Although you might think of Manitoba as a “Prairie Province “ smack dab in the middle of flat and barren Canada far away from any oceans – flat and waterless Manitoba indeed has 3 of the larges lakes in the world. These could be called Manitoba’s “Great Lakes”. The biggest of these lakes is Lake Winnipeg; the other two are Lake Manitoba and Lake Winnipegosis. These large lakes are what are left over from what was the largest freshwater lake in the world – Lake Aggasiz

How and where did these lakes occur smack dab in the middle of the Canadian prairies? These large lakes are the remainder and remainders of a vast glacial lake – a glacial lake that existed before recorded history. As ice ages occurred and glaciers of ice formed in the cold and then melted the waters served to form giant and gigantic “Lake Aggasiz”. Lake Aggasiz was formed not once but at least 4 times during the past 15,000 years. Indeed Lake Aggasiz was the largest freshwater lake in the world before finally drying up and receding approximately 8,000 years ago.

How large was this gigantic freshwater lake, Lake Aggasiz, which was the result of the melting of the ice of these ice ages? Lake Aggasiz was so large that it covered most of the areas of Southern Manitoba along with major portions of what is now Northwestern Ontario. Minnesota, North Dakota along with large areas of the Canadian province of Saskatchewan. All in all this amounted to a size of as much as 450, 00 square kilometers. To put this into context Britain is 130,000 square kilometers.
At its peak Lake Aggasiz was more than three times the size of Britain, and larger than the American state of California.

The mounds and mountains of frozen ice that formed the glaciers and fed Lake Agassiz also prevented its draining. However with climate change resulting in warmer temperatures and weather, the ice age or ice ages ended. The vast mountains and barriers of glacial ice that had restrained and held back the flow out the lake disappeared. The gigantic Lake Agassiz was able to drain its waters into the sea. So much water flowed into the oceans that the oceans and seas levels rose – some estimate by as much as a meter (3 feet in height). It is thought by some authorities that the biblical story of Noah and the great flood correlates indeed to the time of melting of the gigantic glacial fields and the draining, emptying and dispersal of Lake Agassiz.

What were the final impacts of this gigantic lake – Lake Agassiz? For one the great areas of water that remained – the residual leftovers of what was then the largest lake in the world. These lakes are the “Great Lakes “of Manitoba – Lake Winnipeg, Lake Manitoba and Lake Winnipegosis. Geographic reminders of the large lake remain – raised beaches, miles and miles away from any known waterfront areas are one, river and river valleys formed are another. Very importantly the flat fertile fields and soils of the Red River areas including areas of the northern American states of North Dakota and Minnesota are another. However the most important legacy of all of prehistoric, gigantic Lake Agassiz may be mythical tale of folklore – of the great flood. We know this tale best as that of Noah’s flood in the bible. However Lake Agassiz’s effect on the waters of the world has spread across the world and across almost all cultures as their own mythical and moral tale of the giant flood.