Aswan Dam 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 (low transmission) to perennial (high transmission) 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 biharzia was declining in Upper Egypt. S. haematobium has since disappeared altogether. Suggested reasons for this include improvements in irrigation practice. In the Nile Delta,
Toktogul Dam Toktogul Dam Toktogul Dam is a hydroelectric and irrigation dam on the Naryn River in the Jalal-Abad Province of Kyrgyzstan. It is concrete gravity dam with height of and length of . It is a part of the Naryn-Syr Darya cascade. It is named after Toktogul Satilganov. The Toktogul Hydroelectric Station has installed capacity of 1,200 MW, which makes it the largest power plant in the country. It has four turbines with capacity of 300 MW each. Toktogul Reservoir (, ; ) is the largest of the reservoirs on the path of the Naryn River, a northern tributary of the