Maine Hydro Firm Wants Temporary River Flow Adjustments
Published Date: 5/19/2025
Notice
Summary
Great Lakes Hydro America wants to temporarily change water levels and flow at their Mattaceunk Hydroelectric Project on Maine’s Penobscot River. These changes could affect local water conditions and folks have until June 11, 2025, to share their thoughts or objections. No big money moves are mentioned, but the public and agencies are invited to weigh in and help shape the decision.
Analyzed Economic Effects
2 provisions identified: 1 benefits, 0 costs, 1 mixed.
Temporary drawdown of reservoir waters
Starting August 1, 2025, the licensee proposes to lower outflows and draw down the Mattaceunk impoundment for up to nine weeks to allow repair and maintenance work, after which the water surface elevation would be raised back to the normal level. The work includes concrete repairs and gate replacement and may change local water levels and flows during that period.
Fishway repairs before 2026 salmon evaluations
The licensee proposes concrete repairs to the upstream fishway, replacement of the sluice gate and roll gate seal, and repairs to fishway trap supports to ensure the fishway remains operable in preparation for Atlantic salmon (Salmo salar) upstream passage evaluations that begin in 2026. The licensee filed a Biological Assessment addressing effects on the Gulf of Maine Distinct Population Segment of Atlantic salmon and designated critical habitat.
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Key Dates
Department and Agencies
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