Our pool liner has floated two times now with heavy rains. The occasional shower does not cause a problem. The earth under the deck on one side of the pool was like soup and a couple inches below the concrete. It took forever to dry out, and now it has happened again. The area that was affected the most was where the earth was disturbed during construction to make a ramp into the pool for the bobcat to dig. We are considering putting a French drain 2 ft. wide starting at the back deck and all the way across the back of the pool. The back side has 0 grade away and seems to have the most problem. Is a 2 ft. drain adequate to keep surface water from running behind the liner? Our soil is clay. When our pool builder was building the pool we did not have any water table problems.