Special Section Seaway System Special Section

Special Section
Seaway System Special Section

Great Lakes St. Lawrence Seaway System.  If you are a user with disability and cannot view this image, please call 800-853-1351.
Great Lakes St. Lawrence Seaway System.

Since 1959, the Great Lakes St. Lawrence Seaway System (Great Lakes Seaway System or System) has been a vital waterborne transportation link for moving goods between the heartland of North America and international markets. The Seaway System, a binational waterway operated jointly by the United States. and Canada, encompasses the St. Lawrence River and the fi ve Great Lakes, and extends 2,300 miles from the Gulf of the St. Lawrence at the Atlantic Ocean to the Western end of Lake Superior at the twin ports of Duluth, Minnesota, and Superior, Wisconsin.

The U.S. St. Lawrence Seaway Development Corporation (SLSDC), an operating administration of the U.S. Department of Transportation and a wholly owned government corporation, is responsible for the operations and maintenance of the U.S. portion of the St. Lawrence Seaway between Montreal and Lake Erie. This responsibility includes maintaining and operating the two U.S. Seaway locks in Massena, New York, and vessel traffic control areas of the St. Lawrence River and Lake Ontario. In addition, the SLSDC performs trade development functions designed to enhance Seaway System utilization.

The SLSDC coordinates its activities with its Canadian counterpart, the St. Lawrence Seaway Management Corporation (SLSMC), particularly with respect to rules and regulations, overall day-to-day operations, traffic management, navigation aids, safety, environmental programs, operating dates, and trade development programs. The unique binational nature of the Seaway System requires 24-hour, year-round coordination between the two Seaway entities.

This chapter discusses many of the activities and programs of the SLSDC as well as a review of recent studies and analyses. Additional information on the Great Lakes St. Lawrence Seaway System can be found at http://www.greatlakes-seaway.com.


  • Since opening in 1959, more than 2.4 billion metric tons of cargo has moved on the binational waterway, valued at more than $400 billion.
  • A 2001 economic impact study conducted by Martin Associates of Lancaster, PA., found that maritime commerce on the Great Lakes St. Lawrence Seaway System annually sustains 150,000 U.S. jobs, $4.3 billion in personal income, $3.4 billion in business revenues, and $1.3 billion in federal, state, and local taxes.
  • A 2007 economic analysis conducted as part of the U.S. and Canadian, multiagency Great Lakes St. Lawrence Seaway Study concluded that the maritime commerce on the binational Seaway System provides approximately $2.7 billion in annual transportation cost savings compared to competing rail and highway routes and that the economic impact of a shutdown of either of the two U.S. locks would range from $1.3 to $2.3 million per day, depending on the length of the delay.
  • The Great Lakes Seaway System directly serves an eight-state, two-province region that accounts for 60% of Canada’s gross domestic product (GDP), 26% of the U.S. GDP, 55% of North America’s manufacturing and services industries, and is home to one-quarter of the continent’s population.