The U.S. Army Corps of Engineers Nashville District has awarded the final contract for the Chickamauga lock replacement project to heavy-civil and marine contractor C.J. Mahan Construction Co., Urbancrest, Ohio.
The $192.1 million base contract covers construction of downstream approach walls, breaching the existing dam to connect the upstream approach to the new lock, bringing the new lock into operation, and removing the cofferdam. The deal has a total cumulative face value of $558.4 million.
The Chickamauga Dam is located at Tennessee River mile 471 in Chattanooga, Tenn. Its existing 360'x60' lock chamber, built in 1940, can accommodate only one 195'x35' jumbo barge per lockage.
"We are proud to award this contract for this important navigation infrastructure project," Lt. Col. Guillermo Guandique, Nashville District commander, said in a statement. "The entire USACE team managing this project is ready to work with our contract partner and move the project to the finish line and deliver a new and larger operational lock."
The new, larger 600'x100' lock chamber will handle nine jumbo barges in one lockage compared to one barge per lockage in the existing lock, an 80% increase in efficiency for the navigation industry, according to the Army Corps.
"When complete, recreational vessels and commercial tows will maintain access to 318 miles of navigable waterways upstream, and tows will more efficiently deliver commodities up and down the Tennessee River," said Bob Winters, Nashville District project manager.
Construction activities under the final contract will begin after the upstream approach wall work is complete and portions of the cofferdam work area are made available by the lock chamber contractor. Lock chamber construction by Shimmick Construction Co. is approximately 76% complete. Construction of the upstream approach wall, also by C.J. Mahan, is approximately 70% complete as of February 2026.
Navigation traffic will transition to the new lock during the approach wall and decommissioning contract work.
The Chickamauga lock replacement project is part of a broader effort to modernize aging inland waterway infrastructure. Locks and dams throughout the Tennessee River system and other major U.S. waterways have exceeded their design lives, creating delays and maintenance challenges for commercial navigation.
The $954 million project is expected to be operational in 2028, with final project completion by 2029 to address critical structural issues.
