Landmark Africa
Aswan High Dam
The Aswan High Dam is a giant wall of rock across the Nile River in Egypt. It holds back a huge lake. It stops the river from flooding every year.
The Aswan High Dam crosses the Nile River in southern Egypt. Finished in 1970, it is 111 meters high and 3,830 meters long. It controls the Nile's yearly flood, stores water for farms, makes electricity and created a huge reservoir, Lake Nasser. Ancient temples had to be moved to save them from the rising water.
Completed in 1970 and inaugurated in January 1971, the Aswan High Dam is a rock-fill dam 111 m high with a 3,830 m crest, impounding Lake Nasser's 169 billion m³. It placed the annual Nile flood under human control for the first time, irrigating and generating power, but required the relocation of 90,000 people and the UNESCO-led rescue of the Nubian temples, and it traps the silt that once fertilized Egypt's fields.
Photo: شرف الدين, CC BY-SA 3.0, via Wikimedia Commons
Discover the Aswan High Dam
The Aswan High Dam is in Egypt, in Africa. It stands across the Nile, a very long river.
The dam is made of rocks and earth piled up very high. Behind it is a giant lake called Lake Nasser. The dam keeps water for farms and makes electricity.
The Aswan High Dam stands across the Nile River near the city of Aswan, in southern Egypt. Every year, the Nile used to flood. The dam now holds back the floodwater and lets it out when people need it, so farms can be watered all year round.
The dam is 111 meters high and 3,830 meters long. Behind it lies Lake Nasser, a huge reservoir that stretches about 320 kilometers in Egypt and almost 160 kilometers more into Sudan. The dam's 12 turbines can make about 10 billion kilowatt-hours of electricity a year.
Britannica describes the Aswan High Dam as a rock-fill dam across the Nile at Aswan, completed in 1970 and formally inaugurated in January 1971 at a cost of about $1 billion. It is 111 m (364 ft) high, with a crest 3,830 m long and a volume of 44.3 million m³.
For the first time in history, Britannica notes, the annual Nile flood came under human control: the dam impounds the floodwaters and releases them when needed for irrigation, navigation and hydroelectric power, its 12 turbines generating about 10 billion kWh a year. Its reservoir, Lake Nasser, has a gross capacity of 169 billion m³ and also supports a fishing industry.
- Completed
- 1970 (inaugurated January 1971)
- Height
- 111 m (364 ft)
- Crest length
- 3,830 m (12,562 ft)
- Reservoir
- Lake Nasser, 169 billion m³
Taming the Nile's flood
For thousands of years, the Nile flooded every year.
People built a big dam to store the floodwater. Now they let it out when it is needed, all year long.
An earlier dam, the Aswan Low Dam, was finished in 1902, about 6 kilometers downstream. It was raised twice, and it holds back about 4.9 billion cubic meters of water from the end of the flood.
In the 1960s, Egypt built the much bigger High Dam just upstream. It was finished in 1970 and officially opened in January 1971. The lake behind it was named Lake Nasser, after Gamal Abdel Nasser, Egypt's president from 1956 to 1970. Its southern part, in Sudan, is called Lake Nubia.
The Aswan Low Dam, designed by Sir William Willcocks, was completed in 1902 and raised in 1912 and 1933; 2,142 m long and pierced by 180 sluices that once passed the whole Nile flood, it holds back about 4.9 billion m³ from the tail of the flood. The High Dam, 6 km upstream, was built in the 1960s, completed in 1970 and dedicated in January 1971.
Its reservoir is named in Egypt for Gamal Abdel Nasser, president from 1956 to 1970, and in Sudan, where its southern third lies, Lake Nubia. Of the Nile's annual flow, about 74 billion m³ is allocated by treaty between Egypt and Sudan, roughly 55.5 billion m³ of it to Egypt.
A mountain of rock
The dam is not a thin wall. It is a huge hill of rocks and earth.
Rushing water goes through machines called turbines to make electricity.
The High Dam is a rock-fill dam: instead of one smooth concrete wall, it is an enormous bank built mostly of rock. It contains 44.3 million cubic meters of material and stretches 3,830 meters across the valley.
Water from the lake flows through the dam's power plant, where it spins 12 turbines. The spinning turbines drive generators that make electricity, which is carried away on power lines.
The High Dam is a rock-fill embankment: Britannica gives a volume of 44,300,000 m³ (57.94 million cubic yards) along its 3,830 m crest, rising 111 m. Its hydroelectric plant has 12 turbines capable of about 10 billion kWh annually.
