Reclamation Information Sharing Environment (RISE)

Elwha River surrogate bed load continuous bed load measurements for Water Years 2013 through 2019. In 2008 and 2009, a series of bed load impact plates was installed across a channel spanning weir on the Elwha River, Washington. This is the first permanent installation of its kind in North America and one of the largest anywhere. The purpose of this system is to measure coarse bed load during and after the removal of Elwha and Glines Canyon Dams. It is estimated that 21 million cubic meters of sediment have accumulated behind both dams, with 45–50% of the total accumulated volume expected to be eroded through natural processes. The impact plate system consists of 72 plates installed at a diversion weir downstream from both dams and 5 km upstream from the river mouth. Of the 72 plates, 46 are instrumented with a geophone and 26 with an accelerometer. The data is structured such that zeros indicate no bed load activity. If there is no data for a particular date-time then the computers were not recording data at that time. There are also missing periods where there is no date and time, also indicating a computer or power malfunction. References: Hilldale, R.C., Carpenter, W.O., Goodwiller, G., Carpenter, J.P., and Randle, TJ (2014). "Installation of impact plates to continuously measure bed load: Elwha River, Washington, USA", J. Hydr. Engnr. Vol. 141, Issue 3, https://doi.org/10.1061/(ASCE)HY.1943-7900.0000975 Kuhnle, R.A., Wren, D.G., Hilldale, R.C., Goodwiller, B.T., and Carpenter, W.O. (2017). "Laboratory calibration of impact plates for measuring gravel bed load size and mass", J. Hydr. Engnr. Vol. 143, Issue 12, DOI: 10.1061/(ASCE)HY.1943-7900.0001391. Hilldale, R.C., Carpenter, W.O., Pittman, S., Goodwiller, B., and Dombroski, D. (2019). "Final calibration of the Elwha impact plate system", Proc. SedHyd: Sedimentation and Hydrologic Modeling, , 24-28 June 2019, Reno, NV. https://www.sedhyd.org/2019/proceedings/SEDHYD_Proceedings_2019_Volume5.pdf Other References: search Elwha bed load