September 9, 2019: The Low Impact Hydropower Institute has received a complete application for Low Impact Certification of the Millinocket and Dolby Hydroelectric Projects.  LIHI is seeking public comment on this application.  Specifically, we are interested in knowing whether you think the Project meets the LIHI Low Impact Certification Criteria, as revised in the 2nd Edition Handbook.  Please review the program and criteria in LIHI’s revised Handbook and then review the Project’s application materials below.

Comments that are directly tied to specific LIHI criteria (flows, water quality, fish passage, etc.) will be most helpful, but all comments will be considered.  Comments may be submitted to the Institute by e-mail at with “Millinocket-Dolby Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 329 Massachusetts Avenue, Suite 6, Lexington, MA 02420.  Comments must be received on or before 5 pm Eastern time on November 8, 2019 to be considered.  All comments will be posted to the web site and the applicant will have an opportunity to respond.  Any response will also be posted.

Project Description:

The Penobscot Mills Project (FERC No. 2458) consists of four hydroelectric developments and a storage dam located in the general vicinity of Millinocket/East Millinocket, Maine. The four hydroelectric developments are located between river miles 2 and 15 on the West Branch of the Penobscot River. The four hydroelectric developments, listed in order from upstream to downstream, are: North Twin, Millinocket, Dolby, and East Millinocket. The project developments were originally constructed around the turn of the 20th century to meet the hydromechanical and hydroelectric demands of the Millinocket Mill, constructed in 1900, and the East Millinocket Mill, constructed in 1906. The Millinocket Lake Storage Development contains a pumping station, located on the opposite end of the lake from the Millinocket Lake Dam, that allows water to be pumped up approximately 12 ft from Millinocket Lake to Ambajejus Lake (part of the North Twin impoundment).

The Penobscot Mills Project is operated to maintain an instantaneous minimum flow of 2,000 cfs downstream of the Millinocket Development and a minimum flow of 60 cfs into Millinocket Stream. Operation of the project is managed in conjunction with the water flow and storage of upstream and downstream projects.

Two of the four developments are included in the LIHI application:

Project Name Millinocket and Dolby Developments
Owner Brookfield Renewable Energy Group
State Maine
Location West Branch Penobscot River, river mile 12.3 (Millinocket) and 4.2 (Dolby)
Installed Capacity Total: 55.2 MW


Millinocket: 37.4 MW

Dolby: 17.8 MW


Average Annual Generation Total: 280,899 MWh


Millinocket: 178,454 MWh


Dolby: 102,445 MWh

Facility Type Run of river
FERC No. 2458 (part of the Penobscot Mills Project)

Millinocket Development:

The Millinocket Development is located in the town of Millinocket and consists of 1) Quakish Lake and Ferguson Pond, which together form the Millinocket impoundment having a full pond water surface elevation of 458.7 ft; 2) a concrete dam (Stone Dam) measuring approximately 1,262 ft in length located on the West Branch of the Penobscot River approximately 12.3 river miles above the confluence of the East and West Branches of the Penobscot River; 3) a gatehouse located at Stone Dam, containing ten gates and a sluiceway; 4) three earthen dikes located at various points around Quakish Lake and having a total length of 1,854 ft; 5) five earthen dikes (totaling 3,915 ft in length) located around Ferguson Pond, a “western” canal leading from the gatehouse to Ferguson Pond, Ferguson Pond, and an “eastern” canal that leads from Ferguson Pond to the intake structure, all of which are used to convey water from the gatehouse at Stone Dam to the intake structure located approximately 7,300 ft from Stone Dam; 6) an intake structure containing seven head gates, located at the entrance of the penstocks; 7) six 10-ft-exterior-diameter steel penstocks and one 11-ft-exterior- diameter steel penstock ranging in length from 1,007 ft to 1,024 ft; 8) seven operable hydroelectric units, of which five are located within the former Grinder Room; 9) a powerhouse commonly referred to as the Generator Room, where two of the hydroelectric units are located; and appurtenant facilities and equipment.

Millinocket Development

Dolby Development:

The Dolby Development is located on the West Branch of the Penobscot River, between Millinocket and East Millinocket, at approximately 4.2 river miles above the confluence of the East and West Branches.  The Development consists of 1) an impoundment having a full pond water surface elevation of 336.2 ft; 2) a concrete and earth-filled dam measuring approximately 1,395 ft in length, including an intake structure and powerhouse integral with the dam containing five operable units and other appurtenant facilities and equipment.

Dolby Development