Monitoring of the Ice Cover within the Scope of the Eastmain-1-A/Sarcelle/Rupert Hydro Power Project

Implementation of a hydroelectric power project is subject to many conditions and commitments related to environmental protection. Within the scope of the Eastmain-1-A/Sarcelle/Rupert project and in collaboration with the local communities, Hydro-Québec has developed an environmental monitoring program including the follow-up of the ice cover over the course of several winters. The ice monitoring program has begun in the winter of 2009-2010 and is still ongoing. It involves monthly surveys from December to April, and covers a broad territory with 650 km of waterways including stretches of rivers (reduced/increased flow), diversion reaches, lakes, reservoirs and the Rupert Bay. During each survey, the entire territory was flown over by helicopter in order to map the ice cover and to survey the ice thickness at seven transects. The results showed that the diversion reaches and the increased-flow river sections freeze later than the other areas. The lacustrine increased-flow sections (i.e. reservoir) behave almost like the lakes in the area, except for the preferential channels and narrows. The reduced-flow river section (Rupert River downstream from the dam) is influenced by a series of structures built to maintain an upstream water level similar to the pre-diversion level, resulting in an intermediate ice regime that falls between the lacustrine and river regimes. Rupert Bay is strongly influenced by oceanographic and weather factors that affect, control and modify the properties of the ice fields. The bay seems to be unaffected by the hydraulic changes in the river after diversion.