Mackenzie River
At , the Mackenzie River drainage basin encompasses nearly 20 percent of Canada. About , or 54 percent of the basin, lies above Great Slave Lake. Permafrost underlies about three-quarters of the watershed, reaching up to deep in the Mackenzie Delta. As a whole, the Mackenzie basin receives only meager to moderate rainfall, averaging over the entire basin, though mountain areas experience much higher precipitation, and areas near and north of the Arctic Circle receive much lower precipitation.
Geography of Canada
Canada holds vast reserves of water: its rivers discharge nearly 9% of the world's renewable water supply, it contains a quarter of the world's wetlands, and it has the third largest amount of glaciers (after Antarctica and Greenland). Because of extensive glaciation, Canada hosts more than two million lakes: of those that are entirely within Canada, more than 31,000 are between in area, while 563 are larger than .