Flooding events in Canada
Introduction
The water level of a stream, river or lake is constantly rising or falling in response to changing hydrologic conditions in the drainage basin. Each year the water peaks at some level, which may cause flooding of surrounding lands.
This map shows, in general, how the average annual maximum flow of a 1000-square-kilometre river basin varies across the regions of Canada.
Map: Average Annual Maximum Flow

Details can be found below
Average annual maximum flow. This map shows, in general, how the average annual maximum flow of a 1000-square-kilometre river basin varies across the regions of Canada. As climatic and physiographic factors influence the flow of a river, its geographic location is important. At the extreme, a river on the rugged, humid west coast can have an average annual maximum flow hundreds of times greater than that of a river in the relatively dry prairie region.
As climatic and physiographic factors influence the flow of a river, its geographic location is important. At the extreme, a river on the rugged, humid west coast can have an average annual maximum flow hundreds of times greater than that of a river in the relatively dry prairie region.
Flood Events by Province and Territory
The following regional descriptions illustrate these variations. Specific flood events are highlighted to give an impression of the magnitude of the problem and the considerable force contained within a flood.
- British Columbia
- Case Study: Flood Control on the Fraser in British Columbia
- Yukon
- Anecdote: Yukon
- Northwest Territories
- Prairie Provinces
- Alberta
- Saskatchewan
- Manitoba
- Anecdotes: Prairie Provinces
- Case Study: Flood Control on the Red and Assiniboine Rivers in Manitoba
- Ontario
- Anecdotes: Ontario
- Quebec
- Atlantic Provinces
See also: Flood Forecasting Centres Across Canada
Return to Floods menu
Previous page: Reducing Flood Damage
Report a problem or mistake on this page
- Date modified: