This map outlines the boundaries of the 11 major drainage areas and the 164 sub-drainage areas in Canada. These drainage areas cover all the land and interior freshwater lakes of Canada. Description of major drainage areas and sub-drainage areas map of CanadaThis map outlines the boundaries of the 11 major drainage areas and the 164 sub-drainage areas in Canada. These drainage areas cover all the land and interior freshwater lakes of Canada. Major drainage areas 01 Maritime Provinces 02 Canada part St. Lawrence 03 Northern Quebec and Labrador 04 Southwestern Hudson Bay 05 Nelson River 06 Western and Northern Hudson Bay 07 Great Slave Lake 08 Pacific 09 Yukon River 10 Arctic 11 Mississippi River