Micah, my brother has had virtually the same situation happen to his house. For 15 years he never had a problem with his basement flooding until they built more homes to the south of him. As a result, it changed the lay of the land and caused water to back up into the northern section of the development and caused several basements to flood during a heavy storm last year. This wasn't turd water though, just ground water. They had to redo all the ditches on his street by burying drainage socks underground in an effort to fix the problem. He's also added a second sump on the other side of the basement, for insurance since then.
