I am in the texas panhandle. It is flat as a pancake here. No runoof to catch on my property. Will just be digging a hole, sealing it, and pumping it full with irrigation water from the neighbors well. Will use the neighbors well to initially fill it up, and then use my domestic well and rain to keep it full. I don't want to go to big because of cost, and worries about being able to keep it full with my small well.