We have a retention basin on the side of our house, all the rain, from the houses on the uphill side of us, runs down through our backyard like a river and into the basin. After it rains the "river" stays soggy for over a week. Any ideas how to get it to drain better? Or to dry it out? When I mow, the river area gets matted down and looks terrible. It's about 3 feet wide and 125 feet long.