NH

Somersworth P-3820

General information

Waterway  Salmon Falls River
Current status   Active license, Non-operating 
Type of facility Conventional Hydro
Mode of hydropower generation Peaking
Type of permit FERC License

FERC information

FERC docket # P-3820
FERC project name Somersworth
Permit issued 9/24/81
Permit expiration 8/27/21

Ownership and operation

Owner Aclara Meters, LLC
Owner type Industrial
Year first online (conventional hydro) 1984
Transmission or distribution system owner Public Service Co of NH

Power and generating capacity

Number of units 2
Total capacity from hydraulic turbine-generator units within each plant 2.1 MW
Average annual net hydropower generation 4,390.8 MWH

This project has been unoperational since 2011, when the penstock that delivered water to the powerhouse failed. Aclara initially intended to obtain a new license, but in 2019 the company submitted a surrender application to FERC. The company proposed to leave the two dams, Stone Dam and Back Dam, in place rather than remove them. Several parties, including American Whitewater, US Fish & Wildlife Service, Maine Department of Inland Fisheries and Wildlife, Maine Department of Environmental Protection, New Hampshire Fish and Game Department, Trout Unlimited’s Sebago Lake Chapter, and Trout Unlimited’s Great Bay Chapter all filed comments supporting consideration of dam removal as an alternative due to impacts on fish species and river connectivity, as well as recreation and dam safety.

FERC accepted Aclara’s surrender plan in May 2023. American Whitewater filed for rehearing of this decision, which was denied, and subsequently filed a legal appeal seeking review in the DC Court of Appeals.

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