The dam was designed to provide storage of annual floodwater and augment dry season flows to support greater irrigation development[1] and population growth 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 between 1929 and 1933.
[2] 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) was summoned to Egypt by the Fatimid Caliph, Al-Hakim bi-Amr Allah, to regulate the flooding of the Nile.
[5] Following their 1882 victory of the Anglo-Egyptian War leading to the occupation of Egypt, the British began construction of the first dam across the Nile in 1898.
[9] The design also included a navigation lock of similar construction on the western bank, which allowed shipping to pass upstream as far as the second cataract, whereas a portage overland was previously required.
[11] With its final raising (designed and supervised by MacDonald's firm, Sir M MacDonald & Partners),[11] the dam is 1,950 metres (6,400 ft) in length, with a crest level 36 metres (118 ft) above the original riverbed;[9] the dam provides the main route for traffic between the city and the airport.