More than 325,000 people rely on Lock and Dam No. 9 on the Kentucky River for their primary water source. At over a century old, it was definitely in need of inspection. The Kentucky River Authority brought us in, and we assessed the structure. We looked at the above-water conditions, conducted dive inspections, and took samples (rock and concrete) from the lock walls, main and auxiliary dams, and other structures.
Over a decade ago we performed water supply studies that identified a water deficit in the basin during severe droughts. Recent drought conditions, closure of many of the original navigational locks, and growing stability concerns of the lock and dam structures have prompted several projects on the Kentucky River to address these issues and protect the water supply for the next generation.
We then evaluated multiple dam raising alternatives and developed concepts for the highest rated options. To narrow those options down, we conducted a study of the river related to flood frequency impacts and a structural analysis of the lock and dam components.
A new dam, immediately upstream of the existing structure, was designed and constructed. We specified an in-the-wet construction method to reduce costs, risks, project duration, and environmental impacts. Renovations included scour and slope protections and a conveyance system to transfer water from upper to lower pools in droughts. These solutions will protect the water supply of seven nearby communities for 50 years or more.