280 - An Integrated and Multidisciplinary Approach in Fish Passage Barrier Removal and Stream Restoration in Washington State

In 2013, a federal court injunction required Washington State to correct complete or partial fish barriers in Western Washington by removing state owned culverts that block access to spawning and rearing habitat for salmon and steelhead by 2030. As a result of the injunction, the Washington State Department of Transportation (WSDOT) is working to remove over 400 fish passage barriers at state highways by replacing existing culverts that act as barriers to fish passage with new crossings that restore access to habitat to aid in the protection and restoration of fish populations.
This presentation will provide an overview of the WSDOT fish passage barrier removal program, including examples of fish barrier removal projects to illustrate innovative hydraulic design processes and methodology. It will describe the multi-disciplinary, interagency approach used to design stream bed and structure openings that mimic natural channel processes and allow fish passage and improve habitat. It will also present how the hydraulic design process addresses constraints, opportunities, and risks associated with flood risk, potential channel aggradation or degradation, stream restoration, channel complexity, fish habitat, infrastructure safety, future compatibility, and climate resilience. Applications to Milwaukee stream restoration projects, local lead by HNTB, will also be presented.