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Seattle Harbor Navigation Improvement Project

Feasibility Study on the Costs and Benefits of  Channel Deepening at Port of Seattle Terminals

The largest container vessels calling at West Coast ports today have roughly twice the capacity of those that served our ports just five years ago. In order to remain a competitive trade gateway for Northwest shippers and to preserve the many jobs related to maritime trade, the Port of Seattle must take steps to better accommodate these larger vessels. One such step is to study whether deepening is needed in specific areas adjacent to the port’s container terminals in the East Waterway and West Waterway. While our channels are mostly -51’ or deeper, some shallower spots present navigational and safety challenges. The port has asked the U.S. Army Corps of Engineers to study the feasibility of a potential deepening project. 

Project Milestones

The study is on track to be completed on time in the fall of 2017. Port of Seattle is one of the first ports in the nation to participate in the Corps of Engineers’ new, streamlined process for deepening studies. Ours is the only Corps navigation study that remains on schedule for completion within the prescribed three-year target.  This is significant because traditionally studies at other ports have taken much longer—10 years or more in some cases. 
The Corps completed the alternatives milestone on schedule, selecting the alternatives that would be considered during the feasibility study and on the criteria that will be used to evaluate them. The next milestone is the Tentatively Selected Plan Milestone, when the Corps project team submits their recommended alternative to Corps leadership for approval and publishes it for public review. The review and comment period for the public is Aug. 2-31, 2016.

Ships are getting bigger

Today Port of Seattle regularly receives calls from ships with capacities up to 10,000 TEUs,* whereas 5,000 to 6,000 TEUs was the norm just a few years ago.   Seattle ocean carriers are leading the big ship trend. All major West Coast ports are deepening their navigation channels in order to serve these container ships, which have draft requirements deeper than 50’. 

The economic grounds for studying deepening

The deepening initiative seeks to protect jobs and help preserve the infrastructure that allows our region’s farmers and manufacturers to connect to global markets.  Insufficient channel depths require ocean carriers to take on less cargo or delay departures.  These limitations hinder shippers’ ability to operate in the Puget Sound region, especially for exports, which tend to be heavier than imports.  It also has financial implications for ocean carriers and can induce them to discontinue services to a port. 
Port of Seattle faces stiff competition from both East Coast and West Coast ports.  Seattle is losing cargo to the Canadian ports of Vancouver and Prince Rupert, which has no depth limitation.  Nearly 6,200 jobs are at risk from cargo diversion to Canada alone, as are thousands of other jobs with shippers who rely on the Seattle seaport.

The Port’s commitment to environmental protection

The Feasibility Study will analyze the environmental impact of various deepening alternatives. The Port of Seattle is dedicated to environmental stewardship and will ensure any deepening plan supports our commitment to protecting water quality and wildlife in Puget Sound.
Should the study identify an economically viable alternative in the national interest, initial analysis indicates the project’s environmental impacts are likely to be positive:
  • The project would enable the fleet of new, more environmentally friendly container ships to call Seattle.
  • Larger ship capacities result in lower emissions because fewer ships are required to carry the same amount of cargo.
  • Because Elliott Bay is naturally deep, accommodating larger ships should require only minimal dredging.
  • Deepening activity would be coordinated with existing cleanup sites and utilize best practices to mitigate negative construction impacts.



What will a Corps of Engineers Feasibility Study involve?
  • Three year study, beginning in fall 2014
  • Outreach to incorporate input from stakeholders and community members
  • Exploration of several deepening alternatives involving depths between -51’ to -55’
  • Analysis of costs and benefits for each alternative that will consider economics, environmental issues, navigational safety and cultural resources
  • Visit the Army Corps Seattle Harbor Navigation Project Website
  • Read the Notice of Preparation