Grand Ethiopian Renaissance Dam years of future drought, if the countries can reach a compromise. The dam will retain silt. It will thus increase the useful lifetime of dams in Sudan – such as the Roseires Dam, the Sennar Dam and the Merowe Dam – and of the Aswan High Dam in Egypt. The beneficial and harmful effects of flood control would affect the Sudanese portion of the Blue Nile, just as it would affect the Ethiopian part of the Blue Nile valley downstream of the dam. Specifically, the GERD would reduce seasonal flooding of the plains surrounding the reservoir of the Roseires Dam
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