The level of hydroelectric power station reservoirs is falling as a result of climate change and agricultural encroachment. This is reducing Burundi’s hydroelectric production. In an attempt to compensate for this drop, the Régie de Production et de Distribution d’eau et d’électricité du Burundi (REGIDESO) is resorting to thermal power stations, despite their greenhouse gas emissions. Nevertheless, the energy deficit remains. As a result, Burundians experience load shedding and untimely power cuts on a daily basis, which slows down the country’s economic development.
Dry spillway, Pebbles colonised by grass lined up one after the other and level of the lake at Rwegura hydropower station in decline…. In February 2024, the level of the lake fell by around seven metres (7m).
“Before the lake receded, pebbles were invisible. Nobody knew the shape of the funnel. We could only make out its boundary stones.”, says Jonas, an elderly man in his sixties who lives on the Rwegura hill.
Fed mainly by the Gitenge and Mwokora rivers, Rwegura lake, which lies in the north of the country around 110 km from the economic capital, Bujumbura, “often fills up in February and April”, reveals Elie, a resident of Rwegura. That’s not the case this year.
In eight years, Elie remembers seeing the lake fill up until it emptied into the funnel only twice, in 2016 and 2022.
“We are astonished to see the level of Lake Rwegura drop even during periods of high rainfall.”, says Édouard Nduwayo, a resident of Rwegura.
According to Ir. Willy Ciza, Director of Renewable Energies at the Ministry of Hydraulics, Energy and Mines: “For a power station with a dam, electricity is produced according to the amount of water stored. More water means more electricity. To meet demand, we draw heavily on stored water. If we continue to use the Rwegura dam as we are doing, the lake will not be full.”
According to Willy Ciza, Lake Rwegura is declining as a result of over-exploitation of the power station due to the growth in the number of electricity consumers. The annual report published in March 2023 by the Institut National des Statistiques du Burundi (INSBU) supports his view. It shows that the number of electricity consumers rose from 15 571 in 1995 to 163 373 in 2021.
The drop in Lake Rwegura’s water level can be explained by human activity and drought, according to Professor André Nduwimana, a lecturer and researcher at University of Burundi in the Faculty of Agronomy and Bioengineering.
“Looking at its hydrological regime, the Rwegura catchment area is fed by the Gitenge and Mwokora rivers. These two rivers are fed by run-off and seepage water.The problem now, according to a study carried out in 1995, is that when deforestation and tea plantations were introduced, these activities greatly reduced the infiltration phenomenon. Now we have run-off water. And when there’s a drought, you understand that this water that leaves is not compensated for. So the level and volume of water in the lake has fallen.”
In 2017, the drop in the lake’s water level led to electricity production of 4 MW out of the 18 MW originally forecast. “You understand that this is a huge loss for the country.”, he regrets.
According to Nduwimana, the agricultural incursions have not respected a certain distance from this basin, “especially as we are in a forest reserve”. Here, he talks about Kibira National Park.
The study of vulnerability and adaptation to climate change conducted by Salvator Sunzu Ntigambirizwa, Expert in charge of Planning and Projects at Great Lakes Energy (EGL), concludes that the over-exploitation of the Rwegura power station when the other power stations are shut down and climate change are responsible for the drop in the level of Lake Rwegura.
16 years ago, in 2008, the over-exploitation of the Rwegura hydroelectric power station combined with the effects of climate change led to a drop in the level of the Rwegura dam by around 10 m, “which was to reach the level of the water intake level of 2140.50 m, and cause the power station to shut down.”, explains Ir. Salvator Sunzu Ntigambirizwa.
As predefined by the dam builders in 1986, the level of the lake should rise to 2152.20 m.
To date, the Rwegura power station remains a typical state-of-the-art facility with a reserve capacity of 6 MW according to the Burundi Renewable Energy Association website. It cannot produce its maximum output of 18 MW all day long.
Burundi’s main hydroelectric power station, Rwegura’s electricity production has developed in fits and starts. According to the annual report of Burundi’s national statistics institute (INSBU), electricity production at the Rwegura hydroelectric power station fell from 63,732,800 Kwh in 2012 to 35,241,000 Kwh in 2017, before rising to 73,929,590 Kwh in 2021
According to Ir Salvator Sunzu Ntigambirizwa, annual hydroelectric production tends to move in the same direction as annual rainfall.
