Preliminary Decision - Bonny Eagle Hydroelectric Project, ME

July 19, 2021: The Low Impact Hydropower Institute (LIHI) has preliminarily approved the Bonny Eagle Project for a 5-year term of Low Impact Certification. The Certificate includes the following conditions:

  • Condition 1: The facility Owner shall update the Minimum Flow and Pond Level Monitoring Plan to reflect current conditions and monitoring features at the Project in consultation with the USF&WS, MDEP, and MDIF&W, and shall submit it to FERC for approval upon receipt of resource agency approval. The Owner shall provide LIHI with a copy of the submittal cover letter to FERC and a copy of the FERC’s approval of the Plan.
  • Condition 2; In annual compliance statements, the facility Owner shall provide status updates on the proposed decommissioning of the Bar Mills Project as it relates to potential changes in upstream or downstream fish passage requirements or implementation schedule at Bonny Eagle. If the Fish Passage Agreement is amended during the term of LIHI Certification, the owner shall provide a copy of the amendment(s) to LIHI with a summary of changes related to Bonny Eagle.
  • Condition 3: In annual compliance statements, the facility Owner shall provide documentation of consultation with MDIF&W and implementation of any recommended mitigation measures, should any ground disturbance of the Project wetlands or onsite tree removal be needed. This consultation is required due to the possible presence of protected bats and the endangered Blanding’s turtle.

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 "Bonny Eagle Project” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 1167 Massachusetts Ave, Office 407, Arlington, MA 02476. 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 August 18, 2021. The full application and reviewer's report are available below.

If no appeal requests are received and the decision becomes final, the Certification term for the Project will be April 2, 2021 through April 1, 2026.

January 11, 2021: The Low Impact Hydropower Institute has received a complete application for Low Impact Certification of the Bonny Eagle Hydroelectric Project. 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 “Bonny Eagle Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 1167 Massachusetts Avenue, Arlington, MA 02476. Comments must be received on or before 5 pm Eastern time on March 12, 2021 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.

Bonny Eagle Hydroelectric Project is located in York and Cumberland Counties on the Saco River in Maine. The project's dams and generating station are located in the Towns of Hollis and Standish with the tailrace extending into the town of Buxton. The impoundment is located in the Hollis, Standish, and Limington. Bonny Eagle is the fifth-most upstream project of seven hydroelectric facilities on the main stem of the Saco River. The project is owned and operated by Brookfield White Pine Hydro (BWPH), LLC, a subsidiary of Brookfield Renewable Energy Group.

BWPH operates the Bonny Eagle Project as an intermittent peaking facility with seasonal run of river facility. From April 1 through June 30, the Project is operated in run of river mode with only 1 ft of fluctuation from the normal full pond allowed and minimum bypass reach flows of 25 cfs. From July 1 through September 30, a fluctuation of 4.5 ft from normal full pond is allowed with a total Project minimum flow, including at least 25 cfs in the bypass reach, of 400 cfs. From October 1 through November 15, the same reservoir fluctuation is allowed but a total Project minimum flow, inclusive of a 25 cfs minimum bypass reach flow, of 600 cfs is required. For the remainder of the year, the 4.5 fluctuation from full pond is authorized, with a 250 cfs minimum Project flow including the 25 cfs minimum bypass reach flow.

The project consists of a 350-foot long diversion dam, a 164-foot long dam (constituting the intake) and two earth embankments on the main river channel, a powerhouse containing six generating units, a 347-acre impoundment and appurtenant facilities. The nameplate generator capacity of the Project is 7.2 MW. The diversion dam is located at the so called "New River" channel while the intake and earth dikes are situated in a narrow gorge on the main river channel; a fairly large island (Bonny Eagle Island) separates the two channels. The dams create a riverine impoundment extending approximately 6.6 miles upstream.

The project provides downstream passage primarily for Atlantic salmon smolts and upstream passage facilities for American eel. The Bonny Eagle Powerhouse and dam structures are eligible for inclusion on the National Register of Historic Places. The facility represents a period of early hydropower generation development. Notably, the powerhouse interior is unaltered and contains a collection of early twentieth century hydropower generating machinery. The facility houses a picnic and day use area along with a canoe portage trail which are open to public use.

Project Name Bonny Eagle
Owner Brookfield White Pine Hydro, LLC
State Maine
Location Between River Miles 26 and 32.6, Saco River
Installed Capacity 7.2 MW
Average Annual Generation 39,067 MWh
Facility Type Intermittent peaking, seasonal run of river
FERC No. P-2529, issued 1998