Aswan Dam have been flooded by Lake Nasser. Before the construction of the High Dam, the Nile deposited sediments of various particle size – consisting of fine sand, silt and clay – on fields in Upper Egypt through its annual flood, contributing to soil fertility. However, the nutrient value of the sediment has often been overestimated. 88 percent of the sediment was carried to the sea before the construction of the High Dam. The nutrient value added to the land by the sediment was only 6,000 tons of potash, 7,000 tons of phosphorus pentoxide and 17,000 tons of nitrogen. These amounts are
Economy of Egypt border, behind the Aswan High Dam. Just north of Cairo, the Nile spreads out over what was once a broad estuary that has been filled by riverine deposits to form a fertile delta about wide at the seaward base and about from south to north. Before the construction of dams on the Nile, particularly the Aswan High Dam (started in 1960, completed in 1970), the fertility of the Nile Valley was sustained by the water flow and the silt deposited by the annual flood. Sediment is now obstructed by the Aswan High Dam and retained in Lake Nasser. The interruption