to the Mississippi River basin through the Illinois Waterway.

The Great Lakes are the largest group of freshwater lakes on Earth by total area and the second-largest by total volume. They contain more than 20% of the world's surface fresh water by volume. The total surface is 94250 sqmi 0 , and the total volume (measured at the low water datum) is 5439 cumi 0 , slightly less than the volume of Lake Baikal (23615 km3,