EDC, said the removal of mature oaks at the dam should be counterbalanced with an off-site replanting area similar to the wetlands project.

“Because of the considerable amount of mature vegetation removed, that will not be restored for decades,” he said.

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A Solid Future

A 14-month project to reinforce Casitas Dam is now complete. The dam’s crest width has been almost tripled, from 40 feet to 110 feet, and a buttress-like berm now abuts the front. The $42-million project was done after seismologists, studying data from the 1994 Northridge quake, discovered that the structure was more vulnerable to strong ground motion and liquefaction, in which soil behaves like pudding, than previously believed. The berm is heavy enough to hold the rest of the dam in place in case any portion of it were to liquefy in a quake, Bureau of Reclamation officials said. With the improvements, the dam can now withstand quakes of a magnitude 7.2, the strongest that scientists expect in the area. More than 1.5 million cubic yards of dirt--enough to fill the Rose Bowl to overflowing--went into the additions.

Source: Bureau of Reclamation