In other words you had ground water seeping in or was it coming in through the sewer drain? The latter is bad news, been there, done that, It is really a mess that has to be scouered clean using bleach and stuff like that. If it was sewer drain back-up, I would recommend getting an irreversable valve for your sewer line. That is another kink in the sewer line outside the house, but it has a float ball that rises and seals to keep water from entering that way. It will definitely keep the sewage out.

Dave