Tuesday, September 20, 2011

Dam removal begins, and soon the fish will flow

Reporting from Port Angeles, Wash.?

In a deep turquoise pool in a gorge of steep granite and thick Douglas fir, dozens of salmon swam fitfully. Swirling and slow, they made their way up one side of the riverbed, only to run into the steep concrete face of Elwha Dam ? the formidable barrier that for nearly 100 years has cut off most of the Elwha River from the salmon that traditionally populated it.

Some primordial genetic imprint makes these fish keep trying. Nurtured in hatcheries for years, supplemented by the few wild fish that managed to spawn in the limited five-mile stretch of river left below the dam, these 20-pound chinook still fling themselves up the river.

Or try to. Soon, they'll be able to continue on the journey that nature compels them to make.

Interactive graphic: Dismantling the dam

On Saturday, in what is being billed as one of the biggest environmental achievements of a generation, a bulldozer began to etch large chunks of concrete out of the barrier. The removal is the first step toward bringing down two hydropower dams that for a century have straddled the pristine river traversing the northern reaches of Olympic National Park.

The effort is the largest dam removal project ever undertaken in the United States. It comes at a time when the nation's 80,000 dams, many of them aging and backed up with choking silt, are increasingly suspected of having outlived their usefulness.

"This is just breathtaking for me. This is not only an historic moment, but it's going to lead to historic moments elsewhere across the country," said Michael Connor, commissioner of the U.S. Bureau of Reclamation.

He made the comments as a stage full of politicians, including Interior Secretary Ken Salazar, Washington Gov. Chris Gregoire, actor Tom Skerritt, U.S. Sens. Maria Cantwell and Patty Murray, and leaders of the Lower Elwha Klallam Tribe feted the demise of a structure once celebrated as a triumph of engineering and economic development.

"Twenty-five years ago, the idea of removing this dam or any dam was really seen as a crazy idea by a bunch of wild-eyed environmental extremists," said Bob Irvin, president of the nonprofit group American Rivers, which is pushing to restore rivers across the U.S. "Now it is a mainstream idea, because people recognize the benefits of restoring healthy rivers ? benefits not only to the environment, but to communities."

Built in 1913, the 108-foot-high Elwha Dam and its 210-foot companion structure upriver at Glines Canyon have provided river-powered electricity to a large mill in nearby Port Angeles. But other sources of power have now been identified for the mill and the rest of Port Angeles, and Congress nearly 20 years ago passed legislation authorizing the dams' removal. Engineers say it will take two to three years to completely breach the dams, and as long as 30 years before the Elwha River can return completely to its full, glacier-fed natural state.

The project will proceed slowly to accommodate the 24 million cubic yards of sediment that have accumulated behind the dam.

"That's a really big number. It is a football-field-size stack of sediment as high as the Empire State Building, 11 times," said Jeff Duda, research ecologist at the U.S. Geological Survey's Western Fisheries Research Center in Seattle.

Gradually, though, the sediment will wash downstream, and the salmon now barricaded at Elwha Dam will be able to swim up and repopulate more than 70 miles of the river and its tributaries, nearly all of the territory pristine because it lies within the national park.

Their return, scientists say, will allow the creatures that flourish on salmon ? the bears, eagles, otters and orcas that also call this region home ? to experience rejuvenations of their own.

Biologists say the 3,000 salmon that still spawn in the lower Elwha River can eventually multiply to more than 300,000.

Several smaller dams in southern Oregon already have been removed, and another is targeted for removal on the White Salmon River in southwestern Washington in October. More than 235 dams across the country have been pulled down or breached since 2006.

Here in the Northwest, conservationists are setting their sights on a much bigger prize: the big hydropower dams on the Lower Snake River in southeastern Washington ? dams that still have a powerful constituency of farming, transportation and public utility backers who won't give way to salmon without a fight.

Though many species of Pacific salmon are now listed as threatened or endangered, the old stories handed down by Lower Elwha Klallam elders tell a much different story ? of a time when pink salmon were so abundant in Idaho Creek, an Elwha tributary, that horses "shied and refused to cross the channel," one elder told a researcher.

An early homesteader at the turn of the 20th century described in a letter to his sister that the salmon near where one of the dams would be built "lay there with their backs out of water. All I had to do was to reach over them, hook the hook in their back and pull them out."

On Saturday, ceremony-goers stood on the top of the dam and pushed their faces against the fence to see the salmon ? descendants of those old fish ? swimming at the face of the dam down below.

"It's sort of inherent in their systems ? incredible, really. There's some innate homing behavior in these fish; they're responding to some kind of ancient cue to their natural spawning area, upriver," said Lyman Thorsteinson, director of the USGS fisheries center, as he watched them.

"It's as if they know," said Will Hall, deputy mayor of the city of Shoreline, north of Seattle, who had come for the festivities. "'Take down that dam. Let us go through.' This is what it's all about."

Interactive graphic: Dismantling the dam

kim.murphy@latimes.com

Source: http://feeds.latimes.com/~r/latimes/news/science/~3/WsPgDE3BaoU/la-na-0918-dam-20110918,0,1603613.story

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