Southern African countries face serious regional water scarcity constraints to economic growth and development. The water resources in the four most economically diverse countries - South Africa, Botswana, Namibia and Zimbabwe - are approaching closure at the national level. Investigations using the concept of a Hydropolitical Complex, rather than the river basin alone, as the unit of analysis have produced a more subtle understanding of how hydrologically-constrained states are dealing with the problem. The Southern African Hydropolitical Complex (SAHPC) case suggests that where states have water constraints to future economic development options, then the incentives to seek consensual management options are high.