The Nile is the world's longest river, stretching more than 6,000 km. Spring and summer rains in the headwaters of the Blue Nile raise the flows of the lower Nile by 50-fold compared to low flows. The alluvial soils were black, and the early Egyptians referred to their country as the Black Earth. Civilization has been intensive for over 5000 years, with no major interruptions or declines like in Mesopotamia. Civilizations stayed put along the Nile, while they migrated upstream along the Euphrates.
Flooding tends to occur after the spring harvest.
The Nile floodplain is narrower than the Euphrates, so irrigation canals weren't so long, and the waterlogging problem was not as severe. Surpluses later went to military expansions, etc. For example, written records mention a fleet of 40 boats, each 170 feet long, arriving from Phoenicia filled with cedar logs. By 300 BC, even government ministers had trouble getting enough wood to repair their boats, or beams for their houses. Dams The big sustainability story in modern Egypt centers on the Nile dams, and rising population.