Life on the levee: Extreme flooding in South Sudan

Around 20 men, waist-deep in water, work hard to dig a ditch around a mound of mud that extends as far as the eye can see. The group knock pieces of wood into the ground and flatten plastic tarps to reinforce the mound, which is actually a series of dykes, strengthened in 2022 by the World Food Programme (WFP) team to cope with floods then described as unprecedented. This scene takes place in August 2024 in Old Fangak, in South Sudan’s Jonglei state.

In a remote part of northern South Sudan, the town of Old Fangak is situated in the Sudd marshes, one of the largest wetlands in the world. Spanning about 25,000 square miles, this vast network of rivers, swamps, and floodplains borders the White Nile, which originates in Lake Victoria, Uganda.

In May 2024, the South Sudanese government alerted the international community about the risk of exceptional floods in the months ahead. Since July, water levels have increased by an average of 1 centimeter per day in Old Fangak, surpassing levels seen in 2021 and 2022. By August, most villages surrounding the town were under water, forcing residents to evacuate to safe places such as Old Fangak, New Fangak, Tongal, and Malakal. Old Fangak has taken in more than 6,000 displaced people.

A backdrop of violence and displacement

“Old Fangak is considered a refuge by the inhabitants of the region,” explained Pareil Magany Yieh, a supervisor for the Relief and Rehabilitation Commission. “Most of those who fled Bentiu or even Malakal because of war came here, and years later, some of them are still living with us.”

Despite a ceasefire and a power-sharing agreement that came into effect in February 2020, armed clashes continue in several regions of the country. Two years after South Sudan’s independence in 2011, a war broke out between the two groups that shared power at the time. The rivalry between President Salva Kiir and Vice President Riek Machar plunged the country into war and revived ethnic tensions between the Dinkas—Kiir’s ethnic group and the largest community in the country—and the Nuers, the group to which Riek Machar belonged.

MSF teams have worked in the area since 2014, when we first began supporting Old Fangak Hospital. Since then, MSF has expanded operations and now also runs mobile clinics for communities living along the Phow River and the White Nile, reaching them by speedboat. Despite severe flooding around the town, Old Fangak Hospital remains operational as MSF teams continue to treat patients primarily for malnutrition, malaria, and waterborne diseases.

Between January and August 2024, MSF teams in Fangak county vaccinated more than 12,500 women against hepatitis E, an infectious disease that has affected people in South Sudan for several years, particularly in the states of Jonglei, Warrap, Unity, and Western Bahr El Ghazal. “In the short term, flooding leads to a risk of pneumonia, bacterial skin infections, diarrheal diseases, cholera, and hepatitis A and E,” said Léo Tremblay, head of MSF’s Humanitarian Action on Climate and Environment (HACE) unit. Previous outbreaks of hepatitis E in the region—in 1988, 2004 and 2012-13—were all associated with flooding and displacement.

“Floods have an ongoing impact on access to health care, and lead to delays in the diagnosis and treatment of non-communicable diseases such as diabetes and hypertension,” added Tremblay. In the longer term, heavy rains and flooding can lead to an increase in the mosquito population and a heightened risk of vector-borne diseases such as dengue fever, malaria, and yellow fever. They also increase people’s exposure to chronic health issues such as schistosomiasis, a disease caused by parasitic worms.

“We are seeing the cumulative effect of the floods of recent years,” says Mamman Mustapha, MSF’s head of mission in South Sudan. “People in this area have been displaced several times since 2022 and arable land has [decreased], as have food rations provided by WFP. Communities are constantly having to move to a new location, not knowing if they will be able to harvest what they have been able to sow.” 

One of the largest wetlands in the world

Flooding is part of the Sudd’s ecosystem. Fluctuations in the water level of Lake Victoria upstream, as well as seasonal variations in rainfall, particularly during the rainy season from May to October, lead to significant variations in flooded areas from year to year. The Sudd is located in a depression and acts as a reservoir for the White Nile, filling with water during the rainy season and partially emptying into the river during the dry season. The region’s flat topography and impermeable soil hinder water drainage, resulting in prolonged flooding.

While the Sudd’s flooded area is around 18,600 square miles, it can reach close to 80,000 square miles at its peak, close to the size of Greece. Major floods have been documented here since the late 19th century.  Flooding can increase the water surface area for several years at a time, reducing the land available for grazing, cultivation, and housing. This leads to tensions between local communities including the Dinka, Nuer, Anuak, and Shilluk.

