Noah, the world is corrupted. I will create a flood that will cover the whole world, killing all of the bad people. Create an ark, that will be able to hold You, your sons, your wife, your son's wives and two of each species.
Noah and his Sons building the ark
Noah fills the ark with his family and the animals
The flood came and after 40 days and 40 nights Noah sent out a dove, he did this three times. The third time the dove did not come back and therefore had found land.
After the flood, God came to Noah and promised him that he would never flood the earth ever again. As long as Noah would populate the Earth. A rainbow appeared as a sign of Gods promise.