I moved into a house last year with a 16'x32' Kayak rectangular pool. The pool was originally built on a raised base to level it properly. One side of the pool sits on the natural ground while the other side of the base is probably a foot above the natural ground level. The pool has settled over time and has areas with as much of a 4.5" difference. Most areas appear to be 2-3" of difference from the highest point. I am planning to drain, re-level and install a new liner in the spring before I open it. I am looking for tips or recommendations so that I can start planning. I am particularly concerned about trying to re-level it with that much difference. Would the preferred method be to raise the low areas and block or should I dig the high areas in? If I do raise and block, what can I do to help prevent those areas from having the floor wash out after installing the new liner? I can attach pictures if needed.