1999 vw beetle problem

I have a 99 vw beetle with 103,000 miles on it. 2 years aso I put a new water pump on it. Now since I am using the air conditioner it seems there is water leaking from under my car when it sits. Ocassionally I have to fill the water resevior because the water runs out. Is the water pump going out again? Or whats going on?

Water will always leak from under the car when the airconditioning is on as the unit de-humidifies the air in the car and the condensed water drains out thru a tube....but this will be clear water.
Coolant will be red or green.