There are a couple of scientific theories that propose a global flood event, but one in which the water did not cover all land, nor kill all humans and animals outside the Ark.
Geologists Alexander and Edith Tollmann propose that the Flood of Noah was caused by a comet strike about 9500 years ago.
W. Bruce Masse (archaeologist at Los Alamos National Laboratory) and Dallas Abbott
(Lamont-Doherty Earth Observatory, Columbia University) propose a more recent event, a comet strike in the Indian Ocean in 2807 B.C. as the cause of Noah’s Flood.
These theories explain the many flood myths throughout the world, and the Noah story – if it is interpreted in a way that is not entirely literal.
But I don’t think science and reason can support the idea that water covered all land, or that the flood killed all persons and animals outside the Ark.