I think it is entirely likely or even highly likely that there were floods on the earth and that those floods would have wiped out some of the animals but far from all. This could be consistent with PMP's beliefs.
Yeah, but no world wide flood. It's also doubtful that there were any floods that could have wiped out all of humanity, any one well represented species, much less all the species within a certain location.
It's nothing more than a myth. I think they likely borrowed from the Epic of Gilgamesh.