Complete Application Received - Aziscohos Hydroelectric Project, Maine

March 1, 2021: The Low Impact Hydropower Institute has received a complete application for Low Impact Certification of the Aziscohos 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 “Aziscohos Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 1167 Massachusetts Avenue, Arlinton, MA 02476. Comments must be received on or before 5 pm Eastern time on April 30, 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.
Project Description:

The Aziscohos project is located at river mile 17.6 on the Magalloway River in Lincoln Plantation, Parkertown Township, and Lynchtown Township, Oxford County, Maine.  The Project is located in the headwaters of the Androscoggin River approximately 14.75 miles upstream of the confluence with Umbagog Lake in Errol, NH. The headwaters of the Androscoggin River are comprised of an extensive system of storage reservoirs, including Umbagog, Mooselookmeguntic, Richardson, and Aziscohos Lakes.

The Project is operated in conjunction with the other reservoirs of the Storage System to augment downstream flows in accordance with various governing historic operating agreements, while also providing substantial flood control benefits for downstream areas. The Storage System includes Aziscohos, Mooselookmeguntic, Upper and Lower Richardson, and Umbagog Lakes

Aziscohos Dam a concrete, multiple arch- buttress structure originally built in 1911- 1912. The reservoir was created for the sole purpose of providing downstream flow augmentation to support downstream uses. The dam is 881 feet long, with a maximum height of 74 feet.  Starting at the north abutment, the dam consists of a 236-foot-long spillway section topped with 3-foot-high pinned flashboards. A non-overflow concrete section extends 265 feet from the end of the spillway to the south abutment of the dam. Earthen dikes extend from each abutment to complete the dam structure. Concrete cut-off walls extending from the abutments serve as core walls for the dikes. The north dike contains a 120-foot-long core wall, while a 260-foot-long wall lines the southern dike. In 1988, concrete wave barriers were added to the dikes and the southerly 1,600 feet of the non-overflow section of the dam. The wave barriers prevent overtopping during a probable maximum flood. The dam creates an impoundment with a surface are of 7,315 acres at normal full pond, and useable storage of 221,355 acre-feet.

An 8-foot-diameter, 2,462-foot-long steel above ground penstock serves as the water conduit between the dam and the powerhouse and creates the ½-mile-long bypassed reach. There is a year-round minimum flow of 50 cfs into the bypass reach prescribed for habitat and fish protection through there are no migratory fish species in the Magalloway River and no requirements for fish passage. The powerhouse was added in 1985 and contains a single vertical Kaplan turbine unit with an installed capacity of 5.113 MW. Average annual generation and the project is 33,789 MWh.

Project Name Aziscohos
Owner Androscoggin Reservoir Company (Brookfield Renewable)
State Maine
Location River Mile 17.6 Magalloway River
Installed Capacity 5.133 MW
Average Annual Generation 33,789 MWh
Facility Type Seasonal Storage
FERC No. P-4026, issued 1985. Expires March 31, 2025.