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.
Boreal forest of Canada
The boreal forest also has vast areas of wetland, particularly bogs and fens. Two wetland areas, the Hudson Bay Lowland and the Mackenzie River basin, are among the ten largest wetlands in the world. The boreal forest wetlands provide wildlife habitat (particularly for migratory birds), they maintain water flow in rivers, and they store significant amounts of carbon that otherwise would be released to the atmosphere.