Maintaining the Foundation Drainage System Inside Mount Morris Dam

USACE Buffalo District crews clean foundation drains at Mount Morris Dam to relieve water pressure, maintain dam safety and reduce downstream flood risks. As water levels behind the dam fluctuate in response to rainfall, so does the pressure beneath its foundation. A network of drains allows water to move through the underlying rock and helps prevent excessive pressure from building beneath the structure. Over time, naturally occurring bacteria and mineral deposits can accumulate inside the drains, restricting the flow of water. Wrobel explained that the environment within the underlying shale provides conditions where bacteria can grow and gradually coat the interior walls of the drains. Calcium-rich deposits can also form crystals that further obstruct water movement.

Although the cleaning process may sound straightforward, completing the work inside a structure as large as the Mount Morris Dam presents significant logistical challenges. The dam contains more than 100 foundation drains, some extending 50 feet or more into the surrounding rock. Crews must transport cleaning equipment, including lots of hose, by hand down staircases and through the dam's interior galleries before beginning work. The confined working environment requires careful coordination and communication between personnel inside the structure and those monitoring operations at the surface. Foundation drain cleaning typically takes place every five to 10 years. Determining when the work is necessary involves ongoing