After a few days of respite, the rain resumed in Abidjan. A tropical rain, thick and warm, the season of which is customary. The average precipitation in the metropolis in June is 300 mm. As always in such circumstances, the streets of the Ivorian economic capital are emptying, those who can are caulking themselves. We watch, in the media and on social networks, the accidents that follow one another. In 2022, 19 people had died during the rainy season. This year, the toll is already heavier.
At least 10 people were killed on the night of Thursday July 6 to Friday July 7, including nine in landslides and rockslides in the town of Yopougon, according to Ivorian firefighters. A last victim was washed away in that of Cocody. His body was found in a gutter.
A month ago, on June 10, the authorities already announced that 15 children had died because of bad weather, under their collapsed house, by drowning or electrocution. The following day, a family of five, a couple and their three children, were killed in a landslide in Yopougon, in the misnamed neighborhood of Millionnaire-Extension. “The tragedy occurred at 1 a.m., says the president of the Young people of the district, Mamadou Diomandé. When we got there, there was debris everywhere. By the time they cleared the path and extracted the victims from the mud and rubble of their homes, it was already too late. The neighborhood was erected in a hurry, below solid constructions, on either side of an evacuation channel leading to the lagoon. A “risk zone”, recognizes Mamadou Diomandé, fatalistic: “Of course we know it’s dangerous. People tell us all to leave, but to go where? »
The “eviction”, preferred solution
“Precarious” neighborhoods like Millionnaire-Extension are numerous in Abidjan. Faced with high rents, the poorest have no choice but to live in non-buildable areas, which do not interest real estate developers. They slip into the interstices of the urban fabric, including on sloping land and the edges of waterways, to plant these makeshift dwellings made of sheet metal and wood. Fragile constructions, without foundations, particularly exposed to bad weather and likely to be swept away by the first mudslide.
To remedy this, the “eviction”, that is to say the expulsion of the inhabitants and the demolition of the district, is the first solution chosen by the government. On May 11 in Attécoubé-Mossikro (in the commune of Yopougon), the Minister of Hydraulics, Sanitation and Safety, Bouaké Fofana, launched operations of forced evacuation and destruction of “critical” areas of the district of Abidjan. Not only Attécoubé, where six people died during the previous rainy season, were affected, but also Pont-Ferraille in Adjamé and Carena in Plateau. “We prefer living populations, perhaps dissatisfied temporarily, but we prefer them alive”, declared the minister on this occasion.
Except that illegal residential areas are not the only ones at risk. Due to its galloping population growth, the Ivorian economic capital was built without taking into account watersheds and floodplains. Planning is still underway, and the Greater Abidjan Urban Master Plan (SDUGA), which aims to provide the axes for the development of the city, should not come into force until 2030. In the meantime, plans for retail town planning (PUD) laid down an initial regulatory framework, but they are not always followed by real estate developers. Residential districts, such as that of the Riviera Palmeraie in Cocody, thus find themselves built on flood-prone areas.
Network of weather sensors
So, to stop counting its dead, Côte d’Ivoire is investing. First in meteorology, of which it is at the forefront in West Africa. The Director of National Meteorology at Sodexam (the Ivorian organization responsible for aeronautical activities and weather), Daouda Konaté, has also just been elected vice-president of the World Meteorological Organization. Abidjan has an early warning system, provided by the French company HD Rain to Sodexam, in partnership with the international branch of Météo France. “We have installed a network of 200 smart sensors from the Ghana border to Yopougon, in the west of Abidjan, which observe the rain cells, explains Anthony Mocaër, country manager at HD Rain. Artificial intelligence is then used to recreate three-dimensional rain maps and make two-hour forecasts. »
The government has also launched the construction of drainage infrastructure, particularly in Bingerville, a suburb that will also be bereaved by the rains in 2022. The Koumassi wastewater pre-treatment station was also returned to service in mid-June, after five years of rehabilitation works. “There is a whole range of possible solutions, in gray infrastructure [roads, sewers, etc.] and green [green spaces, natural or developed]”, assures Laura Ginisty, the director of Keran West Africa, a design office dedicated to urban and environmental issues. The construction of storm basins, for example, which retain excess rainwater, or even simple sanitation works would constitute solutions, according to her, while many floods are due to the fact that the evacuation channels are blocked. . “Why not also consider the establishment of safety zones at height, as in some coastal cities prone to tsunamis? The short-term priority is to save lives, until better,” she said.
Because the problem is structural: in a city as concrete as Abidjan, where green spaces are lacking, the absorption capacity of the soil is very limited. “We created this city like a basin, decrypts Laura Ginisty. Ledges are the concrete walls of our buildings, with foundations that go deep into the ground. A few escape routes are well planned, but these are just a few holes drilled at the bottom of the basin. When it rains, it’s like filling this basin with a shower head. But an area with dirt, and especially trees, is no longer a basin: it’s a colander! The Ivorian government is beginning to take into account the need for green infrastructure and to commit resources to this end. Thus, the old Akouédo landfill, whose 100 hectares have been rehabilitated and cleaned up since last year, must eventually be transformed into a gigantic green space.
