Are other flood legends relevant to Christians?

There are different flood legends among several civilizations that are similiar to the flood in the Bible. >A flood myth or deluge myth is a mythical or religious story of a great flood sent by a deity or deities to destroy civilization as an act of divine retribution. It is a theme widespread among many cultures, though it is perhaps best known in modern times through the biblical and Quranic account of Noah's Ark , the Hindu puranic story of Manu , through Deucalion in Greek mythology or Utnapishtim in the Epic of Gilgamesh . (Wikipedia ) - Are these other stories relevant to Christianity? - Do they describe the same event? - Why are they so similar and at the same time different (reasons and causes) - How can a valid exhaustive list of flood legends exist if it supposedly killed every man on earth besides the ones that were saved