Ottawa River drainage basin
The Ottawa River drainage basin is the drainage basin in northern North America where surface water empties into the Ottawa River and adjoining waters. Spanning an area of about , it is the 12th largest drainage basin in Canada, occupying the Canadian provinces of Ontario and Quebec. It accounts for about 11% of the total Saint Lawrence River drainage area.
History of flooding in Canada
The province of Manitoba completed the Red River Floodway in 1968 after six years of excavation, put up permanent dikes in eight towns south of Winnipeg, and built clay dikes and diversion dams in the Winnipeg area. Other flood control structures completed later were the Portage Diversion and the Shellmouth Dam on the Assiniboine.