Zambezi

The Zambezi River—also known as the Zambeze or Zambesi—ranks as Africa’s fourth-longest river, the continent’s longest river that flows east, and the largest African river to drain into the Indian Ocean. Its drainage basin spans 1,390,000 square kilometers (540,000 square miles), a little less than half the size of the Nile’s. Stretching 2,574 kilometers (1,599 miles), the river begins in Zambia, then passes through eastern Angola, runs along the northeastern edge of Namibia and the northern border of Botswana, continues along the Zambia-Zimbabwe border, and finally crosses Mozambique before reaching the Indian Ocean. The Zambezi is best known for Victoria Falls, but it also features Chavuma Falls and Ngonye Falls. Two major hydroelectric dams harness its power: Kariba Dam, which supplies electricity to Zambia and Zimbabwe, and Cahora Bassa Dam in Mozambique, which powers Mozambique and South Africa. Two smaller power stations in Zambia operate at Victoria Falls and Zengamina.

The river’s source lies in a black, marshy dambo within dense, rolling miombo woodland, about 50 kilometers (31 miles) north of Mwinilunga and 20 kilometers (12 miles) south of Ikelenge, in the Ikelenge District of Zambia’s North-Western Province, at roughly 1,524 meters (5,000 feet) above sea level. This source area is a national monument, forest reserve, and important bird area. East of the source, the watershed between the Congo and Zambezi basins forms a distinct belt of high ground running nearly east-west, dropping steeply to the north and south. This ridge clearly separates the Lualaba (the upper Congo’s main branch) from the Zambezi, though near the source the divide is less defined, and the two river systems do not connect. The region drained by the Zambezi is a vast, uneven plateau 900–1,200 meters (3,000–3,900 feet) high, composed of metamorphic rock in the interior and fringed by igneous rock at Victoria Falls. At Chupanga on the lower Zambezi, thin layers of grey and yellow sandstone, with occasional limestone bands, appear on the riverbed during the dry season, continuing beyond Tete, where they are linked to extensive coal seams. Coal also occurs just below Victoria Falls, and gold-bearing rocks are found in several places.

In its upper course, the Zambezi flows southwest into Angola for about 240 kilometers (150 miles), where it is joined by sizable tributaries like the Luena and Chifumage, which come from highlands to the northwest. The river then turns south and develops a floodplain that varies greatly in width between the dry and rainy seasons. It enters dense evergreen Cryptosepalum dry forest, while Western Zambezian grasslands appear on its western side. When it re-enters Zambia, the river is nearly 400 meters (1,300 feet) wide in the rainy season and flows swiftly, with rapids ending at Chavuma Falls, where it passes through a rocky fissure. From its source at 1,500 meters (4,900 feet) to Chavuma Falls at 1,100 meters (3,600 feet), the river drops about 400 meters (1,300 feet) over roughly 400 kilometers (250 miles). From there to Victoria Falls, the basin’s level is very uniform, dropping only another 180 meters (590 feet) across about 800 kilometers (500 miles). The first major tributary to join the Zambezi is the Kabompo River in Zambia’s North-Western Province. The savanna here gives way to a wide floodplain dotted with Borassus fan palms. Farther south, the Lungwebungu River meets the Zambezi, marking the start of the Barotse Floodplain—the upper Zambezi’s most notable feature—though this northern part does not flood as heavily and includes islands of higher ground. About 30 kilometers below the Lungwebungu confluence, the land becomes very flat, and the typical Barotse Floodplain landscape emerges, with floodwaters spreading up to 25 kilometers wide in the rainy season. For over 200 kilometers downstream, the annual flood cycle shapes the natural environment and human life, society, and culture. About 80 kilometers further down, the Luanginga River—which, with its tributaries, drains a large area to the west—joins the Zambezi. Just upstream on the east, overflow from the Luampa/Luena system feeds the main river during the rainy season. Shortly after the Luanginga confluence lies Lealui, one of the capitals of the Lozi people, who inhabit Zambia’s Barotseland region in Western Province. The Lozi chief maintains one compound at Lealui and another at Limulunga, which sits on high ground and serves as the capital during the rainy season. The annual move from Lealui to Limulunga is a major event, celebrated as the Kuomboka, one of Zambia’s best-known festivals. After Lealui, the river turns south-southeast. From the east, it receives many small streams, but for 240 kilometers on the west, no major tributaries join. Before this stretch, Ngonye Falls and subsequent rapids block navigation. South of Ngonye Falls, the river briefly borders Namibia’s Caprivi Strip. Below the junction of the Cuando River and the Zambezi, the river bends almost due east. Here it is broad, shallow, and slow-moving, but as it flows east toward the edge of the great central African plateau, it reaches a chasm where Victoria Falls plunge.

Victoria Falls marks the boundary between the upper and middle Zambezi. Below the falls, the river continues due east for about 200 kilometers (120 miles), cutting through vertical basalt walls 20 to 60 meters (66 to 197 feet) apart, set in hills 200 to 250 meters (660 to 820 feet) high. The river flows swiftly through Batoka Gorge, its current constantly interrupted by reefs. This stretch is considered one of the world’s most spectacular whitewater runs, a major challenge for kayakers and rafters. Beyond the gorge, a succession of features follows.