Crooked River Restoration

RDG was retained by The Nez Perce Tribe and Nez-Perce Clearwater National forest to prepare a restoration design for two miles of the Crooked River, a tributary to the South Fork Clearwater River near Elk City, Idaho. The purpose of the project is to address the impacts of historical dredge mining on aquatic habitat conditions in the Crooked River for threatened and endangered fish species including steelhead trout and bull trout, as well as other focal aquatic species including spring Chinook salmon and westslope cutthroat trout. The multi-phase restoration plan addresses 115 acres of valley bottom over several construction seasons.
RDG assisted the project team by providing technical support to address key feasibility issues and overcome complex site constraints. The restoration plan included the design of a temporary bypass channel to divert water around the work area during construction. Hydraulic modeling and habitat mapping were completed to characterize expected improve-ments to aquatic habitat for focal species. Phasing plans were developed to balance earthwork quantities and to meet budget allowances. The first project phase was completed in 2016. RDG is continuing to provide technical support during project implementation.