It gave them water for water supply but it hurt Egypt because i … t flooded the crops Cataracts (the white water rapids of the Nile) prevented potentialinvasions using the River Nile--but they also kept Egyptians fromgetting very far. The cataracts harmed the Egyptians because itheld back ships that tried to move though the River Nile. It helped Egypt because it protected from invaders from coming in. It hurt Epgyt in the sailing portion. The cataract made it impossible for invaders attack the Egyptians