"I sees de whelmin flood roll between; I sees de darkness and de death everlastin"
The blackening of the sky during Christ’s final hours has been referred to as the crucifixion eclipse
Creative Commons Attribution Share AlikeThe blackening of the sky during Christ’s final hours has been referred to as the crucifixion eclipse - Credit: Chosovi

This refers not to a literal flood but to the chaos that figures the very earth’s revolt against Christ’s death. Darkness blots out the sky during his final hours, and all the forces of nature erupt:

 

The veil of the temple was rent in twain from the top to the bottom; and the earth did quake, and the rocks rent; And the graves were opened; and many bodies of the saints which slept arose, And came out of the graves after his resurrection, and went into the holy city, and appeared unto many. Now when the centurion, and they that were with him, watching Jesus, saw the earthquake, and those things that were done, they feared greatly, saying, Truly this was the Son of God.  (Matthew 27. 51-4)