I am asking myself the same question. What were you thinking? Pools were invented by desert people to store water and avoid dying of thirst. They also used them to cultivate plagues and send them to their enemies, say, the Egyptians.
If you live near a body of water or in a place where you actually get water from the sky, you do not ned a pool! :)
If you live in Florida, you already have naturally bred plagues.