The Eastmain-1 Hydroelectric project was carried out by a joint venture between Aecon and HT Civil Canada Inc (Hochtief Construction A.G.). The project involved the construction of the powerhouse, the water intake structure and horizon penstocks.
The surface powerhouse was built into a rocky hill on the left bank of the Eastmain River and is comprised of three vertical-axis generating units. The water intake structure is equipped with three gates and each opening has a track to prevent infiltration of debris into the penstocks. The penstocks themselves are conduits excavated in the rock and are lined with concrete.