The reservoir it creates is about 90 m deep and averages 22 km wide; it backs the Nile up some 320 km in Egypt and almost 160 km farther south in Sudan. Released water has brought about 324,000 hectares of new land under irrigation and converted another 283,000 hectares from flood to year-round (perennial) irrigation.
Lake Nasser and the rescued temples
When the lake filled up, old temples were in danger of going under the water.
So people from many countries helped. They cut the temples into big blocks and built them again on higher ground. The giant temples of Abu Simbel were moved up high!
As Lake Nasser filled, it threatened to cover many ancient temples and tombs. Egypt asked UNESCO for help, and from 1960 to 1980 an international campaign rescued them. Most temples were carefully cut apart, moved to safer ground and put back together.
The two great rock temples of Abu Simbel were rebuilt 60 meters above their original site. To thank countries that helped, Egypt gave four small temples away. One of them, the Temple of Dendur, went to the United States.
Lake Nasser threatened to submerge monuments from Philae to Sudanese Nubia under some 50 m of water. In UNESCO's International Campaign (1960 to 1980), all but three of the threatened monuments were dismantled, cut up and reassembled in six groups, including the Abu Simbel temples, rebuilt in place but 60 m above their original site, and the Philae temples on Agilkia island; the Sudanese temples went to the museum garden in Khartoum.
Egypt thanked contributing countries with four temples: Debod to Spain, Taffa to the Netherlands, Dendur to the United States and Ellesyia to Italy. The rescued temples of Abu Simbel and Philae are now part of the World Heritage property 'Nubian Monuments from Abu Simbel to Philae'.
- Lake Nasser depth
- about 90 m
- Lake length
- about 320 km in Egypt plus about 160 km in Sudan
- Turbines
- 12 (about 10 billion kWh a year)
- Abu Simbel temples
- moved 60 m above their old site
Benefits and costs
The dam gives Egypt water and electricity.
But many families had to move to new homes. And the river no longer brings rich mud to the fields, so farmers add fertilizer instead.
The dam brought big benefits: water for farms all year, electricity, easier boat travel and fishing on Lake Nasser. But it also had costs. About 90,000 people, Egyptian farmers and Nubians from Sudan, had to move to new homes.
The Nile flood used to spread about 40 million tons of rich mud, called silt, over the fields each year. Now most of it settles in the lake instead. Farmers use about 1 million tons of fertilizer a year, which Britannica says does not fully replace the silt.
Britannica weighs the dam's large economic benefits against human, archaeological and agricultural costs. Some 90,000 Egyptian fellahin and Sudanese Nubian nomads were relocated: 50,000 Egyptians to the Kawm Umbu valley north of Aswan, forming a new farming zone called Nubaria, and most of the Sudanese around Khashm al-Qirbah.
Because the dam controls the flood completely, the fertile silt that once settled on farmland is now trapped in reservoirs and canals, gradually reducing the productivity of riverside fields; about 1 million tons of artificial fertilizer a year is, in Britannica's words, an inadequate substitute for the 40 million tons of silt the flood used to deposit. Land-reclamation projects began in the desert around the lake in the early 1980s.
Amazing facts
-
A whole temple from Egypt was given to the United States.
To thank countries that helped save the Nubian temples, Egypt gave away four small temples. The Temple of Dendur went to the United States.
Egypt gave Debod to Spain, Taffa to the Netherlands, Dendur to the United States and Ellesyia to Italy in gratitude for their help in the Nubia campaign.
-
Part of Lake Nasser is in Sudan, where it has another name.
Lake Nasser reaches across the border into Sudan. The southern part, in Sudan, is called Lake Nubia.
The northern two-thirds of the reservoir, in Egypt, is named for Gamal Abdel Nasser; the southern third, in Sudan, is Lake Nubia.
-
The dam stopped the Nile's yearly flood.
For the first time in history, the Nile's yearly flood is under human control, thanks to the High Dam.
Britannica notes that, with the High Dam, the annual Nile flood came under human control for the first time in history.
-
The old dam nearby has 180 gates for water.
The older Aswan Low Dam, finished in 1902, has 180 sluices, gates that once let the whole Nile flood pass through.
The 2,142 m Aswan Low Dam is pierced by 180 sluices that formerly passed the entire silt-laden Nile flood.
Words to know
- dam
- a strong barrier built across a river to hold back water
- reservoir
- a lake made by people to store water
- rock-fill dam
- a dam built mostly from piled-up rock instead of one concrete wall
- silt
- fine, rich mud carried by a river
- irrigation
- bringing water to fields so crops can grow
- turbine
- a machine with blades that spins when water pushes it, used to make electricity
Discovery challenge
-
Which river does the dam cross?
Which river does the Aswan High Dam stand across?
Which river's annual flood did the Aswan High Dam bring under control?
