Zambia Zimbabwe Advance Dam Project Despite Climate Worries

The governments of Zambia and Zimbabwe have committed $220 million each, totaling $440 million, towards the construction of the Batoka Gorge Hydro Electric Scheme (BGHES). This pledge, made at a December 29, 2023 meeting of the Zambezi River Authority (ZRA), aims to improve the project’s financial viability and attract private investors. The ZRA, which already manages the Kariba Dam and its hydropower station, will oversee the proposed BGHES.

A 2,400-megawatt Hydropower Project

The BGHES plant is planned for the Zambezi River, near Victoria Falls on the border of Zambia and Zimbabwe. The plant is designed to generate 2,400 megawatts (MW) of power, with each country expected to receive 1,200 MW. The project, initially conceived in 1972, has faced numerous delays. However, declining water levels on the Zambezi River, attributed to climate change and erratic rainfall, have raised concerns about the project’s long-term viability. The Zambezi River, Africa’s sixth-largest, flows through Zambia, Angola, Namibia, Botswana, Zimbabwe, and Mozambique. Major dams along the river include Lake Kariba (shared by Zambia and Zimbabwe) and Cahora Bassa in Mozambique.

Studies Raise Viability Questions

Recent studies have questioned the financial viability of the BGHES due to climate change impacts. Research from the University of Edinburgh found that while renewable energy expansion is crucial for mitigating climate change, the changing availability of water resources is adversely affecting hydropower projects. Simulations indicated significant reductions in river flows, declining power production, and reduced electricity sales revenue. Another 2014 study warned that worsening climate change and increased demand for irrigation would further reduce flows on the Zambezi. This study also found that Kariba is highly vulnerable to a drying climate, potentially reducing electricity generation by 12 percent, and that the planned Batoka Gorge plant may not reach anticipated production levels.

Project Proceeds Despite Risks

Despite these concerns, both Zambia and Zimbabwe are proceeding with the BGHES. Zimbabwe’s Energy Minister July Moyo stated the project is a priority, while Zambia’s Energy Minister Makozo Chikote defended the decision, citing comprehensive feasibility studies that confirm the Zambezi River can sustainably support the project. Chikote emphasized that Batoka Gorge is part of a sequential hydropower system designed to maximize power generation. ZRA chief executive officer Munyaradzi Munodawafa added that the project will mitigate hydrological challenges at Kariba and significantly increase power supply capacity.

Hydropower Remains Central Despite Climate Risks

Engineer Stephen Dihwa, executive director of the Southern African Power Pool Coordination Centre, believes hydropower will remain central to electricity supply. He noted that periods of low rainfall are often followed by higher rainfall, allowing dams to refill. Dihwa emphasized the need for plant operation based on well-forecast hydrology and careful reservoir water management. Studies are underway to reduce the impact of drought on hydropower plants, including exploring inter-basin water transfers. Zambia has proposed a 300-km canal to transfer water from the Luapula River to the Kafue River, while Zimbabwe is exploring a 1,200-km tunnel to draw water from the Lualaba River to Lake Kariba. IPCC climate projections suggest Central Africa will likely become wetter, while southern Africa continues to dry.