Wednesday, January 29, 2014

Glines Canyon Dam now invisible

In case you didn't notice the latest happenings on the Elwha River - the Glines Canyon Dam, while still a bit there, is now invisible. A blast a few days back (see John Gussman's footage of the blast here) took out the last remaining section of the dam visible to the web cam.

Before: Glines Canyon Dam Site on 26 January 2014

After: Glines Canyon Dam Site on 27 January 2014

The blast also lowered the river at the dam site, increasing the gradient of the river, and thereby increasing its erosive capacity. As a result there was an almost immediate uptick in turbidity downstream:

turbidity at the MacDonald Bridge gage on the Elwha River, 26-28 January 2014

Typically turbidity is closely linked to river flow, but in this case there was no increase in river flow - this turbidity was generated by the dam blast.

River discharge, MacDonald Bridge, 26-18 January 2014

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