Katse Dam, Concrete arch dam in Maluti Mountains, Lesotho

Katse Dam is a concrete arch structure spanning 710 meters across the Malibamat'so River with a height of 185 meters. The reservoir holds massive amounts of water that powers hydroelectric generation while also transferring water to neighboring regions through underground channels.

South African civil engineer Ninham Shand identified the site's potential in 1953 to supplement water for the Witwatersrand. A World Bank-arranged treaty between South Africa and Lesotho let work proceed; a consortium including Bouygues, Hochtief and Impregilo completed the dam in 1996, and the reservoir filled by 1997.

The dam displaced residents of several villages before the reservoir filled. A local group has documented this human legacy, and the environmental and human-rights NPO International Rivers produced a detailed account of the effects. The reservoir also induced earthquakes that made some nearby houses uninhabitable.

The dam lies on the Malibamatšo River just below its confluence with the Bokong River, and Katse Airport is 3 km southeast. The intake tower stands about 18 km north of the dam. The reservoir is 45 km long, and the dam's crest reaches 1,993 m above sea level.

Water is channeled through an underground tunnel system spanning about 45 kilometers to industrial areas in a neighboring country. This water transfer arrangement is an example of how two nations cooperate to manage shared water resources.