Hudson Bay drainage basin
The Hudson Bay drainage basin is the drainage basin in northern North America where surface water empties into Hudson Bay and adjoining waters. Spanning an area of about , the basin is almost totally in Canada (spanning parts of the Prairies, central and northern Canada), with a small portion in the United States (in Montana, the Dakotas, and Minnesota). The watershed's headwaters are in part on the Continental Divide of the Americas, and the watershed's connection to the Labrador Sea is at the Hudson Strait's mouth between Resolution Island in the Qikiqtaaluk Region and Cape Chidley on the Labrador Peninsula. On the Continental Divide the basin is bounded at Triple Divide Peak to the south, and Snow Dome to the north.
Water supply and sanitation in Canada
Metro Vancouver's water system is one of the largest in North America. Almost 600 square kilometers of mountainous land is closed to public access to protect the large reservoirs which collect rain and snow melt. 
Three watersheds - the Capilano, Seymour and Coquitlam Watersheds are the water source for more than two million residents in the most populated urban region of British Columbia. Each watershed supplies about one-third of the region’s tap water. The regional district’s long-standing closed watershed policy is one component of a water supply system that provides multiple barriers to contamination, from source to tap.