Seepage issue resolved, construction resumes at Soo Locks area crib dam project

Published May 26, 2011
The U.S. Army Corps of Engineers, Detroit District announces construction begins again after an
interruption of work involving repairs under the crib dam on Soo Locks area property at Sault Ste. Marie, Mich.

Increased rates of seepage through the crib dam have been brought under control. After thorough investigation, Corps of Engineers staff discovered a hole in the concrete liner on the dam structure adjacent to the crib dam which was allowing water to flow into the crib dam on the north side and seep out on the south side. Crushed stone was used to fill the void and the hole was capped with a steel plate. The interruption of work on the Crib Dam Rehabilitation Project has ended and crews returned to work May 24.

Recently, 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. The increased seepage has been stopped and all construction work will resume as scheduled.

Ryba Marine, from Cheboygan, Mich., was awarded a more than $4 million contract to complete the project that will rehabilitate the 60-year old timber crib dam structure adjacent to one of the hydroelectric power generation plants located on Corps property.

The contractor is scheduled to remove the upper 12 feet of the existing crib dam structure and replace it with
reinforced concrete, stone fill and a steel sheet pile face to provide a more durable and water-tight structure.
The purpose of the crib dam is to control flow so water elevation is maintained at a level that will allow hydroelectric power generation and navigation above and below the dam.

While seeking the cause of the increased seepage and developing solutions, the Corps had to shut down the power plant only a few times with minimal impact to the area. However, throughout the construction project there are anticipated hydroelectric power plant shutdowns scheduled during off-peak hours, also with minimal impact. Although, the Soo Locks facility uses three percent of the power generated, the other 97 percent is sold for use in the eastern Upper Peninsula.

Additional details maybe available on our website at, or call Lynn Duerod, public affairs officer, at 313-226-4680. Photos of the crib dam at the Soo Locks are available on our Flickr site at Media wishing high-resolution photos should contact the Public Affairs Officer.
Lynn Duerod

Release no. 052611-01