Lake Kariba, the Colonial Dam That Displaced 57,000 Tonga People

Lake Kariba holds roughly 180 cubic kilometers of water, making it the largest artificial lake and reservoir by volume anywhere in the world, larger than any dam-created lake built since. It sits along the Zambezi River where the border between Zambia and Zimbabwe runs through Kariba Gorge, the product of a dam project that colonial administrators in the Federation of Rhodesia and Nyasaland pushed through between 1955 and 1959, designed by the French engineer André Coyne to generate hydroelectric power for the region’s growing copper-mining and industrial economy.

Building it took a heavy toll on the people constructing it: floods repeatedly damaged the dam site during construction, and by the time it was finished, roughly 86 workers had died in accidents and disease outbreaks tied to the remote, disease-prone gorge environment. But the dam’s greatest human cost fell on people who had no say in its construction at all. Filling the reservoir meant flooding the Gwembe Valley, ancestral farmland of the Tonga people along both banks of the Zambezi, and colonial authorities forcibly relocated an estimated 57,000 Tonga men, women and children to higher, less fertile ground with little compensation and minimal consultation. Historian JoAnn McGregor, in her 2009 study “Crossing the Zambezi: The Politics of Landscape on a Central African Frontier,” documents how that displacement reshaped Tonga political and economic life for generations, severing communities from river-based farming and fishing traditions and leaving a legacy of dispossession that outlasted colonial rule itself; a chapter of her book, titled “Unsettled Claims,” traces how Tonga communities have continued pressing for recognition and compensation decades after independence.

The flooding also triggered one of the largest wildlife rescue operations in African conservation history. As the reservoir rose and stranded animals on shrinking islands of high ground, game warden Rupert Fothergill led what became known as Operation Noah between 1958 and 1964, a campaign that captured and relocated an estimated 6,000 animals, including rhinos, elephants, zebras and lions, to safety on the reservoir’s shores, a rescue effort that received far more international attention at the time than the human displacement happening alongside it.

Kariba’s claim to a surface-area record was actually short-lived, though not for the reason often cited: Egypt’s Aswan High Dam, completed in 1970, created Lake Nasser, which at roughly 5,250 square kilometers is smaller than Kariba by area, not larger. The reservoir that genuinely surpassed Kariba’s surface area was Ghana’s Lake Volta, formed by the Akosombo Dam and completed in 1965, which at about 8,502 square kilometers remains the world’s largest reservoir by surface area. Kariba’s lasting record is by volume of water held, not surface area. Today the dam remains a critical source of electricity for both Zambia and Zimbabwe, even as structural concerns about the aging dam wall, first built to a design later found to need reinforcement, have prompted a multi-decade international rehabilitation effort to keep one of the world’s largest reservoirs from becoming one of its most catastrophic failures.