FY 2019 Elwha ELJ Support

This project was finally completed in the fall of 2024. The project was delayed by Covid, permitting, and need to acquire additional funding due to inflation to complete the project. Seventeen engineered logjams were installed in the 0.5 mile Ranney Reach during the summer of 2024. PCSRF funding was used to purchase materials for the project, namely logs with rootwads attached.

Construction of ELJs in the Ranney Reach (River Mile 3.0-3.5) is designed to affect channel morphology by promoting conditions consistent with a forested island or anastomosing channel type. An array of ELJs has been arrayed (in the design process) to slow stream velocities and split flows though the reach in order at achieve the target geomorphic conditions. Two-dimensional modelling in the reach show that the ELJs will work to slow stream velocities through the reach which will result in reductions in shear stress on the bed. As a result, substrate will change from cobble dominated to gravel which will result in improved spawning habitat for all species of Pacific salmon. ELJs will also result in the formation of new pools with complex cover that will provide rearing for both juvenile salmon as well as pre-spawning holding habitat for adult salmon. Floodplain revegetation will be conducted following ELJ construction so that trees can grow to support natural habitat forming processes.