My kiddie pool has turned my gr into a swamp?

My kiddie pool/slide has turned my gr into a swamp? Every time the kids come down the slide the water splashes out onto that side of the gr. The gr has a drain in the middle of it but the water seems to be pooling on the area of the gr where the slide splashes and the drain is uphill from there. Now I have a 3 feet x 3 feet stinky swamp in a portion of my gr. What can I do?