Grand Ethiopian Renaissance Dam on the initial storage in the Aswan High Dam and this filling schedule of the GERD, flows into Egypt could be temporarily reduced, which may affect the income of two million farmers during the period of filling the reservoir. Allegedly, it would also "affect Egypt's electricity supply by 25 to 40 percent, while the dam is being built". However, hydropower accounts for less than 12 percent of total electricity production in Egypt in 2010 (14 out of 121 billion kWh), so that a temporary reduction of 25 percent in hydropower production translates into an overall temporary reduction in Egyptian electricity
Aswan Low Dam in the lower Nile. The dam, originally limited in height by conservation concerns, worked as designed, but provided inadequate storage capacity for planned development and was raised twice, between 1907 and 1912 and again in 1929–1933. These heightenings still did not meet irrigation demands and in 1946 it was nearly over-topped in an effort to maximize pool elevation. This led to the investigation and construction of the Aswan High Dam upstream. The earliest recorded attempt to build a dam near Aswan was in the 11th century, when the Arab polymath and engineer Ibn al-Haytham (known as "Alhazen" in the West)