Tacoma Harbor Navigation Improvement Project



The purpose of this project is to make 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 Seattle District completed a feasibility study in 2022 of navigation improvements at Tacoma Harbor; received authority for the navigation improvements in 2022; and received appropriation to move to the next phase Pre-Construction Engineering and Design in 2023.

Before completion of the Feasibility study, the Blair Waterway was authorized to -51 feet relative to mean lower low water (MLLW). 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 Port of Tacoma is a rapidly expanding major port, currently ranking as the 29th largest U.S. port in terms of total tonnage (containerized and non-containerized), ninth largest container port individually, and the fifth largest container gateway when combined with the Port of Seattle as the Northwest Seaport Alliance. Tacoma Harbor is an essential part of the U.S. west coast and national transportation system and is a critical gateway for the import and export of goods moving between Asia, the Pacific Northwest, and the U.S. Midwest.

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 final 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 (USACE) and the Port of Tacoma was signed August 21, 2018. The USACE 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 USACE accepted public comments on the draft IFR/EA during a 60-day comment period beginning December 18, 2019, through February 16, 2020. USACE responses to public comments are included in the final IFR/EA posted on this web page. State & Agency Review occurred July 13, 2021, through August 12, 2021. USACE Northwestern Division approved the final IFR/EA on May 3, 2022. The Report of the Chief of Engineers was signed May 26, 2022, at USACE Headquarters. USACE Seattle District Commander Col. Alexander Bullock signed the Finding of No Significant Impact (FONSI) on September 27, 2022. The signed Chief’s Report and FONSI are posted in the Links section of this web page. Congress authorized the Tacoma Harbor Navigation Improvement Project in Section 8401(1) of the Water Resources Act of 2022 (Public Law 117-263, December 23, 2022).


The Design Agreement between the U.S. Army Corps of Engineers (USACE) and the Port of Tacoma was signed December 12, 2023. USACE and the Port of Tacoma began the Pre-Construction Engineering and Design (PED) phase of the project on December 12, 2023.