My basement flooded last week. The water came from a 3 or 4" clay pipe, flush with my basement floor next to my hot water tank. The water was 20" deep and drained back out this hole in less than an hour so I believe my pipe is flowing freely. My street flooded from heavy rain and the extra water flooded a few houses. How do I handle this? I believe the drain ties into the perimeter drain tile and not the sanitary sewer. I've heard suggestions of back-flow preventer, filling the drain with concrete, installing a test plug, putting a pipe in the drain that's about 2 ft tall to allow the "straw effect" to work, etc.... I really do not want to tear up the floor if there is an alternative way to handle this. I've lived there for 5 yrs and never experienced anything like this. Please help!!!!