I once rented a place where, during a heavy rain, the water would come in through the front door, flow in a stream along the wall, and pool in the recessed area by the back door, where it would eventually find its way outside. And because I was young and naive, I actually took the time and money to clean and repair any damage we may have caused when moving out and they kept the deposit anyway because they're slumlords. Never made that mistake again lol