LIHI Certificate #188 - Cascade Project, New Hampshire

Project Name Cascade
LIHI Certificate No. 188
LIHI Certificate Term March 1, 2022 – February 29, 2032
Owner Great Lakes Hydro America, LLC, a subsidiary of Brookfield Renewable Energy Group
State New Hampshire/td>
Location Located at river mile 135.6 on the Androscoggin River in Berlin and Gorham, Coos County
Installed Capacity 7.92 MW
Average Annual Generation 39,191 MWh
Facility Type Run-of-river
FERC No. P-2327 issued in 1994, expires 07/31/2024

The Cascade Project is located on the Androscoggin River in the city of Berlin and the town of Gorham, New Hampshire. The dam and a grinder room were originally constructed in 1903 by the Berlin Mills Company to provide hydro-mechanical power for paper making activities. The grinder room was converted to a hydroelectric generating powerhouse between 1913 and 1918 which included the replacement of the hydro-mechanical units with hydroelectric turbine/generators. Hydroelectric energy was first produced in 1914.

The Androscoggin River, spanning 178 miles, drains 3,450 square miles within New Hampshire and Maine. It joins the Kennebec River at Merrymeeting Bay in Maine before emptying into the Gulf of Maine and subsequently the Atlantic Ocean. The Androscoggin River is host to nineteen hydroelectric projects, including the Sawmill (LIHI #173), Cross Power (LIHI #174), Upper Gorham (LIHI #175), Gorham (LIHI #153), Shelburne (LIHI #176), Rumford Falls (LIHI #38), Androscoggin (LIHI #48) and Worumbo (LIHI #10) Projects. The Cascade project is located just downstream of the Cross Power Project (LIHI #174) and immediately upstream of the Upper Gorham Project (LIHI #175).

The dam is in the same configuration as it was in 1903. It is a 583-foot-high concrete gravity dam consisting of:

  • A 15-foot-wide concrete abutment which extends for about 20 feet upstream and 30 feet downstream perpendicular to the end of the spillway,
  • An ogee spillway section, 313 feet long with 3-foot-high flashboards,
  • A forebay gate structure, 168-feet-long by 15-feet-wide. It consists of 15 three-feet-wide concrete piers and a concrete deck with wooden gates, each 9-feet-wide and 11-feet-high,
  • An abutment adjacent to the forebay gate structure consisting of two parallel 3-foot-wide concrete retaining walls with earth fill. The retaining walls extend approximately 88 feet, including 77 feet located inland of the riverbank,
  • A forebay, downstream of the forebay gate structure, approximately 300-feet-long by 240-feet-wide with a maximum depth of 24 feet. The forebay wall is a concrete gravity structure that extends approximately 326 feet downstream. The wall has a maximum height of 41 feet, with a 4-foot, 11-inch-wide crest.

Within the forebay wall is:

  • A deep gate located about 90 feet downstream.
  • A 4-foot-wide by 2.5-foot-deepsluiceway located about 193 feet downstream.
  • A concrete platform located on top of the forebay wall, measuring 19-feet by 24-feet, to support an electrical tower with transmission lines.
  • A steel framed brick and block powerhouse, measuring 135-feet-long, 43-feet-wide, and 67-feet-high with a concrete structure addition measuring 19-feet by 24-feet. Three penstocks lead from the head gates to the three Francis turbines.

A 400-foot-long bedrock channel bypass reach is fed by the water passing over the spillway.

The project operates in a run-of-river mode and impounds a 28-acre reservoir. Inflow to the project is regulated by five storage reservoirs at the headwaters of the Androscoggin River system. The project provides a minimum flow of 6 cfs or inflow, whichever is less, through an orifice in the spillway flashboards to provide stable habitat for resident species. This minimum flow regime was developed in consultation with the US Fish and Wildlife Service and New Hampshire Fish and Game Department.

Waters within the project reach are designated Class B, considered acceptable for aquatic biota habitat, fishing, primary recreation, and drinking water supply after treatment. Sampling of the impoundment and bypassed reach in 2020 confirmed that water quality parameters met or exceeded the accepted standards for Class B waters.

Downstream natural barriers preclude access for migratory species in this reach of the Androscoggin River. The National Marine Fisheries Service has concluded that due to the downstream Lewiston Falls and Rumford Falls, species such as Atlantic salmon, alewife, river herring, and striped bass would not be able to reach the waters in the project vicinity. American eel, a catadromous species, is present in the lower Androscoggin River, though in relatively low numbers. No American eel have been collected during fish sampling studies in the upper Androscoggin River. However, the upper Androscoggin River is a popular cold-water trout and landlocked salmon fishery. This fishery is bolstered by trout stocking and wild reproduction in the upper watershed and in tributaries. Other resident fish species include fallfish, smallmouth bass, white sucker, longnose dace, common shiner, spottail shiner, rainbow trout, bullhead, and yellow perch.

The limited project lands consist of those associated with project structures. A Shoreline Management Plan governs land usage in the project area and implements provisions from the New Hampshire Comprehensive Shoreland Protection Act (now the Shoreland Water Quality Protection Act). This policy lists uses of the shoreland within a 250-foot buffer that are permitted, prohibited, or restricted and established planting and vegetation removal standards within any existing woodland buffers.

Threatened or endangered species potentially present in the project vicinity include Canada lynx, Northern long-eared bat, Eastern small-footed bat, little brown bat, and the tri-colored bat. Due to the limited maintenance activities that occur at the project, it is not expected that the project has any impact on the listed species. Run-of-river operations also limit impoundment fluctuations and minimize any potential for adverse impact on the shoreline habitat and resident species.

The project area does not host any archaeological or cultural resources. The project owner provides an annual report on management of the property’s structures, specifically the dam and powerhouse.

No recreational resources are provided in the project’s limited area. Informal access is provided in the tailrace of the upstream Cross Power project and there are two municipal parks nearby. Downstream access is available from a gravel hand carry boat site roughly two miles from the project. Otherwise, there is no safe access to the impoundment, bypass reach, or tailrace as the surrounding lands are forested and steep.


Certification History

May 19, 2022: The decision to certify the Cascade Project became final after the close of the appeals period on May 18, 2022 with no appeals filed. The Certification term is from March 1, 2022 – February 29, 2032.

April 18, 2022: The Low Impact Hydropower Institute (LIHI) has preliminarily approved the Cascade Project for a 10-year term of Low Impact Certification. The full application and reviewer’s report are available below.

The Certificate includes the following condition:

  • 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.

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 comments@lowimpacthydro.org with “Cascade 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 May 18, 2022.

If no appeal requests are received and the decision becomes final, the Certification term for the Project will be March 1, 2022 through February 29, 2032.

February 7, 2022: The Low Impact Hydropower Institute has received a complete application for Low Impact Certification of the Cascade 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 comments@lowimpacthydro.org with “Cascade 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 April 8, 2022 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.


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