Climate Risks : Cotonou Weakened by Occupation of Wetlands

The settlement of populations in marshes and other wetlands, along with the failure to enforce the decree prohibiting the occupation of flood-prone areas, has made Cotonou vulnerable to climate-relate

A semester has passed, but Vossa, a neighborhood with over 6,000 residents in the 6th arrondissement of Cotonou, still bears the scars of the October 2022 flood from Lake Nokoué. "It was too much. The waters reached a height we couldn't have imagined," says Jude Salomon Houetchekpo, president of the Neighborhood Development Association located near Lake Nokoué, the largest body of water in Benin.

In his bedroom, everything is raised. A precaution to avoid electrocution. "I had to place my electrical installations on 15 cm bricks each. The first three levels were submerged. It's the fourth one that kept us safe," Jude continues.

The lake overflowed its banks, claiming more rights over the surrounding areas. Its tantrums lasted for two endless months for the residents of Vossa. Jude, like many others affected, stayed put, with feet in the water, and some in precarious dwellings with damaged roofs. "We stayed out of fear that people would break in and steal our belongings. At one point, I had to send the children and my wife to another place," justifies Jude, who sees the lake getting closer each year. "Before, we were two, maybe three kilometers from the shore. Now, it's less than a kilometer. Several houses have already been ravaged," he emphasizes.

In reality, the flooding in the peripheral neighborhoods of Lake Nokoué is not solely caused by the rains in Cotonou but also by the Ouémé River's floods. Pierre Vennetier, Honorary Research Director at the National Center for Scientific Research (CNRS), sounded the alarm in a pioneering scientific contribution published in the 1991 edition of Les Cahiers d'Outre-Mer. The Ouémé River, originating at the foothills of the Atacora Mountains in the north of the country, experiences only one rainy season from June to October. Due to the slope of the riverbed and the nature of the basin rocks, the floodwaters propagate rapidly, reaching the lake by mid-July.

"Cotonou mainly experiences river overflow flooding due to water from the north. When the lake is too full, like a basin, it overflows. We have created maps to model, based on elevation levels, the parts of the city susceptible to flooding," explains Professor Eric Tchibozo, Secretary-General of the National Geographic Institute of Benin, who has authored numerous cartographic works on wetlands.

The worst is to be feared. Climate change and its consequences have severely tested the lagoon system in the region. The 2022 flood was particularly hard for the Vossa neighborhood. Germain Agbo, the neighborhood chief of Vossa, recalls that the last similar situation to what Vossa is experiencing now dates back 12 years. "Many were tempted to leave their homes. Personally, I chose to stay. As a neighborhood chief, I can't abandon my constituents," he recalls.

The climate scenarios outlined in Benin's National Adaptation Plan are not particularly reassuring; some might even say they are alarming. In the 2020 edition, it is stated that "annual precipitation levels generally show a decreasing trend by 2050 and an increasing trend by 2100."

According to Professor Michel Boko, a climatologist and co-recipient of the 2007 Nobel Peace Prize, explained these scenarios in a scientific communication. He pointed out that if the tributary rivers of the lake decrease in flow and, consequently, flooding becomes less dangerous, it won't necessarily free up space for city expansion. However, if climate change intensifies, leading to a rise in the global average sea level, there will be additional concerns. "According to some projections, the city of Cotonou could have anywhere from 40 to 200 years, depending on the scenarios, before being engulfed by rising groundwater in the interdunal areas that occupy 40% of the city's surface area, as well as accelerated coastal erosion and saline intrusions," Professor Boko warns.

Concrete in the marshes. In this context, the sustainability of the city of Cotonou is in question. Wetlands play a crucial role in managing climate risks. According to the Ramsar Convention, of which Benin has been a signatory since May 24, 2000, inland wetlands such as floodplains, rivers, lakes, and marshes act as natural sponges by absorbing and storing excessive rainfall, thereby reducing the risk of flooding. "They serve as natural outlets for water during the rainy season," confirms Professor Tchibozo.

However, Cotonou is already handicapped when it comes to managing climate risks, especially large-scale flood scenarios. The beds of Lake Nokoué, lowlands, marshes, and other natural channels, which naturally act as sponges and should protect the city from certain types of flooding, are occupied and seized by constructions.

"What we have lost is significant. It's evident to everyone that wetlands are receding in favor of urbanization. This is the moment to see the consequences of what has been happening for several years and how to stop it," explains Professor Tchibozo, who described the situation in this sector of the city in a 2013 study on peri-urbanization and coastal area degradation west of Cotonou Airport. His research results show a significant decline in marshes (41.30%), water bodies (8.89%), and bare soil (37.33%). The land occupancy rate for housing in this area had already increased by 36.29% between 1988 and 2006, and this percentage has not decreased since.

