Historic Park and is administered by the National Park Service. Following damage caused to several canal structures caused by Hurricane Agnes and other flooding incidents in the early 1970s, the National Park Service and the Federal Highway Administration designed a steel banding system to stabilize the structure and installed a steel rod reinforcing system. The National Park Service and park supporters were concerned about the structural stability of the aqueduct and a major engineering evaluation was undertaken to determine stabilization needs and associated cost. The C&O Canal National Historical Park and its partners restored the aqueduct to its original appearance in 2004-2005. The aqueduct was formally rededicated in May 2005. References National Park Service, Hagerstown, MD (2013). "The Monocacy Aqueduct: An Icon of American Civil Engineering." Smithsonian Associates, Washington, D.C. "The Monocacy Aqueduct." Smithsonian Associates Civil War E-Mail Newsletter, Volume 5, Number 7. Accessed 2013-01-09. External links Transportation buildings and structures in Frederick County, Maryland Navigable aqueducts in the United States Monocacy River Chesapeake and Ohio Canal Water transportation in Maryland