Ge o’ the Lantern »« Dana’s Dojo, Week 2: Letting Go

Out, Out, Damned Dam! White Salmon River

Did I mention it’s a bad year to be a dam in the Pacific Northwest? Well, it’s a bad year to be a dam that’s outlived its usefulness, providing a pittance of hydroelectric power at great cost to salmon runs and so forth. Just ask the Condit Dam. Oh, wait, you can’t – we killed it dead.

Andy Maser, the outstanding photographer who shot the dam being blown open, gave me his kind permission to embed the resulting video for the two or three of you who may not have seen it yet. I’d advise you to get a good grip on something before you press play. Ready? Steady? Launch!

Look at that sediment go! Aside from that breathtaking burst of muddy water from beneath the dam as it was breached, that was my favorite part. I’m hoping one of our lovers of fine sediments will weigh in below to discuss the slumping and sediment transport and relevant bits. Hard rock folk may sneer at those sedimentary softies (all in good fun, o’ course), but you have to admit that was awesome.

A lot of you linked to this on Twitter and G+ and in the comments on our last installment of dam-busting mayhem. Fact is, Condit’s demise is what inspired me to write up Elwha. I wanted a warm-up. The dam removal on the Elwha River was impressive, I grant you that, but kind of pales in comparison to what they did to the Condit. Explosive breaches make for awe-inducing footage, especially when you’ve got photographers like Andy around to capture the moment.

So why the pyrotechnics rather than a slower breach like we saw at Elwha?

They wanted to flush out sediment quickly. This dam was holding back lots of the stuff. No kidding, right? There’s a great article up at the Columbian about the speed of the drainage and our old friend large woody debris (LWD). The river seems on track to become a typical Pacific Northwestern free-flowing stream complete with LWD and happy fishies. And we get to play in the mud for a while. Win for everyone!

The University of Montana Geomorphology Lab, along with the USGS, caught this footage of the reservoir draining. This one’s also got some hot sediment action: pay particular attention beginning at the 57-second mark.

Thick, muddy soup and debris, there. Rather put me in mind of a lahar, that did.

And this has got further sedimentary sensation: watch closely at 1:36, lower left corner.

Drained you like a bad bathtub. Heh.

And another, not time lapse this time, so you can really get a feel for the thing:

And, I think, one more, this one showing a brand-new waterfall and some really neat collapsing bits.

Right. I think that’s about enough dam demolition for now. Although I’m quite willing to revisit the subject if any of you have found delightful dam demolitions in other parts of the world…

Those interested in the Condit Dam’s history should check out Steve Stampfli’s posts part 1 and 2.

And everyone, please, raise a glass to Andy, whose time-lapse project isn’t stopping at giving us one of the best dam removal videos in the known universe, but will provide us an ongoing look at the restoration of a river. Be sure to follow his blog so you can keep up on the news. Gracias, Andy!

Comments

  1. geocatherder says

    Cujo359, I think the images were all taken too near the dam, where sedimentary infill has probably been going on at too high a rate to support plant life.

    Now that the dam’s gone, there’s still a heckuva lot of work to restore the river. They’re left with lots of unstable mud and no soil.

  2. F says

    It looks like it was almost completely filled with sediment.

    Lovers of fine sediments; hmm. If the sediment is more directly detritus of a clastic nature, I’d ring up Brian Romans. If were particularly sandy, Michael Welland. Right now, I’m thinking Anne Jefferson.

    I haven’t read up on the entire situation, but it seems like letting all that highly sediment-laden water go all at once like that can’t be a good thing. Visually cool as hell, though.