As part of a project to improve dam safety members of Resolute’s Hydro-Saguenay team worked with engineers at WSP to design an improved culvert that would enable the American eel and other fish species to recolonize a territory conducive to their growth. Once thought to be among the most abundant fish species in Quebec, the American eel is in decline.
After assessing the impact of hydroelectric dams to the slimy, scaleless, yellow and brown American eel, the team members set to work. They replaced a culvert on the Benouche stream in Saguenay−Lac-Saint-Jean (Quebec), with a specially designed fishway.
Sensitive species
Eels are sensitive to changes in their environment, therefore, habitat loss and dams are potential factors in their population’s decline. Unlike salmon that run from the sea to freshwater breeding grounds, American eels do the reverse, migrating from fresh water to the sea to spawn. The young eels then make their way back to freshwater habitats to grow.
It’s a challenging journey for the little eels;, they must travel all the way from the Sargasso Sea, near Florida and the Bahamas, to the freshwater lakes of Quebec – some of which are dotted with hydroelectric dams.The Éternité River watershed, which includes the Benouche stream, is a known habitat for the American eel, and experts determined that replacing an old culvert with a more fish-friendly solution can help recolonize the territory and grow its eel population.
Building a more eel-friendly culvert
With this goal in mind, our Hydro-Saguenay hydroelectric generation and transmission division invested in the redevelopment of the Beénouche stream culvert. Making the culvert more eel-friendly was not a simple matter of smoothing out its small waterfall; the team had to redesign the culvert entirely.
The challenge is that most culverts are meant to facilitate the flow of floodwaters, not fish. As a result, water coming from culverts often flows too fast, or the water level is too low for eels and other fish to navigate easily. So, rather than build a round culvert, engineers developed a concrete-formed rectangular shape fitted with curbs and stones that simulate natural hydraulic conditions favorable to the movement of eels.
The Benouche stream culvert project was completed last summer. It’s part of our commitment to actively protect the biodiversity of the habitats where we operate.
Learn more about our other conservation initiatives in the Conservation and Biodiversity section of Resolute’s website, including our commitment to maintaining biodiversity in the forests we manage.