Water in Porta Potty Cuddy Compartment
 

We recently bought a Z272 and are getting it ready for summer. The previous owner had removed the porta potty so both under inside storage cuddys are empty. The porta potty side has fiberglass floor but water seems to be seeping in. Whenever I open the door, there is an inch or so of water in the floor. I have vaccummed it out and next time I look it has seeped back in. There is fabric on the walls and it is not wet, nor is anything around the window. There are 4 small screw holes in the floor (probably from the old porta potty) Could the water be coming up through those? Any help would be greatly appreciated!