Ten years after the publication of this study, the researcher, when approached on the issue, maintains this regressive trend of wetlands in Cotonou and its surroundings. On this issue, the land use mapping in the city of Cotonou over the past 30 years speaks volumes.

"We should not develop plots... "

The uncontrolled urbanization of Cotonou has been facilitated by legislative gaps, the lack of an effective urban policy, and informal practices. Indigenous people, relying on customary law, have divided land without considering environmental risks. The cost of land parcels was affordable in these areas, leading to a massive influx of people and rapid occupation. "Vossa is not a flood-prone neighborhood. I came here in 1971. It was after the construction of the new Cotonou bridge that the lake overflow began. We paid for these plots from the city's indigenous people. Some paid 150,000 Fcfa, others 200,000 Fcfa," defends Germain Agbo, the chief of the Vossa neighborhood in the 6th district.

The Real Estate Management Company (Sonagim), established by the state on August 14, 1978, couldn't stop the trend. This structure did not last long. On February 7, 1992, the very first Minister of Environment of Benin, Eustache Sarré, issued a decree to prohibit the occupation of unsuitable areas for habitation. "What served as a municipality was subdividing and perpetuating the settlement of populations in these unsanitary areas. No measures were taken to prevent these practices. We were told that there was an inter-ministerial committee that had been meeting for years and never finished its work. Therefore, no administrative document prevented people from settling in these areas. We issued the decree to address the urgency," said the octogenarian former Minister.

He acknowledges that issuing a decree would take time, but the measure could not stop the practice. People settle improperly, and district chiefs, to gain popularity, divide these areas in contradiction with the decree. The government is protected against these violations. Those who acted, whether it be the population, surveyors, or urban planners, could have opposed this situation. If people continued to do it, it was due to populist motivations contributing to the suffering of the population. One can say that this decree did help restrain the administration in this practice,he notes.

The former minister regrets that there were no sanctions to discourage these practices and prevent the occupation of flood-prone areas. "The government did not impose sanctions. What would have been interesting is to inform people about the damage, financial and health losses. That should have been an action," he adds.

What was mainly lacking was the delineation and popularization of these areas. This view is widely shared by Professor Tchibozo. "These areas should have been delineated and prohibited from occupation. When there was initial settlement, these restricted areas should have already been cleared. It is true that it was not so easy because there was still available land. People were buying everywhere, but with the recent rains, we saw what Vossa has become. Vossa should not have been developed, but it was. It's urbanized," he laments.

Taking Action In Benin, the cost of flooding is extremely high. The losses and damages from the 2010 floods were estimated at around 48.8 billion FCFA (approximately 100 million US dollars). The damages and losses from the 2019 floods could be estimated at 53.29 billion CFA francs (91.8 million US dollars), according to the National Civil Protection Agency (ANPC). Faced with these damages and growing risks, the country is mobilizing significant investments for resilience.

In recent years, substantial resources have been mobilized for the implementation of the Cotonou Stormwater Management Program (PAPC). With an estimated implementation cost of 264 billion FCFA (434,499,384 US dollars), this project, according to the government, will alleviate the 34 watersheds out of the 50 that the city has, which have shown their limitations in terms of rainwater drainage capacity. Cotonou will also be equipped with 46 kilometers of drains and large collectors, as well as 90 kilometers of medium-sized drains.

Despite the ongoing investments in rainwater management in Cotonou, the restoration of outlets occupied by housing remains imperative. "The government is making a lot of efforts to preserve flood-prone areas, but it is not enough. The phenomenon of occupation of these areas has thrived and led other residents of Benin to settle in such areas. Authorities must make a significant effort not only to sanction but also to inform and raise awareness," insists Eustache Sarre, who hopes that the population will realize the importance of not occupying these areas.

With the threat of climate change, strong actions are needed to clear risk-prone areas, as is the case in Xwlacodji near the Cotonou channel. "This must be done gradually as needed. Work is underway to assess these areas. The remaining action is raising awareness, with some constraint and force to clear these wetlands of illegal occupation. The problem is that some of these areas have already been developed," explains Professor Eric Tchibozo. By neglecting to address the issue of wetland occupation head-on in its strategy to combat the adverse effects of climate change, Benin could inadvertently deploy colossal efforts but in vain.

This article was produced in March 2023 with the support of the Media Foundation for West Africa as part of its climate change scholarship program.