When Lake Tanganyika rose around Gatumba, families did what they could to survive: they carried belongings to higher ground, abandoned flooded homes, and in many cases left the area altogether.
For some, leaving was not the end of the story. They returned when the water receded, rebuilt what they could, and tried to resume their lives only to face the same choice again in the next rainy season.
That cycle has exposed a problem larger than any single flood: in one of the world’s lowest-emitting countries, entire communities are absorbing the cost of a changing climate they had almost no role in creating.
Burundi contributes less than 0.02% of global greenhouse-gas emissions, according to World Bank analysis, with per-capita emissions estimated at just 0.8 tonnes of CO₂ equivalent in 2018 a fraction of levels in wealthier economies. Yet the country ranks among the most vulnerable in the world to climate-related disasters, and nowhere is that imbalance more visible than in Gatumba, near Burundi’s border with the Democratic Republic of Congo, where repeated flooding has damaged homes, farmland, infrastructure and livelihoods.
Between September 2023 and September 2024, more than 298,000 people across Burundi were affected by torrential rains, floods, landslides and the overflow of Lake Tanganyika, according to UNHCR. Homes, classrooms, health facilities, roads, crops, water networks and electrical infrastructure were damaged or destroyed.
For families in flood-prone communities, the toll isn’t only structural. It shows up as lost farmland, interrupted schooling, displaced livelihoods and repeated moves in search of somewhere safe to live.
Gatumba was among the hardest-hit areas during the 2023-24 flooding. UNHCR reported that 1,938 people from 728 households affected by the El Niño-driven floods were voluntarily relocated from Gatumba to Mubimbi, in Bujumbura. An earlier regional assessment by the agency had already put the number at 936 households relocated, with plans at the time to move as many as 2,000 households in total.
Those figures point to a crisis that has stopped behaving like a temporary emergency. Relocation offers immediate safety, but it also separates families from homes, farms, businesses and the communities they’ve built their lives around — and when water levels eventually fall, returning does not mean returning to the life that existed before.
A shared lake, a global imbalance
Lake Tanganyika is shared by Burundi, the Democratic Republic of Congo, Tanzania and Zambia, so changes in its water level carry consequences across all four countries’ shorelines. During the 2023-24 crisis, rising lake levels combined with heavy rainfall and river flooding to overwhelm low-lying communities on the Burundian side.
That experience underscores why Burundi’s climate vulnerability can’t be understood through its own emissions record. A separate World Bank analysis found that the country’s mean temperature rose by roughly 0.31°C per decade between 1979 and 2018, a warming trend layered onto what the Bank describes as a negligible carbon footprint paired with very high climate vulnerability.
That’s the central contradiction facing Burundi: a country that has contributed almost nothing to the greenhouse-gas buildup driving global warming, but whose largely rural, agriculture-dependent population is exposed to its consequences all the same.
The next test is approaching
The more urgent question now is not what happened in the last major flood, but what’s been done since because another rainy season, and the risks that come with it, is already on the way.
The IGAD Climate Prediction and Applications Centre (ICPAC) said in its latest outlook that the Greater Horn of Africa is expected to see wetter-than-normal conditions between October and December 2026, with a high likelihood of seasonal rainfall exceeding 400 millimetres in parts of Burundi, the Lake Victoria basin and neighboring areas. The World Meteorological Organization said in September that the El Niño driving that outlook is expected to intensify further and persist into early 2027, with the potential to significantly disrupt rainfall and temperature patterns and raise the risk of extreme weather.
A forecast is not a guarantee, it does not mean Gatumba will flood again this year. But for communities that have already been displaced once, twice, or more, it is advance warning that preparedness can no longer wait for the water to rise first.
