You've stepped into a hole that most creationists are wise enough to avoid...
Now that you've dated the flood, you've opened the entire concept up for scrutiny, the least of which being that recorded Egyptian culture runs happily along through that time period without ever slowing down. The Pyramids at Giza, even, predate your "flood".
Ancient Egyptian Timeline -
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There's no geologic evidence for a flood of that scale, at all. None. Not even a little bit.
Also, please note that the absolute oldest reference to "Israel" in antiquity comes from 1200 BCE, as evidenced in the Merneptah Stele
Merneptah Stele -
Merneptah Stele - Wikipedia, the free encyclopedia
There is no evidence to it prior to that period. Sumerian texts, on the other hand, are evidenced with actualy physical artifacts and have been dated as late as the 26th century BCE. Which, as math will tell you, is from a time period
before the supposed Biblical flood of Noah. They prospered right up until their demise, around 2100 BCE. Again, there is evidence of them existing prior to and even after this supposed flood date. Directly after the end of the Sumerians, we see the Babylonian influence start it's expansion, around 1800 BCE. Please note that Israel, as mentioned, doesn't show up as being evidenced for another 600 years, and there's no physical link to their culture until 700-500 BCE, which is 1300 years
after the Babylonian expansion... Coincidentally, this time period also matches the absolute oldest evidence for the Torah's existence, the Ketef Hinnom, from 600 BCE...
Ketef Hinnom -
Ketef Hinnom - Wikipedia, the free encyclopedia
So, archaeologically and historically, Judaism (and the root ideas behind your religious texts) developed sometime between 1200 - 600 BCE.
You can make all the claims that you want about the Bible giving an accurate Historical account of humanity, from the beginning of time to the present, or whatever. But it's simply an unsupported and unsubstantiated claim. It's nothing more than wishful thinking. To deny that Judaism and Christianity are simply evolutions of previous forms of earlier Mesopotamian religions is to lack even a basic understanding of history.