LIHI Certificate #167 - Millinocket-Dolby Project, Maine

Project Name Millinocket and Dolby Developments
LIHI Certificate No.
LIHI Certificate Term
September 6, 2019 – September 5, 2029
Owner Great Lakes Hydro America, LLC, a subsidiary of Brookfield Renewable Energy Group
State Maine
Location West Branch Penobscot River, river mile 12.3 (Millinocket) and 4.2 (Dolby)
Installed Capacity Total: 53.7 MW

Millinocket: 37.2 MW

Dolby: 16.5 MW

Average Annual Generation Total: 280,899 MWh

Millinocket: 178,454 MWh

 Dolby: 102,445 MWh

Facility Type Run of river
FERC No. P-2458 issued 1996, expires 10/01/2026

(part of the Penobscot Mills Project)

The Millinocket-Dolby Developments are the middle two of four developments included in the Penobscot Mills Hydroelectric Project on the West Branch of the Penobscot River, near Millinocket and East Millinocket, Maine. 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 feet from Millinocket Lake to Ambajejus Lake (part of the North Twin, LIHI #183 impoundment). Downstream about 1.7 miles of the Millinocket and Dolby developments is East Millinocket, also part of the Penobscot Mills Project. The Medway Project (LIHI #65) is located  approximately 2 miles farther downstream.

The LIHI certification includes two developments:

  • Millinocket: The Millinocket development is located in the town of Millinocket and consists of:
    1. Quakish Lake and Ferguson Pond, which together form the 1,344-acre Millinocket impoundment
    2. A concrete dam (Stone Dam) measuring approximately 1,262 feet 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 feet
    5. Five earthen dikes (totaling 3,915 feet 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-foot-diameter steel penstocks and one 11-foot-diameter steel penstock ranging in length from 1,007 feet to 1,024 feet
    8. Seven operable hydroelectric units, of which five are located within the former Grinder Room with a total installed capacity of 37.38 MW
    9. A powerhouse commonly referred to as the Generator Room, where two of the hydroelectric units are located as well as appurtenant facilities and equipment.
  • Dolby: 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. A 2,048-acre impoundment
    2. A concrete and earth-filled dam measuring approximately 1,395 feet in length with:
      • An abutment 27 feet long adjacent to the southwestern shore
      • A 550-foot-long earthen dike extending from the northeastern end of the powerhouse to the northern shore
      • A 521-foot long main spillway with 4-foot-high flashboards
      • A 22-foot-long side spillway with 4-foot-high flashboards, located between two concrete abutments
      • A waste gate structure containing six steel gates approximately 6 feet wide by 9 feet high
    3. An intake structure and powerhouse integral with the dam containing five operable units having a total installed capacity of 17.81 MW, and other appurtenant facilities and equipment.

The project operates in a run-of-river mode and provides an instantaneous minimum flow of 2,000 cfs to the West Branch of the Penobscot River at Millinocket. This base flow protects water quality and aquatic habitat in the Penobscot River. This flow was developed in collaboration with the US Department of the Interior and the Penobscot Indian Nation. The Dolby impoundment receives all flow released from the Millinocket development and continues run-of-river operations with flows often in excess of 2,000 cfs including waters overtopping the spillway into the bypass reach.

Waters within the project reach are designated as Class B at Millinocket and Class C at Dolby. Both classes are suitable for treated drinking water supply, primary and secondary recreation, and habitat for fish and aquatic life. The base flow provided at the project as well as run-of-river operations have helped to maintain these water quality designations in the river reach. Historically, the reaches were impaired due to non-attainment of dissolved oxygen criteria. Water quality improved as a result of the closure of the Millinocket and East Millinocket paper mills.

The West Branch of the Penobscot River does not currently support anadromous fish species. Though the West Branch is within the historical range of Atlantic salmon, it is not designated as critical habitat and thus is not managed for Atlantic salmon. Similarly, the river reach is not managed for alosines (river herring, American shad) and few American eels are present in the lower portion of the river. Resource agencies are expected to assess the need for anadromous fish passage on the West Branch during the next relicensing of the downstream Medway Project as well as the next relicensing of the Penobscot Mills Project. Resident fish species in the West Branch include brook trout, smallmouth bass, various species of suckers, shiners and sunfish, fallfish, eastern blacknose dace, creek chub, slimy sculpin, burbot, and landlocked Atlantic salmon. Trashracks at the developments reduce entrainment of fish into the penstocks. At the Millinocket development, trashracks approximately 216 feet long are located upstream of the powerhouse intake gates. There are six gates 12.5-feet by 12.5-feet and one gate 13.5-feet by 13.5-feet. All eleven penstocks have trashracks with clear spacing of 25/8 inches. At the Dolby development, trashracks for units 2 through 4 have clear spacing of 111/16 inches. Trashracks for unit 5 through 8 have clear spacing of 25/8 inches.

