LANCASTER – The U.S. Army Corps of Engineers Nashville District is placing the final concrete to complete a barrier wall in the main dam embankment of Center Hill Dam this week. These concrete pours complete the $115 million foundation barrier wall, a key component of the Center Hill Dam safety remediation project.
The wall provides a permanent “barrier” to potentially harmful seepage beneath the main dam earthen embankment, Linda Adcock, project manager, said in a release. “Completion of this phase of the project significantly increases the safety of the dam,” she added.
The concrete barrier wall is approximately 2.5-feet thick constructed vertically along the embankment in overlapping rectangular columns as deep as 308 feet from the top of the dam and deep into the solid-rock foundation.
Florida-based Bauer Foundation Corporation performed the work to protect the earthen portion of Center Hill Dam. The “first bite” of a giant auger drill rig turned up the first dirt of the project July 11, 2012.
This is the second of three contracts to remediate the Center Hill project. The third and final contract expected to be awarded later this year involves the installation of a concrete berm downstream of the auxiliary dam embankment. The auxiliary dam is a secondary earthen embankment that fills a low area in the landscape just east of the main dam.
The lake levels continue to be operated between elevation 630 feet above mean seal level in the summer and no lower than elevation 618 MSL during the late fall and early winter.
Center Hill Dam is rated in the Corps’ “Dam Safety Action Classification I,” which is the most urgent category for dam safety modification in the Corps. Even though the concrete barrier wall is complete, the classification of the dam cannot be changed until the third and final contract is completed, the remediation works are assessed and the project is reclassified. The final reviews are expected to be completed in 2018; the lake level is expected to be raised in time for the summer recreation season.