Water Table in a Habitat

Whetehr a Habitat will have rain from overhead pipes or from some
type of weather system, what will happen to the water that reaches
the ground?

Some will evaporate. Some will be soaked up by biomatter. Some will
bind with the soil. But some will also percolate through the soil
and go where? What mechanism will be in place to capture the water
that works its way through the soil and now approaches the pressure
shell?

Any thoughts?

TangoMan