As I understand it the two issues are separate......apologies if I am wrong.
The radiator water is topped-up by removing the bonnet. The water expansion tank is clearly found then.
The water you are seeing from the air-con system is purely condensation and not water leaking as such. This is quite natural and you’ve nothing to worry about.
By loads of water do you mean actually mean a small puddle of water or is it really loads? You may just have another kind of leak if that is the case.
2004 1.4 TDi (90) SE, Cobalt Blue, Climate control, Cruise control, DIS, Sport seats, Winter pack, Symphony II.