The amount of water in Lake Superior continues to climb and is now at its highest point since 1997. Thanks to the brutally cold winter and a very wet spring and early summer… evaporation has been at a minimum and runoff has been unusually high. The longest ice cover in history is likely mostly to thank for the higher water levels. The ice coating the surface of the lake prevents evaporation during the cold winter months. With the lake water protected from evaporation, any and all water stays in the lake with all remaining precipitation helping it to fill further.
Now the lake level itself doesn’t fluctuate all that much to begin with. The highest and lowest recorded levels of the lake are less than 5 feet apart, but many hydrologists have been concerned about the “generally low water level” since 2000 and were afraid it may never recover to pre 21st century levels. Well, they can stop worrying now. The graph above shows the levels of the lake since 1996 with monthly average points marked with a dot. The graph below shows the water level of just the last few months at the city of Marquette in Michigan. The dark blue squiggly line indicates the current water level. The black squiggly line indicates the water level at this same point last year. The red straight line shows the climatological average of the lake. And then the light blue line at the top and the brown line on the bottom indicate record monthly levels.
So where does all the water come from? Well, here is where the water drains in from… the picture below is the watershed for the lake.