There is? What is it?It's between a scientist's hypothesis and a documented occurrence fighting over the evidence that is there.
But more importantly, there is evidence. A lot of it.
Tell you what: because there's so much evidence, how about you just tell us about the one piece that you consider the strongest evidence for a global flood.
BTW - when do you think this flood occurred? I don't need an exact date, just a ballpark: billions of years ago? Millions? Thousands? Hundreds? Since you talked about it wiping out human civilizations, I take it you're talking about something that occurred thousands of years ago, right?