The difference between falling off your motorbike and scraping your knee, and a dare-devil stunt involving a run from the law, gun-toting bad-guys and a battle-scar as you escaped the burning building clutching the broken remains of your bike over one shoulder and the rescued damsel over the other is about a hundred retellings.
Or in other words, sure - a local flood would very easily expand to be a year-long disaster that only saved one pious family and drowned the rest in about four generations.
On the other hand, it could just be a stupid story that doesn't make any practical sense intended as an object lesson and taken way too seriously by god-bothering idiots who can't do basic math.