Water: surplus, deficiency, control & sharing

Every tap in Windhoek, every irrigated field beside the Orange River and every borehole on a Kalahari farm depends on one scarce, unevenly spread resource — water. In this AS lesson we first define exactly what a water surplus and a water deficiency are, and work out why some regions drown while others, like Namibia, go permanently dry — the roles of climate, relief, geology, population and industry. We then face the central problem of this topic: that the water is so often far from the people who need it, so humans build great transfer schemes to bridge the gap, from Namibia's own Eastern National Water Carrier to the giant dams of southern Africa. We discuss the serious problems that water scarcity brings — disease, hunger, cost and conflict — and the social, economic, political and environmental issues raised whenever we control and share water. We study a required case study of the Lesotho Highlands Water Project, and finish with the physical problems that sharing and controlling water can cause: health and disease, salination, pollution, and the twin troubles of erosion and deposition, all seen through a Namibian lens of shared border rivers, water reclamation and desalination.