Silting
The Marangara hydroelectric power station, located about 200 km from Bujumbura, in Ngozi province in the north of the country, has been shut down due to severe water erosion.Upstream of the dam and the Ndurumu river, farmers have planted cassava fields, banana plantations and so on.
In addition, they cut down almost all the trees. The ground above the river Ndurumu has become fragile.
When it rains heavily, erosion carries tonnes of earth, stones and trees down into the valley. It cuts huge furrows as it goes. And it forms a mountain of mud and stones in the reservoir.
According to the Director of Renewable Energies, the farmers who once used the land overlooking the hydroelectric dams received compensation to free up this space. However, they took over the land again a few years later.
During heavy rainfall, » says expert Salvator Sunzu Ntigambirizwa in the study on vulnerability and adaptation to climate change, « crops weaken the soil and encourage an increase in extremely high levels of solid transport.
« This phenomenon is a direct consequence of deforestation in the hills, » he explains.
« The desander removes waste from the water in the canal. For our part, we block the channels where the water flows to clean them. However, because the channels remain open, we can’t prevent erosion from depositing fertile alluvium in them. Sometimes the earth sludge sticks to the turbines, disrupting their operation or even damaging them, » confided a technician from the power station, who requested anonymity.
“This sometimes leads to a complete power station shutdown,’ explains expert Salvator Sunzu Ntigambirizwa.
In fact, the hydroelectric power station has not been operational for around three months now, the same official from the Marangara power station told us when we visited in April 2024.
Technicians from Régie de Production et de Distribution d’eau et d’électricité du Burundi (REGIDESO) recently came to repair the turbines. However, they were unable to restore them,’ he adds.
There is as yet no database on the evolution of silting in hydroelectric power stations. However, the annual silting-up of dams in service follows the same pattern as rainfall and could lead to the shutdown of low-volume hydropower stations such as Marangara and Buhiga if appropriate measures are not taken in time, warns expert Sunzu.
During the dry season, around a third of the lake’s surface area shrinks as a result of the reservoir drying up, our source tells us. Part of the lake, which was previously full of water, is now overgrown, » he continues.
This situation is the result of soil erosion. This leads to a reduction in hydroelectric production,’ says expert Salvator Sunzu Ntigambirizwa in his study.
According to the INSBU’s annual report published in March 2023, electricity production at the Marangara power station is falling. In 10 years, it has plunged by 454.7% between 2012 and 2021, from 1,393,836 Kwh in 2012 to 306,480 Kwh in 2021.
When Marangara was inaugurated in 1981, “it supplied electricity day and night to three communes, including Marangara, Ntega and Kirundo.”, says Claver Siboniyo, who lives near the Marangara power station.
Currently, it only lights Marangara when it is operational. What’s more, we’re experiencing untimely power cuts. “The Rwegura hydroelectric power station had to take over from Marangara in the communes of Kirundo and Ntega.”, he adds.
Flooding, another challenge
The Ruvyironza hydroelectric power station, located on the river of the same name in Gitega province in the centre of the country, was out of service between 2004 and 2007, when it was rehabilitated, due to flooding during heavy rainfall.
The Third National Communication on Climate Change states that serious flooding of the Ruvyironza hydroelectric power station has also occurred three times, in 2014, 2016 and 2018.
The floods of 18 April forced the Ruvyironza hydroelectric power station to cease all production, says Avit Nibaruta, REGIDESO director for the central region. « The 1.5 MW of electricity produced suddenly evaporated« .
According to INSBU, Ruvyironza production is volatile. It rises and falls depending on whether there is enough rain or not. It rose from 6,594,710 Kwh in 2012 to 8,237,200 Kwh in 2015, before falling back to 4,686,100 Kwh in 2021.
Burundi’s National Development Plan (NDP) 2018-2027 states that only 300 MW of the country’s estimated 1,700 MW hydroelectric potential is technically and economically exploitable. Installed electrical capacity is currently close to 50 MW, including 32.9 MW of national production from hydropower.
Electricity consumption in Burundi is very low. It is less than 30 KWh/inhabitant/year. This is below the African average of 150 kWh/capita/year, according to the 2018-2027 NDP.
It is also because of poor access. The World Bank shows that Burundi’s electricity access rate is 10.2% in 2021
Until now, the electricity deficit is obvious. It manifests itself in widespread and systematic load shedding.
