At the southern end of the majestic Lake Kivu bordered by green hills, a compact sheet of plastic waste is constantly forming, to the point of blocking the turbines of the largest hydroelectric power station in the east of the Democratic Republic of Congo.
The Ruzizi dam attracts like a magnet the thousands of bottles, cans, and other rubbish thrown into the lake which stretches for some 90 km on the border between the DRC and Rwanda.
"As the lake flows towards the Ruzizi River, little by little all the waste that is thrown there comes to fail here", explains an AFP team Liévin Chizungu, production manager at the Ruzizi 1 power plant. Even those coming from Goma, just north of the lake.
The mountainous relief and the rainy climate of the city of Bukavu do not help. "The rainwater carries the waste, which ends up in the lake and then in the river", also explains the engineer Jovy Mulemangabo, responsible for South Kivu of the National Electricity Company (Snel).
According to Mr. Chizungu, this waste is piled up in the facilities "at a depth of 14 meters". Divers must clean the bottom of the river to prevent the turbines from being clogged and the towns in the region without electricity, he adds.
Byunanine Mubalama, clears as much as he can on the surface, in a boat. "I've been doing this job for 13 years... Every day there's garbage that I have to clean up," he says.
But nothing helps. Since the end of January, one of the four groups of the plant, damaged by the waste, has been shut down.
"The impact is huge, we have a deficit of 6.3 megawatts out of a total of 30 MW that we have to produce, not only for the province of South Kivu, but also for the neighboring province of North Kivu and Burundi. “Very close, notes the production manager.
With an alternator failure at the Ruzizi 2 power plant, about 25 km south of Bukavu, also caused by waste, a total of 20 MW is missing from the distribution network, also indicates the provincial manager of Snel.
This leads to "a lot of load shedding in the cities of Bukavu and Uvira", he regrets.
Raising awareness, depolluting
What to do to remedy the problem? "First, educate the population, tell them that the lake is not the place to throw waste", no more than "the channels which in the end come to flow into it", suggests Liévin Chizungu. The authorities must crackdown, he said, by taking sanctions against "people who throw rubbish into the lake".
"Our houses are stuck together on small plots, there is no way to manage the household waste and I have no choice but to throw it in the Kawa river which overlooks the lake", justifies a resident of the lake, Mathilde Binja, housewife.
Malgache Malyanga, head of the Household Waste Management Program (PGDM) in Bukavu, affirms for his part that his structure takes care, among other things, "of the collection and evacuation of the city's waste", for 3 $5 per month per household.
But "is it for lack of means? Or by ignorance? Many inhabitants prefer to throw their garbage overnight on the road or in the lake, for those who live near it".
Nicole Menemene, 29, picks up plastic waste on the shore of the lake to make "baskets, flower pots, trash cans, stools, pedestal tables...".
At the head of a private company, Plastycor, and a team of ten people, she deals with the recovery of this waste, transformed into "useful and beautiful" objects.
"The work is done by hand", but the ideal would be "to industrialize what we do", underlines the business manager, who would thus like to contribute to "a 90% reduction in the pollution of Lake Kivu".
At the beginning of March, the United Nations launched negotiations in Nairobi for a global treaty against plastic pollution, to fight against this scourge that threatens the environment and contributes to the collapse of biodiversity.