Work continues apace for a major stabilization project for Bagnell Dam. The 1930 era gravity dam that creates the Lake of the Ozarks is having upgrades done several different areas as it nears 90 years of age.

Work continues apace for a major stabilization project for Bagnell Dam. The 1930 era gravity dam that creates the Lake of the Ozarks is having upgrades done several different areas as it nears 90 years of age.

Now in the latter stages of the $52 million project begun in Spring 2017, the two main parts consist of installing 69 anchors at the base of the dam and adding concrete between the piers under the road, according to information provided by Ameren Missouri.

The electric company owns and operates the hydroelectric facility.

The anchors are metal strands or tendons which are grouted into bedrock and then tensioned with as much as 2,000,000 pounds of force each.

Adding concrete between the piers, referred to as in-fills, will add 66,000,000 pounds of weight to the dam, further increasing stability of the dam, and helping it continue to hold back the force and pressure of nearly 100 feet of water.

Along with these two major stages of the project, the back side of the 87 year old dam has been stripped of the outer 3 to 9 inches of weathered concrete and a new outer layer is being installed, referred to as an overlay.

The in-fill additions and the overlay are the two most visible phases of the project. Finally, new drains will be installed from the concrete to bedrock interface, as well as a new drain trough along the back of the dam.

The project is scheduled to be completed in early fall of 2018.

The last major structural update at Bagnell Dam was completed in the late 1980s when 277 post-tension anchors were installed to hold the dam into the bedrock. The anchors were the best technology at the time and have performed well since they were installed, according to Ameren Missouri. However, officials understood at the time that the 1980s-era anchors would not hold forever due to corrosion.

That isn’t occurring yet, but according to Ameren they won’t hold another 100 years, necessitating the current project.

Most importantly, the dam remains structurally sound.

As part of Ameren’s Federal Energy Regulatory Commission license they’re required to conduct regular safety inspections. In addition to daily, weekly and quarterly inspections by Ameren experts, Bagnell Dam is inspected annually by an independent safety engineer.

The new technology being installed with the new anchors, which are mechanically tightened and sealed, will also allow them to be unsealed and tightened in future years as needed.