Dam synchronisation and flood releases in Zambezi river basin

The “Dam Synchronization and Flood Releases in the Zambezi River Basin Project” investigated the extent to which the timing of releases for electricity production, agricultural demands, environmental flow, dam safety, and flood protection from existing and proposed new dams can result in more overall advantages. To effectively manage the inflows, storage and releases for these purposes, the Zambezi system requires forecast of flows at key locations. Short term forecasts for floods and seasonal forecasts for environmental flows can be incorporated in reservoir operation decision-making as well. At present the predominant interest is on the multi-million dollar hydropower generation sector, and any new operation changes or re-allocation of the water, has to earn the confidence of this sector. Forecasts and appropriate models can be used to reliably demonstrate that the power generating levels/storage will be sustained when releases are made for environmental flows or flood protection.

Often, the environmental requirements are perceived as competing with other interests such as hydropower generation. During the Project, effort was made to show that flood management and release of environmental flows can be achieved. This falls in line with the concept that environmental flow management should provide flows needed to sustain freshwater and estuarine ecosystems in coexistence with competing interests such as agriculture, hydropower production, public water supply and industries.

Recommendations on improved basin-wide reservoir management are given. In particular the potential of flood forecasting, information sharing, synchronised operation and new infrastructure have been considered for improving reservoir management. The requirements for basin-wide flow forecasting have been established based on user requirements. The impact of climate change on reservoir management has also been assessed.

The main services provided are:

  • establishment of user requirements for a basin-wide flow forecasting and associated forecast requirements (data and forecasting products);
  • analysis of suitability of satellite rainfall estimation for basin-wide flow forecasting;
  • estimation of climate change impact on reservoir inflows; and
  • establishment of a pilot forecasting system.

Our associates:        

SSI, WRNA consultants, Rankin Engineering, SEED