The Pyramids’ Water Damage (?)

Most scientific and historical sources today point to the Pyramids at Giza being built during the 2500s B.C.E. Mount Catherine is Egypt’s tallest mountain, it reaches a height of nearly 8700 feet. Anyway, time for some scripture.

Genesis 7: 17-20- “The flood continued forty days on the earth; and the waters increased, and bore up the ark, and it rose high above the earth. The waters swelled and increased greatly on the earth; and the ark floated on the face of the waters. The waters swelled so mightily on the earth that all the high mountains under the whole heaven were covered;the waters swelled above the mountains, covering them fifteen cubits deep.

According to the Ussher Chronology used by Answers in Genesis, the Flood occurred in the year 2348 B.C.E. So here’s my question.

If the Pyramids were complete by the time of the Flood, why don’t they show any evidence of having been submerged under thousands of feet of water?

T9R