MELISSA BLOCK, Host:
People are good at building dams. There are an estimated 75,000 of them on American rivers. But we don't have much practice removing them. In Washington state, that's changing today.
(SOUNDBITE OF POUNDING)
BLOCK: Workers have begun cutting into the concrete on the 210-foot-high Glines Canyon Dam, the tallest dam ever taken down. It's part of an ambitious dam-removal project on the Elwa River inside Olympic National Park. NPR's Martin Kaste hiked to a spot above the river to get a good look at the demolition work and he's on the line with us now. Martin, what are you seeing there from your vista?
MARTIN KASTE: Well, I'm actually sitting on a piece of old driftwood, an old log that was probably cut down in the 1920s when this dam was built here. The lake is slowly descending and a bunch of workers are on a barge here on the upside of the - upriver side of the dam and they're - they've just begun jack-hammering into the concrete itself. They're starting to notch into the top of it. And what they're gonna do is slowly, but surely, over the next few months, notch the dam down, letting the water come out in small doses.
MICHELE NORRIS, Host:
You know, as you continue to paint this picture for us, help us understand why it takes so much work to take apart one of these massive structures.
KASTE: Well, we in radio were hoping that there would be the possibility of them just blowing the thing up, 'cause it would be a great scene. But you can't do that because there's almost a century's worth of sediment built up behind this high dam. And all that sediment, this muck and mud, would go careening down this narrow, beautiful valley here. And basically it could kill the river they're trying to save.
NORRIS: Why are they removing these dams, anyway?
KASTE: This is the Olympic National Park. This is a river that has never had any major development along it, so it's about bringing the park back to its natural state.
NORRIS: You know, when I listen to you talk about a hundred years of sediment, I wonder if it's really possible to take a dammed river and restore it to its natural state.
KASTE: The one factor, the one unnatural factor on this river are the dams. And they are going to monitor every aspect of this and find out if it's possible. Because if it is, that means a lot for other dam removal projects, or possible dam removal projects, around the country.
NORRIS: Congress passed the legislation authorizing this dam removal back in 1992. Why has it taken so long to reach this moment to finally start the process?
KASTE: A lot of eyes are on the Snake River, which feeds into the Columbia River. Those are very contentious dams; they've been tied up in lawsuits for years and the question is, well, if this goes well, the people who want to keep those dams for economic reasons are worried that they might be next.
NORRIS: Martin Kaste, thanks so much.
KASTE: You're welcome.
NORRIS: That's NPR's Martin Kaste. He's at the Glines Canyon Dam at the Elwha River inside Olympic National Park in Washington State. Transcript provided by NPR, Copyright NPR.