Introduction to the great lakes: which argument between canada and the us was renewed in september 2012, great lakes water quality agreement, boundary waters treaty, columbia river treaty, juan de fuca strait water agreement. More than 12,000 km from west to east. The largest system of fresh, surface water on earth. Have played a major role in the history and development of the united states and canada. Home to more than 25% of the population of canada. More than 10% of the population of the u. s. 25% of the agricultural production is located around the great lakes. 7% of the agricultural production of the us is around the great lakes. Map of the great lakes basin in terms of their relief. 23,000 km3 of freshwater is contained in the great lakes. The total surface area is 244,000 km2. There"s higher relief near the north and lower relief near the south. The green areas are much closer to sea level.