The Columbia Lock and Dam is owned and operated by the United States Army Corps of Engineers’ Vicksburg District. In the face of an “exponentially increasing risk of failure” of the lock structure due to foundational undermining, the District declared an Official Dam Safety Emergency and suspended navigation through the lock in July 2018. We partnered with USACE to perform emergency repairs to the structure and restore the Ouachita River’s navigability, including the development of an alternative construction approach to address voids that were significantly larger than anticipated.

The project involved the drilling of nearly 300 holes ranging in diameter from 4 to 15 inches, subaqueous grouting and concrete placement, and the installation of a sheet pile cutoff wall. Other major scope elements included the removal and replacement of a portion of the lock floor without dewatering the structure, and the installation of a permanent relief well and dewatering system.