At A Glance: Chickamauga Lock Final Contract
- Contractor: C.J. Mahan Construction Company LLC
- Base Award: $192,143,924.90
- Location: Tennessee River Mile 471 (Chattanooga, TN)
- Project Phase: Final Contract (Approach Wall & Decommissioning)
- Impact: 80% Efficiency Increase for Navigation
NASHVILLE, Tenn. – The U.S. Army Corps of Engineers Nashville District announces the award of the Approach Wall and Decommissioning Contract yesterday to C.J. Mahan Construction Company LLC. This is the final contract to complete the Chickamauga Lock Replacement Project at Tennessee River mile 471 in Chattanooga, Tennessee.
USACE is awarding a base contract of $192,143,924.90. Under this base contract, C.J. Mahan will construct the downstream approach walls, breach the existing dam to connect the upstream approach to the new lock, bring the new lock to operation and remove the cofferdam.
“We are proud to award this contract for this important navigation infrastructure project. 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,” said Lt. Col. Guillermo Guandique, Nashville District commander.
Construction activities included in the final contract are primed to start after the upstream approach wall work is complete and portions of the coffer dam work area are made available by the lock chamber contractor. Current lock chamber construction by Shimmick Construction Company Inc., is approximately 76% complete. Construction of the upstream approach wall, also by C.J. Mahan, is approximately 70% complete as of February 2026 and on schedule to complete prior to the release date for work to commence on the new contract.
Navigation traffic will transition to the new lock during the Approach Wall and Decommissioning Contract. The new lock will handle nine jumbo (35-foot by 195-foot) barges in one lockage compared to one barge per lockage in the existing lock, an 80% increase in efficiency to the navigation industry.
“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.
Frequently Asked Questions: Chickamauga Lock Project
Why is the Chickamauga Lock being replaced?
The existing lock is suffering from “concrete growth” (alkali-aggregate reaction) which threatens its structural integrity. Additionally, the old lock is small (60×360 feet), creating a bottleneck for modern barge traffic.
When will the new lock be operational?
While specific completion dates depend on construction progress, this final contract covers the transition of navigation traffic to the new lock, the breaching of the existing dam, and the decommissioning of the old lock.
What is a “cofferdam”?
A cofferdam is a temporary enclosure built within a body of water to allow the enclosed area to be pumped out. This creates a dry work environment for major construction tasks, like building the new lock chamber.
