Like most other Genesis stories, the flood account is found in more places than just Genesis, brother.
Psalm 104 directly eliminates any possibility of a global flood.
Psalm 104 describes the creation of the earth in the same order as that seen in Genesis 1 (with added detail).
The verse that eliminates a global flood follows:
He founded the earth on its foundations; it shall not be shaken forever and ever.
You have covered the deep as with a robe; the waters stood above the mountains.
From Your rebuke, they flee; from the sound of Your thunder, they hurry away.
They go up the mountains; they go down the valleys to the place which You
founded for them. You have set a boundary that they may
not pass over; they shall not return to cover the
earth. (Psalm 104.5-9)
Obviously, if the waters never again covered the earth, then the flood must have been local.
Biblical clues to the geographical limits on human habitation can be found in the place-names Genesis mentions or does not mention.
In Genesis 1-9 the text mentions place-names only in the environs of Mesopotamia.
From Genesis 10 onward, we encounter references (by name or direction) to places beyond Mesopotamia, in fact, to places covering much of the Eastern hemisphere.
This sudden shift from narrow to wider geographical range after Genesis 10 strongly suggests that until the time of the Flood, human beings and their animals remained in and around Mesopotamia. Therefore, to fulfill His purpose in sending the deluge, God would need to flood only the Mesopotamian plain and perhaps some adjacent territories.
Few readers seem to catch the significance of statements about the source of the floodwater. In one respect the text itself rules out the global Flood interpretation by telling us where the water came from (Genesis 7) and where it returned (Genesis 8), namely, earthly sources.
The quantity of water on, in, and around our planet comes nowhere near the amount required for global inundation.
According to Genesis 7.11-12, the floodwaters came from "the springs of the great deep" and "the floodgates of the heavens." The respective Hebrew phrases are ma'yenoth tehom rabah and 'aruboth hashamayim. These terms refer to subterranean reservoirs, today called aquifers, and to heavy rain clouds.
Genesis 8 gives us the most significant evidence for a universal (with respect to man and his animals and lands), but not global, flood. The four different Hebrew verbs used in Genesis 8.1-8 to describe the receding of the flood waters indicate that these waters returned to their original sources. In other words, the waters of the flood are still to be found within the aquifers and troposphere and oceans of planet Earth. Since the total water content of the earth is only 22 percent of what would be needed for a global flood, it appears that the Genesis flood could not have been global.
To describe the receding of the floodwaters, the writer employs four different Hebrew words: shakak, shub, kaser, and qalal, which mean, respectively, "subsided or abated"; "returned to its original place or condition"; "diminished or lessened"; and "lowered or flowed away." These verbs indicate that the floodwaters returned to the places from which they came, the aquifers and the clouds.
Genesis 8.1 describes how God removed the floodwaters from the land: He sent a wind. This removal technique perfectly suits the requirements of water removal from a gigantic flat plain such as Mesopotamia.
What does the New Testament tell us about the flood?
There is an interesting passage from 2 Peter that gives some insight into the nature of the flood:
For this is hidden from them by their willing it so, that heavens were of old, and earth by water, and through water, having subsisted by the Word of God, through which the world which then was, being flooded by water, perished. (2 Peter 3.5-6)
Peter, instead of just telling us that the entire planet was flooded, qualifies the verse by telling us that the "world which then was" was flooded with water.
What was different about the world "at that time" compared to the world of today?
At the time of the flood, all humans were in the same geographic location (the people of the world were not scattered over the earth until Genesis 11).
Therefore, the "world which then was" was confined to the Mesopotamian plain. There would be no reason to qualify the verse if the flood were global in extent.
ref: RTB