Floods are a recurrent phenomenon and represent the most frequent type of natural disaster in Quebec. In fact, most of Quebec’s population lives near the province’s network of waterways and approximately 80% of all riverside municipalities are exposed to flood risk. The history of extreme hydrological events that have occurred in Quebec is testimony to its vulnerability to this hazard.
The population must periodically contend with the social, environmental and economic impacts of flooding, the costs and consequences of which are borne by the government, society and individuals alike. Between 1991 and 2013, annual costs incurred from flooding stood at approximately $79M, but with the extreme events such as the Richelieu River flood in 2011 or those of 2017 and 2019, these figures surged.
Even if flooding represents an economic and public safety issue that tends to be magnified by climate change, its repercussions are not strictly limited to monetary aspects. Indeed, beyond its material and financial consequences, flooding also has significant social and health impacts that are more difficult to identify and quantify. There are also impacts on cultural heritage, the environment, risk management expenses at the municipal level as well as impacts stemming from hazard combinations that are still poorly understood.
Over the course of the 21st century, it is anticipated that the physical processes related to flooding (rain, snow, thaw, etc.) will be disturbed by climate change. Even if the hydroclimatic trends caused by climate change throughout Quebec are variable and fraught with uncertainty, it is expected that these changes will affect the likelihood of flooding and generally magnify material damage as well as any ensuing health, psychosocial and economic impacts.