Project overview

In 2017, the City of Seattle  completed major elements of the Seawall Project, replacing the aging, failing seawall along the waterfront and improving the lost nearshore environment. The new seawall:

  • Protects public safety
  • Meets current seismic standards
  • Improves the salmon migration corridor
  • Will last more than 75 years
  • Acts as the foundation of Seattle’s future waterfront

Original seawall

The existing seawall had protected Seattle for more than 70 years, but time and a harsh marine environment weakened the structure. Cracks within the wall allowed salt water and gribbles to infiltrate and eat away at the estimated 20,000 old growth timber piles that supported the old seawall. As the tide receded through cracks in the wall, it carried with it fill soil that resulted in dangerous voids underneath Alaskan Way.

New seawall

The new seawall was built to current seismic standards and is designed to last more than 75 years. Improvements include stabilizing the existing soil behind the seawall face, as well as moving the seawall 10-15 feet eastward to accommodate construction and create additional space for habitat.

The Seawall Project is designed to maintain flexibility for future opportunities. All surface features west of the restored sidewalk were built in their final state at the completion of the seawall project. Elements east of the sidewalk, such as the roadway, were restored in an interim condition and will be redesigned and rebuilt as part of the  Waterfront Seattle Program.

Several structural elements make up the new seawall, including jet grout columns, light penetrating surfaces, face panels and more.

Habitat enhancements

When Seattle’s waterfront was developed, Elliott Bay lost many of the habitat features associated with its native intertidal habitat, including sloping beaches, crevices, and vegetated hiding places for fish. Restoring the salmon migration corridor and improving ecosystem productivity are important objectives of the Seawall Project.

The City of Seattle aimed to create an enhanced fish migratory corridor in four primary ways:

  • Providing more light: Light penetrating surfaces in the cantilevered sidewalk will allow light to pass through to the water below.
  • Creating shallower habitat: Habitat benches will provide a shallow water habitat with gravel surfaces to act as hiding and foraging places for aquatic life.
  • Incorporating more texture: The face of the new seawall has cobbled surfaces and shelves to promote growth of vegetation and marine invertebrates.
  • Providing riparian vegetation: Native riparian vegetation will be planted along the seawall and at a new intertidal beach.

Quick links

Photos + videos

Check out our photos and videos to learn more about past Seawall Project work. More photos of past construction can be found on the SDOT Flickr account.

Contact us

Major construction work on the Seawall project is now complete and all calls are now directed to the Waterfront Project hotline (206-499-8040; staffed from 8 AM to 5 PM, Monday through Friday). 

Environmental review

The Seattle Department of Transportation (SDOT) conducted a thorough environmental review process, as part of the State Environmental Policy Act (SEPA), for the Elliott Bay Seawall Project. 

Supplemental Environmental Impact Statement

Final SEIS

Draft SEIS in Focus

Draft SEIS

The release of the FEIS on March 14, 2013 completed the SEPA process for the Elliott Bay Seawall Project.

Final EIS in Focus

Final EIS

Draft EIS Executive Summary

Draft EIS

Scoping Materials

Background Information