Twenty one years ago in another house we had our basement flood twice in one week and on my son's graduation day. Living in another house for over 16 years and today we had our basement flood. My son who is an architect (the one who had the graduation flood) came over and helped and checked all the possibilities. We all think it is ground water. It has been raining and raining and the ground is just saturated with water.We have a few things we need to do outside to prevent it from happening again...and I'll get flood insurance just in case it does happen again. What a mess.