Whenever Genesis states "the waters swelled for 150 days" if you go back to the Hebrew original text the word used is "גָּבַר" (gavar) this word means to prevail, it rained for 40 days and 40 nights, but water stayed on the earth for 150 days, disproving your point that there are two seperate flood stories.
Whenever Genesis states "the waters swelled for 150 days" if you go back to the Hebrew original text the word used is "גָּבַר" (gavar) this word means to prevail, it rained for 40 days and 40 nights, but water stayed on the earth for 150 days, disproving your point that there are two seperate flood stories.