Zim News Blog -NEWS NETWORK

The governments of Zambia and Zimbabwe are brushing aside concerns about the worsening effects of climate change, with the two southern African nations recently pledging $220 million each in seed capital for the construction of the Batoka Gorge Hydro Electric Scheme (BGHES).

The decision by the two countries to commit the $440 million — about 10 per cent of the project’s expected cost of $4.5 billion — was taken at a December 29, 2025 meeting of the Council of Ministers of the Zambezi River Authority (ZRA), the bi-national body that manages water resources on the shared river. The ZRA will manage the proposed project, just as it already manages the bi-national Kariba Dam and its hydropower station.

The $440 million is intended to improve the project’s bankability and attract private investors. Funding has previously been one of the major obstacles faced by the project.

A 2,400-megawatt hydropower project

Located on River Zambezi, a short distance from the Victoria Falls on the border between Zambia and Zimbabwe, the BGHES plant has a design power-generating capacity of 2,400 megawatts (MW). Once completed, it is expected to supply 1,200 MW to each country, helping boost electricity supplies for two countries currently experiencing severe power cuts.

The project was first conceived in 1972 but has remained on the drawing board, with several false starts over the decades. However, as climate change increasingly affects southern Africa — making the region drier due to erratic rainfall and increased evapotranspiration driven by rising temperatures — water levels on the Zambezi River have been declining. This has led to serious misgivings about the long-term viability of the hydropower project.

The Zambezi is Africa’s sixth-largest river. It originates in Zambia and flows through Angola, Namibia, Botswana, Zimbabwe and Mozambique. Two major dams lie on the river: Lake Kariba, shared by Zambia and Zimbabwe, and Cahora Bassa, downstream in Mozambique. Hydropower plants on both dams — with a combined capacity of 3,800 MW — have in recent years been affected by climate change-related low water levels.

Power generation at Kariba — downstream from the proposed project site — was halted in 2022 and 2024, due to low water levels. Generation was also reduced at Cahora Bassa in Mozambique. In Zambia, climate change has not only affected power generation on its plant on River Zambezi, but also at three others, namely Kafue Gorge, Lower Kafue Gorge and at Itezhi-Tezhi.

Studies raise viability questions

These developments reflect projections from earlier studies that raised concerns about the viability of the BGHES. One study by researchers at the University of Edinburgh in the United Kingdom, which used the Batoka Gorge scheme as a case study, found that while expanding renewable energy — including hydropower — is a key strategy for limiting climate change, the paradox is that climate change itself is altering the availability of water resources, adversely affecting the financial viability of both existing and planned schemes.

The study assessed the relationship between climate change and the technical and financial viability of hydropower development, and the results were not encouraging.

“Simulations with climate change scenarios illustrate the sensitivity of the Batoka Gorge scheme to changes in climate,” the study noted. “They suggest significant reductions in river flows, declining power production, reductions in electricity sales revenue and, consequently, an adverse impact on a range of investment measures.”

It concluded that trends towards deregulation in the electricity sector would require increasing levels of private investment, which may not favour hydropower projects.

“More importantly, the very fact that climate is changing may alter the availability of this natural resource, and the impact of such changes on the financial viability of schemes will be of particular interest to investors.”
Another study, conducted in 2014 by four researchers focusing on southern Africa, warned that worsening climate change would not only reduce available water but also increase demand for irrigation and other uses, resulting in much lower flows on the Zambezi River.

“Accelerating economic growth increases the potential for competition for water between hydropower and irrigated agriculture, and climate change will add further stress to this system,” the researchers wrote. “The objective of this study was to assess the vulnerability of major existing and planned hydropower plants to changes in climate and upstream irrigation demand.”

“Our results show that Kariba is highly vulnerable to a drying climate, potentially reducing average electricity generation by 12 per cent. Furthermore, expansion of Kariba’s generating capacity is unlikely to deliver expected increases in production even under a favourable climate. The planned Batoka Gorge plant may also fail to reach anticipated production levels outlined in the original feasibility study.”

“This implies that climate change and upstream development must be explicitly incorporated into both project planning and system expansion.”

Project proceeds despite risks

Despite these warnings, the governments of both countries insist on proceeding with the project.

“Batoka was high on our agenda, and we agreed that the two governments must put some money on the table to demonstrate commitment,” Zimbabwe’s Energy Minister July Moyo said after the most recent Council of Ministers meeting. “The intention is clear — this project must take off.”
In a statement, Zambia’s Energy Minister Makozo Chikote defended the decision. “Comprehensive feasibility studies, including climate change assessments, confirm that the Zambezi River can sustainably support the project,” he said.

“The Batoka Gorge Hydro Electric Scheme remains technically sound, environmentally compliant, economically justified and central to Zambia’s long-term energy security.”

Chikote added that Batoka Gorge is part of a sequential hydropower system on the Zambezi River — alongside Victoria Falls, Kariba and future developments — designed to maximise power generation from the same water resource in line with international best practice.

ZRA chief executive officer Munyaradzi Munodawafa also said the project remains viable. “Batoka will serve as a mitigation measure for some of the hydrological challenges at Kariba, while directly contributing a significant increase to the urgently needed power supply capacity of Zambia and Zimbabwe.”

Hydropower remains central despite climate risks

Engineer Stephen Dihwa, executive director of the Southern African Power Pool Coordination Centre, which coordinates regional power systems, said hydropower would remain central to electricity supply despite climate risks.

He noted that periods of low rainfall are often followed by higher rainfall, allowing dams to refill. “This shows there is still a future for both existing and planned hydropower plants,” he said.

“What is required is plant operation based on well-forecast hydrology and careful management of reservoir water use,” Dihwa told Down To Earth.

He added that studies are under way on reducing the impact of drought on hydropower plants, including the possibility of inter-basin water transfers.

Two years ago, after all four of Zambia’s hydropower plants were either severely restricted or shut down due to climate change-related drought, Lusaka proposed an inter-basin water transfer project. It engaged the Chinese government to help dig a 300-km canal to transfer water from the Luapula River — a tributary of the Congo River in the north — to the Kafue River in the south, where two major hydropower plants are located.

Zimbabwe’s hydropower generation at Kariba has also been severely affected by poor rains and the country is exploring a 1,200-km tunnel to draw around 16 billion cubic metres of water annually from the Lualaba River in the Democratic Republic of the Congo to Lake Kariba.

IPCC climate projections indicate that Central Africa is likely to become wetter, while southern Africa continues to dry. The two regions lie in different river basins.

“There are ways to reduce the impact of drought on hydropower plants, but much more effort is needed,” Dihwa said. “Studies on drought resilience in southern Africa are already under way and should provide practical and sustainable solutions.”

“Some solutions are based on regional integration and coordinated operation of plants on shared watercourses. Others recognise that not all river basins are affected by drought at the same time. For example, the Congo Basin in the DRC is relatively less affected, and ways in which it could support power generation in other basins should be explored.”