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.
Geography of Canada
The northern parts of Alberta, Manitoba and British Columbia, most of Northwest Territories and Nunavut, and parts of Yukon are drained by the Arctic watershed. This watershed has been little used for hydroelectricity, with the exception of the Mackenzie River, the longest river in Canada. The Peace, Athabasca and Liard Rivers, as well as Great Bear Lake and Great Slave Lake (respectively the largest and second largest lakes wholly enclosed by Canada) are significant elements of the Arctic watershed. Each of these elements eventually merges with the Mackenzie, thereby draining the vast majority of the Arctic watershed.