PREV     of     NEXT

Removing two dams on the Olympic Peninsula's Elwha River would flush enough dirt and gravel downstream to fill a million dump trucks.

Even so, the state Department of Ecology on Wednesday issued a water-quality permit that is critical to plans for tearing down the dams. Though the debris will muddy the river and kill fish in the short term, environmentalists and government officials say that the project will be a boon in the long run.

This would be the biggest dam removal in the nation — and one that has been eagerly awaited. The two dams, the 210-foot Glines Canyon Dam and the 108-foot Elwha Dam, block 70 miles of pristine river and salmon-spawning grounds.

In addition to opening habitat to salmon, the release of sediment will eventually change the river's character and make it more hospitable to fish, said Patricia Olson, an Ecology Department hydrogeologist. It is expected to meander more, split by small islands and gravel bars.

Rivers naturally collect sediment from erosion, depositing it downstream. When a dam traps gravel and silt, the downstream river can become "sediment starved," creating a straighter river and more erosion on river banks, Olson said.

The Ecology permit is one of several bureaucratic hurdles expected to be cleared in the next few months.

But "this one's pretty meaningful," said Brian Winter of the National Park Service. "Without it, we can't do the project."

It is not clear when demolition of the dams will begin, though officials have previously slated it for 2009.

It all depends on when two new water-treatment plants are completed to provide clean, dirt-free water to nearby Port Angeles, a paper mill and two fish hatcheries, said Winter, the Elwha project manager for Olympic National Park, which is leading the removal work.