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Getting ready to breach the dam
by Dan Olson, Minnesota Public Radio
April 7, 2004

Two dams on the Olympic Peninsula's Elwha River system have cut fish populations from 400,000 annually to less than 4,000. Researchers at the University of Minnesota are helping determine the best ways to remove those dams. (Photo courtesy of Elwha Restoration Project)

A researcher at the University of Minnesota is part of a salmon rescue mission. The work is helping officials in the state of Washington prepare for the country's largest dam removal project. The goal is restoration of a legendary salmon river to its original condition.

Minneapolis, Minn. — Water runs over Chris Bromley's model dam as he removes sections from the top. One day soon, this may be what happens to the Glines Canyon dam holding back water on the Elwha River in the state of Washington.

"The primary benefit is that it's going to restore fish passage for salmon," Bromley says.

Bromley is a U of M geography graduate student from England. A grant from the National Science Foundation is paying for his research to show the best way to remove the dam. There are two dams on the Elwha. The plan is to remove both. Bromley's research is on the larger structure.

	Researcher Chris Bromley

The Glines Canyon dam is 246 feet high. If the structure is taken down too fast, a thick and suffocating layer of sediment would spread across the river bottom.

Bromley's 30-yard-long model of the dam and the lake behind it is at the U's St. Anthony Falls hydraulic laboratory on the banks of the Mississippi River in Minneapolis.

Robert Elofsen is directing the river restoration. Elofsen, a member of the Lower Elwha Klallam tribe, says before the dams were built the tribe's culture and economy were based on the fish taken from the Elwha.

The Klallam began lobbying the federal government nearly 30 years ago to remove the two dams. Congress gave the go-ahead 12 years ago, because the power produced from the dams was replaced by other sources.

Elofsen says once the dams are removed, it will be be years before millions of tons of sediment are redeposited and the river valley floor is reforested.

	The Glines Canyon dam

"You might get some harvestable salmon in 10 or 12 years returning to the river," Elofsen says. "But to actually reach an equilibrium, where natural runs approach where they were before, could take 20 years or more."

The Elwha River starts in the 7,000-foot-high snow-capped peaks of the Olympic peninsula. Most of the area lies within the Olympic National Park.

Before the dams were built, the river coursed through a thickly forested valley. The land was clearcut after construction.

Connie Kelleher, a spokeswoman for the advocacy group American Rivers, says 10 species of fish reproduced and thrived in one of North America's most productive waterways.

"Huge individual chinook salmon sometimes exceeded 100 pounds. There were also sea run cutthroat trout, and native char, and winter and summer runs of steelhead there -- as well as coho, pink, sockeye, and spring and summer and fall chinook salmon. And they numbered approximately 400,000 each year," Kelleher says.

After the dams went in, Kelleher says, fish populations declined to about 4,000 a year, nearly all planted from hatchery stock.

	What the river will look like

Grad student Chris Bromley's work predicts the course the water will take once the dam is breached. The release will cause turbid water for a time. He says the salmon returning to the river will tolerate some sediment in the water.

"The sediment to a certain extent will make the fish uncomfortable," Bromley says. "But the removal of the dam has been designed in such a fashion that when the bulk of the sediment is moving ... will be the times when the fish and their eggs -- and their young, when they've hatched -- are least sensitive to that sediment."

The two Elwha River dams on Washington's Olympic Peninsula are owned by the federal government, and federal taxpayers are footing the $180 million dam removal and river restoration cost.

The dam removal effort began when Robert Elofsen was finishing college. Now 51, Elofsen says his Klallam tribe is confident the river and its remarkable fish producing ability will one day be restored.

"I told my daughter, in fact, when we were visiting the dam that if I don't get this done then she'll have to. She was kind of shocked at that thought," Elofsen says.

Elwha River dam removal is scheduled to begin in 2007.

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