Zambia is poised on September 14 to unprecedentedly halt power generation at its largest hydro plant at Kariba due to critically low water levels caused by the country's worst drought in 40 years.

Built in 1959, the dam, where Zambia has a 1,080-megawatt (MW) facility, had a usable live storage of 8.7% on August 26 compared to 26% on the say day a year ago.

As a result of the abysmal water level, ZESCO, the national power company, has, since the first quarter of 2024, been generating only 215 MW at the complex. Other hydro facilities in the southern African country are similarly affected, hitting the nation's power output, 84.2% of which is hydro-based.

“The Zambezi River flows at Victoria Falls are also currently receding as expected for this time of year but are substantially lower than average due to the severe drought that was experienced during the 2023/2024 rainfall season,” the Zambezi River Authority (ZRA), a body that manages the dam and the river on which the reservoir is built, said on August 27.

Amid the depressed local output, a technical fault on a line routing imported electricity from neighbouring Namibia as well as maintenance work at the country's sole coal-fired facility, Maamba, ZESCO, said on September 1 that it had intensified power blackouts from 17 to 21 hours daily.

It warned that it would, for the first time in history, halt production at Kariba on September 14, as the country would have exhausted its 2024 water quota for power generation.

The southern hemisphere rainy season begins in October yearly, ending around March the following year.  If, as climatologists projected on August 28, southern Africa receives normal rainfall, Kariba's water level will likely start improving from February-March 2025, at which point the ZRA could decide to review the water allocation between Zambia and Zimbabwe with which it shares the dam.

Zambia's installed generation capacity is 3,223.5 MW but the actual available electricity generation is about 3,000 MW.  Peak demand is around 2,400 MW. Hydropower accounts for 84.2%, coal (8.8%), heavy fuel oil (2.8%), diesel (2.2%) and solar photovoltaic (2%).

Plan International, a non-governmental organisation, said the drought in Zambia is having “critical” consequences on energy, agriculture, water and food security.

About 9.8mn people in 84 out of 116 districts have been affected with 6.6mn people in need of support by as far back as April 2024. President Hakainde Hichilema's government appealed for $941mn to feed the hungry.

“While the imports [of electricity] are critical, they may not be sufficient to fully balance supply and demand,” African Arguments cited ZESCO spokesperson Matongo Maumbi as saying on September 11.

“Emergency power rationing remains a possibility, and ZESCO is exploring all available options to stabilise the situation.”

While September 14 is likely to be the first time in 65 years for Zambia to shutter its plant at the lake due to drought, a similarly low dam level in November 2022 led to the ZRA ordering Zimbabwe to cease generation on its facility on the southern bank of the same water body. 

Zimbabwe had depleted its share for that year but still has a little more left on its 2024 quota, the country's energy and power development minister, Edgar Moyo, told state-owned daily the Chronicle recently.

“We will still maintain our generating capacity up to the end of the year. However, we will continue to monitor our water levels against our generation capacity,” he said.

“But as it stands, I want to assure the public that we have not exhausted our generation capacity. So, we will be maintaining our production capacity although with a measure of load shedding [rolling blackouts].”

He expressed hope for a wetter rainy season to improve inflows into Kariba, resulting in water available for electricity production.

Zimbabwe's peak demand is estimated at 1,800 MW but on September 13 it was generating 1,281 MW.  Kariba was generating 215MW while the country's biggest coal-fired plant was dispatching 1,019MW.  Independent power producers were contributing the balance. 

Like Zambia, Zimbabwe also rations electricity for as long as 18 hours daily. 

Angola, Malawi, Mozambique, Namibia, South Africa, and Zimbabwe are all grappling with the impact of the drought. Namibia, Malawi, Zambia and Zimbabwe have declared states of emergency, the UN said on June 5.

Leaders from southern Africa held an extraordinary summit a month earlier to discuss the drought and appealed for $5.5bn in emergency funding to feed some 30mn hungry people and to enhance their long-term climate resilience.

Zimbabwe has experienced the detrimental effects of El Niño every two to six years since 1982, according to the UN.  El Niño is a climatic phenomenon characterised by the warming of sea surface temperatures in the central and eastern equatorial Pacific Ocean. 

“The phenomenon has been associated with prolonged dry spells, reduced rainfall, and increased temperatures. These conditions often lead to droughts, water shortages, and crop failures, posing significant challenges to health, agriculture, and food security in the country,” the world body noted on May 9.

It is estimated that in Zimbabwe some 6mn people, almost half the population, will be food insecure until March 2025 when the next harvest is expected.

The central bank has revised its economic growth forecast for 2024 from 3.5% in April 2024 to 2%, citing the adverse impact of the drought.

In Zambia, the drought wiped out up to 50% of the country’s staple crop, corn/maize, depleted water resources and prompted authorities to reduce the 2024 economic growth projection from 4.8% to 2.3%.

While hydropower production fell this year and could become more unreliable amid increasing frequency and intensity of droughts in the future, it is set to remain central to electricity generation in Zambia and Zimbabwe, said Stephen Dihwa, executive director of the Southern African Power Pool Coordination Centre, which coordinates power systems in the region.

“Hydropower has the advantage of providing clean power and yet also providing the base load and ancillary services required by power systems, which intermittent renewable energy sources such as wind and solar cannot provide,” he said, according to African Arguments.

“As such, [hydropower] will play a critical role even in future power supply.”

To lessen the impact of droughts on hydro capacity, Dihwa suggested improved forecasting and water use protocols.

“Some of the solutions are hinged on regional integration and conjunctive operation of plants on the same water courses,” he added. “Other solutions take cognisance of the fact that it’s not all the river basins that are affected by droughts in the region or they could be affected during different seasons. For example, the Congo basin in the DRC [Democratic Republic of Congo] is not affected much and ways in which this could assist plants on other basins could be pursued.”

The electricity shortage, The East African wrote on September 5, has left Zambians seeking alternatives with solar systems the most preferred.

SunnyMoney Zambia, a solar social enterprise owned by UK-based charity SolarAid, noted it has seen a 540% increase in office-based sales of its products in a year.

“Cooking was difficult during blackouts,” Abigail Mufwabi from SunnyMoney is quoted as saying. “We would depend on charcoal or wait until power was restored. Now, with the gas stove and my solar light, I can prepare meals and help my children do their homework without worrying about power cuts.”