Previous floods have caused displacement, damage to roads and public infrastructure, and difficulties in accessing health care. Food reserves, livestock, and arable land have been destroyed on a scale not seen before by community elders. Between May and September 2021, more than 174,000 people were displaced by the floods in Jonglei state. At that time, Fangak and Ayod counties were the hardest hit. MSF launched an emergency response, providing medical care and vaccinations and distributing essential relief items to communities in the region.

“When it happened for the first time, you were not even born,” said John Yuot Ruot, who is from Wangchoat village in Jonglei state. “Our parents used piles of grass and branches to protect themselves from the water and stay dry. It was devastating. Then we started building dykes to protect the village.”

Many villages that were previously accessible by foot have become isolated islands that can now only be reached by boat. To protect themselves from the floodwaters, many communities build dykes out of mud because it is the only material available to them. 

Extreme flooding and climate change

South Sudan is currently considered both the country most vulnerable to climate change, and the country with the least capacity to manage and adapt to its consequences. Over the past 30 years, South Sudan has experienced some of the world’s fastest rates of global warming, with temperatures rising up to 0.53°C per decade. Across large parts of the country, temperatures have increased by more than 1°C.

South Sudan is also affected by El Niño and the Indian Ocean Dipole, two weather phenomena that frequently coexist in the tropics, leading to significant changes in climate on both a regional and global scale. Long-term climate projections  forecast more precipitation in some regions of South Sudan and upstream of the Lake Victoria basin. "El Niño and the positive Indian Ocean Dipole, especially when concurrent, accelerate this trend over a short period," explained Tremblay. "When these events occur, they bring more upstream rainfall."

In late 2018 and early 2019, the combination of El Niño and a positive Indian Ocean Dipole brought heavy rains to the Lake Victoria basin and led to massive flooding in the Sudd region over the following years. "The level of Lake Victoria is a crucial factor for MSF projects around the White Nile, such as those in Leer, Bentiu, Aweil, Malakal, and Fangak," said Mustapha. "The country also experiences frequent droughts, particularly in the south and northeast, which affect the mobility of herders and farmers who depend on pastures and agricultural land to survive."

In March 2024, South Sudan experienced extremely high temperatures countrywide as part of a larger heat wave that affected East Africa. Temperatures reached 45°C in some regions, leading to travel restrictions as well as the closure of schools and businesses in some areas. In the past 40 years, South Sudan has experienced long periods of drought, affecting more than 50 percent of the country, including in 1984-86, 2004-07 and 2008-09. The 2017 drought was concentrated in the eastern states.

“After long periods of drought, the soil becomes even drier, harder, and less permeable, leading to increased runoff and decreased soil absorption, which in turn exacerbates the risk of flooding,” said Tremblay.

According to the Centre for Research on the Epidemiology of Disasters, the frequency of natural disasters of hydrological origin (e.g., floods, landslides, and mudflows) has doubled over the past 20 years. “People living in Old Fangak and more generally in the Sudd region are among those who have contributed least to climate change but are suffering its worst consequences,” said Mustapha. “As such, they should be prioritized and directly compensated through the loss and damage fund* currently being set up, or through any other mechanism.”

An underfunded humanitarian response

Humanitarian needs, particularly those related to nutrition and health, continue to grow across South Sudan, yet further funding cuts are expected this year. As of September 2024, the Humanitarian Response Plan for South Sudan was only half funded, while that of 2023 was funded at just 56 percent.

“Malnutrition rates in South Sudan are among the highest in the world and, without additional funding, vital interventions for children and mothers suffering from malnutrition are threatened,” warned Yusra Shariff, MSF humanitarian affairs coordinator in Juba. Due to decreased funding, the WFP, for example, can only provide half the food rations in certain areas and is forced to prioritize the most vulnerable people. This neglects those with less severe health conditions, risking the deterioration of their health.

"People in Old Fangak still need more material to reinforce the dykes, such as wooden poles and ropes," said Mustapha. "Our outreach teams have also been seeing worrying signs of malnutrition among children in the surrounding villages. A significant increase in humanitarian funding for food and nutrition programs is crucial to sustain access to food amid ongoing displacement and economic challenges."

According to the UN, 735,000 people are currently affected by flooding across nearly half of South Sudan’s 79 counties.

* In 2023, COP28 agreed to establish a loss and damage fund to help developing countries cope with the effects of climate change. Esther Duflo, winner of the 2019 Nobel Prize in Economics, proposed an alternative mechanism, advocating for direct cash transfers to individuals funded by taxes on multinational corporations and billionaires.