Dams 7-10 on the Brandywine are owned, or partially owned, by the Eleutherian Mills-Hagley Foundation.
Dams 8, 9 and 10 are located on the grounds of the Hagley Museum and Library. Dam 7 is located adjacent to Breck’s Mill. The dams are located within the Brandywine Powder Mills National Historic Landmarks District. (Cultural Resource Survey Number N00339). The buildings, landscapes, cultural features, archaeological resources and dams within it are of the highest historic significance and worthy of preservation.
These dams will not be removed due to their historic significance and importance to the educational mission of the Hagley Museum and Library. Instead, alternative solutions to enable fish passage will be developed as part of a Feasibility Study being conduced by the U.S. Army Corp of Engineers in partnership with the Hagley Museum and Library.
Dam 7
Known as Breck’s Mill Dam and Walker’s Mill Dam, Dam 7 was constructed c. 1822 as an ascending ramp, bowed, stone dam with plank decking on its upstream face and a descending ramp loose stone apron.
Dam 8
Known as Hagley Dam and Henry Clay Dam, Dam 8 is an ascending ramp, bowed, stone dam augmented by a later gently ascending and steeply descending, straight, engineered stone and concrete dam. The ascending ramp, bowed, stone dam was constructed in 1813.
Dam 9
Known as the Upper Hagley Yard Dam, or Birkenhead Dam, Dam 9 was originally constructed c. 1779, likely as a descending ramp, bowed, stone dam with two distinct spans. It retains its mill race as well as head wall and head gates.
Dam 10
Known as Eleutherian Mills Dam, Dam 10 was initially constructed in 1803 as a descending ramp, straight, stone apron dam with plank decking. Dam 10 is the original dam built by E. I. du Pont, the founder of the DuPont Company, during the establishment of his original gunpowder manufactory at Eleutherian Mills.
The first Du Pont black powder was made in the Hagley powder yards in 1804, launching one of the longest standing and most innovative American enterprises since this country’s founding.
Between the company’s founding in 1802 and 1840, the yards expanded twice to include three dams, upper and lower mill races, dozens of mill buildings, and over a mile of infrastructure, much of which can still be seen today.
