Humans are the only species to master nature to the extent we can block rivers in their entirety and regulate their flow. To do so is necessary for maintaining steady river depths downstream, to prevent floods and generate hydroelectricity. Since ancient times we have been doing this and other hydraulic engineering. The Romans built huge aqueducts that have lasted millennia and are still in use today. Since the re-discovery of concrete in the 19th century and the introduction of earthmoving equipment, we’ve been extending our dam building skills to extraordinary levels. In this post I’ll go through the largest dams of the world.
Photo of the dam from space, courtesy of NASA.
This is by far the largest dam in the world by the volume of its reservoir. It holds the Nile back and stores a massive 132 cubic kilometres of water! Egypt is an incredibly dry country, so they rely on the dam for irrigation, otherwise nothing would grow.
Prior to the dam’s construction, the Nile flooded the fertile plains on its banks every year and this was unreliable. Some years it would flood too well and other years not enough. The Egyptians needed to control the floods.
In the 1950s, Egypt was a progressive society after having overthrown the monarchy. During Nasser’s presidency, the decision to build the dam was finally made, hence the name of the reservoir is Lake Nasser and construction started in 1960. The dam started filling in 1964 and construction was finished in 1970.
In addition to the dam, there is a hydroelectricity station with an installed capacity of 2 100 MW.
For further reading, Wikipedia has the details. https://en.wikipedia.org/wiki/Aswan_Dam
Photo taken by. https://en.wikipedia.org/wiki/Nurek_Dam#/media/File:Nurek_Dam.JPG
Nurek Dam is the tallest dam in the world at 300 m high. It holds back the Vakhsh River and it is thought that when it first filled, the water column stressed a fault and caused a minor earthquake.
The reservoir is over 70 km in length and irrigates local land in Tajikistan. At the base of the dam is a hydroelectricity plant with an installed capacity of 3 015 MW.
For further reading, Wikipedia has the details. https://en.wikipedia.org/wiki/Nurek_Dam
Photo taken during the 2010 floods.
The largest dam by volume of its structure is Tarbela Dam in Pakistan. This massive dam impounds the Indus River approximately 50 km northwest of Islamabad.
It’s an earth filled dam with a volume of 153 million cubic metres! Total height is 143 m and has a 3 478 MW hydroelectricity plant at the bottom.
The Indus River is filled from the snow melt in the Himalayas each year and this carries sedimentation with it. The amount of sedimentation deposited in the reservoir has been lower than expected, but the dam is still expected to be full of sediment and non-useful by 2060.
For futher reading, Wikipedia has the details. https://en.wikipedia.org/wiki/Tarbela_Dam
We’re a marvelous species and we know how to secure the resources we need to sustain our lifestyle. Each dam is a sophisticated piece of engineering and requires countless hours of study and research by environmental scientists, geologists, meteorologists, hydrologists, civil, mechanical and electrical engineers. These three dams are by different measures, the largest dams in the world and they are engineering masterpieces.