Sardis is a flood control reservoir it's in place to keep from flooding the delta. The rule curve is there guide to keep water when it rains the most and drain it when it rains the least. You can drive your truck on the lake bed in the winter and in the summer water is "about" 20' deep there. Every year is different from the next due to unpredictable rain or drought. You learn to hate it or enjoy it. Best thing is to deal with it and learn from it.