As Lake Nasser rose behind the High Dam, flooding ancient Nubia, an international effort ensured that mud-brick fortresses and burial grounds were excavated and photographed, before being abandoned to the rising waters. Half a dozen temples and tombs were salvaged to be reassembled on higher ground or in foreign museums. Since then, however, many temples in Upper Egypt have been affected by damp and salt encrustation, blamed on the rising water table and greater humidity.
Although the human, cultural and environmental costs are still being evaluated, the dam has delivered most of its promised benefits. Egypt has been able to convert 3000 square kilometres of cultivated land from the ancient basin system of irrigation to perennial irrigation – doubling or tripling the number of harvests – and to reclaim more than 4200 square kilometres of desert. The dam’s turbines have powered a thirty percent expansion of industrial capacity; fishing and tourism on Lake Nasser have developed into profitable industries. Only the Toshka Project has turned out to be a failure.
While the main losers have been the Nubians, whose homeland was submerged by the lake, other consequences are still being assessed. Evaporation from the lake has caused clouds and even rainfall over previously arid regions and the water table has risen. Because the dam traps the silt that once renewed Egypt’s fields, farmers now rely on chemical fertilizers, and the soil salinity caused by perennial irrigation can only be prevented by extensive drainage projects, which create breeding grounds for mosquitoes and bilharzia-carrying snails. And with no silty deposits to replenish it, the Delta coastline is being eroded by the Mediterranean.
Some fear future water wars. When Ethiopia commissioned a study on damming the Abbai River (the source of the Blue Nile), Cairo warned that any reduction of Egypt’s quota of Nile water, fixed by treaty at 59 billion cubic metres annually, would be seen as a threat to national security, and that Egypt would, in fact, need a larger share in the future. Egypt and Sudan are boycotting the Nile Basin Initiative by the “upstream” states (Ethiopia, Uganda, Kenya, Rwanda, Tanzania, Burundi and the Democratic Republic of Congo) to renegotiate the treaty.