Botswana: Delta water level down

Molapo (flood recession) farming and water based tourism activities have so far become the first casualties of the on-going drought as water levels go down in the Okavango Delta.

According Professor Joseph Mbaiwa of the Okavango Research Institute (ORI), as water levels in the delta decrease, some activities have been affected.

Professor Mbaiwa is a Professor of Tourism at the Maun-based University of Botswana campus – ORI. Mbaiwa indicates that students who were supposed to carry out a study on Molapo farming as part of their course work could not do such as farmers have not ploughed their fields this year.

Due to the fact that water is readily available for Molapo farmers, they usually have early yields but this was not the case this year. According to a study done by ORI experts in 2014 (Influence of Flooding Variation on Molapo Farming Field Size in the Okavango Delta, Botswana) , the climate of the Okavango Delta makes flood recession farming much more lucrative than dry land farming because rainfall in the area is relatively low (an annual average of 500 mm). In addition, the distribution of annual rainfall across the season is erratic, making it hard for farmers in the surrounding dry land savannah areas to decide whether or not to plant.

According to the study, there is frequently not enough moisture from rainfall to last the whole cropping season, and the sandy soils are generally low in nutrients. These factors make it difficult to attain high crop yields through dry land agriculture. In the Okavango Delta, however, there are exceptionally good soils due to annual deposition of alluviums. The higher levels of soil nutrients, combined with flood-induced higher soil moisture also make higher crop yields possible with minimal use of expensive inputs. “Usually around this time, Molapo farmers are already selling produce from their fields especially maize, unfortunately this is not the case this year,” said Mbaiwa. Maize is the main crop grown in Molapo farms however other crops such as water melons, sorghum and beans are planted as well.


Water is obviously at the core of the tourism business in the North West region and with the water levels going down, it can’t be good for the sector. Though there is no scientific study done yet, Mbaiwa said the sector should brace itself for a rough time ahead. He said for now only small scale players such as those operating boat cruising and canoe poling will feel the pinch while international bookings are likely to be affected after a while.

“Businesses such as the Mbiroba Poler’s Trust in Seronga depend greatly on the Delta for business. If the water levels go down it means less income for them, which can subsequently lead to people losing income and employment,” said Mbaiwa. He, however, posited that international tourist bookings are not likely to get affected much this year as they are usually done well in advance. “Bookings are usually done a year or two in advance, so for now the effect is not likely to be much,” he said.

Fauna & Flora

Meanwhile two other experts from the ORI are of the view that it is not all doom and gloom as far as the Okavango Delta and the dependant flora and fauna is concerned. The Okavango Delta, including the Thamalakane River, apparently depends almost entirely for their water supply from the flood water from the Angolan Highlands. Most of the water in the delta is lost through evapotranspiration, with approximately only 2% of what comes into the delta via Mohembo, leaving the delta through the Thamalakane River. So water flow dynamics in the delta are more a reflection of the rainfall situation in Angola, rather than local rainfall.

Therefore, according to Edwin Mosimanyana – a research scholar at ORI – local drought will have very little impact on water levels in the Okavango Delta water levels. However, a combination of reduced inflow into the delta (because of poor rains in Angola, for instance) coupled with the very high evapotranspiration rates in the delta, are more likely to be the cause of the reduced water levels in the delta, and the Thamalakane River. However Mosimanyana acknowledged that away from the delta, livestock grazes in the communal areas, and because of the prevailing lack of rainfall in the country, the whole region will be severely affected in as far as grazing is concerned.

Dr Mike Murray-Hudson – a Senior Research Scholar in Aquatic Ecology – has this to say about the on-going drought: “There have been droughts before this one (1986-7 and 1995-6 for example), and there will be droughts in the future. Most of the flora and fauna of the Delta are well-adapted to such droughts (as well as being able to take advantage of the years of good or average rainfall in between droughts). Such variation is one of the essential ecological drivers of diversity and production in the Delta and its surroundings”.

According to Murray-Hudson, an increase in the area of grassland in place of less nutritious sedges is the typical response of Delta floodplain flora to drought. This, she said, in the medium-term (2-10 years) can work in favour of the larger grazing wildlife species. However, she highlighted that population numbers of water-dependent fauna may decline slightly in response to lower food availability, but said that these populations are ecologically resilient, and will be able to make a come-back in future years of better rainfall.


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