Find the low point between the pool and the wall. start at the high side. Dig a 1 foot wide trench 3to 4 feet deep( rent a bobcat with a one foot bucket or by hand with a pick ax and spade shovel. Go as far down hill as needed to get beyondthe ponding. Fill with no 2 stone to within 7 inches of grade . install 4" draint tile cover with no 2 stone and filter fabric. cover with " of top soil and seed.( if its possible to run tile to day light on the low side do it and wrap with wire mesh to prevent citters from crawling in , dying and plugging up.( probably won"t be necessary to run to day light.