LIHI Certificate #173 - Sawmill Project, New Hampshire

The Sawmill Project is located on the Androscoggin River in Coos County, in northern New Hampshire. The Androscoggin River is runs through the states of New Hampshire and Maine. The river joins the Kennebec River at Merrymeeting Bay in Maine before emptying into the Gulf of Maine and subsequently the Atlantic Ocean. The Androscoggin River watershed contains 19 hydroelectric projects located along the 178-mile-long river.

The Project is one of seven hydroelectric projects within an 11-mile reach of the Androscoggin River between Berlin and Shelburne, New Hampshire. There are five hydroelectric projects within 8 river miles of the Project including, among others, four downstream projects: Cross Power (LIHI #174), Upper Gorham (LIHI #175), Gorham (LIHI #153), and Shelburne (LIHI #176). The Sawmill dam was originally constructed in 1903 and was refurbished in 1965.

The project includes a dam, concrete retaining walls, intake canal, penstock, powerhouse, and transmission equipment.

The dam is 72 feet long with a maximum height of 15 feet. It is comprised of a 135-foot-long non-overflow section, a 169-foot-long concrete section varying in height from 6 to 14 feet, a 134-foot-long wastegate section with five wooden gates each 22 feet high, a 137-foot-long spillway section with hinged 7.5-foot flashboards, and a 145-foot-long by11-foot-high spillway with 21-inch steel flashboards. A 4-foot-wide, 80-foot-long concrete retaining wall on the east riverbank separates the 0.3-mile-long bypass reach from the powerhouse intake canal. A 4-foot wide, 55-foot-long retaining wall extends from the edge of the powerhouse on the west riverbank. The 360-foot-long intake canal directs inflows through a steel penstock to the powerhouse. The powerhouse is a brick and block structure that is integral to the dam and contains:

  • Four turbine inlet bays 14 feet wide by 19 feet long. Each bay passes flow through14-foot-wide by 19-foot-high trashracks each with 3-inch clear spacing.
  • Four identical horizontal generators. Turbines 1 and 3 are Allis-Chalmers fixed blade propeller turbines. Turbines 2 and 4 are adjustable blade propeller units. Total capacity is 3.17 MW.

Project Name Sawmill
LIHI Certificate No. 173
LIHI Certificate Term August 31, 2020 - August 30, 2030
Owner Great Lakes Hydro America, LLC (a subsidiary of Brookfield Renewable Energy Group)
State New Hampshire
Location River Mile 138.2 - Androscoggin River
Installed Capacity 3.17 MW
Average Annual Generation 15,899 MWh
Facility Type Run of river
FERC No. Sawmill P-2422

Issued in 1994, expiring July 31, 2024

The project operates in a quasi-run-of-river mode and impounds a 72.5-acre reservoir. The impoundment is allowed to fluctuate over a 6-inch range. The project provides a minimum flow of 12 cfs into the bypassed reach to provide passage flow and protect aquatic resources. This flow regime was developed in consultation with US Fish and Wildlife Service (USFWS) and the New Hampshire Department of Environmental Services (NHDES).

Waters within the project reach are designated as Class B, suitable for fishing, primary contact recreation, and water supply after treatment. The project waters are listed as impaired due to prior discharges from several paper mills. Given run-of-river operations, the project is unlikely to adversely impact water quality.

The Androscoggin River is not accessible to diadromous fish species in the project reach. Species such as alewife, blueback herring, striped bass, sea lamprey, and American shad are not present in the area due to downstream natural falls – Lewiston and Rumford Falls. American eel are present in the lower reaches of the Androscoggin River though none have historically reached the upper sections of the river. The project area supports cold-water fishery habitat. New Hampshire Department of Fish and Game annually stocks brook, rainbow, and brown trout upstream of the projects. Resident river species include fallfish, smallmouth bass, white sucker, longnose dace, common shiner, spottail shiner, and yellow perch. Downstream passage can occur by means of spillway flow, low-level gate releases, and power intake flow through the trashracks. The project does not impede the successful completion of resident fish life cycles.

