yeah, the outer ring around the inner tank opening is not water resistant. But it does have a drain that comes out the bottom of the bike via a hose. If it's filling up and overflowing into the inner opening where the fuel is, then there is something plugging up the drain.
You might use compressed air to blow out the obstruction. Like R&R said, it could also be pinched from raising and lowing the tank.
It's supposed to drain like the lip around a car sunroof if that helps explain it better.
OH... and if you do have water in your tank you should either drain it (best idea), or take the chance on actually adding even more alcohol over several tankfuls to get rid of it. If you do indeed have "several ounces" in there ... that's bad, get it out before it rusts the tank.