the heater core has got a hole in it or your top has a hole init. If the water is green it is your heater core. if not it is your top.
Bad heater core? replace Evaporator drain plugged if A/C equipped - try to unplug from under vehicle
Are you running the air conditioner? If the drain line is plugged, it will leak water (condensation) onto the passenger side floor.
The air conditioneer drain is probably plugged. or the drain has been icked and is disconected from the pan so it is draining directly onto the floor
A/C condenser drain line is stopped up. This is allowing the water to enter the cabin. Crawl under the van and find the drain line. Usually located near the firewall passenger side. Clean out the drain tube.
heater core may be leaking or hole in floor
Is it blood, oil, water, or urine?
There is a drain on the outside firewall that is clogged.
Stopped up condenser drain line, unless this water is coolant. In that case it is a leaking heater core. Coolant tastes and smells sweet. Crawl under the car and look for a drain line on the passenger side, near the firewall. Clean this out with a blunt pencil.
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.
bad heating core
Probably have a leak in the heater core>
Heater. Core