Hello folks! New here, new to our house, and new to pools. I need some guidance please. We are looking to setup a 18 foot, 48 inch round above ground pool and of course our yard is hilly here in North GA. The flattest part of the yard where it will go still has a 16 inch slop from the highest to lowest side of our location. My question is, if we dig down the high side are we going to need a retaining wall for the 16 inch drop?