I don't know about your and others mentioning ramps in all this though...seems like an off-topic thing folk have been debating for decades let alone once more, please...oh, yes, let's debate the same thing once more because we haven't had enough of arguing the same things over and over again because we are all so simple in our memories that we forget where we left off last time, and would rather do it all over again instead of what this topic is about...I might as well throw in block and tackle and arranging several blocks and its tackle to single handedly pull 4 ton of rock up a slope while eating an icecream. It might take me an hour to go forty feet up a 30deg slope but I'll certainly do it by myself...I'm sure they knew about such things considering they had shipping for transportation not only up and down the Nile but where ever they voyaged to, and had to load their boats somehow.
Anyway, back to water. Any congregation of water that stays for a time will attract plant life or those who grow plants there, that's just natural. When the Nile isn't in flood, it is where compared to the plateau? How far do folk have to travel to get water? With anywhere between 20,000 and 100,000 folk on site every day, how many more are used to bring water up to their needs every day? You are better to have storage areas on higher ground, aren't you?