You've got yourself a pond! The rain is driving me crazy. It seems it's been raining for the past 3 months here. I've been trying to set some fence posts, and the ground is so saturated that the holes fill up as fast as I pump them out. It's so frustrating. Hopefully, things dry up for you soon and you can get the pool in. I'm looking forward to seeing your build. Please post a lot of pis along the way, especially the drainage.