1991 Citroen ZX losing water

I have two water problems that are possibly linked, only i can't work it out. i'm no mechanic but here are the problems.

1. i'm losing water from the radiator, but there are no leaks that i can see. I've watched the water level drop over a period of 8 minutes, but i have no leaks from the waterpump,radiator or engine. I've checked the oil and it's fine. no gunk, no sign of any water problems there. It just seems to disappear.... Which leads me onto my other problem. the passenger foot well is filling up with water... is this linked ? and could someone please tell me how as it's driving me crazy. i can't see how the water is getting there.. please help.


regards

jimjam