Located on the Hall River near Sept-Îles, some 6.2 km upstream from the junction with the St. Lawrence River, a concrete dam built in 1964 and owned by the Société ferroviaire et portuaire de Pointe-Noire impedes the migratory path of the American eel. The dam is 7.60 m high and 427 m long.
To restore habitat connectivity for the American eel on the Hall River, AECOM designed and installed in 2021, along with partners from the Huron-Wendat Nation Council and Organisme de bassins versants Duplessis, an eel ladder on the dam.
The main components of this fishway are an aluminum ramp encasing AECOM climbing substrate, and a conveyor pipe for eel release or capture at the exit upstream of the dam. The eel ladder and its associated components have been designed and positioned to facilitate maintenance and avoid any constraints on the integrity and operation of the dam.
Away from inhabited infrastructures, this fishway is notable as much for its simplicity as for its ingenuity, where a gravity-fed attraction flow system at the ladder entrance and a solar-powered substrate flow system ensure autonomous operation and minimize personnel intervention.
As part of this project, AECOM provided its expertise to:
- Determine the ideal location for an eel ladder on the dam
- Design an eel ladder adapted to the site and the customer’s needs
- Undertake custom fabrication of the components
- Install and commission the eel ladder
- Produce a maintenance plan including start-up, operation and shut-down tasks to ensure the eel ladder’s longevity.
Since its installation, the Duplessis OBV has been monitoring the migration of American eels in the migratory ramp of the Hall River dam.
