Evolution and Process Improvements to Support Fish Passage & Stream Restoration at WSDOT

Year: 2022
Presenter/s: Gabe Ng
Symposium Session: 2022 - 04 Stream Restoration from the (WSDOT) Transportation Perspective
Topics covered: fish passage, fish-salmon, instream structure (culvert/bridge/dam), lessons learned, stream, and wood


The Washington State Department of Transportation is the steward of a multimodal transportation system and responsible for ensuring that people and goods (fish?) move safely and efficiently.

WSDOT has evolved from replacing fish barrier culverts with stream simulation designs (openings; 1.2 x BFW +2 feet) to considering larger scale channel continuity and stream restoration beyond the project limits to better support our natural resources.

What are we learning from the natural world, our past successes and failures and how do we apply these improvements inside our crossings and within our project limits? How does our in-water features, channel complexities, mimic the surrounding natural processes and geomorphic characteristics using biomimicry? How are we developing bank strength inside crossings where soils and root structure is limited?

Where can we get better, what ideas do you have?

The greatest challenge is balancing stewardship of our natural resources and stewardship to our transportation system in a fiscally responsible manner. What is the benefit and at what cost? Effort to create larger openings can be minimal at times. Effort to add LWM adjacent to the project when you’re already doing work, seems trivial.

WSDOT is designing for the future of a stream and recognizing channel response after a project is built by accounting for changes to future flow, long-term aggradation or degradation as well as ensuring forward compatibility with future upstream/downstream barrier corrections.

This presentation will share the evolution of WSDOT’s journey to improve on fish barrier removal projects; identify our mistakes and taking pride in our successes as well as see where we are moving for a better tomorrow. Project examples may include SR530 Schoolyard Creek, SR9 Gribble Creek, SR9 Landingstrip Creek, SR203 Loutsis Creek, SR504 Wooster Creek, SR532 Secret Creek and others.