Ntahangwa river, one of the affluents of Lake Tangayika, threatens households as residents are forced to relocate. According to natives, the plea has been haunting them for years.
Mugoboka I Quarter located in the south of Mutanga Zone, eastern Bujumbura City is on the verge to collapsing as results of constant landslides observed.
In the east, Mugoboka is encircled by a small riverbank, a common tiny-ravine locally known’’ Kamugoboka’’. In the west it borders another ravine locally known ‘’AGENA’’. In the north it flanks the Ntahangwa river and in the south, it borders on Murya Pirina cemetery.
It is 10 a.m in Mugoboka I Q, western Bujumbura City. The weather is sunny and dusty. Some pedestrians are wearing hats as they commute to protect themselves from sun while others are not wearing any head coverings.
At the small market situated just a few meters away from the extensive ravine, vehicular movement is relatively restricted. Car owners disembark from their vehicles and must make their way home on foot.
The north area is exceedingly battered by the constant landslides.
The landslides observed in the northern Mugoboka are gradually extending at a high level ever recorded, according to residents.
Before its devastating landslides to appear
Mvomayogusesa Anatole,61 born in Mugoboka, is a mother of 9 children. Before Ntahangwa river fell, it was well set and the situation was stable.
“I am a native of Mugoboka, a 10th child in our family. When we were too young, there were very few people,” said Anatole.
Mugoboka, a small mountainous hill, had less residents most of them natives and Congolese’s, he said.
As Anatole reported, the gradual landslides began to expose with the falling of Ntahangwa river.
In 1983, Ntahangwa river started to descend slowly, according to experts betting on the effect oof climate change while residents associate it with spirits.
“They told us they were demons who were looking for refugee into the valleys and on the edges of the river, therefore the mountains would be cracked, that’s how we were told”.
The situation aggravated deliberately 1997.
“During a 1972’s civil war, we took refuge at Kanga northern Bujumbura city. Amid 1993 we came back to our respective home. After 4 years amid 1997, the river downward slope escalated at high level,” said Anatole.
On the shores of Ntahangwa river, houses and schools were there. Babembe, one of Congolese tribes, had banana cultivation.
The residents urge that the early warning and hazardous signs appeared for the first time in 2002 but they could not think that the landslides would escalate at high level to the point of falling.
Economic crisis as results of the landslides
A lot of residents lost their properties and pieces of land following the landslides as they moved to other localities.
“In that time, numerous plots were not registered in cadastral plan so that they would get compensation. Therefore, many landlords lost their pieces of land. The government at the time helped nothing”.
Besides that, Anatole says that they had water supply but following the continual landslides, the pipes carrying water supply were ruined.
“Prior to these hazardous landslides, we had water supply but now it is not the case. Cars can’t reach a remote area. Before, we had a public phone to use for emergence case”, she said.
In the past we had not cars to carry goods for us, no. We had to carry them on head, said Butoyi another resident.
“As Burundi faces the highest cost of living ever recorded, in Mugoboka, the situation is alarming as the bridge linking Mugoboka I and Mugoboka II has been critically destroyed,” said Jean Marie Sabushimike, Lecturer at the National University in Department of Geography.
Mugoboka I delimitation and the loss already recorded following the continual landslides notably in northern area, he added.
For example, said Jean Marie, there are roads and schools that have deported by landslide. As of the road and bridges, they linked Mugoboka I and Mugoboka II which is no longer exists due to banks overflowing, which later on caused a road to collapse, he concluded.
Landslides in a nutshell
According to environment experts, landslides are movement of a mass of rock, debris, or earth down a slope. of “mass wasting,” which denotes any down-slope movement of soil and rock under the direct influence of gravity.
Environmentalists associates the term “landslide” to five modes of slope movement including falls, topples, slides, spreads, and flows.
“These are further subdivided by the type of geologic material (bedrock, debris, or earth). Debris flows (commonly referred to as mudflows or mudslides) and rock falls are examples of common landslide types,” said an independent environmentalist, Claver Rurihose.
However, according Sabushimike, almost every landslide has multiple causes. Slope movement occurs when forces acting down-slope (mainly due to gravity) exceed the strength of the earth materials that compose the slope. Causes include factors that increase the effects of down-slope forces and factors that contribute to low or reduced strength.
“Landslides can be initiated in slopes already on the verge of movement by rainfall, snowmelt, changes in water level, stream erosion, changes in ground water, earthquakes, volcanic activity, disturbance by human activities, or any combination of these factors,” said Sabushimike
Earthquake shaking and other factors can also induce landslides underwater. These landslides are called submarine landslides. Submarine landslides sometimes cause tsunamis that damage coastal areas, he concluded.
The current situation from 2018
In fact, in 2018, the road leading to Mugoboka II through the coordinate points, was trafficable but about few miles away there was an extensive havoc wreaked.
Ravine gradually extended and now the road is not trafficable.
As reported by former ministry of Agriculture and livestock Albert Mbonerane, president of Action Ceinture Verte (ACV), the landslides in that area occasionally blocked the road’s traffic. The houses are on verge to collapse. The supplying pumps are critically ruined.
“The damages are constant till now as heavy rains usually multiply overflowing which ultimately provoke the soil to crumble” he said.
So far, in Mugoboka especially at a highly- battered area, a lot of houses, both public and private infrastructures, a small church, shops, a health center, etc., have been intensely ruined
“The environment is totally threatened. The inhabitants of the area profit the ravine to throw the trash away which contribute to the Ntahangwa River pollution”, said Mbonerane.
After the road closure, traffic has become a rocket science. The residents of Mugoboka I & II, Bisekuro and Mirwa ingeniously maneuver through the narrow passage which winds its way through houses. The residents nicknamed the situation ‘’human traffic jam’’ due to the stampede.
A lot of residents live in run-down buildings.
The government’efforts to curb the situation
After the population calling for the government’s urgent landslides mitigation measures to prevent as early as possible the people’s welfare, the government through the national agency for road construction (ARB), has recently initiated the activities to rehabilitate the battered- road following the landslides.
The residents now salute the state’s efforts made to bring the situation at normal state.
Human action: the source of anger in the River Ntahangwa
“People who extract rubble, sand, gravel and stones from the river are making the situation worse. They’re doing it so badly that the riverbeds are becoming very wide and therefore fragile,” says Jean Marie Sabushimike.
As a result, he added, even the trees planted to protect the river banks are often swept away by the water. The speed of the water becomes high, destroying the banks and widening the riverbed.
Professor Sabushimike said that the behaviour of the Ntahangwa River starts upstream in the foothills overlooking the city of Bujumbura. He pointed out that the mountains influence rainfall dynamics.
“As the soil is not protected by plant cover, its structure and steep slopes mean that the run-off coefficient is higher than the infiltration coefficient,” he said.
For Ambassador Albert Mbonerane, the river is in revolt, and now soon or later its voice is going to be heard for years, and with great anger.
“If nothing is done in the immediate future, many homes and public infrastructures will be washed away by this river, which has already caused a great deal of damage”, he concluded.
