Lake · Lesotho
Katse Reservoir
The Katse Reservoir is a long lake high in the mountains of Lesotho, in southern Africa. It was created by the Katse Dam, which sends water through a tunnel towards South Africa.
Picture credit: SkyPixels (CC BY-SA 4.0) · Amada44 (Public domain) · Wikimedia Commons
Where is Katse Reservoir?
Countries on its shores: Lesotho.
Largest body of water of: Lesotho.
Middle of the lake: 29.31° S, 28.51° E
The story behind it
The Katse Dam was finished in 1996, and by 1997 the valley behind it had filled with water. The curved concrete wall is 185 metres tall. For many years it was the tallest dam in Africa, until the Tekeze Dam in Ethiopia was finished in 2009. The Katse Dam also lies almost 2 000 metres above the sea, higher than any other dam in Africa. It holds back the Malibamatso River, and the lake can store about 1.95 cubic kilometres of water. Since 22 January 1998, about 30 cubic metres of water every second have flowed from the lake into a 45-kilometre tunnel on their way to South Africa, which pays Lesotho for the water. Along the way, the water also helps to make electricity. Some families had to leave their villages, and the heavy weight of the new lake even caused earthquakes that damaged nearby houses. Lesotho has no natural lake of this size; the largest body of water in Lesotho is this reservoir.
Find it on the globe
Katse Reservoir is there as a small blue dot with its name, right on the water. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.
It sits at its real coordinates, not near them — the same numbers listed in the facts above. Switch off the layer for this kind of place and it disappears again; the buttons for that are down the right-hand edge.
Questions children ask
How big is the Katse Reservoir?
The Katse Reservoir covers about 36 km² and can hold about 1.95 cubic kilometres of water. That is about twice as much as the Mohale Reservoir, another big lake of the same water project.
Where does the water from the Katse Reservoir go?
It flows through a 45-kilometre tunnel, about 30 cubic metres every second, and then on to South Africa. On the way it helps to make electricity for Lesotho.
Is the Katse Reservoir the largest lake in Lesotho?
Yes. Lesotho has no natural lake of this size, so its largest body of water is this reservoir, which was built by people.
Where these numbers come from
Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.
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