Modern Wonders of the World
Architectural Wonders of
Wall of China
House of Pharos in Alexandria
of Angkor Wat
Warriors of Xian
huge dam was a vast and
ambitious project. It was built to hold back the waters of the
river, the Nile. The dam has helped to create a steady flow of water
round, and provides electricity for the country's factories and towns.
Since ancient times, the River
Nile has flooded every year. The floods spread fertile mud over the
helping farmers to grow their crops. But often big floods destroyed
farmland. At other times of the year there was drought.
In 1902 engineers built a dam
just south of Aswan to control the floods. This dam was made higher in
again in 1933. But this first Aswan Dam was still not enough to control
Building work started on the
Aswan High Dam in 1960. The dam is made of earth and granite rock-fill,
core of clay and cement. It is over 3.6 kilometers wide, 111 meters
high and 40
meters thick at the too. At its base on the river bed it is a massive
meters thick. The dam took ten years to build.
Aswan High Dam was officially
opened in 1971. During the rainy season, the dam holds back the Nile's
waters. As the waters rose behind the dam, they gradually formed a
more than 500 kilometers long. The new reservoir was called Lake Nasser
the Egyptian president.
Around 50,000 people had to
leave their homes to make way for the reservoir. They were taken to a
farming region 50 kilometers north of Aswan. Several ancient temples
islands were flooded, but some were rescued. In a huge-scale operation,
temples of Ramses II and Nefertari were cut into 30-tonne blocks and
together again, piece by piece on hills overlooking the river. This
work took four years. Other small temples were also moved from an
island in the
Nile which was to be totally submerged.
The water stored in Lake Nasser
is used to irrigate farmland during dry periods and throughout the
crops can now be grown every year, producing more food to feed the
population. As the water pours through the dam, it also drives
generate half of Egypt's electricity.
human attempt to control nature has brought
many problems as well as benefits. The dam stops fertile mud from
downstream. So that farmers have to use more chemicals to fertilize
Since the dam was built, there has also been an increase in a disease
by tiny worms in the Nile's water snails. Yearly floods used to keep
numbers of snails down. A rise in the water table has also brought
salts to the
surface, which makes the land infertile.