where do the great lakes get their water
Great Lakes In 2009, the lakes contained 84% of the surface freshwater of North America;[40] if the water were evenly distributed over the entire continent's land area, it would reach a depth of 1.5 meters (5 feet).[15] The source of water levels in the lakes is tied to what was left by melting glaciers when the lakes took their present form. Annually, only about 1% is "new" water originating from rivers, precipitation, and groundwater springs that drain into the lakes. Historically, evaporation has been balanced by drainage, making the level of the lakes constant.[15] While the lake levels have been preserved, intensive human population growth only began in the region in the 20th century and continues today.[15] At least two human water use activities have been identified as having the potential to affect the lakes' levels: diversion (the transfer of water to other watersheds) and consumption (substantially done today by the use of lake water to power and cool electric generation plants, resulting in evaporation).[41]
Great Slave Lake The Great Slave Lake (French: Grand lac des Esclaves) is the second-largest lake in the Northwest Territories of Canada (after Great Bear Lake), the deepest lake in North America at 614 metres (336 fathoms; 2,014 ft),[1] and the tenth-largest lake in the world. It is 469 km (291 mi) long and 20 to 203 km (12 to 126 mi) wide.[2] It covers an area of 27,200 km2 (10,502 sq mi)[1] in the southern part of the territory. Its given volume ranges from 1,070 km3 (260 cu mi)[4] to 1,580 km3 (380 cu mi)[1] and up to 2,088 km3 (501 cu mi)[5] making it the 10th or 12th largest.