Ojai Valley News Blog

With loss of $155 million for Matilija Dam project, officials propose alternatives

By Daryl Kelley
Faced with the possibility of losing the $155-million Matilija Dam Removal Project, local officials proposed Wednesday a long-discarded alternative for disposing of 2.1 million cubic yards of silt now wedged behind the obsolete dam near Ojai.

At a meeting of the local-state-federal committee formed to oversee the dam’s demolition, county officials offered an unexplored option that may save the project by moving it along more quickly and for much less money.

A basic study of the new alternative by the federal Bureau of Reclamation could be ready in two months, said County Supervisor Steve Bennett, who represents the Ojai Valley.

“There are a lot of reasons to suspect that delay is the way the project dies,” Bennett said in an interview. “We need to make good-faith efforts to make sure that doesn’t happen.”

State and federal budget deficits have placed into question even money previously approved for projects such as taking down the silt-and-sediment filled Matilija Dam and restoring the Ventura River to its natural state, he said.

Funding for $90 million of the project, the first large dam removal in the nation, was approved by Congress last year after a decade of lobbying.

But with every passing month, costs continue to rise, and the probability that the project will be completed continues to drop, officials said.

“It’s dying a slow death, because we’re in a stall,” said county Public Works director Jeff Pratt. “Every year, construction costs escalate $5 million to $6 million. And every dollar this project’s cost goes north of $150 million is a dollar less likely that this project will get done.”

Storing the fine silts behind the dam could save $20 million, he said.

A decision on what to do with those 2.1 million cubic yards of silt was to be made by last February.

But the costs of two main options — disposal along the Ventura River at Meiners Oaks or farther downstream near Baldwin Road — have increased exponentially, and now range from between $30 million and $50 million, officials estimate. Plus, owners of the Meiners Oaks property decided not to lease it to the county because of community opposition.

So officials shifted their attention back to another alternative that had been discarded years ago during early stages of study because of widespread opposition.

Officials will now will focus on the costs and engineering involved in storing the silt in a disposal area behind the dam, instead of pumping it miles downstream below the Robles fish ladder.

The behind-the-dam option had not been seriously analyzed initially because of concerns by Casitas Municipal Water District that the silt would clog the Robles facility and dirty the water that the agency diverts during storms into Lake Casitas, the Ojai Valley’s main source of drinking water.

But Steve Wickstrum, Casitas general manager, said after hearing the county’s briefing on the new option that it might be workable.

“This is the first time this option has been presented to our (design and oversight) group,” Wickstrum said. “This sounds great and has some good chance of being a success, but it’s very preliminary.”

Blair Greimann, a Bureau of Reclamation expert in the migration of soil, will study whether the silt could be placed in the reservoir area behind the dam, but well away from the flows of Matilija Creek, so it would not erode during storms.

The concept is not new, since about 4 million cubic yards of heavier sediment that also fill the Matilija Dam reservoir are already planned for distribution in several spreading areas behind the dam.

“The idea already was to use sites above the dam so erosion takes place in stages — some during a 10-year storm, some during a 20-year storm and so on, so it would take one section at a time,” Wickstrum said. “This new site would not erode during normal storms, but maybe (somewhat) during a 100-year storm.”

Erosion of the sediment downstream is not a problem, he said. But the fine silts could be a big one, he said.

If diverted to Lake Casitas, the silt-laden runoff waters filled with organic materials “could cause algae blooms, (foul) taste and odor, cause a loss of dissolved oxygen (in the water) and maybe even warrant additional water treatment,” Wickstrum said.

Russ Baggerly, a Casitas director who also attended the briefing, said the behind-the-dam alternative “could be a useful mechanism to reduce costs and allow the project to proceed. There seems to be terracing,  they can do it so the silt would be there for some time. It seems like it could work.”

Paul Jenkin, founder of the Matilija Coalition and executive director of the local chapter of the Surfrider Foundation, had pushed a Baldwin Road alternative, but its costs have soared to the $50 million range, officials say.

And Jenkin said this week that the behind-the-dam storage alternative could be workable, as long as the government does not insist that the silt be stored and capped in a way that does not jibe with the primary goal of removing the dam and returning the river valley to its natural state.

“If this is done right, there may be something to it,” Jenkin said in an e-mail to the Ojai Valley News. “If it’s mixed in and ‘stabilized’ without concreting the canyon, episodic release of fines (silt) may be tolerable for Casitas.”

But the county’s Pratt said that the new analysis will be looking only at permanently capping the silt with rock after it is spread on about 30 acres in the reservoir area. The analysis will not consider allowing the silt to erode because of possible dire consequences for the Casitas water agency, he said.

The earliest actual dam demolition could happen is during 2010-2012, according to a feasibility study completed by the U.S. Army Corps of Engineers four years ago.

In addition to the federal government’s contribution, about $65 million would be required from state and local sources. Almost all of that would come from bonds issued by the state. So far, the state has spent several million dollars to design the dam removal project. But state and federal budget crises have raised questions about the reliability of that funding.

Matilija Dam, built in 1948 for flood control and water storage, has been obsolete for decades, because it quickly filled with sediment from Matilija Canyon runoff. Now, only 5 percent of its storage contains water.