Could be ruptured heater core which is inside pass compartment and part of cooling system, find location using hoses (2) in eng. compartment, examine ductwork under the core and open slightly to check for leak. If so you can bypass until repair. Your coolant needs checked immediately.
The drain line for the cowl is stopped up or the windshield is leaking.
If it's not related to outside weather, then check the drain for your AC condenser.
it is leaking
you could have a heater core leaking or your windshield is leaking and the water is running down behind the dash and onto the floor.
you should dig the floor.
It is either a leaking heater core or the air conditioning evaporator drain plug is clogged.
Because the case is cracked and/or a cell is ruptured. That's probably not just water leaking on the floor. I suggest you buy some cat litter or floor dry and clean that up, quick.
Yes, a leaking toilet tank can cause damage to the floor and inconvenience due to water leakage.
heater core may be leaking or hole in floor
if it's not raining, the heater core is leaking
There is a drain on the outside firewall that is clogged.
The purpose of a drip tray is to protect water leaking to the floor service level. This is to prevent any water damage to the floor and or other floor areas.