clov... that's partly true only
There have been floods, that much we can assume... icecaps melting, ending of the ice age but most important from a social point of view:
MANY stories about the flood... and if I'm not mistaken, they all took place 10 000 years ago. So the entire story about only Noah surviving thanks to a big ship is utter and utter crap. The indians (or to be political correct I believe the latest term to be used is native americans?) had one survivor (on a whale) and he met this city (if memory serves) and repopulated "earth" (in other words, his part), etc.