Ameren Bagnell Dam Stabilization
The first major structural update to the historic Bagnell Dam in more than 30 years vastly improved the safety and overall stability. The 2,453-foot-long, 148-foot-tall dam not only helped create one of the largest tourist attractions in the state of Missouri — the Lake of the Ozarks — it also is a major source of clean energy that reliably powers homes and businesses throughout the region.
Originally designed in the 1920s, this is an unreinforced gravity dam with three sections and an abutment section that is 1,512 feet long. A highway bridge runs across the top of the dam. Other notable parts of the structure include a 520-foot-long spillway section that includes five sealed sluiceways and 12 floodgates — with each floodgate measuring 22 feet high and 34 feet wide and weighing 54,000 pounds. In 2017, the dam’s Ameren Missouri Osage Energy Center produced more than 624,000 megawatt-hours of energy.
Work began in March 2017 and included the removal of worn and eroded concrete from the surface of the dam. Crews installed 67 post-tension anchors that strengthened the dam’s connection to bedrock below.
We developed an integrated construction solution aligned with Ameren’s expectations and requirements for the dam project. That was followed by executing the safest, high-quality installation that included a detailed approach to quality and safety and the environmental protection plan, logistics and access, aggressive scheduling approach and utilizing value engineering to drive cost reductions.
Hydro-demolition of the back slope area of the dam between the bridge piers was key to the success of the project. A high level of self-perform work helped drive the schedule, retained control of the job and ensured certainty of outcome in all aspects of the project.