Aswan High Dam

Egypt

The Aswan High Dam, replacing earlier dams, contains the River Nile nearly 600 miles (1,000 kilometers) upstream from Cairo by a massive embankment 375 feet (114 meters) high and 3,280 feet (1,003 meters) long, built of earth and rock fill with a clay and concrete core. It impounds Lake Nasser, one of the largest reservoirs in the world, covering an area more than 300 miles (480 kilometers) long and 10 miles (16 kilometers) wide, that holds enough water to irrigate over 7 million acres (2.8 million hectares) of farmland for many years. Its economic and social impact on the lower reaches of the Nile (that is, in the north of Egypt) makes it an engineering feat of some importance, although not necessarily always beneficial.

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Aswan High Dam, Egypt, 1952–1968.

The annual flooding of the Nile has been the historical life source of Egypt, in what is almost a rainless region. Almost all the population lives within 12 miles (20 kilometers) of the river. The flooding—13 billion to 169 billion cubic yards (12 billion to 155 billion cubic meters)—is caused by late-summer rains on Ethiopia’s plateaus that find their way into the Nile’s tributaries. Late in the nineteenth century, regional population growth was outstripping agricultural production, and the river had to be controlled to recover stability. The first Aswan Dam was built from 1899 to 1902 and raised in 1907–1912 and again in 1929–1934. When its potential to generate