I believe it was a global flood as mankind had surely spread beyond the middle east region, just not as deep as Mt. Everest is high. It was a supernatural event in any case, so there's that.
I agree that it was a supernatural event. And completely trust Scripture.
But I can't see how it was a global flood. Below is listed some of my concerns.
1. Biblical evidence for a universal Noachian Flood is the
“universal” language of Gen. 6-8—words like “earth,”
“all,” “every,” and “under heaven.” However, these
words are used in other places in the Bible to describe
local or regional events and, therefore, cannot necessar-
ily be taken as all-inclusive over the entire planet Earth.
2. Likewise, the terms “rain” and “mist” in Gen. 2:5–6
cannot be taken to support a canopy theory or universal
deluge, because “earth” in these verses does not mean
the planet Earth but only the “earth” or “ground” in the
area of the Garden of Eden.
3. Absolutely no geologic evidence exists for the canopy
theory, flood geology, or a universal flood.
4 The actual geology of the Mount Ararat region, where
Mount Ararat cuts across sedimentary rock, precludes
the Noachian Flood from being responsible for all of the
sedimentary rock in the world, as claimed by flood
geologists.
5. The most likely landing place for the ark is considered
to have been Jabel Judi in the Cizre, Turkey region. This
site meets all of the Bible’s requirements, including “the
mountains of Ararat,” Noah’s vineyard, and the dove’s
plucking off the olive leaf and bringing it back to the
ark. It is also the earliest traditional site for the landing
place of the ark. A landing site in the Cizre region is
compatible with a local flood model, as this region lies
within the boundaries of the Mesopotamian hydrologic
basin.
6. The problems concerned with putting all of the animal
species on Earth into the ark, as per a universal flood
model, are insurmountable barring miracles that the
Bible never claims happened. The Bible indicates that
Noah collected the animals and brought them to the
ark, and this implies a local, not universal, flood.
7. There is no archaeological evidence for a universal
flood. Even regions close to or surrounding Mesopota-
mia do not contain correlative flood deposits.
8. The picture that emerges from all of the biblical and
nonbiblical evidence is that Noah’s Flood was confined
to Mesopotamia, extending over a vast alluvial plain
as far as the eye could see, from horizon to horizon
(under the “whole heaven” or sky). The top of all the
hills (ziggurats?) were covered by this flood, and all
people and animals were drowned except for Noah, his
family, and the animals on the ark. The flood was a real,
historical event that covered—not the whole world—
but the whole of Noah’s world.
9. The idea that the Noachian Flood was a universal flood
stems from a centuries-old interpretation of the Bible
not warranted by either the biblical or scientific evi-
dence. The King James Version, written in the seven-
teenth century, reflects the very limited view that
people had then of the planet Earth and its geology, and
it is this centuries-old, traditional view that has been
passed down to generations of Christians ever since.
The Bible should always be interpreted within the
framework of the culture in which it was originally
written—in this case, the Mesopotamian culture of the
third millennium BC, not the European culture of the
seventeenth century AD. It is only by considering the
culture and world view in which Gen. 6–8 was written
that the Noachian Flood can really be understood.
http://www.csun.edu/~vcgeo005/Carol 1.pdf
