Nasser doesn't but somebody else does?
Or no major dam across the Nile at all?
(There was already a dam in place there since 1902.
If the latter, major changes.
No dam means no control, totally at the mercy of the annual flooding.
Less agriculture, less population, less stabilization in the region.
Less urbanization and industry, smaller economy for the country and the region.
Less tourism, too, what with the nile being less navigable.
All the above lessers mean less protection, exploration and exploitation of historical sights and items.
Israel will have to look towards, who, Jordan, to show power and peaceful intent.