At the end of Parashat Bereshit (6:6-7), Hashem expresses explicit remorse over having creating man ("וַיִּנָּחֶם ה' כִּי עָשָׂה אֶת הָאָדָם", "כִּי נִחַמְתִּי כִּי עֲשִׂיתִם"), and decides to reverse His actions by wiping out humanity ("אֶמְחֶה אֶת הָאָדָם אֲשֶׁר בָּרָאתִי"). Further similarities between Parashat Noach's description of the world's destruction and the original Creation story are in content more than language. However, they too serve to underscore the obvious, that the Deluge undid much of what the original creation had achieved.
Separated waters re-mingle – Hashem's original separation between the waters on high and below is undone, as both the heavens and the depths release the flood waters.
Land re-submerges – In Parashat Bereshit, the ingathering of the waters allows for the land to emerge, while in Parashat Noach, water floods back over the dry ground.
All die – Bereshit 1 describes the creation of bird, animal, beast, and human, while the account in Parashat Noach tells of their deaths.
Breath of life extinguished – Whereas Bereshit 2 emphasizes Hashem's breathing life into His handiwork, Bereshit 7 highlights the extinguishing of that breath.3
The description of the re-emergence of life, in the second half of the Flood narrative, similarly draws the reader back to the original creation story. Here, the numerous parallels are direct and highlight how Hashem renewed the world, giving mankind a fresh start. The similarities between the two accounts include:
State of the world pre-creation – In both cases, before life is created, water filled the earth and a wind or spirit hovered or passed over it.
Dates – Bereshit 8:13 records that the flood waters dried up on the first day of the first month, the very same day on which the world was created.4
The elements and order of creation – Both stories contain explicit mention of the separation of higher and lower waters, the appearance of land and vegetation, markers of time, and the emergence of birds, animals, and man.5
Blessings – Both accounts detail Hashem's blessing of abundant procreation to both birds6 and humans as well as the promise that mankind will have dominion over the animals.
Command to eat – In Bereshit 1, Hashem allows man to eat from all vegetation, while in Bereshit 9, He adds that they can also eat from living creatures.7
Restrictions – Hashem bans certain foods in both stories. In Bereshit 2, the fruit of the tree of knowledge is prohibited, while in Bereshit 9, Hashem warns against eating the blood of animals.
Occupation of man – The first human is named "אָדָם" and is commanded to work the land. Noach is similarly referred to as "אִישׁ הָאֲדָמָה", and soon after the flood subsides, he plants a vineyard.
To determine whether these parallels are intentional allusions or simply coincidental similarities, one must consider the number and concentration of the parallels, the degree of their linguistic similarity, and the relative uniqueness of the shared phrases or concepts.8 In this case, there are a significant number of conceptual parallels between the two narratives, but the extent of the linguistic overlap and the rarity of the choice of terms must be examined more closely:
Wind over water – The concept of wind/spirit passing over water appears only in the stories of the Creation, the Flood, and the splitting of Yam Suf. In addition, the phrase "עַל פְּנֵי הַמָּיִם" appears, besides in these two stories,9 only in Shemot 32:20 and Kohelet 11:1.
Mingling or separation of waters – Although there is no linguistic similarity between the descriptions of the mingling/separation between the higher and lower waters, it is only in these two stories that such a concept appears.10 Additionally, the word "תְּהוֹם" appears in both stories,11 accounting for three of its five appearances in Torah.12
Elements of Creation – The words used in the two accounts do not overlap significantly, and most of them are not unique to these stories.
Heavens and earth – The "יַבָּשָׁה" of Bereshit 1 is alternately referred to in Bereshit 6-9 as "אֲדָמָה" or "אָרֶץ".13 This, though, might be expected, as the text states that after its appearance Hashem called the dry land "אֶרֶץ".14 Similarly the word "רָקִיעַ" is replaced by "שָׁמָיִם", its new name.
Vegetation – There is merely an allusion to the renewed vegetation in the mention of the olive branch, with no direct connection to the plant list of Bereshit: "דֶּשֶׁא עֵשֶׂב מַזְרִיעַ זֶרַע עֵץ פְּרִי".
Animals – The combined mention of birds, animals, beasts, and swarming creatures is not unique to these stories.15
"לְמִינוֹ" / "לְמִינֵהוּ" – In contrast to the above, this term is somewhat unique, appearing only by the names of the plant and animal species created in Bereshit, the list of animals entering the ark, and the list of prohibited foods in Vayikra 11 and Devarim 14.
Blessings – The language of the two blessings is almost identical. Moreover the phrase "פְּרוּ וּרְבוּ" appears in only these two sets of chapters as well as Yirmeyahu 23:3 and Yechezkel 36:11.16
"נִשְׁמַת חַיִּים" – This phrase appears only by the creation of man in Bereshit 1 and by the world's destruction in Bereshit 7.
Contrasts
In addition to the many similarities between the stories, there are several points of divergence:
Active / passive intervention – In the Creation story of Bereshit 1, Hashem plays an active role in every step of creation, commanding on each day that another aspect of the world be engendered. In the Flood story, in contrast, although Hashem remembers Noach and begins the process by sending a wind over the waters, everything afterwards seems to evolve through natural processes.
Duration of creation – Bereshit 1 gives the impression that Hashem originally made the world in a mere seven days,17 with each new form of life generated instantaneously upon command. In contrast, the re-creation of the world takes many months, with the waters receding gradually rather than immediately.18
Absence of fish – All of the created beings mentioned in Bereshit 1 appear in the Flood narrative with the exception of fish and other water creatures. Does the absence of fish here suggest that they had not been destroyed in the Flood (and thus, there was no need to replenish their populations)?19
Evaluation of Creation – In Bereshit 1, after each day of Creation Hashem observes that his handiwork "was good". In Bereshit 6, on the other hand, Hashem's realization that "רַבָּה רָעַת הָאָדָם" leads Him to bring the Flood. Even after the Flood, Hashem still concludes that "יֵצֶר לֵב הָאָדָם רַע מִנְּעֻרָיו", this time leading to the promise never again to destroy the world.
Creation of man – In the original Creation story, man is created last, as Hashem's grand finale. After the Flood, in contrast, man emerges into the new world before the animals. Does the difference in order hint to some change in the status of man, or is the change insignificant, relating, instead to practical considerations?
Food permitted – After the Deluge, man is allowed to eat from living creatures,20 while originally only vegetation had been allowed. What led to this change? For elaboration, see Permission to Eat Meat.
Conclusion
On the most basic level, the many similarities between the accounts show that the Flood and its aftermath were both an undoing and redoing of creation. Although man sinned grievously, Hashem does not give up on him, but rather gives the world a fresh start, creating it anew and returning it to its innocent beginnings.21 The new world though is not created in exactly the same manner as the first, and Hashem's view of and relationship to man changes. The miraculous nature of the original construction is replaced by a much more natural development, and Hashem is more distant.