Maintaining the Foundation Drainage System Inside Mount Morris Dam

Official Statements

• U.S. Army Corps of Engineers, Buffalo District, November 10: “MOUNT MORRIS, N.Y. — Inside the Mount Morris Dam, crews are tackling an important maintenance operation that most never even hear about but plays an important role in keeping the massive concrete structure operating safely.

  The U.S. Army Corps of Engineers, Buffalo District, is conducting foundation drain cleaning at the dam, a recurring maintenance activity designed to relieve water pressure beneath the structure and support its long-term reliability.

  "The purpose of a foundation drain cleaning is to clear debris from the wells, which relieve water pressure from the base of the dam," said Cedric Wrobel, a geotechnical engineer with the Buffalo District.

  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.

  "Eventually the deposits stop water from being able to move through the drain," Wrobel said. "So we use pressurized water to clean the bacteria from the inside of the drain and allow the drains to move the maximum amount of water."

  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 monitoring and inspections.

  "The drains are assessed annually as part of our inspection program by me and other geotechnical engineers to determine exactly when drain cleaning is needed," Wrobel said.

  The current operation is expected to take approximately another month, allowing crews to clean the drains throughout the structure and remove the specialized equipment once the work is complete.

  "Orchestrating such a complex cleaning operation is one of the many ways that the U.S. Army Corps of Engineers solves our nation's toughest challenges," Wrobel said.

  By keeping the foundation drainage system functioning as designed, the work supports the continued safe operation of the Mount Morris Dam and its mission of reducing flood risks for communities throughout the Genesee River valley.

  This information includes elements of SI-generated content, which were reviewed and edited by relevant DoW personnel to verify appropriateness and compliance with DoW policies and guidance.

  The Buffalo District delivers world class engineering solutions to the Great Lakes Region, the Army and the Nation to ensure national security, environmental sustainability, water resource management, and emergency assistance during peace and war. Learn more at www.lrd.usace.army.mil/buffalo.”