In April 2013, at the request of the company that operates the dam, the Federal Energy Regulatory Commission (FERC) authorized the replacement of the historic wooden flashboard system of Pawtucket Dam with a pneumatic crest gate system, which uses an inflatable bladder to raise and lower gate panels. This change would permanently alter this living—and working—example of 19th century hydraulic engineering.

The National Trust believes that FERC violated federal laws in approving the modernization of the dam, including the National Historic Preservation Act and the Lowell National Historical Park(Lowell Act). The Lowell Act established the park in 1978 and specifically prohibits federal approval of licenses or permits that adversely affect contributing resources to the Lowell National Historical Park.

Originally constructed in 1847 and 1875, the Pawtucket Dam is a rare hydraulic structure with a granite block base topped with wooden flashboards supported by iron pins that follow the natural ledge of the Pawtucket Falls on the Merrimack River. The dam was instrumental in establishing Lowell, Massachusetts, as the first large-scale planned industrial city in the United States by diverting much of theriver's flow into the Northern and Pawtucket Canals. During flooding events, the five-foot tall pins bend, releasing the flashboards and redirecting the water to bypass the canals, in order to reduce the impacts on the water-powered mills below and to minimize upstream flooding. The pins and flashboards are then manually replaced.

The Pawtucket Dam contributes to the Lowell Locks and Canal National Historic Landmark District, the Lowell National Historical Park and the Downtown Lowell Historic District, a local historic district.It is also designated as a Historic Civil and Mechanical Engineering Landmark.