The Okavango Delta Floods

The hot, dry Kalahari Desert appears as an uninhabited wasteland unable to support life. Dried up riverbeds wind through dusty plains; even a light breeze creates swirls of dust in this hot and unrelenting environment. Then, almost overnight, a natural phenomenon occurs. Water floods into the desert creating a beautiful wetland. At the heart of the Kalahari sands is the Okavango Delta, an expanse of floodplains and forested islands criss-crossed by an expanse of waterways. As the floodwater filters through to the lagoons and grassy plains, the Okavango Delta becomes an extraordinary hive of animal activity.

During the floods animals arrive in their thousands; swarms of dragonflies appear in thick clouds as if by magic as soon as the flood begins. Bullfrogs awake contributing to the deafening chorus of frogs celebrating the arrival of the floodwater. The sky turns pink with the arrival of great flocks of flamingos, returning home to breed. A multitude of other birds and insects, fill the skies as the plains come to life. Great herds of wildebeest, buffalo and zebra gather. Thousands of elephants congregate, while large hippos battle over prime breeding territories. With them come Africa’s great predators. Hungry lions congregate while crocodiles lurk in wait.

Why?

While the majority of rivers in the world flow to the sea, the Okavango River ends in its Delta, right in the middle of the southern African landmass. Rising in the highlands of Angola some 500km away, during the wet season rainfall causes the river to swell, sending a cascade of water down towards the Okavango Delta. Due to the distance involved it takes time for the water to filter down to the floodplains, with the flood normally arriving at the start of the dry season between July and August. During the wet season from December to March, Botswana wildlife is widely dispersed. As the outer lying areas start to dry up and popular waterholes disappear, vast numbers of animals migrate back in to the Okavango Delta to coincide with the arrival of the floodwater. A key feature of the Delta is its extraordinary nutrient base; this enables vegetation to grow quickly and also means that it has a higher nutritional quality. This may help explain why this region is so rich in wildlife.