The water erosion of the Sphinx is just a fact; the geologist Robert Schoch suggested a more conservative 7000 year figure based on the length of time exposure to rain would cause the damage (iow, not a worldwide flood, which wouldn't cause the damage anyway), given that rainfall is no longer that much of a problem at Giza, for some reason. :^)
Annual Nile river flooding. . .
I was wondering if the 12 thousand year age North American bolide strike(s) could have caused excessive rain erosion in Egypt. Also, while we are at it whether that could have shut down the civilization that created the great irrigation works near the Okavango Delta.