Agreements signed for the Seattle and Tacoma Harbor dredging projects

The Port of Tacoma (POT) and the Port of Seattle (POS) have signed design agreements with the U.S. Army Corps of Engineers for the Seattle Navigation Improvement Project and the Tacoma Harbor Navigation Improvement Project.

Photo courtesy of the Northwest Seaport Alliance

The two projects are part of a comprehensive modernization initiative for the Northwest Seaport Alliance (NWSA) gateway that began nearly a decade ago.

The execution of design agreements with the Army Corps marks a critical milestone in this ongoing commitment to modernization and global competitiveness.

To address the evolving needs of the Port of Tacoma and Port of Seattle, the NWSA have worked alongside USACE to complete integrated feasibility studies and environmental assessments.

The results indicated that deepening both the Blair Waterway in Tacoma and the West Waterway in Seattle would significantly enhance the competitiveness of the gateway, enabling the waterways to meet the heightened draft requirements of larger ships and ensuring they can continue to support international trade and trade-dependent jobs across our region.

The Seattle Harbor Navigation Improvement Project was authorized by Congress in 2018 and the Tacoma Harbor Navigation Improvement Project was authorized in 2022.

Close coordination with nearby tribes and with stakeholders, including the U.S. Coast Guard, Puget Sound Pilots, and the Washington State Department of Natural Resources, will be integral to the deepening projects’ success.

Port of Tacoma Blair Waterway Deepening

The Port of Tacoma executed a design agreement with USACE for navigation improvements in the Blair Waterway on December 12, 2023.

The project’s scope includes the design of the Blair Waterway navigation channel deepening along with minor footprint modifications to facilitate larger vessel transit, sediment characterization, ship simulation, and the further consideration of the beneficial use of dredged material at the East Commencement Habitat Opportunity (formerly Saltchuk) area.

Port of Seattle West Waterway Deepening

On September 14, 2023, the Port of Seattle executed a design agreement with the USACE for the West Waterway Channel Deepening Project. This project aims to deepen the navigation channel to -57’ mean lower low water (MLLW) to keep the Seattle Harbor fully accessible to deep-draft vessels.

The project’s scope includes sediment characterization, engineering, and preparing of plans and specifications for construction.