I thought the geologists had already found the evidence for that global flood. Why would you still question it?
A meteorite hit the Indian ocean, it caused a large tsunami which left giant chevrons on Madagascar with seashells from the ocean bottom. We can also see the crater it left on the bottom of the Indian Ocean. This took place about 8,000 years ago. This event would have caused a huge amount of water to be vaporized and sent up into the stratosphere where it would have circled the globe and then returned as precipitation. Since this was the end of the last ice age this rain would have caused massive flash floods on these mountains. We have also seen the evidence of what are described as "Biblical" floods from the Himalayas and Rocky mountains at this time.
Also, if the the ocean rose and flooded the Black Sea at this time you could have a situation where a large ark containing all of the domesticated animals could have risen with the black sea. There are over 100 different stories of this flood from many different civilizations and many include a story of a boat with animals. We also know that at this same time over 100 large species of ungulates went extinct on North America, South America, and Australasia.
This would explain why virtually all large domesticated animals are native to Mesopotamia. Which is also the reason that the European civilization spread across the globe. They had oxen to do the plowing, they had horses which were the "tanks" until WWI, they had all of the childhood diseases associated with keeping herds of animals.