[Two videos: The first, a time-lapse video of the deconstruction of the Elwha Dam on the lower Elwha River (YouTube here), the second a video of the blasting of one of the last remaining sections of concrete on the Glines Canyon Dam on the upper Elwha, shot by my brother-in-law.]

Timothy Egan had a superb contribution at the NYT's blog space the other day, describing the effects of the Elwha Ecosystem Restoration project, which is the largest dam-removal project in U.S. history:

It defies experience-hardened cynicism whenever any big public works project is under budget and ahead of schedule. But the Elwha has served up something even better: life itself, in the form of ocean-going fish answering to the imperatives of love and death. Not long ago, scientists were stunned to find wild steelhead trout scouting habitat well past the site where the Elwha Dam had stood for nearly a century. They didn’t expect fish to return this soon.

This biological boomerang is a tribute to stubborn DNA memory, and it is a precursor for what the wild Elwha will be in the not-so-distant future. Beyond that, the restoration of the Elwha, as in the revival of the much-abused southern end of the Bronx River at the other end of the country, is proof that American ingenuity is alive and well and hard at work on with the tricky task of healing parts of the natural world that we’ve trashed.

Be sure to read the whole thing, since Egan is such a fine writer. Here's more about that steelhead run, as well as further good news: the downstream flow of silt is not turning out to be nearly as noxious as originally feared.

But it's not just the Elwha where this is happening. As these structures age, removal is often the sensible solution. And it's creating opportunities for river restoration in a wide variety of places.

A recent Boston Globe piece examined the local benefits of another dam-removal project:

Tim Purinton makes the analogy that removing dams from a river is akin to getting rid of clogged arteries in the body.

"If you're interested in rivers and river ecology, there's no better thing you can do for a river than remove a dam," said Purinton, director of the Division of Ecological Restoration for the state Department of Fish and Game.

Removing the obstruction allows not just better passage for fish and other aquatic species, but also the movement of sediment and a change in water temperature, he said. "If you can clean the arteries and allow for the free flow of water, sediment, and nutrients, you bring back river health almost immediately."

Obviously, dams remain extremely useful things, especially in places like the Northwest, where they provide most of our carbon-neutral energy (though at the expense of salmon runs). But when they outlive their usefulness, it's a wonderful thing to watch Mother Nature come rushing back to her domain.