big pond,why dont you take some of the dirt and make ridges with all this deep water.you will see ray scott did this with his lake.it also worked very well for me,i took dirt and made these ridges about 10-15 feet wide and 6-8 feet tall.now you have water that is about 6 'deep on top falling down to 20'.not sure were you live but i dont think you would have any fish below the 10'depth.it's also cheeper moving the dirt and you have a place to put it,rather than hauling long distance to get it out of hole.