US Army Corps of Engineers
Seattle District

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 will analyze alternatives associated with opportunities for channel deepening in the NWSA’s Tacoma Harbor. Opportunities may exist to increase safety while improving efficiency of vessels transiting Tacoma Harbor’s Blair Waterway. Future evaluation may be done for the Sitcum Waterway, but early analysis led USACE and the Port to drop the Sitcum Waterway from this General Investigation’s study area. Deepening the  Blair Waterway may result in cost and time savings, potentially lowering project operations and maintenance costs, as well as potentially allowing for the removal of draft restrictions for certain vessels. By being able to more fully load vessels, transportation costs will potentially decrease, ultimately leading to more cost-efficient transportation system as well as improved capacity for increased trade and lower priced goods. The feasibility study will determine whether 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 resource development opportunities.

The feasibility cost sharing agreement between the U.S. Army Corps of Engineers and the Port of Tacoma was signed August 21, 2018. An alternatives milestone meeting held in November 2018 confirmed alternatives to be evaluated during the study, including full channel deepening (-52 feet Mean Lower Low Water (MLLW) through -58 feet MLLW) and channel segments defined by container terminal location. The team will evaluate depths up to -58 feet MLLW to determine the preferred alternative (National Economic Development plan) based on commodity forecast, vessel loading analysis, fleet forecast, transportation cost savings modeling and project life-cycle costs. The no action alternative will also be evaluated. 

The U.S. Army Corps of Engineers 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 Corps will analyze alternatives for navigation improvements to the Blair Waterway of Tacoma Harbor, including potential deepening and widening of the waterway. The purpose of this Public Notice was to solicit comments during an open comment period through February 21, 2019, from interested persons, groups and agencies on the environmental impact of the proposal and issues for consideration in the EA.

Officials with the Port of Tacoma and the U.S. Army Corps of Engineers, Seattle District, held a public informational meeting January 17 to outline the feasibility study and environmental assessment for potential improvements to the Blair Waterway. Such improvements could include deepening and widening to increase big-ship access along the waterway. Interested members of the public were invited to attend one of the sessions or comment in email or mail. The Corps is considering all submissions received in the public comment period December 21, 2018, through February 21, 2019.