Creating a Salmon-Friendly Seawall

 

 

The Elliott Bay Seawall Project will replace the failing seawall from S. Washington Street to Broad Street, providing the foundation and structural support for a new waterfront. In addition to protecting the waterfront, replacing the seawall provides opportunities for habitat restoration in our urban environment. Restoring the salmon migration corridor and increasing ecosystem productivity are important objectives of the Elliott Bay Seawall Project. Tens of thousands of salmon and trout migrate through Elliott Bay and then up the Duwamish River and its tributaries every year to spawn. The juvenile fish  return downstream to enter Elliott Bay in the spring and summer. We like to say that some “turn left” and some “turn right”—those that travel left head out around Alki Point and those that turn right travel right through the Elliott Bay Seawall project area. 

Today, 60 percent of Seattle’s waterfront is covered by piers and other over-water structures, resulting in stark contrasts between light and dark areas. The naturally lighted areas along the central waterfront show a diversity of habitat, while the dark areas (under piers) do not support plant growth or other significant habitat life. Migrating salmon are less susceptible to predators in locations with better habitat conditions, including lighted waters, substrate for plant life, and shallower water. To make life better for juvenile salmonids and other marine creatures, SDOT is designing a shallow, lighted migratory corridor along the seawall to enhance habitat for juvenile salmon and other marine life. This design is being informed by ongoing field research by the team’s biologists and the University of Washington on fish behavior and existing marine life in the project area.

Watch this video to  learn more about how ecosystem restoration is being incorporated into the Elliott Bay Seawall Project.

We are planning to restore habitat by using the following features: