Seasonal Flooding of the Okavango Delta
Thursday, May 31st, 2007
The Okavango Delta, the jewel in the middle of the Kalahari Desert of Botswana, is Africa’s largest and most beautiful oasis - an isolated, lush green paradise with some of the richest wildlife in the world. This exceedingly beautiful maze of waterways, lagoons, vast grassy plains and palm-fringed and wooded islands is home to crocodile, hippo, elephant, lion, leopard, hyena, giraffe, wild dog, rare antelope and around 400 bird species. We are often asked about the seasonal flooding of the Okavango Delta in Botswana – Why does it happen? When does it happen? Why do some lodges have water all year and others only during the flood? So I thought I’d try to address this issue in more depth…
Where does the source of the Okavango come from?
The source of the Okavango Delta lies in the extremely wet highlands of Angola to the north. From here the Cubango River flows south, through Namibia, away from the sea, gathering ever more water until it finally reaches Botswana, where the river becomes known as the Okavango. Here, the fate of the river is determined by a series of fault lines deep below the desert surface. Once the river passes over the first fault line, it splits into several channels forming a vast, fan-shaped, astonishingly luxuriant wilderness of flood plain and forest, stream and lagoon, the ideal breeding ground for an incredible diversity of wildlife. When the water meets the final two fault lines, the water is literally dammed and cannot go further. (Before the fault lines, the river flowed through the area which is now the Okavango Delta and the Makgadikgadi pans, and probably on to the Indian Ocean by flowing into the Limpopo river.)
When does it happen?
Something that often confuses people is that Botswana and the Okavango Delta has a summer rainfall and yet the flood occurs in the dry winter months. The rain falls during the summer and first seeps into the parched ground before the rivers start flowing. It takes months for the river flow to reach the Okavango Delta. (The flood travels very slowly at only a kilometre a day, partly because of the shallow gradient and because the swamp vegetation slows the water.) The flood starts coming into the northern reaches of the Okavango Delta in late April and makes its way steadily down reaching many camps sometime in June or possibly early July, depending on their precise location, and peaking in August. As it is the dry season, gradually the flood waters evaporate over the next few months, leaving their valuable salts and minerals in the ground, and the waters recede through October and November.
The evocative mokoro trips - a traditional dugout canoe made from an ebony or sausage tree - largely take place in these shallow waters and seasonal flood plains of the Okavango Delta. Gliding along in a mokoro, in total harmony with nature is an experience not to be missed.
Why do some lodges have water all year, others only during the flood and others not at all?
In the south-eastern part of the Delta lies a slightly higher area of land, known as Chiefs Island. This forms part of the Moremi Wildlife Reserve and the higher ground means that the waters never flood this area. The lodges here are predominantly land camps offering game drives. If they’re on the edges of the Moremi, they may offer some water-based activities during July to September but this would be secondary to the main focus which is game drives. Prime examples would be Mombo Camp, Chief’s Camp and Khwai River Lodge.
To the north of the Moremi lie some deep river channels which are fed through the summer rains and then by the Okavango Delta. The camps in this area such as Kwara Camp, Vumburu Plains and Shinde are what is called ‘multi-activity’ camps (for want of a more elegant term) in that they offer a choice of water or land based game-viewing activities throughout the year because of the presence of these deep river channels.
Broadly speaking, to the south of the Moremi are the seasonal camps which focus on game drives in the green season and offer a mix of activities as the flood comes in. As the Okavango Delta flood varies from year to year, no-one can say precisely when the flood waters will arrive so if you are booking early on in the season, in June for example, there may be an element of luck (but the price usually reflects this). Depending on the camp’s exact location, land-based activities can be quite limited in the full flood so the camps literally become surrounded by water. The advantage is that the animals also get restricted to limited island areas making for excellent game-viewing on foot, by mokoro or by boat. Excellent examples would be Nxabega, Jao and Baines Camps.
Finally further towards the northern and western stretches of the Delta are the permanent water camps, which as their name suggests, offer boat-based game-viewing and game walks on the surrounding islands. The game-viewing is more limited here but the birding is excellent. It’s worth noting that mokoro trips are not usually on offer here as the water is too deep to pole. Examples would be Jacana and Eagle Island Camp.
Point for the Safari Visitor
Change is the essence of the Okavango Delta. The delta changes from year to year depending on flood levels and rains and the flood constantly forges new channels which prevents the delta becoming silted up. This dynamic nature leads to great diversity of water depth, soils, vegetation and animal distribution. The exact location of each camp dictates what activities are available and when and this can vary within a short distance. Assuming you are booking well in advance, we’ll be able to match a particular camp to your needs.
It also follows that staying at two different camps in different habitats will give you the best feel for the dynamic mood of the Okavango Delta.