I have an area in my lawn that is the low spot. It drains poorly( core aerate twice last year). Must be a layer of clay under the topsoil layer. It collect rain and run off from the house. It isn't a big area but might be 1500-2000 sq ft. I have celebration Bermuda. I thought about top dressing the area a little at the time to raise the low spot up? I thought I might be able to use the bagged playground sand found at home improvement stores in a push spreader?? How would you solve this? Top dress a little at the time? Let the grass get tall and put a very thick layer down and rake it to pull runners to top?