The project lands consist of roughly 4,000 acres. The project operates under a shoreline management plan which outlines protection and enhancement measures related to project lands and waters. Provisions include building setback restrictions of 200 feet, a 100-foot vegetative buffer restriction, public access for recreation, and effective management of the renewable forest and water resources in the boundary. Additionally, a wildlife management plan was designed for the protection and enhancement of forest and habitat diversity on 2,300 acres of project lands. Provisions of this plan relate to forest management, waterfowl nesting sites, and vegetation management which promotes favorable wildlife conditions.

Threatened or endangered species potentially present in the project vicinity include the Canada lynx, Northern long-eared bat, Atlantic salmon, tidewater mucket, yellow lampmussel, little brown bat, and eastern small-footed bat. As mentioned above, Atlantic salmon and American eel, though historically present in the river reach, are not currently present in the West Branch of the Penobscot River. Run-of-river operation protects habitat for the listed aquatic species and is not likely to impact any terrestrial species. Vegetation clearing occurs periodically for dam safety/access and is conducted in accordance with the US Fish and Wildlife Service Section 4(d) rule concerning protection of the Northern long-eared bat. Thus, no adverse impacts are expected to occur on any listed species due to project operation.

The Penobscot Mills project area supports seven historic archaeological sites deemed eligible for listing on the National Register of Historic Places. None of these sites are within the bounds of the Millinocket or Dolby developments. The Penobscot Mills project operates under a cultural resources management plan developed with the Advisory Council on Historic Preservation and the Maine State Historic Preservation Office. The project owner submits annual reports on activities related to the management of historic properties.

Recreational resources at the project include several boat ramps/access sites. Public access is provided free of charge.

Compliance Status

The Certificate includes the following facility-specific conditions:

Condition satisfied in 2020. Condition 1:The facility Owner shall develop and implement a deviation reduction plan or procedure in an effort to proactively reduce future occurrence of potentially avoidable deviations. The plan or procedure shall include an implementation schedule and shall be submitted to LIHI for review and approval with the first annual compliance submittal due in September 2020. The plan or procedure should discuss, as applicable: Ways to avoid minimum flow deviations when ROR deviations are planned for flashboard repairs and installation; Ways to improve preventative maintenance programs and/or to make facility modifications to reduce equipment malfunctions and failures, which could include: Review of current preventative maintenance program to ensure maximum reliability of generating assets and ensuring that operating procedures are current and applicable staff is trained in the application.

Condition 2: The facility Owner shall provide annual reports to LIHI documenting all operational deviations that occurred during the year, whether unintentional or planned and whether or not they were found to violate the license by FERC. The report shall include root-cause analysis of each deviation and any facility or operational changes being made to reduce similar deviations in the future. The report will be due at the same time as the annual compliance submittals to LIHI.

2023: No material changes or significant compliance issues were identified.  The project remains in compliance based on the annual review.  For relicensing, the project is in the first study year. For Condition 2, the project reported five unplanned deviations, none of which were considered FERC violations.

2022: No material changes or significant compliance issues were identified.  The project remains in compliance based on the annual review.  For relicensing, the project filed the Initial Study Report and held the study meeting.  Additional studies are planned or in progress. For Condition 2, the project reported on seven deviations, one of which FERC considered a license violation and the project submitted the required corrective action information.

2021: There were no reported changes or compliance issues. The project remains in compliance based on the annual review.   The project entered FERC relicensing with filing of the PAD on 06/11/2021. For Condition 2, the project reported on seven deviations that were not considered FERC license violations.

2020: There were no reported changes or compliance issues. The project remains in compliance based on the annual review.  For Condition 1,  the project submitted and LIHI approved the deviation reduction plan, satisfying the condition. For Condition 2, the project reported on two deviations that were not considered FERC license violations.

Certification History

January 1, 2022: The LIHI Certificate term has been extended in accordance with Revision 2.05 of the LIHI 2nd Edition Certification Handbook issued January 1, 2022. Refer to the facility table above for the new term.

February 7, 2020: The decision to certify the Millinocket-Dolby Project became final after the close of the appeals period on February 6, 2020 with no appeals filed.  The Certification term is from September 6, 2019 – September 5, 2024.

January 7, 2020: The Low Impact Hydropower Institute has preliminarily approved Low Impact Recertification for the Millinocket-Dolby Hydroelectric Project, pending LIHI #167. This decision is preliminary pending the 30-day appeal window. Only those who commented on the initial application during the 60-day comment period are eligible to file an appeal. Such appeal needs to include an explanation as to how the Project does not meet the LIHI criteria. Appeal requests can be submitted by email to with “Millinocket-Dolby Hydroelectric Project” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 329 Massachusetts Ave, Suite 6, Lexington, MA 02420. All requests will be posted to the website.  The applicant will have an opportunity to respond and any response will also be posted. Requests must be received by 5 pm Eastern time on February 6, 2020.  The full application and reviewers report are available below. If no appeal requests are received and the decision becomes final, the Certification term for the Project will be from September 6, 2019 to September 5, 2024.

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.

Certification Files

2019 Certification

Key Documents