Nature-Like Fishway, Hooksett, New Hampshire

The Hooksett Nature-Like Fishway (NLF) project restores historic fish and aquatic organism passage along the Merrimack River between the Garvins Falls and Amoskeag hydroelectric stations. Constructed below the existing dam, the 150-ft-long nature-like fishway is a step-pool configuration with six concrete notched weirs anchored to bedrock along the west side of the river. An innovative inflatable gate installed on the dam allows precise flow control to maintain consistent passage conditions under variable river flows.

DuBois & King led the planning, permitting, hydraulic modeling, final design, and construction contract administration and observation of the project on behalf of Patriot Hydro, working closely with federal and state regulators. The finished project fulfills hydropower relicensing requirements, supports recovery of migratory fish species, such as American Shad, River Herring, and American Eel, and demonstrates a sustainable, cost-effective approach to integrating ecological restoration with renewable energy infrastructure.