We’ve known for some time that there is evidence of human settlements deep under the Black Sea, suggesting that some sort of flood, whether gradual or catastrophic, overtook the region.
I have a high degree of respect for stories that are common across a wide spectrum of cultures, since I navigate by the general assumption that humans are not complete morons and that when a huge number of widely divergent civilizations all preserve an ancient ancestral tradition of a massive flood, the best bet is to assume that something, rather than nothing, happened.
What that something was historically is much harder to pin down precisely. I see no particular reason for thinking the Genesis account commits us to a worldwide flood and no evidence from the sciences that such a thing did (or could) happen. But I also see no reason why a limited human population should not regard a local flood as “destroying the world” if it destroyed their world. Nor do I think such a catastrophe would be forgotten. Rather, it would be remembered as a childhood trauma of the world and ruminated upon by every human civilization, as indeed it seems to have been. That civilization that God chose as the vessel of revelation would preserve, in its ruminations, an inspired understanding of the meaning of the Flood story. And, indeed, what is striking about the various ancient near eastern flood myths is how different they are from Israel’s flood myth. In Sumerian myth, the flood is undertaken due to noisy humans bugging the gods. In Israel’s myth it is an act of divine justice. And, of course, it is incorporated into the overall story of both Genesis and Exodus (and ultimately the gospel) in which a world (and a nation and a human being) is born out of water.
I live in Washington State, which happens to be the site of upwards of a hundred gigantic catastrophic prehistoric floods. These are what created things like Grand Coulee. They were caused when glacier dams that created a now-vanished lake in Montana called “Lake Missoula” broke and a volume of water equal to Lake Michigan disgorged itself (in the space of a couple days, mind you) into eastern Washington and down the Columbia to the sea. Seeing Grand Coulee
and realizing that, at full flood that canyon was completely full of water up to the top of the cliff gives me an appreciation for how devastating such an event would be for the ancient humans who survived it and why it would be only natural, not just for them, but even for moderns, to ask “Why?”
So I have no particular difficulty thinking there is a historical basis for the story of Noah.