Tacoma Harbor Navigation Improvement Study



The purpose of this study is to investigate navigation improvements to the Blair Waterway in the Port of Tacoma in Washington to achieve transportation cost savings (increased economic efficiencies) for larger vessels calling at the port.

The Blair Waterway is currently authorized to -51 feet. In the past decade, ships calling at the Northwest Seaport Alliance (NWSA) have increased in size and draft at a dramatic pace. The larger vessels have draft requirements deeper than -51 feet when fully laden, and therefore will face tidal delays and other transportation inefficiencies when arriving and departing the waterways. The NWSA is a rapidly expanding major port, ranking as the 28th largest U.S. port in terms of total tonnage, and the fourth largest container gateway.

The feasibility study determined there is a federal interest in participating in a cost-shared modification of the existing Tacoma Harbor project in the interest of navigation improvements and water resources development opportunities. The draft integrated feasibility report and environmental assessment (IFR/EA) identifies a recommended plan to deepen the existing channel to an authorized project depth of -57 feet MLLW, expand channel widths ranging from 450 feet to 865 feet, and expand the turning basin boundary to a diameter of 1,935 feet. Approximately 562,000 cubic yards (cy) of dredged material would be placed in the Dredged Material Management Program (DMMP) Commencement Bay open water disposal site and approximately 392,000 cy would be placed at an upland facility. In addition, the Saltchuk site, located northeast of the Blair Waterway, is a potential location for beneficial use of dredged material for environmental benefits. Although not the least-cost disposal option, the recommended plan includes beneficial use of approximately 1.85 million cy of material at the Saltchuk site reducing the amount of dredged material going to the DMMP Commencement Bay site.


The feasibility cost sharing agreement between the U.S. Army Corps of Engineers (Corps) and the Port of Tacoma was signed August 21, 2018. The Corps issued notice December 21, 2018 of plans to prepare, pursuant to the National Environmental Policy Act, an environmental assessment for the Tacoma Harbor, Washington, Navigation Improvement Project.  The purpose of this Public Notice was to solicit comments during an open comment period from interested persons, groups and agencies on the environmental impact of the proposal and issues for consideration in the IFR/EA. The Corps accepted public comments on the draft IFR/EA during a 60-day comment period beginning December 18, 2019, through February 16, 2020. Corps responses to public comments are included in the revised draft IFR/EA posted on this web page.

Posted to this page is the Draft Final IFR/EA along with the Draft Report of the Chief of Engineers. Currently the Draft Chief’s Report is in State, Agency and Tribal review.