How should the water drain / air pump system work?

I'm thinking that we should have some pipes and a couple of pumps: one inserting air, and one removing water. Could be fun watching the vent system get overloaded with water and being unable to pump gasses into areas :) although I think there would also need to be something like the air alarm system which should allow people to deal with such shitty Nanotrasen-level tech.

Which reminds me...