i live in a duplex condo townhouse .since i am closest to the driveway i get flooding in my garage and porch and both units we have sewer backup. a few years ago we had a contractor level a part of the driveway and put in a sump pump. we are still having the same problems. does anyone have any other ideas that would solve this problem permanently.
I would hire a sewer contractor to do a full sewer inspection with a camera.