Monday, January 2, 2012

Ediz Hook getting a new dose of gravel

Just wanted to add a few views of the most recent gravel nourishment on Ediz Hook. The Army Corps contracted with Bruch & Bruch construction (a local P.A. based construction firm), agreeing to pay them $626,000 to dump and spread 50,000 tons (about 40,000 cubic meters - probably somewhere, in a sorta kinda way- around what the Elwha spits out during a big flood) of mostly gravel (with some sand mixed in) in the intertidal zone. For the two short (~500') hook segments over which the gravel is spread the hook gets about 20' wider. But its obvious that this material is quickly transported along shore (and, I am guessing a lot of it is transported off-shore), spreading out along the hook, due to the oblique wave angle. It would be pretty cool to tag some of these...

Its amazing to see the slopes maintained by the seaward edge of this gravel pile. Unlike most of our beaches, which are mixed, the "beach" formed by this temporary sediment pile is a true gravel beach, of the sort studied in the UK. Waves interacting with this beach crash impressively on the steep beach face, and standing on top of the pile you feel like you are going to get washed away by the run-up. But then, the whole wave just dies as the energy is dissipated into the void in the rocks. As a result, even though the beach is so steep, there is very little apparent reflection.

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