The best known of the flood accounts is, firstly, the biblical account in Genesis, and secondly, the one found in the Gilgamesh Epic. Here is a summary of the Gilgamesh Epic:
The council of the gods decided to destroy mankind with a flood, but Utnapishtim was warned by the god who had made man, Ea, to build a boat to take all living beings. The length, width, and height were each 120 cubits (about 180 feet). It had seven stories.
The gods got frightened by the flood and retreated to heaven where they cowered and wept.
The flood lasted six days and seven nights, and was accompanied by wind and storm.
Utnapishtim send out a dove followed by a swallow, but both returned, unable to find land. He then sent a raven, which didn't return.
Dr. Jonathan Sarfati comments on the Gilgamesh Epic:
“ It is common to make legends out of historical events, but not history from legends. ... For instance, in Genesis, God’s judgment is just, he is patient with mankind for 120 years (Genesis 6:3), shows mercy to Noah, and is sovereign. Conversely, the gods in the Gilgamesh Epic are capricious and squabbling, cower at the Flood and are famished without humans to feed them sacrifices. That is, the human writers of the Gilgamesh Epic rewrote the true account, and made their gods in their own image.