https://en.wikipedia.org/wiki/Sumerian_creation_myth :
The earliest record of a Sumerian creation myth,called The Eridu Genesis by historian Thorkild Jacobsen,is found on a single fragmentary tablet excavated in Nippur. It is written in the Sumerian language and dated to around 1600 BC.Other Sumerian creation myths from around this date are called the Barton Cylinder, the Debate between sheep and grain and the Debate between Winter and Summer, also found at Nippur.
The beginning of the tablet is lost, but at the point of the story where the surviving portion begins, it describes how the gods An, Enlil, Enki and Ninhursanga created the Sumerians and comfortable conditions for the animals to live and procreate. Kingship then descends from heaven, and the first cities are founded: Eridu, Bad-tibira, Larak, Sippar, and Shuruppak.
After a missing section in the tablet, we learn that the gods have decided not to save mankind from an impending flood. Zi-ud-sura, the king and gudug priest, learns of this.In the later Akkadian version recorded in the Atra-Hasis Epic, Ea, or Enki in Sumerian, the god of the waters, warns the hero (Atrahasis in this case) and gives him instructions for building an ark.
This is missing in the Sumerian fragment,but a mention of Enki taking counsel with himself suggests that this is Enki's role in the Sumerian version as well. After a missing section in the tablet, we learn that the gods have decided to send a flood to destroy mankind. The god Enki (lord of the underworld sea of fresh water and Sumerian equivalent of Babylonian god Ea) warns Ziusudra, the ruler of Shuruppak, to build a large boat (the passage describing the directions for the boat is also lost).
When the tablet resumes, it is describing the flood. A terrible storm raged for seven days and nights. "The huge boat had been tossed about on the great waters." Then Utu (Sun) appears and Ziusudra opens a window, prostrates himself, and sacrifices an ox and a sheep.
After another break, the text resumes, the flood is apparently over, and Ziusudra is prostrating himself before An (Sky) and Enlil (Lordbreath), who give him "breath eternal" for "preserving the animals and the seed of mankind". The remainder of the poem is lost.
https://en.wikipedia.org/wiki/Genesis_flood_narrative :
The Genesis Flood narrative is a flood myth found in the Tanakh (chapters 6–9 in the Book of Genesis). The story tells of God's decision to return the Earth to its pre-creation state of watery chaos and then remake it in a reversal of creation. The narrative has very strong similarities to parts of the Epic of Gilgamesh - which predates the Book of Genesis. As it was written ca.1600 bc.
A global flood as described in this myth is inconsistent with the physical findings of geology and paleontology. A branch of creationism known as flood geology is a pseudoscientific attempt to argue that such a global flood actually occurred.
The myth was adopted and adapted by the Jews. As the original flood myth states the flood lasted 6 days,the latter by the Jews in the Old Testament, lasted 40 days and 40 nights and Utanapishtim in The Epic of Gilgamesh who was said to have become an immortal, suddenly became Noah,a mortal who eventually died.
The Sumerian Great Flood and the Origins of Noah’s Ark
