The staggering rise of Minnesota's most famous lakes this spring

Water levels are high pretty much statewide after a wet spring has brought above normal snowfall to northern Minnesota and above normal precipitation elsewhere. The obvious impact has been felt this spring in our rivers, but our lakes – especially in northern Minnesota – are also rising. 

We started spring with lots of snow already in much of northeast Minnesota. The map below shows the equivalent amount of water (in inches) in the snow pack on March 20.

Once spring got going, parts of northwest Minnesota saw triple their normal precipitation for the past 60 days while much of northeast Minnesota and pockets of central Minnesota (including the Twin Cities) saw double the normal precipitation.

That rainfall combined with above normal snowfall added A LOT of water to the watersheds. Up to 2-3 feet for late March into the start of May fell in northeast Minnesota. All that extra precipitation (rain and snow) ends up in one of two places in northeast Minnesota: Lake Superior or the Lake of the Woods/Rainy Lake watersheds.

Lake of the Woods is up 3-4 feet this spring. Upper and Lower Red Lakes are up 2 feet. The increases are less as you go south but still high. Lake Mille Lacs, for example, is up almost 1.5 feet and Lake Minnetonka is up a foot.

The BIG question you might have is what about the BIG lake? It takes A LOT of water to raise the levels of Lake Superior since it’s such a large surface area. And weather can vary substantially on the west or east side of it since there’s over 350 miles between Duluth and Sault Ste. Marie.

Lake Superior also is up about a foot just in the last 6 weeks. That is a huge increase for a lake that size. An increase of a foot equates to 6.6 trillion gallons of water, or to put that in perspective it's like dumping Lake Minnetonka into Lake Superior 47 times!

That is a staggering number but on average, between April 1 and May 31, the lake goes up about 16 inches due to the winter snow melt (which can be slow on the north shore) and spring rainfall. This April’s increase is above normal. We’ll see what the rest of May does.