All that fill dirt would make for a nice shooting backstop!
A lot more than just digging a hole. You would think a pond will hold about any were but not really. A ton of money has went into many a dry hole. The farm accoss from me the owner has had three different excavation companies in all ready and poor guy still hasn't had much luck. He would have been much better off buying a property with existing lake or pond if he really wanted water.
I dont know where you are from but to me it sounds like bad soil. It is hard to build a water hole in sandy soil. If it is clay soil like in southern indiana then you have problems with water pooling everywhere due to the water not being able to drain through. Not just anywhere is suitable for a pond or lake. Digging a test hole is a good way to start off and just get a feel for what you have to work with without spending much if any money.