Floods

Rashi opens his commentary on Tanach with a question about the relevance of Bereishit, and posits that creation is necessary to clarify God's prerogative to give and take the land to whomever God wants (hence, legitimacy of the Hebrews' claim to Israel). This explains the creation story, the promises to Abraham/Isaac/Jacob, and the introduction to Exodus (Joseph and co. in Egypt). Does it work for Noah?
What is the purpose of the flood story? Is it didactic, historic, and/or theological?
What implications does it have for the God-man relationship?

Atrahasis
18th c BCE
And the country became too wide, the people too numerous. The country was as noisy as a bellowing bull. The God grew restless at their clamour, Ellil had to listen to their noise. He addressed the great gods, 'The noise of mankind has become too much. I am losing sleep over their racket.

Epic of Gilgamesh, Tablet XI
12th c BCE

Utanapishtim spoke to Gilgamesh, saying:
"I will reveal to you, Gilgamesh, a thing that is hidden,
a secret of the gods I will tell you!
Shuruppak, a city that you surely know,
situated on the banks of the Euphrates,
that city was very old, and there were gods inside it.
The hearts of the Great Gods moved them to inflict the Flood.
Their Father Anu uttered the oath (of secrecy),
Valiant Enlil was their Adviser,
Ninurta was their Chamberlain,
Ennugi was their Minister of Canals.
Ea, the Clever Prince(?), was under oath with them
so he repeated their talk to the reed house:
'Reed house, reed house! Wall, wall!
O man of Shuruppak, son of Ubartutu:
Tear down the house and build a boat!
Abandon wealth and seek living beings!
Spurn possessions and keep alive living beings!
Make all living beings go up into the boat.
The boat which you are to build,
its dimensions must measure equal to each other:
its length must correspond to its width.
Roof it over like the Apsu.
I understood and spoke to my lord, Ea:
'My lord, thus is the command which you have uttered
I will heed and will do it.
But what shall I answer the city, the populace, and the
Elders!'
Ea spoke, commanding me, his servant:
'You, well then, this is what you must say to them:
"It appears that Enlil is rejecting me
so I cannot reside in your city (?),
nor set foot on Enlil's earth.
I will go down to the Apsu to live with my lord, Ea,
and upon you he will rain down abundance,
a profusion of fowl, myriad(!) fishes.
He will bring to you a harvest of wealth,
in the morning he will let loaves of bread shower down,
and in the evening a rain of wheat!"'
Just as dawn began to glow
the land assembled around me-
the carpenter carried his hatchet,
the reed worker carried his (flattening) stone,
...
On the fifth day I laid out her exterior.
It was a field in area,
its walls were each 10 times 12 cubits in height,
the sides of its top were of equal length, 10 times It cubits each.
...
The boat was finished by sunset.
The launching was very difficult.
...
All the living beings that I had I loaded on it,
I had all my kith and kin go up into the boat,
all the beasts and animals of the field and the craftsmen I
had go up.
Shamash had set a stated time:
'In the morning I will let loaves of bread shower down,
and in the evening a rain of wheat!
Go inside the boat, seal the entry!'
That stated time had arrived.
In the morning he let loaves of bread shower down,
and in the evening a rain of wheat.
I watched the appearance of the weather--
the weather was frightful to behold!
I went into the boat and sealed the entry.
...
Compare description of flood below to Genesis 7:11-12, 7:19-24, 8:1
Stunned shock over Adad's deeds overtook the heavens,
and turned to blackness all that had been light.
The... land shattered like a... pot.
All day long the South Wind blew ...,
blowing fast, submerging the mountain in water,
overwhelming the people like an attack.
No one could see his fellow,
they could not recognize each other in the torrent.
The gods were frightened by the Flood,
and retreated, ascending to the heaven of Anu.
The gods were cowering like dogs, crouching by the outer wall.
Ishtar shrieked like a woman in childbirth,
the sweet-voiced Mistress of the Gods wailed:
'The olden days have alas turned to clay,
because I said evil things in the Assembly of the Gods!
How could I say evil things in the Assembly of the Gods,
ordering a catastrophe to destroy my people!!
No sooner have I given birth to my dear people
than they fill the sea like so many fish!'
The gods--those of the Anunnaki--were weeping with her,
the gods humbly sat weeping, sobbing with grief(?),
their lips burning, parched with thirst.
Six days and seven nights
came the wind and flood, the storm flattening the land.
When the seventh day arrived, the storm was pounding,
the flood was a war--struggling with itself like a woman
writhing (in labor).
The sea calmed, fell still, the whirlwind (and) flood stopped up.
I looked around all day long--quiet had set in
and all the human beings had turned to clay!
The terrain was as flat as a roof.
I opened a vent and fresh air (daylight!) fell upon the side of
my nose.
I fell to my knees and sat weeping,
tears streaming down the side of my nose.
I looked around for coastlines in the expanse of the sea,
and at twelve leagues there emerged a region (of land).
On Mt. Nimush the boat lodged firm,
Mt. Nimush held the boat, allowing no sway.
One day and a second Mt. Nimush held the boat, allowing
no sway.
A third day, a fourth, Mt. Nimush held the boat, allowing
no sway.
A fifth day, a sixth, Mt. Nimush held the boat, allowing
no sway.
When a seventh day arrived
I sent forth a dove and released it.
The dove went off, but came back to me;
no perch was visible so it circled back to me.
I sent forth a swallow and released it.
The swallow went off, but came back to me;
no perch was visible so it circled back to me.
I sent forth a raven and released it.
The raven went off, and saw the waters slither back.
It eats, it scratches, it bobs, but does not circle back to me.
Compare post-flood story below to Genesis 8:15-18, 8:20-22

Then I sent out everything in all directions and sacrificed
(a sheep).
I offered incense in front of the mountain-ziggurat.
Seven and seven cult vessels I put in place,
and (into the fire) underneath (or: into their bowls) I poured
reeds, cedar, and myrtle.
The gods smelled the savor,
the gods smelled the sweet savor,
and collected like flies over a (sheep) sacrifice.
Just then Beletili arrived.
She lifted up the large flies (beads) which Anu had made for
his enjoyment(!):
'You gods, as surely as I shall not forget this lapis lazuli
around my neck,
may I be mindful of these days, and never forget them!
The gods may come to the incense offering,
but Enlil may not come to the incense offering,
because without considering he brought about the Flood
and consigned my people to annihilation.'
Just then Enlil arrived.
He saw the boat and became furious,
he was filled with rage at the Igigi gods:
'Where did a living being escape?
No man was to survive the annihilation!'
Ninurta spoke to Valiant Enlil, saying:
'Who else but Ea could devise such a thing?
It is Ea who knows every machination!'
Ea spoke to Valiant Enlil, saying:
'It is yours, O Valiant One, who is the Sage of the Gods.
How, how could you bring about a Flood without consideration
Charge the violation to the violator,
charge the offense to the offender,
but be compassionate lest (mankind) be cut off,
be patient lest they be killed.
Instead of your bringing on the Flood,
would that a lion had appeared to diminish the people!
Instead of your bringing on the Flood,
would that a wolf had appeared to diminish the people!
Instead of your bringing on the Flood,
would that famine had occurred to slay the land!
Instead of your bringing on the Flood,
would that (Pestilent) Erra had appeared to ravage the land!