Corps of Engineers, TVA earn national geology award for Chickamauga Lock project

CHATTANOOGA, Tenn. — The U.S. Army Corps of Engineers Nashville District and the Tennessee Valley Authority received the 2026 Outstanding Environmental… CHATTANOOGA, Tenn. — The U.S. Army Corps of Engineers Nashville District and the Tennessee Valley Authority received the 2026 Outstanding Environmental and Engineering Geologic Project Award on Sept. 16, 2026. Presented by the Association of Environmental & Engineering Geologists, the honor recognizes engineering achievements on the Chickamauga Lock Replacement Project. Craig Carrington, USACE Nashville District deputy district engineer for project management, accepted the award on behalf of the project team. The annual award recognizes innovative engineering solutions that resolve complex, high-risk geological challenges to protect public safety and critical infrastructure. Chickamauga Lock, originally constructed in 1940, has long suffered from "concrete expansion," a chemical reaction known as alkali-aggregate reaction.

The reaction between the cement and river stone causes the concrete to expand, warping metal gates, cracking walls, and threatening the structural integrity of the vital shipping corridor. To keep 318 navigable stream miles accessible upstream on the Tennessee River, USACE embarked on a massive effort to build a new 110-by-600-foot navigation lock. The project unites two federal agencies with deep ties to the region: TVA owns and manages Chickamauga Dam, while the Nashville District designs, oversees construction, and operates the navigation lock. The bedrock beneath the new lock presented