Demolishing Dam May Not Help Fish

A proposal to remove Matilija Dam near Ojai to save the endangered southern steelhead trout has gained favor with environmentalists, but a growing number of critics say it would be costly, complicated and potentially dangerous for the few remaining steelhead left in Southern California.

A variety of scientists, government officials and two recent studies contend there are cheaper and simpler ways of restoring the steelhead’s habitat than spending millions of dollars to dismantle a 145-foot-tall dam.

Removing the dam is “very attractive to talk about, but it’s mind-boggling to do,” said Alex Sheydayi, deputy director of public works for Ventura County. “Someone needs to look at this whole picture other than tearing down the dam. It’s very complicated.”

The proposal to tear down the 51-year-old dam on the Ventura River is part of a national crusade that has already led to the destruction of dams in several states. The campaign against Matilija is being led by Ed Henke, who lives in Oregon and has championed recovery efforts for salmon in the Northwest. He returned to his boyhood home in Ventura in November and began rallying support against Matilija.

“That dam was a historical error that needs to be corrected,” Henke said. “If we’re going to have a great river and a great fishery, then we’re going to have to take that dam down. There’s no way around it.”

Groups such as Friends of the River, the Surfrider Foundation and the Environmental Defense Center have signed on to the dam-busting proposal. Officials at the National Marine Fisheries Service also endorse the dam’s removal, provided it’s done properly. And Ventura County’s Washington lobbyist is seeking federal aid for the project.

The reason for the concern is that Matilija Dam sits on one of the last remaining stretches of steelhead trout habitat in Southern California, 19 miles of spawning streams in Matilija Creek, enough to sustain 1,100 adult steelhead.

As recently as 60 years ago, tens of thousands of the metallic-colored, ocean-going trout migrated up the Ventura and Santa Clara rivers to the mountains, where they spawned in shallow creek beds. Prized by anglers for their cunning and power, the steelhead can leap 5-foot-high barriers and muscle through currents powerful enough to sweep a man away. But today--as a result of development, pollution and water barriers such as dams--the number has dwindled to a few hundred fish in Southern California.

The southern steelhead was declared an endangered species in August 1997.

So far, the National Marine Fisheries Service, which is charged with protecting steelhead under the Endangered Species Act, has not developed a strategy for restoring the fish. Absent such a plan, Matilija Dam has become a target for environmentalists, in part because, if the fish is to be saved, it will be saved in Ventura County, with its extensive back country and freshwater streams.

“Ventura County is ground zero with respect to recovering steelhead south of San Francisco,” said Jim Edmondson, conservation director of California Trout Inc., a sportfishing organization. “If we’re going to have any hope in the next 10 years of recovering the steelhead, these efforts will have to be focused on the Ventura and Santa Clara rivers.”

Built at a time when the nation’s dam builders were taming rivers all across the continent, Matilija Dam was designed to prevent flooding on the Ventura River and store water for farmers and Ojai Valley residents. But it has been dogged by problems for years. Made of unstable concrete, the dam’s top 30 feet were removed in 1965. It filled nearly to the brim with sediment years ahead of schedule and no longer protects against floods or holds much water, according to officials.

“It was a fiasco from the start,” Sheydayi said. “Its value is not very significant. If the dam all of a sudden disappeared, it would have a minuscule impact on the water supply. I don’t think anyone would be hurt by [removing] it. I don’t think we’d notice.”

The fate that may await Matilija Dam has been carried out elsewhere. Throughout the nation, obsolete dams are coming down to help migratory fish. Interior Secretary Bruce Babbitt has taken a sledgehammer to small dams in North Carolina and Northern California. Three were removed in Wisconsin, one in Maine and another in Oregon during the past two years.

“We breached the dams and the fish came back immediately,” said Babbitt spokesman Jamie Workman. “It’s a whole new way of thinking. Dams are not forever.”

