LOUISVILLE, KY — The U.S. Army Corps of Engineers (USACE), Louisville District, awarded a base contract for $320 million to Thalle-Bauer LLC, out of Hillsborough, North Carolina, for Phase 2 of the Rough River Dam Safety Modification project. This is a base and option contract with the total contract value expected to be around $655 million at contract completion. Phase 2 will include construction of a new outlet works and a full-depth cutoff wall across the dam, which will provide permanent risk reduction to communities downstream.
Phase 2 will involve creating a new outlet works on the left abutment, which will consist of a new control tower and stilling basin with a new tunnel connecting the two features. Once completed and operational, the existing tower will be abandoned, and the cutoff wall will be constructed across the crest of the dam varying in depth from 75 to 180 feet. The final portion of work will relocate Kentucky State Highway 79 back to the top of the dam.
“We are looking forward to seeing this critical project — the Rough River Dam Safety Modification Project — get underway,” said Colonel L. Reyn Mann, U.S. Army Corps of Engineers Louisville District Commander. “The work planned in Phase 2 will help to lower the dam’s risk and will ensure that it can continue to provide flood risk reduction benefits and serve the local community for years to come.”
The Dam Safety Modification project is a result of a report from July 2012, which highlighted unacceptable risk due to the dam’s foundation being constructed on karst geology. The report recommended major rehabilitation to ensure the structure’s integrity and to lower the project’s risk. Phase 1, which relocated the crest road and completed exploratory drilling and grouting across the centerline of the dam, was finished in May 2017. In 2023, USACE implemented several Interim Risk Reduction Measures to ensure life safety and further protect the integrity of the dam until Phase 2 is completed.
Groundbreaking for the construction is expected to take place in the spring of 2026. Phase 2 construction is anticipated to take approximately six to seven years.
