Funny, now we are worried about low levels. I remember back in the mid 80's we were worried about record high levels.
The fact is the Great Lakes vary constantly in lake levels. This has been happening for hundred of years. Look at this link. http://www.in.gov/dnr/water/files/07...keMichigan.pdf
It shows Lake Michigan levels from 1918 to present. The lake has been at these "record" lows 3 times before, 1964, 1934 and 1926. Look at how it hit close to a record high in 1929-1930. Big change in a couple of years time. Also note that the variation is about 6 ft.
The big factor that affects lake levels are rain/snow amounts. There is nothing that man can do to change that. And don't give me the ridiculous line about global warming, oops, I mean global climate change, or what ever it's called today. Again look at the graph and how it changes from a period of 2-3 years.
If we think that we can increase the levels by reducing water usage we will be on a fool's errand. What we do when the levels hit highs? Will we have to drink more water and have mandatory lawn watering?