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Soo Locks Complex


Soo Lock Information

The St. Marys River connects Lake Superior with Lake Huron in Sault Ste. Marie, Michigan.  The water drops approximately 21 feet in an area known as the St. Marys Rapids.  This natural barrier to navigation led to the construction of the St. Marys River Complex.   The Complex consists of the four navigation locks (MacArthur, Poe, Davis, and Sabin Locks), two hydropower units, and Compensating Works structure. All of the Complex features as well as the connecting dikes function as a dam.  All depths are referenced to low water datum plane at Father Point Quebec, International Great Lakes Datum 1985 (IGLD 85).  The low water datum for the upstream end is 600.4 ft (IGLD 85) and the low water datum for the downstream end is 578.7 ft (IGLD 85

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News Release

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Seepage issue causes work delay at Soo Locks area crib dam project

The U.S. Army Corps of Engineers, Detroit District announces an interruption of work and the possibility of modifying the repairs for the Soo Locks Crib Dam project. While the contractor was working in the area, Corps of Engineers staff noticed an increased rate of seepage through the structure above what was observed prior to construction. Because of this increased seepage the Corps has stopped all work on the project to evaluate erosion rates, find possible sources of the seepage, and develop solutions for controlling or eliminating the increased seepage. Click here for official press release.

As additional details are available or changes in conditions occur, information will be posted on this site and distributed through the Detroit District's Public Affairs Office.

Crib Dam

Soo Locks

Soo locks property with timber crib area near buidling (hydroelectric power plant) on the far left

Crib Dam Power Plant

One of the hydroelectric power plants at the Soo. Work area for the Soo crib dam repair project is near the center of the photo where the foot bridge ends.

Crib Dam Power Plant

Hydroelectric power plant in the foreground -- looking west towards Lake Superior.

Two Soo Power Plants

Both hydroelectric power plants at the Soo with entire Center dike between the two plants where the crib dam is located.