Water
The Nile crosses Egypt from south to north, water was present everywhere in the Nile valley, it was and it is still its raison for being. It was used for food, domestic needs and transportation. The plateau water supply was done by precipitations, free flow or capillary suction from the ground water.
What was probable and now confirmed by researchers, is the presence of natural or dug channels on the plateau, just as it was the presence of karstic cavities or dug networks under the plateau.