Thank you. I too remember reading about this years ago. I even checked the date of the paper to see if it was from years ago.
The water came most of the way up to the now seasonal lake near the pyramids there.
But also the river used to flood so there were some seasons when the water was high enough to easily transport the stone directly from Tora I assume.
https://www.smithsonianmag.com/history/ancient-egypt-shippin...