The total annual rainfall in southern Africa doesn’t seem to have changed much over the last century since measurements began. But it has become more variable: droughts and floods are more frequent than before. The region’s urban authorities, industries, farmers and other citizens will have to adapt to these conditions.
The experience of other countries may offer useful lessons. Some arid countries, Australia and Israel for example, have been forced to develop novel technologies and strategies to survive extremely dry conditions. After drought from 1997 to 2009 forced Melbourne to take drastic measures to conserve water, residents changed the way they used water – and that behavior has persisted. On average, they still use only a quarter of the water used by the average Californian.
Australia encouraged households to save water through technology and behavior. It provided rebates for residential greywater (water that is relatively clean enough to be reused e.g. from bath, sink or washing machine, in contrast to black water which is water from toilets) systems for gardening, encouraged investment in rainwater tanks and implemented water restrictions.
Israel has, over many decades, developed a centralized water management system. It has invested in continuous technological innovations, improvements in practice and development of long-term management plans. Its greatest innovation relates to irrigation. It has developed an efficient drip irrigation system that uses up to 75% less water than some other irrigation techniques.
Countries in southern Africa must also start using the water they have more efficiently.