Namibia is the driest country in southern Africa. The Cuvelai-Etosha Basin (CEB) in central-northern Namibia is particularly affected. It covers four regions, namely Ohangwena, Omusati, Oshana and Oshikoto. The climate is characterised by the high ly variable nature of its water supply. People normally have abundant water during one half of the year while there can be drought during the other half, making them dependent on a water supply. The rainy season lasts from October to March, with an average annual rainfall of 470 millimetres. However, annual rainfall varies up to 60 per cent due to natural variations. This means that annual rainfall can be as low as 200 millimetres in some years, or up to 770 millimetres in others. This makes the availability of water even more unpredictable for the populace.