Studies Raise Some Questions

But some experts are beginning to have second thoughts about the wisdom of pulling down Matilija Dam. Two recent studies raise questions about the project. One of the studies was prepared in April as a thesis project by graduate students at the UC Santa Barbara Bren School of Environmental Science and Management. The other was prepared by Walnut Creek-based ENTRIX Inc. and Woodward-Clyde Consultants of Santa Barbara last December.

The UCSB study says it would cost $64 million to $82 million to remove the dam and the sediment that has backed up behind it. Though expensive, excavating sediment is necessary because it reduces the impact on fish and property owners downstream.

The cost could soar to $150 million if habitat above and below the dam is restored and debris from the demolished dam is hauled away, according to the ENTRIX report.

Henke said he hopes the dam could be removed for less. He also said there are benefits to removing the dam that have nothing to do with steelhead recovery. Without the dam, sand could be flushed to beaches to stem coastal erosion.

In an August 1997 letter to California Trout, California Department of Fish and Game Director Jacqueline Schafer estimates removing Matilija Dam could cost as little as $3 million or as much as $45 million, depending on how sediments are handled. However, those figures underestimate by nearly half the amount of debris in Matilija Reservoir.

Digging and disposal of the 6.1 million cubic yards of mud, boulders and trees behind Matilija Dam account for about 90% of its removal cost, according to the UCSB study.

A cheaper alternative would be to gradually lower the dam and allow the river to skim away mud over several years and wash it downstream to beaches. But that option could release enough silt to “decimate the remaining steelhead populations” in the Ventura River and increase danger of destructive floods, according to the UCSB report.

The report by ENTRIX warns “the adverse environmental impacts associated with removing Matilija Dam are greater and more complex than those impacts associated with removal of other dams that are closer to the ocean. Increased sediment loading in the highly developed Ventura River would . . . potentially increase property damage due to flooding.”

The Problem With Robles

Moreover, even if Matilija Dam was eliminated, steelhead might never reach that far upstream. Other impediments--such as the Robles Diversion Dam two miles below Matilija--block their passage. Critics say any recovery plan must deal with Robles dam, even before Matilija.

“Robles is the place to focus our immediate attention,” Edmondson said. “It is the No. 1 problem.”

Since 1960, Robles dam has diverted water from the Ventura River and Matilija Reservoir into Lake Casitas. Robles lacks a fish ladder, which would give steelhead access to several miles of quality habitat in the north fork of Matilija Creek even if Matilija Dam was left alone. Fish screens would also help, officials say.

“Providing access to habitats upstream of Robles Diversion Dam is one of the most important actions that can be taken to improve steelhead populations in the Ventura River,” states the ENTRIX study. The report says it would cost only $1 million to $2 million to install fish passage devices at Robles dam.

“You get a lot better bang for your buck getting [steelhead] up over Robles dam,” said ENTRIX fisheries biologist Jean Baldrige.

Other actions that might help the steelhead include improvements to the fish ladder at the Freeman Diversion Dam in the Santa Clara River. That would enable more steelhead to reach Sespe Creek above Fillmore, opening 50 miles of habitat.

“If you get more adult steelhead to the Sespe, then you get more reproduction, and that could mean a lot more fish,” Edmondson said.

The Ventura River and its tributaries could be made more fish-friendly by adding gravel, native vegetation and objects where fish could hide, such as roots and logs, the report says. Also, flows of water must be increased during dry spells to enable steelhead to navigate shallow stretches of the Ventura River. Without extra water, fish will not be able to reach Robles dam, much less habitat behind Matilija Dam upstream, according to the ENTRIX study.

Then there are the bridges, concrete aprons across streams and culverts that have turned the Ventura River into a formidable obstacle course for migrating fish. Replacing or redesigning those structures would help the fish, too, without touching Matilija Dam.

“The largest impediment to half of the historical habitat is the Matilija Dam,” the UCSB study concludes. “[But] it is uncertain if dam removal alone would improve conditions enough for the fish to recover their numbers. . . . Many other plans that would be much less costly could restore steelhead numbers in the region.”