Reclamation Information Sharing Environment (RISE)

The purpose of this study was to assess and document historical and current geomorphic conditions and model current hydraulic conditions in the mainstem Clearwater River corridor. We conducted hydraulic modeling along approximately 20.5 river miles of the Clearwater River using 14 single-inlet discharge flows as well as flood flows that exhibit increasing discharge with distance downstream, for the 2-yr, 5-yr, 10-yr, 25-yr, and 50-yr recurrence interval median peak flow discharge based upon flow frequency analysis. The model output includes attributes for depth, velocity, shear stress, and Froude number, offering the ability to assess potential restoration areas based on hydraulic thresholds relevant to specific goals. The hydraulic modeling results are available at https://data.usbr.gov/catalog/8042/item/133852. In addition to hydraulic modeling, we conducted geomorphic mapping from 1939 to 2017 and to identify historical channels, bars, and landslides along the mainstem Clearwater River. The geomorphic mapping shapefiles are available at https://data.usbr.gov/catalog/8042/item/133851. This work is part of a larger geomorphic analysis and hydraulic modeling study on the Clearwater River. The study results provide baseline data to inform Quinault Indian Nation efforts to prioritize river corridor segments future restoration alternative analysis.