Climate Change: Implications for Canadian Water Resources and Hydropower Production

Abstract

In this paper the possible effects of climate change on Canada’s water resources, and the attendant implications for hydropower production are discussed. A change in climatic conditions could spawn drastic changes in the way that the Canadian hydroelectric sub-sector manages the operations of its hydropower stations. Supporting arguments draw largely on four modelling studies in which general circulation models (GCMs) and hydrological models have been used to predict significant climatic and hydrological changes in Canada’s major watersheds. The areas investigated include the interior of British Columbia and southern Yukon (Coulson, 1997), the basins surrounding James Bay in Quebec (Singh, 1988), the Great Lakes Basin in Ontario (Cohen, 1986), and the Saskatchewan sub-basin which transects the provincial borders of Alberta, Saskatchewan and Manitoba (Cohen, 1991). A synthesis of the results of these studies is used to decipher the multitude of annual and seasonal changes in runoff, precipitation and evaporation that may occur in the future. There are indications that the annual volume of runoff and hydropower capacity may increase in northern regions, and decrease in southern regions. As for seasonal changes, northern areas may see a more intense spring runoff due to an increase in snowpack, while southern areas may experience heavier winter runoff due to larger winter rainfalls. A greater number of spring or winter floods could force hydropower installations to divert flood water to their spillways more frequently, amounting to missed opportunities to produce energy. The frequent occurrence of extreme events such as large storms and flash floods could also jeopardize the integrity of certain hydropower stations. Other problems such as melting glaciers, ice jams, sediment loading and hydraulic surging could adversely affect the operations of hydropower stations. These problems may be exacerbated by increases in demand for domestic and irrigation water, as well as energy for interior cooling. The paper concludes by enumerating mitigatory and managerial strategies to alleviate the possible difficulties faced by the hydropower sub-sector.