Because "big" numbers like 7M are scary I think a little perspective is warranted. The great lakes contain 380 quadrillion gallons of water which means even if

Because "big" numbers like 7M are scary I think a little perspective is warranted. The great lakes contain 380 quadrillion gallons of water which means even if they did not return a single drop it would take 54 billion years(or ~10x the age of the earth it's self) to drain the basin. This is of course ignoring the whole fact that the water they don't return does not just disappear it increases the humidity of the air and causes increased rainfall somewhere. Also I find the idea that humans should only use fresh water for drinking and public utilities laughable. Water is and has been an integral part of making damn near everything for millennia.