Helping salmon thrive on the Olympic Peninsula

Salmon protection and habitat restoration are at the heart of an extensive fish passage barrier removal project initiated by the Washington State Department of Transportation (WSDOT).

Throughout Washington state, there are thousands of rivers and streams that flow under roads and highways. When the highways were designed decades ago, culverts were installed so water could pass under them. Many were installed before scientists fully understood the needs of salmon, steelhead, and other fish.

Over time, studies have shown that these culverts are impeding fish migration and contributing to dwindling numbers of salmon. And in March 2013 a federal court ruled that by 2030, WSDOT is responsible for removing approximately 1,000 state-owned culverts that block habitat for salmon and steelhead.

A team of four civil engineering and environmental services firms—Parametrix (the project lead), SCJ Alliance, David Evans Associates, and HDR—has been selected to design solutions for removing 24 of these culverts. This initial phase covers six of the seven WSDOT Olympic Region counties.

An example of a culvert replacement on Mill Creek, a tributary of the Cowlitz River in Lewis County by Washington DNRCC BY-NC-ND

Removing just one barrier can improve fish access to significant high-quality habitat, upstream and down. This includes enhancing access to the habitat they need to spawn and rear their young, helping their overall populations thrive. Replacing the culverts with new fish-passable structures also benefits stream and river ecosystems, the sport and commercial fishing industries, Tribal communities, and wildlife such as the southern resident orca.

Many of the initial 24 culverts are on remote sections of U.S. Highway 101. This will require careful planning to minimize travel interruptions during construction where detour routes are limited or simply don’t exist. Minimizing impacts to the surrounding environment, such as trees, wetlands, potential cultural resources, is a priority.

An example of a culvert replacement on Toodie Creek, a tributary of the Tahuya River in Mason County by Washington DNR / CC BY-NC-ND

To efficiently tackle these challenges, the project team is divided into four smaller teams each responsible for delivering the design for a bundle of culvert replacements. SCJ Principal and Transportation Design Manager Scott Sawyer, PE, is serving as one of the bundle managers. His team includes SCJ staff who specialize in roadway and stormwater design, traffic engineering, and soil and wetland science. In addition, the preparation and management of the environmental documentation and permit support for all 24 culvert replacements is being led by SCJ Principal Jean Carr, LEED AP BD+C, and supported by SCJ’s environmental planning team.

Salmon and steelhead are some of the Pacific Northwest’s most important foundation species. SCJ is proud to be a part of an experienced team of professionals working to restore habitat so that fish, and the communities that depend on them, can thrive.

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