The Book of Enoch's account of the flood is different from the one in Genesis — not because it contradicts it, but because it operates at a different level. Genesis shows us what happened to Noah and his family. Enoch shows us what was happening in the heavenly court at the same time.
According to 1 Enoch, the archangels — Michael, Gabriel, Raphael, Uriel — were watching the corruption that the Watchers had spread across the earth. They brought a petition before the divine throne: the earth was crying out, the blood of the innocent was rising to heaven, the souls of the dead were calling for justice. Something had to be done.
God's response was the flood — but it was also something more. The flood was the judgment of the Watchers. Their offspring, the Nephilim, were to be destroyed. The Watchers themselves were to be bound in the earth until the great day of final judgment. Raphael was sent to bind the ringleader, Azâzêl, hand and foot, and bury him in darkness under a pile of sharp rocks. Gabriel was sent to destroy the children of the Watchers. Michael was sent to bind Semjâzâ and his companions in the earth for seventy generations.
The flood in Enoch's telling is not just a natural disaster or even a divine judgment on human wickedness. It's a cosmic reset — a punishment of angelic rebels and their hybrid offspring, a clearing of the earth so that human civilization can begin again under different conditions.
This is the backstory Genesis doesn't tell. The Book of Enoch does.