Elwha River Restoration Designs within the Surface Water Diversion Reach

This project supported the development of final project designs within a reach of the Elwha River reach that contains the Elwha River surface water diversion (ESWD). This reach of the Elwha River was historically channelized by bank armoring in order to force the river to flow through a water diversion structure utilized by the city of Port Angeles. We conducted an analysis and engineering design that incorporated instream large woody debris placement and channel reconfiguration to promote long-term ecological functions. This design was implemented by the National Park Service and Bureau of Reclamation and use constructed in the summer of 2018. The project has performed successfully to date and has alleviated the need for any further bank armoring.

The project resulted in improved habitat conditions in the reach of the river flowing through the Elwha Surface Water Diversion. These improvements will benefit multiple species of salmonids at both juvenile and adult life stages. The designs developed through this project incorporated features that increased channel complexity and access to off channel habitat that will benefit migrating salmon and provide rearing habitat for juvenile salmonids. An ancillary benefit includes maintaining flow levels to an diversion structure that provides rearing water to tribes hatchery that is used to support recovery programs in the Elwha River and a municipal water supply.