About Aswan Dam
The Aswan Dam, or more specifically since the 1980s, the Aswan High Dam, is one of the world’s largest embankment dams, which was built across the Nile in Aswan, Egypt, between 1960 and 1970. Its significance largely eclipsed the previous Aswan Low Dam initially completed in 1902 downstream. Based on the success of the Low Dam, then at its maximum utilization, construction of the High Dam became a key objective of the government following the Egyptian Revolution of 1952; with its ability to better control flooding, provide increased water storage for irrigation and generate hydroelectricity, the dam was seen as pivotal to Egypt’s planned industrialization. Like the earlier implementation, the High Dam has had a significant effect on the economy and culture of Egypt.
Before the High Dam , even with the old dam in place, the annual flooding of the Nile during late summer had continued to pass largely unimpeded down the valley from its East African drainage basin. These floods brought high water with natural nutrients and minerals that annually enriched the fertile soil along its floodplain and delta; this predictability had made the Nile valley ideal for farming since ancient times. However, this natural flooding varied, since high-water years could destroy the whole crop, while low-water years could create widespread drought and consequently famine.
Both these events had continued to occur periodically. As Egypt’s population grew and technology increased, both a desire and the ability developed to completely control the flooding, and thus both protect and support farmland and its economically important cotton crop. With the greatly increased reservoi storage provided by the High Aswan Dam. The floods could be controlled and the water could be stored for later release over multiple years.
Construction and filling,
Contrary to many predictions made prior to the Aswan High Dam construction and publications that followed. That the prevalence of schistosomiasis (bilharzia) would increase, it did not. This assumption did not take into account the extent of perennial irrigation that was already present throughout Egypt decades before the high dam closure.
By the 1950s only a small proportion of Upper Egypt had not been converted from basin to perennial irrigation. Expansion of perennial irrigation systems in Egypt did not depend on the high dam. In fact, within 15 years of the high dam closure. There was solid evidence that bilharzia was declining in Upper Egypt. S. haematobium has since disappeared altogether.
Suggested reasons for this include improvements in irrigation practice. In the Nile Delta, schistosomiasis had been highly endemic. With prevalence in the villages 50% or higher for almost a century before. This was a consequence of the conversion of the Delta to perennial irrigation to grow long staple cotton by British. This has changed. Large-scale treatment programmes in the 1990s. Using single-dose oral medication contributed greatly to reducing the prevalence and severity of S. mansoni in the Delta.