The project lands are limited to the area occupied by project infrastructure. The project is located on the northern edge of the City of Berlin. The east shoreline of the impoundment is bordered by sand and gravel terraces, most of which have been altered by industrial, commercial, and residential development, as well as railroad and bridge construction. The east shoreline of the impoundment is also characterized by low terraces and was altered by the railroad yard, railroad bed, mill yards, and commercial and residential development. The project’s run-of-river operations provides protection of the shoreline areas.

Threatened or endangered species potentially present in the project vicinity include the Northern long-eared bat, Canada lynx, eastern small-footed bat, little brown bat, tri-colored bat, bald eagle, Cape May warbler, evening grobeak, rusty blackbird, wood thrush, wood turtle, American marten, peregrine falcon, and common nighthawk. Plant species include auricled twayblade, mountain sweet-cicely, ovoid spikesedge, parasol sedge, pink shinleaf, purple virgin's-bower, round-leaved orchid, smooth cliff fern, dwarf blueberry, fragrant wood fern, heart-leaved twayblade, and Hornemann's willow-herb.

The listed bat species are not likely to be impacted by project operations as there are generally no tree-clearing activities or corridor maintenance activities. Some vegetation removal and maintenance occur to ensure dam safety but said activities adhere to the USFWS 4(d) rule concerning habitat protection for the bat species. Most of the other listed species have been noted in the project vicinity but run-of-river operations and impoundment fluctuation limits mitigate any impact on these species.

The project area does not support any known historic or cultural resources. However, the project operates under a Programmatic Agreement (PA) in consultation with the State Historic Preservation Office. The PA provides provisions detailing annual monitoring and reporting concerning repair and improvement activities conducted as well as any scheduled activities for the upcoming year.

There are no recreational facilities at the project due to safety concerns, but there are several facilities in the project vicinity. Immediately west of the Sawmill dam is Northern Forest Heritage Park, which was established by a 12-acre donation from the project’s previous owner. The park hosts river tours, cultural events, concerts, and parties. Rotary Park is located adjacent to the impoundment and provides access to the shoreline. Centennial Park, located on the impoundment, provides access via a boat launch.


Certification History

November 30, 2020: The decision to certify the Sawmill Project became final after the close of the appeals period on November 27, 2020 with no appeals filed. The Certification term is from August 31, 2020 – August 30, 2025. The Certificate includes the following conditions:

  • Condition 1: The facility Owner shall provide updates to LIHI on the ongoing status of Project relicensing, including studies, FERC filings, resource agency consultation, prescriptions and recommendations, and agency comments on study results. LIHI reserves the right to modify the Certificate or conditions based on the outcome of the relicensing.
  • Condition 2:The facility Owner shall provide updates to LIHI on the ongoing status of the Proposed Recreation Plan including efforts with the City of Berlin’s Riverwalk project.

October 27, 2020:The Low Impact Hydropower Institute (LIHI) preliminarily approved Low Impact Certification for the Sawmill, Cross Power, Upper Gorham, and Shelburne Hydroelectric Projects located on the Androscoggin River in New Hampshire.

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 for one or more of these projects can be submitted by email to comments@lowimpacthydro.org with “Androscoggin River-NH Projects” 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 November 27, 2020.

The full application and review report are available below. If no appeal requests are received the certification term for each project will be August 31, 2020 through August 30, 2025.

August 13, 2020: The Low Impact Hydropower Institute has received a complete application for Low Impact Certification of the Sawmill, Cross Power, Upper Gorham and Shelburne Hydroelectric Projects located on the Androscoggin River in New Hampshire. LIHI is seeking public comment on this application. Specifically, we are interested in knowing whether you think the Projects meet the LIHI Low Impact Certification Criteria, as revised in the 2nd Edition Handbook. The application can be found 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 comments@lowimpacthydro.org with “Androscoggin River-NH 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 October 12, 2020 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.