I have a 21ft round pool and I seemed to develop a leak. It seemed to start last summer as the pool levels were depleting rapidly. I just assumed I was having more than usual evaporation and then I suspected a leak. Anyway, it was close to closing time so I closed the pool and now the pool has emptied over the winter. I opened the pool yesterday and I still have about a foot of water left but I cannot find a hole anywhere? The pool is always full and crystal clear every year I open it. Could it be on the bottom even with water in the pool? I think a mole got under the pool the year before and tunneled a bit under the liner, but again, I went under with googles and I did not see any holes, but he did create some large dimples or could have this been caused by a leak and it wrinkled the pool liner? I'm lost! Any tips would be appreciated Thanks.