Aswan Dam improved the efficiency and the extension of the Old Aswan Hydropower stations by regulating upstream flows. Lake Nasser flooded much of lower Nubia and 100,000 to 120,000 people were resettled in Sudan and Egypt. In Sudan, 50,000 to 70,000 Sudanese Nubians were moved from the old town of Wadi Halfa and its surrounding villages. Some were moved to a newly created settlement on the shore of Lake Nasser called New Wadi Halfa, and some were resettled approximately 700 kilometres south to the semi-arid Butana plain near the town of Khashm el-Girba up the Atbara River. The climate there had a
Hydropower policy in the United States of 90% efficiency. More importantly, Francis's mathematical and graphical calculation methods advanced turbine design and engineering and allowed confident design of high efficiency turbines to exactly match a site's flow conditions. In the 1870s and deriving from uses in the mining industry, the high efficiency Pelton wheel impulse turbine was developed to use hydropower under very different flow and pressure conditions. Advances in dam design also progressed, with the completion of Old Aswan Dam being considered a milestone of engineering over nature. At the time of its construction, nothing of such scale had ever been attempted: it also became one