- The Nile
- The Amazon
- The Yangtze
Show the answer
The Nile
The Nile! It is the great river of Egypt.
The dam crosses the Nile near the city of Aswan in southern Egypt.
The Nile: for the first time in history its annual flood came under human control.
-
What is the big lake behind the dam called?
What is the name of the reservoir behind the Aswan High Dam?
What is the Egyptian part of the dam's 169 billion m³ reservoir called?
- Lake Victoria
- Lake Nasser
- Lake Titicaca
Show the answer
Lake Nasser
Lake Nasser! It is a very big lake.
Lake Nasser, named after Egypt's president Gamal Abdel Nasser. Its part in Sudan is called Lake Nubia.
Lake Nasser, named for Gamal Abdel Nasser; the Sudanese third is Lake Nubia.
-
What did people do to save the temples of Abu Simbel?
How were the temples of Abu Simbel saved from the rising lake?
How were the Abu Simbel temples saved during the UNESCO campaign?
- They built a wall around them
- They moved them 60 meters higher
- They let the lake cover them
Show the answer
They moved them 60 meters higher
They cut them into blocks and moved them up high!
Engineers cut the temples apart and rebuilt them 60 meters above their old site.
They were dismantled and reassembled on the same site, 60 m above their original position.
-
What does the river no longer bring to the fields?
What did the Nile flood use to spread on Egypt's fields that the dam now traps?
What do farmers now replace with about 1 million tons of fertilizer a year?
- Sand
- Rich mud called silt
- Seashells
Show the answer
Rich mud called silt
Rich mud! Now it stays in the lake.
The flood used to spread about 40 million tons of rich silt a year. Now most of it settles behind the dam.
The 40 million tons of fertile silt the flood once deposited each year.
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Abu Simbel
Abu Simbel is two temples cut into the rock by King Ramesses II of Egypt, around 1264 BCE. Four seated statues of the king, each 21 meters tall, guard the Great Temple. In the 1960s, a new dam was about to flood them, so workers cut them into more than a thousand blocks and rebuilt them higher up.
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Experiments to try
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Abu Simbel
Abu Simbel is two temples cut into the rock by King Ramesses II of Egypt, around 1264 BCE. Four seated statues of the king, each 21 meters tall, guard the Great Temple. In the 1960s, a new dam was about to flood them, so workers cut them into more than a thousand blocks and rebuilt them higher up.
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Egyptian pyramids
Egypt's pyramids were giant stone tombs for kings. They did not start out pointed: the first, King Djoser's Step Pyramid, was a stack of six giant steps. King Snefru's builders tried again and again, making the Bent Pyramid and then the Red Pyramid, the first planned true pyramid. Soon after came the great pyramids of Giza.
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Giza pyramid complex
The Giza pyramid complex is a group of ancient tombs on a rocky plateau beside the Nile River in Egypt. Three kings from one family, Khufu, his son Khafre and his grandson Menkaure, built huge pyramids there about 4,500 years ago. Around them are temples, small pyramids for queens, rows of tombs for nobles, the Great Sphinx and even the town where the builders lived.
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For parents & teachers
What children will learn
- Locate the Aswan High Dam on the Nile and explain how it controls the yearly flood.
- Describe how ancient temples were rescued from the rising Lake Nasser.
- Weigh the benefits of a big dam (water, electricity) against its costs (people moved, lost silt).
Recommended ages: 3 to 17 · About 15 minutes
Talk about it
- Egypt's farms once depended on the Nile's yearly flood. What changes when people can control the water instead?
- Countries around the world helped save the Nubian temples. Why might people care about saving monuments in another country?
- About 90,000 people had to move because of the lake. What would help families who must leave their homes for a big project?
Try at home or in class
- Put soil and water in a jar, shake it and let it settle; watch how the silt sinks, just as it does in Lake Nasser.
- Build a dam of pebbles across a sand channel and pour water behind it; then compare a pebble dam with a dam made of one flat board.
Key vocabulary: dam, reservoir, rock-fill dam, silt, irrigation, turbine
Where these facts come from
- Wikidata , Wikimedia Foundation (CC0 1.0)
- Aswan High Dam , Encyclopaedia Britannica
- Lake Nasser , Encyclopaedia Britannica
- The Rescue of Nubian Monuments and Sites , UNESCO World Heritage Centre
- Nubian Monuments from Abu Simbel to Philae , UNESCO World Heritage Centre
- Wikimedia Commons , Wikimedia Foundation (Per file (public domain, CC0, CC BY or CC BY-SA); see each media record)
Checked, not yet human-reviewed. Last updated October 27, 2026. Spotted a mistake? Tell us.