Point is, Red Eye, big dams and water transfer programs have troublesome consequences.
1. The land which is flooded by those dams is land where people live. Where are they to go?
2.   I assume the "mountains" you are talking about are in Ethiopia. I could be wrong, but I believe the main tributaries of the Nile rise in Ethiopia. I would think the Egyptians would have a legitimate grievance if you took all the water that flows into the Nile and pumped it somewhere else.
3. Irrigation systems destroy ecologies. In the United States, we are busily pumping out aquifers that took thousands of years to fill. Iraq was once the cradle of civilization.