Some of the great bunkers suck the ball into them if it goes any near it. I'd guess this means that the surrounding land also drains into the bunker.
What does this mean for the life of the bunker and bunker sand? Sand changed more often? Bunker firms up quicker?
Should the draining water be deflected away from the bunker or will this reduce the effectiveness of the bunker to magically attract the ball? Is there a way around this?