The Eastmain-1 Hydroelectric project was carried out by a joint venture between 91ÖÆƬ³§ 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.