Aswan Dam links the reservoir to the Toshka Depression. The reservoir, named Lake Nasser, is long and at its widest, with a surface area of . It holds of water. Due to the absence of appreciable rainfall, Egypt's agriculture depends entirely on irrigation. With irrigation, two crops per year can be produced, except for sugar cane which has a growing period of almost one year. The high dam at Aswan releases, on average, water per year, of which some are diverted into the irrigation canals. In the Nile valley and delta, almost benefit from these waters producing on average 1.8 crops per
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