To cover its electricity needs, Burundi imports energy from the Rusizi I and Rusizi II community hydroelectric power stations, which have a capacity of 4 MW and 8.3 MW respectively.
Nevertheless, the drought and rainfall deficit led to a reduction in electricity production at the Ruzizi II and Ruzizi I hydroelectric power stations of 32% and 14% respectively.
To compensate for the drop in hydroelectricity, electricity network operators, such as REGIDESO and private individuals, are activating thermal power stations and generators, powered by fuel. These generate more than 35 MW of electricity.
However, thermal power stations and generators emit more greenhouse gases. Although Burundi emits less than 0.02% of greenhouse gases (GHGs), the energy sector accounts for the lion’s share. It represents 43% in 2005, 36% in 2010, before reaching a peak of 45% in 2015. What’s more, the supply of electricity, whether from renewable or thermal sources, remains insufficient.
To increase hydroelectric production, Burundi is building hydroelectric power stations, “in particular the Rusumo Falls regional dam and Kabu16, Jiji Murembwe and Ruzibazi local dams, according to the Director of Renewable Energies.”
Soon – in around 3 years’ time -, “we’ll be adding more than 80 MW of power. We’ll be transporting it and distributing it to REGIDESO households and customers”, continues Willy Ciza.
Electric transport
However, electric transport still faces a number of challenges in both rural and urban areas. Top of the list of challenges is the climate.
Climate change is also having an impact on the transmission of electricity across the country. Power lines have collapsed as a result of excessive rainfall, often accompanied by hail and violent tropical storms.
For example, during the night of 12 to 13 March 2024, exceptional rainfall combined with very violent storms toppled the pylons carrying electricity to the Nyakabiga III district, in the Mukaza commune of the Bujumbura town hall in western Burundi, near the Mutanga Campus of the University of Burundi.
“We heard something falling during the night. Then darkness set in. We didn’t realise until this morning that the pylons had collapsed.” says Innocent ndayikengurukiye, a resident of Nyakabiga III. »
Three days after the pylons collapsed, REGIDESO restored the network.
Neither the children nor the adults could contain their cries of joy when REGIDESO once again lit up Nyakabiga.
The Renewable Energy Director also points out that the Ruzibazi dam is at a standstill following the collapse of the Gabaniro hill, in the commune of Muhuta, in Rumonge province in the south-west of the country, which was supporting the electricity transmission poles.
“REGIDESO is working to re-establish the network so that we can have the 15 MW from this dam.”, he comments.
Because of climate change, the inadequacy of the distribution system, which is very small, and ageing cables, the technical and commercial losses of electricity vary between 20% and 30%, estimates the Director of Renewable Energies based on annual reports.
Ir Salvator Sunzu Ntigambirizwa, for his part, points the finger at inadequate maintenance and various forms of fraud.
To distribute electricity properly, Willy Ciza tells us, you have to replace old and small cables with cables that have a good cross-section.
There is an urgent need to rehabilitate distribution equipment, particularly in Bujumbura and other towns with large numbers of customers.
Ciza is calling on the private sector to invest in electricity distribution. Currently, a few companies have invested in electricity transmission. These include Burunga Power. It is implementing a Maison Power project to distribute this energy, which will be circulated.
Untimely power cuts, a source of misunderstanding between service providers and customers?
Since the beginning of 2024, untimely power cuts have been frequent in both urban and rural areas. day and night. The burden of widespread and systematic load shedding is being felt. Economic operators are bearing the brunt.
On forced leave, sitting on the sofa outside his hairdressing salon, Goldien listens to the soft music on his phone through the headphones. He is eagerly awaiting the arrival of electricity on Monday 29 April in the Kajiji district, Kanyosha zone and Muha commune in the south of the economic capital, Bujumbura, to welcome his customers.
This hairdresser has noticed unusual and systematic power cuts recently: « There are at least four power cuts a day. We’re put on forced leave every day. »
“Due to untimely power cuts, we are incurring significant losses. On the other hand, the owners of the houses insist that there are no late payments of rent despite the power cuts.”, says Goldien.
After graduating from university in 2023, Ezéchiel and Aline enthusiastically invested in public secretarial work. Their business was barely up and running when the power cuts began. ‘We can go all day without working because of the power cuts. If God doesn’t work miracles, we’re two steps away from locking up our business,’ complains Aline.
