this is not important.
the article says nestle can sell 250,000 gallons a day as bottled water.
at that rate it would take 14,000 years to empty the lake (assuming no net additions or deletions of current water).
By then, there is a good chance the Ice sheets will have returned covering the entire area.
Lake Erie is only 4,000 years old and has a depth of only 62 feet (average). The bottom of erie is rising too.
The Great Lakes as we know them are a wonderful if temporary resource.
That amounts to 0.77 acre-feet/day, maximum.
By contrast, the Saint Clair River, flowing out of Lake Huron, thus draining Lake Michigan in the process, averages 4.25 acre-feet per second; over 15,000 times as much water per day.
Putting it another way, Lake Michigan contains 1,180 cu mi of water, and 1 cubic mile = 3 379 200 acre feet, or 4.3 million times the amount Nestle can suck out. And that doesn't include what's in Lake Huron, essentially a part of Lake Michigan.
Rather than worrying about where the water is going, ask where is the money flowing.