Unstable temperature conditions throughout the year drove water variations in the lake as every year the waterbody overbanked which is at the helm of nasty socio-economic and biodiversity shocks.
Between February and May since 2018, Lake Tanganyika must rise, forcing proxy residents to displace until it calms down. The case of Gatumba.
Not only for Gatumba but also for Kibenga lac residents. Houses have been chased by water.
According to people who fled, it has cost them a lot of money, from their investment (loans taken to build) to relocating to becoming rentees.
“The main problem is not the cost but being unstable. It has been three years that I am in and out. At first, I relocated for three months until June and came back thinking that the problem is over but the next year, the same scenario occurred”, said Nzeyimana Paul, resident of Kibenga who lives in Kanyosha now.
Six years ago, It [Lake Tanganyika] started to rise and reached its highest level in May, 2021, up to 776.58 meters, which is 3.58 meters higher than the normal situation of 773 meters of surface elevation.
As of March 18, 2024, the lake is at a level of 776.74 meters, which is 3.74 meters higher than the normal situation.
“This means that all Burundian, Zambian, and Tanzanian lands below this altitude are underwater. From the small Rusizi River separating Burundi and the DRC to Kabonga, many properties are heavily impacted, including the port of Bujumbura”, said Bernard Sindayihebura, a professor at the University of Burundi and an environmental and territorial planning specialist.
Port infrastructures on the balance
For him the port is at risk as it is built 777 meters above the shoreline. It is 26 centimeters away from being completely flooded, he said.
This port is threatened, and the lake is currently at 776.74 meters compared to today’s situation, which means it is 26 centimeters away from being completely flooded,”.
As a matter of fact, some infrastructures have started to shuttle on its south side, the bank cannot hold the strength of water, added Bernard.
Apart from the port itself, warehouses H 7.8 and 6 at the port of Bujumbura are overflowed with water from the south side because the concrete wall, installed in 1964 to protect the port buildings, has multiple holes.
Mr. Sindayihebura thanks the government, which has just started work by placing rocks, especially to protect the road that connects the Navy to the Burundi Revenue Authority (OBR), which unfortunately relocated since March 12.
He also recommended protecting the road by building dikes for its rehabilitation as well as the dike located inside the navy compound, which protects the dock.
“If this is not protected, the boats could float, which is dangerous and can cause heavy loss. However, the dock is damaged in several places, and it urgently needs to be mended,” said Bernard Sindayihebura.
The rock placement work and the construction of the dike, with a variable width of 7 to 6 meters, are currently underway from the La Pirogue bar-restaurant and will run along the coast to the Navy office to protect the latter, the port of Bujumbura, and the area known as Safi Beach.
Worst at the door in May,
According to Sindayihebura, by May the tendency on this speed will be that 90% of the water will reach the maximum level 777meters.
He requests that the sector ministries urgently send their technicians, especially engineers, to assess the public assets and infrastructure that could be damaged.
According to him, May represents heavy rain, that is precipitation that feeds the lake will increase, and the decrease is related to evapotranspiration, which is lower.
From March 31st to April 7th, 2021, Lake Tanganyika rose up to 6 cm, which is an increase of 6.7 mm per day while between April 7th and 15th of the same year it grew up to 12 cm, which is a daily increase of 8.6 mm.
“I take measurements very regularly, and this data will help us understand the rise of the lake level, stop it, and inform the population to ensure their safety”, said Eric Mateso, representative of Burundi Institute of Geography at the port.
According to projections, the lake could reach 777.12 meters at shore. However, if there is less precipitation, it may not reach this figure, Professor Sindayihebura clarified.
According to information from the IGEBU (Geographic Institute of Burundi), the expected precipitation will be above normal, which is why the lake level continues to rise.
For environmentalists, the rise is due to high temperatures as a result of the effect of climate change.
In addition, recent research has established that climate has an influence on the hydrodynamic, physicochemical, and biological parameters (in particular the plankton) and that all these phenomena are closely linked in Lake Tanganyika
Lake Tanganyika temperatures range between 23 °C and 28 °C, but for the last 5 years it added 1.3°C at the surface while it added 0.2°C in deep waters. Aquatic species have been the most endangered, especially small fish that live at 0-100 metres depth.
“It is hard to breed for fish. When water rises it washes their eggs where ponded”, said Jean Marie Sabushimike, Environmentalist and Lecturer at the National University of Burundi in Geography Department.
For him, they will wait to pond in the next months and if they do not die they are forced to run away or simply migrate.
Those thrown in the marshland near the lake die at the banks when water regains the lake, he said.
Sabushimike said also that another problem is air temperature increase which causes water temperatures to high as well.
As water temperatures increase, water pollution problems will increase too, and many aquatic habitats will be negatively affected, he concluded.
