 | This articleneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Great Lakes Waterway" – news ·newspapers ·books ·scholar ·JSTOR(June 2015) (Learn how and when to remove this message) |
TheGreat Lakes Waterway (GLW) is a system of natural channels and artificiallocks andcanals that enable navigation between the North AmericanGreat Lakes.[1] Although all of the lakes are naturally connected as a chain, water travel between the lakes was impeded for centuries by obstacles such asNiagara Falls and the rapids of theSt. Marys River.[2]
Its principalcivil engineering works are theWelland Canal between LakesOntario andErie, and theSoo Locks betweenHuron andSuperior. Dredged channels were constructed in theSt. Marys River, theDetroit River,Lake St. Clair and theSt. Clair River between Huron and Erie. Usually, one or moreU.S. Coast Guardicebreakers help keep the water passage open for part of the fall and early winter, although shipping usually ceases for two to three months thereafter. TheSt. Lawrence Seaway allows navigable shipping from the GLW to the Atlantic Ocean, while theIllinois Waterway extends commercial shipping to the Mississippi River and the Gulf of Mexico. The Great Lakes Waterway is co-administered by the governments ofCanada and theUnited States.
The waterway allows passage from the Atlantic Ocean to the inland port ofDuluth on Lake Superior, a distance of 2,340 miles (3,770 km) and toChicago, on Lake Michigan, at 2,250 miles (3,620 km).[3] The elevation change from Lake Superior to sea level is 601 feet (183 m).
Together with theSaint Lawrence Seaway, the Waterway accommodates both ocean-going vessels and ore, grain, and coal-bearinglake freighters that travel fromthe system's saltwater outlet to itsfar interior. The Waterway has largerlocks and deeperdrafts than the lower Seaway, limiting large freighters to the four lakes upstream of the Welland Canal and Lake Ontario and similarly restricting passage beyondSaint Lambert, Quebec by larger ocean vessels. The two waterways are often jointly and simply referred to as the "St. Lawrence Seaway", since the Great Lakes, together with theSt. Lawrence River, comprise a single navigable body offreshwater linking theAtlantic Ocean to the continental interior. Major ports on the Great Lakes Waterway includeDuluth-Superior, Chicago, Detroit,Toledo, Cleveland,Two Harbors,Hamilton andThunder Bay.[4]
Shipping channels separate upbound traffic from downbound traffic. The upbound direction is away from the St. Lawrence River (westerly or northerly except in Lake Michigan where upbound is southerly). Channels are marked with navigation buoys in constricted areas and pilots are required on foreign boats. Recreational boats can use or cross the ship channels, but the large boats, with limited maneuverability, have right of way.
Map of the North American Great Lakes and the St. Lawrence Seaway based on a document from 1959, depicting the entire length beginning at the Gulf of Saint Lawrence in the east to the westernmost terminus at Lake Superior.
