The U.S. Army Corps of Engineers (USACE) broke ground on Mahoning Creek Dam, a flood control structure that also provides recreational opportunities in the Allegheny River basin in western Pennsylvania, in 1939. By 1941, the concrete dam was fnished. The design included a conduit that would allow the potential energy of water stored behind the dam to be used to produce hydroelectric power. However, the plans to develop hydropower at this dam were postponed due to steel shortages associated with the country’s accelerating mobilization efforts for World War II.
Seventy-two years later, Cube Hydro Partners LLC, a Maryland-based company, fulflled the vision of those early engineers. In a public-private partnership with the USACE’s Pittsburgh District and enabled by the 2009 American Recovery and Reinvestment Act and Pennsylvania Alternative and Clean Energy Program, Cube Hydro Partners constructed a 6-MW hydroelectric facility utilizing Mahoning Creek Dam.
The Mahoning Creek Hydroelectric Company Project is located on Mahoning Creek in Armstrong County, Pa. Mahoning Creek Dam is one of 16 facilities in the USACE’s Pittsburgh District used to provide food protection to the lower Allegheny River Valley and upper Ohio River. This concrete gravity dam is 187 feet high and 926 feet long. The hydro project includes a 50-foot-high intake structure attached to the upstream face of the dam equipped with a removable trashrack and a vertical slide gate. A secondary penstock closure device, a butterfy valve, is located in a concrete vault downstream from the dam. A steel liner pipe was inserted into the existing conduit through the dam. Water is conveyed from the dam through a 1,090-foot-long, 10-foot-diameter buried penstock to the powerhouse containing two Francis turbines (4 MW and 2 MW) with two vertical-shaft generating units.