Project overview

The City of Seattle is replacing the aging, failing seawall along the waterfront and improving the lost nearshore environment. The new seawall will:

  • Protect public safety
  • Meet current seismic standards
  • Improve the salmon migration corridor
  • Last more than 75 years
  • Act as the foundation of Seattle’s future waterfront

Original seawall

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

New seawall

The new seawall will be 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 will be built in their final state at the completion of the seawall project. Elements east of the sidewalk, such as the roadway, will be restored in an interim condition and then redesigned and rebuilt as part of the Waterfront Seattle Program.

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 is aiming to create an enhanced fish migratory corridor in four primary ways:

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

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