Some lessons from Southern Africa about the challenges posed by water nexuses

Abstract

Southern Africa is a semi-arid region with limited perennial water courses, an overall rainfall well below the global average and substantial inter-annual and inter-seasonal variability. As a consequence, water resource systems have to be carefully planned and operated if their users are to enjoy desired levels of water security. In order to meet the needs of growing populations and expanding economies, the interactions between the demands of the different sectors have had to be considered. Optimising the approaches to meeting the requirements of energy and agriculture has been a significant concern. However, the primary challenge has been to supply another ‘nexus’, the growing demands for water for urban and industrial use. Another issue that has arisen in recent decades has been the need to maintain an acceptable aquatic environment. The experience of water managers in South and Southern Africa illustrates the usefulness of a focus on the energy–land–water nexus, but also its limitations. This experience illustrates the importance of applying a range of more generic methodologies in order to achieve effective and sustainable water resources management.