Climate change, irrigation and hydropower in the Zambezi

Climate Knowledge Development Network (CDKN) and the World Bank

Accelerating economic growth across southern Africa is increasing the potential for competition for water between hydropower and irrigated agriculture. Climate change will add additional stress to this system. This is especially so in the Zambezi River Basin, where the potential for irrigation development, further hydropower expansion and energy trade and export into the Southern African Power Pool is substantial.

OneWorld was part of a team from Zambia, Mozambique, the US and South Africa that is combining hydrological models of riverflow responses to the various changes to create new scenarios of hydropower production potential, and combines these with models of the evolving energy demands of the SADC region (this last part of the project is still in development). The outcomes will be used to influence policy within the Southern African Power Pool and the Zambezi River Authority, as well as other regional and national stakeholders.

This project is a research initiative designed to address the major uncertainties facing hydropower development in the region, and to deepen understanding among stakeholders of the risks to hydropower from changes in climate and increased upstream water demand. For 18 months, researchers from the University of Cape Town, the Centre for Energy, Environment and Engineering (Zambia) at the University of Zambia, OneWorld Sustainable Investments, University of Eduardo Mondlane, and Pöyry Management Consulting developed and applied a water supply and demand modelling tool for the Zambezi River Basin.

The research was guided by a Steering Committee led by the Southern African Power Pool and including the Zambezi River Authority, the ZAMCOM Interim Secretariat, Southern African Development Community Energy, the UK Department for International Development, and the Climate and Development Knowledge Network. The model was applied to two future climate scenarios, reflecting possible “wetting” or “drying” climates, and two scenarios for irrigation expansion in the region. The results of the analysis point to dramatic potential negative impacts on major existing and planned hydropower investments. 

Publications

Socio-Economic Futures of the Zambezi River Basin

Policy Brief: Hydropower in the Zambezi River basin at risk due to changing climate and increased irrigation

Water supply and demand scenarios for the Zambezi River Basin: Climate change and upstream development impacts on new hydropower projects in the Zambezi Project