Daily sediment loads during and after dam removal in the Elwha River, Washington, 2011 to 2016

15-minute stage data and discharge rating curves from McDonald Bridge gage (USGS Gage 12045500) were used with a routing time and precipitation volume-based adjustment model to derive daily discharge estimates for the diversion weir reported here. Daily records of suspended-sediment concentration (SSC) were calculated using a combination of standard flow-weighted suspended-sediment samples, automated point-sampler daily composite samples, and three sediment-surrogate instruments--two optical turbidimeters and one acoustic Doppler velocity meter (ADVM)--using established techniques (Magirl and others, 2015). Daily bedload sediment transport values for three size fractions were calculated using a combination of steel bedload-impact plates and physical bedload sampling during November, 2012; March, May, and June 2013; and April 2014 at the Diversion Weir gauge (Magirl and others, 2015; Hilldale and others, 2015). These techniques estimated the proportion of bedload in the > 16mm and the 2-16mm size classes, but did not capture bedload transport of particles smaller than 2 mm, which were estimated from a combination of regional and comparative studies in high-sediment load rivers--including other dam removal studies--using constant ratios of measured total bedload to total sediment discharge of 15 percent for water year 2012 and 25 percent for later years.

Corrected name of theme keyword thesaurus from ISO 19115 Topic Categories to Category.

Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed.