Elwha sediment not just mud, it’s nourishment – Seattle Times

The sediment loads in the Elwha River are spiking because the reservoir behind former Elwha Dam is now completely gone. That means the settling of fines that used to occur in the lake is no longer happening so all that material is pouring into the river, and heading on down to the Strait of Juan de Fuca…. And while the amount of sediment is large — about 50 times normal levels for the Elwha — don’t call it mud. Sediment is a single word for a whole range of material that the river has been depositing behind the two dams for the past 100 years: rocks, gravel, cobble, sand, silt, and clay. About 40 percent of that material is expected to eventually make its way out to sea. Lynda Mapes at the Seattle Times explains.

http://seattletimes.nwsource.com/html/fieldnotes/2018106884_big_slugs_of_sediment_hitting_the_elwha_–_new_aerial_photos.html

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