Powering Southern Africa - the future of hydro in the Zambezi River Basin CDKN is supporting a study on the impact of climate change and upstream irrigation development on hydropower in the Zambezi River Basin. Most of the northern SADC countries already rely primarily on hydropower, and this will increase in the future. However, many of these countries are also periodically under water stress during drought, while the water demand continues to grow, largely due to major irrigation investments.