Orono : P-2710

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  • P-2710
  • Stillwater R
  • East
  • ME
  • 2.78 MW


  • Download License
  • 12-08-2005
  • 12-01-2045


The Orono Hydroelectric Project is a run-of-river hydroelectric generating facility located on the Stillwater Branch of the Penobscot River in Orono, Maine with a gross nameplate generating capacity of 2.78 MW.

The Orono Project commenced initial commercial operations in 1949, but stopped operating in 1996 due to catastrophic failure of the facility’s penstock which caused the project to be shut down. After the Federal Energy Commission issued a new license for the Orono Project on December 8, 2005, the Orono Project was refurbished and thereafter began commercial operation of the first two units on January 11, 2009, and the other two units on March 3, 2009.

The Orono Project consists of the following facilities: (1) a 1,178-foot-long by 15-foothigh dam with a 320-foot-long spillway topped with 2.4-foot-high flashboards; (2) a 2.3-milelong reservoir, with a surface area of 175 acres at the normal full pond; (3) 866-foot long concrete penstock (20 feet wide by 12 feet tall inside diameter); (4) a 40-foot-wide, 94-foot-long and 27- foot-high surge tank; (5) a powerhouse with four existing generating units with a total installed generating capacity of 2.332 MW; (6) three existing 325-foot-long transmission lines.



The Orono Hydroelectric Project is one of the three projects included in the the Penobscot River Restoration Agreement. The other two are: Stillwater Hydroelectric Project (P-2712) and Medway Hydroelectric Project (P-2666).