Rent costs for the public secretariat and their home mean that Ezéchiel and Aline are between a rock and a hard place if nothing is done immediately to stop the power cuts. They are currently struggling to make ends meet. What’s worse is that the incessant power cuts have damaged their electronic equipment. They don’t see how they’re going to replace their equipment.
Evelyne, who runs a pastry shop, has just thrown away over 100 litres of milk after it deteriorated due to power cuts. “It’s a huge loss for us.”, she says bitterly.
In the centre of the country, in Gitega, the political capital, Cédric Hakizimana describes his despair: ‘We spend up to three days without electricity.”
Nowadays, business is slowing down. This is leading to misunderstandings between welders and their customers: “We’re always late in delivering our customers’ orders. This puts us in confrontation with our customers. Customers whose orders are due to be delivered threaten us with a refund. They think it’s down to us, when in fact it’s down to a lack of electricity.”
Félicité Nicayenzi: ‘We’re having trouble getting our milling machines to work because of the lack of electricity, so our business is at a standstill.
To continue operating, public secretariats, hairdressing salons, etc. are switching on generators. However, they are increasing the prices of their services. Printing a page has gone up from 100 to 150 FBu, hairdressing from 2000 to 3000 FBu, and so on.
Call for Action
Félicité does not know the cause of the frequent power cuts. As for Pierre Hakizimana, a welder close to Gitega’s central market, he implores the authorities to take immediate measures to alleviate the energy crisis.
In response to these complaints, the Director General of REGIDESO, Ing. Major Albert Manigomba, told Radio Bonesha Fm in March that the incessant power cuts were due to tests on injecting electricity from the Rusumo Falls and Kabu16 dams.
« We are currently testing the Rusumo Falls and Kabu16 power stations. These tests involve cutting off some outgoing feeders because we have to rehabilitate our equipment, modernise it and adapt it to receive this energy. »
Testing power stations takes between three months and a year. Today, while I’m talking to you, we’re testing three Rusumo Falls generators on the Tanzanian grid,’ continues Manigomba.
These tests often mean that our network is disrupted or unbalanced. The Director of REGIDESO is keen to reassure the population and has promised that by the end of April, power from Rusumo Falls will be restored to 27 MW every day. However, power cuts and load shedding are still being experienced throughout the country until June.
In the public broadcast hosted by the ministers on 28 June in Makamba in the south of Burundi, Ibrahim Uwizeye, Minister for Water, Energy and Mines, said that the turbines at the Rusumo Falls power station had broken down. Technicians are in the process of restoring them. He promises that the first turbine will be operational at the beginning of July.
What can be done to protect hydroelectric dams?
To raise the water level in the Rwegura basin, André Nduwimana proposes effective water management throughout the catchment area:
‘A buffer zone should be created around the water retention basin that feeds the Rwegura dam to allow infiltration during the rainy season. When there is a high level of water infiltration during the rainy season, the water from the water table will compensate for the evapotranspiration during the dry season’.
The director of renewable energies says that dams should be built to store water efficiently. Salvator Sunzu Ntigambirizwa adds: ‘REGIDESO should look into ways of enabling dams to store water more efficiently during rainy periods, so that it can be reserved for use during droughts.
REGIDESO and Agence Burundaise de l’Electrification Rural (ABER), with the support of the local administration and the grassroots population, should prohibit crops from being grown near the reservoirs and extend the protection zones around the dam and the power station, as was done at the Mugere hydroelectric power station. Ntigambirizwa recommends reinforcing the retaining wall around the power stations to protect them from erosion. Farmers need to dig out the contour lines to reduce erosion,’ he concludes.
Prof. André Nduwimana is urging REGIDESO to set up the buffer zone and reforest it, as this will help purify run-off water. In addition, he recommends growing the fixing grasses that try to retain the soil. This will protect against erosion from the hills and, in turn, from the dams.
What about flooding? Pr Nduwimana suggests that a small tax should be levied on the water and energy consumed to rehabilitate public infrastructure affected by climate change, because the lack of financial resources at local level means that this cannot be done.
This survey was conducted by Arthur Bizimana and Ferdinand Mbonihankuye with the support of the Network of French-speaking Science Journalists of Africa (RJSAF) as part of the investigation grant from the World Conference of French-speaking Science Journalists.