Optimal Flow Allocation in the Zambezi River System

The optimal flow allocation in the Zambezi system, the largest multi-reservoir water resources system in southern Africa, is analysed. The problem is formulated in network terms and solved with a network flow algorithm. The present configuration of the system is taken as the reference to evaluate the benefits of the proposed modifications to the existing hydropower schemes. The introduction of additional operational constraints is also considered in order to analyse the costs of environmental protection of paludal ecosystems and to account for secondary objectives (e.g. irrigation, fishery, navigation). The results show that the upgrade of Kafue Gorge scheme through the addition of a new generator stage is the most advantageous from the hydropower production view point. In addition, the protection of paludal ecosystems through periodic controlled flooding and an increase of withdrawals for irrigation purposes may be achieved without dramatically changing the hydroelectric energy production.