Originally Posted by idiot magnet
Check your cowl for leaves and crap along with your a/c drain hose which is probably plugged as well.
X2....Pull the cowl off in front of the windshield, and stick something long and flat (like a yardstick) down through the bottom of it. There's a rubber flapper on the bottom that you can't really see. Kind of open the flapper with the yard stick then use a hose sprayer to flush out the debris down there.
Your heater issue is probably not related to the water on the floor unless there's coolant in it.