Okavango Delta

The Okavango River starts far away, in a country called Angola.

It flows a very long way. Then the land gets flat. The river spreads out like the fingers of a hand. The water sinks into the sand and dries up in the sun.

The Okavango River begins in the highlands of central Angola, where it is called the Kubango. Britannica says it flows about 1,600 kilometers southeast, along part of the border with Namibia and across Namibia's narrow Caprivi Strip, into Botswana.

Inside Botswana the river enters flat, swampy land, widens and spreads out into a triangle-shaped delta. UNESCO explains that the shape of the land here, part of the great African Rift Valley system, "captured" the river and made the delta. Thick papyrus reeds keep blocking channels, Britannica says, so the water keeps changing its path.

Britannica traces the Okavango from the Bié Plateau of central Angola, where it rises as the Kubango at about 1,780 m, southeast for about 1,600 km; it forms part of the Angola-Namibia border, is joined by the Kwito, crosses the Caprivi Strip and, about 110 km (70 miles) inside Botswana, fans out into a triangular delta whose base extends for about 240 km. UNESCO gives the river as 1,500 km long; the two sources give different lengths.

UNESCO attributes the delta to the region's geology, part of the African Rift Valley system, which "captured" the river. Changes in the land's shape alter flow directions, flooding some areas and drying others (UNESCO), and dense papyrus continually blocks channels (Britannica). Subsurface precipitation of calcite and amorphous silica helps build islands and habitat gradients (UNESCO).

You might expect a flood to come with the rain. The Okavango is different!

Its flood comes when the land is dry. Dusty hollows fill with clear water. Thirsty animals hurry to drink and splash.

Every year, a pulse of water flows down the Okavango River and spreads through the delta. The surprise is its timing: UNESCO says the flood reaches its peak in June and July, in the middle of Botswana's dry season.

When the flood arrives, huge sandy, dry hollows turn into clear pools and lagoons. Herds of elephants, buffalo, red lechwe and zebras come to drink and splash, some after weeks-long journeys across the Kalahari. The plants and animals of the flooded grasslands time their growth and breeding to match the coming of the water.

UNESCO highlights the paradox at the heart of the property: an annual flood pulse that peaks during the height of Botswana's dry season (June and July), transforming dry depressions into clear, nutrient-carrying water and revitalizing the ecosystem when rain is absent. Plants and animals of the flooded grasslands have synchronized their growth and reproduction with its arrival.

The flood drives constant change in islands, channels, banks, floodplains, oxbow lakes and lagoons, which UNESCO cites under criterion (ix) as an outstanding example of interacting climatic, geomorphological, hydrological and biological processes: flood inundation, channel formation, nutrient cycling, breeding, migration, colonization and plant succession. Britannica adds that flow varies sharply with the seasons, tributaries, evaporation and absorption into the riverbed.

Many animals live in the delta.

Elephants, hippos, zebras and buffalo come to the water. Lions, cheetahs and wild dogs live here too. Hundreds of kinds of birds fly over the swamps.

The delta is one of Africa's great wildlife places. UNESCO says it supports strong populations of some of the world's most endangered large mammals, including cheetahs, white and black rhinoceroses, African wild dogs and lions.

It counts 1,061 kinds of plants, 89 fish, 64 reptiles, 482 birds and 130 mammals. Botswana has the largest elephant population in the world, about 130,000 when UNESCO listed the delta, and the Okavango is the core area for their survival. Birds include vultures, the southern ground hornbill and the wattled crane.

UNESCO records 1,061 plant species (134 families, 530 genera), 89 fish, 64 reptiles, 482 birds and 130 mammals, with robust populations of cheetah, white and black rhinoceros, African wild dog and lion. It is an Important Bird Area with 24 globally threatened bird species, among them six vultures, the southern ground hornbill, wattled crane and slaty egret, and 33 waterbird species occur in numbers above 0.5% of their global or regional populations. At inscription Botswana held the world's largest elephant population, around 130,000, with the delta as its core area.

UNESCO also records concerns: elephant numbers rising while other species decline, unclear survey data, poaching (for example of giraffe for meat) and veterinary cordon fences that disrupt wildlife movement, notably for roan and sable antelope. The Moremi reserve protects about 40 percent of the property; Britannica lists lions, cheetahs, buffalo, wildebeests, hippos, zebras, wild dogs and crocodiles there.

People have lived around the delta for hundreds of years.

Some fished, and some hunted. Today villages sit around the edges. Three countries share the river and work together to keep its water flowing.

UNESCO says small groups of Indigenous people have lived in the delta for centuries, each adapting to the resources around them, such as fishing or hunting. Today, mixed villages of Indigenous people and later arrivals sit mostly around the edges of the delta. Britannica names the Tswana as the main inhabitants of the delta.

The river's water comes from Angola and Namibia, upstream. When UNESCO listed the delta, there were no dams or big water takings upstream, and the three countries, Angola, Namibia and Botswana, manage the river together through a joint commission called OKACOM. Keeping that water flowing is the key to keeping the delta alive.

UNESCO notes that the delta has been inhabited for centuries by small numbers of Indigenous people living as hunter-gatherers, with groups adapting their identity and way of life to particular resources such as fishing or hunting; this low-level use did not harm the wetland. Mixed settlements of Indigenous peoples and later immigrants now lie mostly around the fringes, outside the property. The land is communally owned Tribal Land under the Tawana Land Board, and UNESCO asks that residents be included in management and share in tourism benefits.

Because the water originates in Angola and Namibia, UNESCO stresses that upstream flows must remain unimpeded: the source catchment is free of dams and major abstraction, and the three riparian states coordinate through the Permanent Okavango River Basin Water Commission (OKACOM). Mining and prospecting are not permitted within the property, and UNESCO asks for monitoring of activities outside it that could affect water flow or quality.

Many visitors fly in on small planes. They sleep in tents in small camps.

Wild animals are big and strong. Stay with your guide and watch quietly from far away.

Because the delta is so big and hard to reach, it has never been heavily developed. UNESCO explains that tourism in the inner delta is limited to small, temporary tented camps reached by air, and that they are checked to make sure they follow environmental rules.

The delta is home to hippos, elephants, buffalo, lions and crocodiles, so it is a place to watch, not to wander. Travel with trained guides, keep a respectful distance from animals on land and in the water, and leave no trash behind.

UNESCO attributes the delta's near-pristine condition to its size and difficult access: tourism in the inner delta is restricted to small, temporary tented camps with access by air, monitored for compliance with environmental standards, which UNESCO says have minimal ecological impact.

Britannica lists lions, buffalo, hippopotamuses and crocodiles among the wildlife of the Moremi reserve, and UNESCO describes large herds of elephants, so visitors should follow their guides, stay in vehicles or boats when told to, and keep well away from wildlife. Protecting the delta also means protecting its water: no dams, irrigation schemes or mining that would alter the flood that everything here depends on.