Protecting Cultural Resources
Floods occur at regular intervals in the Potomac Valley. Between 1829 and 1998 there have been 144 recorded floods or high water occurrences. repairing flood damage was a continuing battle for the C&O Canal Company and is still a problem for the National Park Service. During periods of low water, the remains of the original crib and rubble dam, destroyed by floods can be seen downstream from the present dam built in 1857.
In 1998, the guard lock and flume were filled with soil to halt the collapse of the stone walls. A section of the towpath that was collapsing was replaced with "Roller Compacted Concrete (RCC)" which is a concrete mix with a small amount of cement and a high amount of gravel. The stone for the aggregate was acquired locally to match the stone already used here. The RCC is spread and compacted by a roller and does not require formwork like conventional concrete. By filling the lock and bypass flume and reconstructing the towpath and guard dike, the National Park Service is trying to protect the historic structures from future flood damage.
Marker is on Dam No. 5 Road, on the left when traveling west.
Courtesy hmdb.org
