A/C's don't have water in them, but your heater core could; if it is broken, this would require immediate attention as coolant fumes can harm nervous systems,liver, and kidneys in our bodies even if you can't smell them, rather quickly!
A leaky heater core would leak engine coolant not water. The AC system has a condensation drain. If the drain gets plugged up it will backup and drip water on the floor.
The condensate drain is plugged.
heater core
water in passenger floorboard, where is the hose that would cause this?
A damaged heater core will cause coolant or water to leak onto the passenger floorboard.
If that water is engine coolant, the heater core is leaking.
You have a leak either around your windshield or in the firewall. The best way to find the leak is to bring it through a car wash and watch it
Either your windshield or driver's side window has a major leak
plugged evaporator drain tube or the heater core has gone bad
Heater core is shot, its monted on the firewall behind center console/instrument cluster. When turning on heater fan, will dischrge coolant out of the vent. Replace heater core to resolve the leak
This would be caused by a leaking heater core, or a leak in the plumbing associated with it.
Water pump gasket, head gasket, water tube,
You have a leak in the cooling system. Could be water pump, hoses, radiator, headgasket, etc.