Look, she's true :
1 Peter 3:20-21
once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water. The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ.
The Flood literally happened. And the waters were also the symbol of baptism (which is really a symbol of death - the flood - and resurrection - the ark).
And you have symbolism in most of all the true historical accounts of the Bible (Adam & Eve, Israel in the desert, Joshua & Jericho, ...).