Imposing structures that strike the observer with their majestic presence: in the collective imagination, dams represent the places where they are located. Their structures are dictated by the geography of their surroundings: the rock formations that surround them, the valleys where they stand and the shape of the rivers that they block.
And the records to beat are many.
The hydroelectric dam of Itaipù on the Paraná River between Paraguay and Brazil, for example, is the biggest of its kind in the world in terms of annual production of electricity.
The Jinping -1 on the Yalong River in China is the tallest in the world at 305 metres. It will eventually be replaced by Rogun, which Salini Impregilo is building in Tajikistan at 335 metres.
But which are the biggest dams in the world in terms of reservoir size?
Three are located in Russia and another three in Canada, while the others are found in Africa and South America.
Built between 1955 and 1959 on the Zambesi River between Zambia and Zimbabwe according to the plans of French architect André Coyne, Kariba is the biggest. It is an arch dam, 128 metres high and 579 metres long that has a reservoir capacity of 185 billion cubic metres of water. It was built by an Italian consortium including Impresa Umberto Girola, Impresa Italiana all’estero, Impresa Ing. Lodigiani, and Impresa Ing. Giuseppe Torno e Co.
As was unfortunately the case for many dams under construction at the time, many lives were lost, Italians in particular.
With two turbines, the dam produces 1,320 megawatts for the two countries that share it.
Work is under way to repair and restore the Kariba to avoid it from collapsing.
The second biggest dam in the world by reservoir is located in Siberia, Russia. Built between 1954 and 1964, it holds 169 billion cubic metres of water, stretching for 5.4 square kilometres. It is 125 metres high and nearly 1.5 kilometres long with a railway and a highway running along it. Its 18 turbines give it a production capacity of 4,500 megawatts.
With a reservoir of 144 billion cubic metres, the third biggest dam in the world by reservoir is behind the Lake Volta, the largest artificial body of water by extension. Located in the southeast of Ghana, it was built between 1961 and 1965 thanks to the financial support of the World Bank, the United States and the United Kingdom. With a height of 114 metres and a length of 660 metres, the power station that it supplies serves Ghana, Benin and Togo.
In addition to being the fourth biggest by reservoir, this Canadian dam on the Manicouagan River in Québec is the longest multiple-arch buttress dam. Rising 214 metres in height and stretching for 1,300 metres in length, it has a reservoir of nearly 140 billion cubic metres. Built between 1959 and 1968, it is named after the premier of Québec who pursued the development of hydroelectric power in the province.
The fifth biggest dam by reservoir is officially known as the Simón Bolívar Hydroelectric Plant. Located in Venezuela, it has a reservoir of 135 billion cubic metres. This gravity dam is 162 metres high and 7.5 kilometres long. For many years, it was the most powerful with a capacity of 10,200 megawatts. It supplies more than 70 percent of the country’s energy needs.
This is the biggest dam on the Nile River in Egypt. The lake created by the reservoir is named after Gamal Abdel Nasser, the former Egyptian president who wanted the dam built. It has 132 billion cubic metres of water. Built between 1960 and 1968, the dam generates 2,100 megawatts but also provides water for agricultural in Egypt and Sudan. It mitigates flooding and facilitates navigation along the river. The Abu Simbel temples also figure in its history. At the time of the dam’s construction, the rising waters of the reservoir threatened to put at risk this famous archaeological site. This led to an international rescue effort between 1965 and 1966 involving construction companies like Salini Impregilo to transfer the temples to higher ground.
Located on the Peace River, this dam created the Williston Lake in British Columbia, Canada. The reservoir’s capacity is 74 billion cubic metres of water, contained by a structure 183 metres high and more than two kilometres long. Built between 1961 and 1967, it carries the name of the former premier of the province who promoted its construction as part of an economic development plan. In operation since 1968, it has an installed capacity of 2,790 megawatts.
Located on the Enisej River in Siberia, Russia, it has a reservoir with a capacity of 73 billion cubic metres. Built between 1956 and 1972, this gravity dam is 124 metres high and a little more than a kilometre long. The Krasnojarsk hydropower station has an installed capacity of 6,000 megawatts, a big part of which is dedicated to supplying electricity to an aluminium plant run by UC Rusal.
Completed in 1975, it has a reservoir with a capacity of 68 billion cubic metres in Russia near the border with China. More than two billion cubic metres of concrete were used to build the dam, which stands 112 metres high and stretches for 714 metres.
At a height of more than 162 metres and a length of 2.8 kilometres, this dam in the Canadian province of Québec has a reservoir of 61.7 billion cubic metres of water that covers nearly three square kilometres. The power station, which is being restored, has an installed capacity of 5,616 megawatts. It is named after Tobert Bourassa, the former provincial premier who oversaw the James Bay Project, the construction of a series of hydroelectric plants that created one of the largest of its kind in the world by extension territory.