Changing Flow in the Okavango Basin: Upstream Developments and Downstream Effects

Abstract

The Okavango basin is shared between the countries of Angola, Namibia and Botswana and terminates in the Kalahari MOZ (Makgadigadi-Okavango-Zambezi) depression as an extensive alluvial fan often referred to as a “Delta” (Ringrose et al., 2005a). The upper catchment area receives 1200 mm/year rainfall and flows to the semi-arid Kalahari where the nominal average 460 mm/yr is considered a good rainfall year. Most of the streamflow in the basin is generated within the Angolan upper catchment. After 27 years of civil war, the cease-fire in 2002 may ultimately result in large number of refugees returning to the Angolan headstreams area with anticipated increased demands both for irrigation water and sites for dam construction for electricity generation. As the level of development is not high most of the returning people will be dependent on natural resources. Though the provision of needs to basin inhabitants is undisputed, there are concerns that the resettlement of displaced communities might have downstream environmental impacts (Green Cross International, 2000). Development will however be slow because of the large number of remaining landmines (Mendelsohn and El Obeid, 2004).