Stormwater Drainage and Infrastructure in Cotonou: The PAPC
Cotonou is built on a narrow strip of land between the Atlantic Ocean and Lake Nokoué, on sandy, largely flat ground. This geography explains why the city has long suffered from recurring flooding during the rainy season, with entire neighborhoods underwater for days after heavy rain. Since 2022, the Programme d'Assainissement Pluvial du Grand Cotonou (PAPC) — Greater Cotonou's Stormwater Drainage Program — has been transforming the city's drainage network from the ground up, aiming to put an end to this cycle of flooding.
This guide explains what the PAPC is, where the work currently stands, which neighborhoods are affected, and what it actually changes for residents and future residents of Cotonou.
1. Why Cotonou floods regularly
Cotonou's geography combines several factors that make it vulnerable to stormwater. The city is nearly flat, with an average elevation close to sea level, which limits how well water can drain away naturally by gravity. The sandy soil absorbs some rainfall but saturates quickly during heavy downpours, a phenomenon made worse over the decades by urbanization, which has reduced the amount of permeable ground.
The city's historic stormwater system, built in stages since the colonial era, was never sized to handle the population growth and urban sprawl of outlying neighborhoods. A significant share of housing has developed on low-lying land or drained former marshland, which increases exposure to standing water.
In May 2026, a heavy rainfall event illustrated this ongoing vulnerability: according to the Société d'Investissement et de Réalisation d'Aménagements Territoriaux (SIRAT, the territorial development company), 17.3 centimeters of rain fell in three hours over parts of the city, temporarily overwhelming existing drainage infrastructure and causing traffic disruption in several neighborhoods. Things returned to normal in around two hours thanks to preventive gutter clearing and a quick response from technical teams — a much better outcome than would have been seen before the PAPC launched.
2. The PAPC: goals and scale of the project
Officially launched on April 21, 2022 by the Beninese government, the PAPC is a national-scale infrastructure program meant to put a lasting end to the cyclical flooding of Greater Cotonou. The overall cost of the program is estimated at around 264 billion FCFA, funded by several international partners including the World Bank, the European Investment Bank, and the French Development Agency (AFD).
The planned infrastructure
The program covers the construction, rehabilitation, or extension of an extensive network of hydraulic works:
- 46 kilometers of primary collectors, the large canals that carry the biggest volumes of water out to the Cotonou lagoon or directly to the ocean.
- 90 kilometers of secondary collectors and side gutters, connecting streets and residential neighborhoods to the primary network.
- 7 retention basins, structures that temporarily store rainwater during peak rainfall to smooth out the flow and avoid immediately overwhelming the canals downstream.
- 49 kilometers of paved, upgraded roads, since drainage work is systematically paired with resurfacing the affected roads.
Ultimately, the PAPC is meant to relieve 34 of the 50 watersheds that make up Greater Cotonou, which had insufficient drainage capacity before the program launched.
A project organized by lots and by funders
The work is split into several geographic lots, each funded by different backers, which is why progress varies from one neighborhood to another. The priority areas identified as most vulnerable to flooding, particularly in the western part of the city along Lake Nokoué, were among the first sites to break ground.
3. The neighborhoods covered by the work
The PAPC isn't limited to downtown. A significant share of the program specifically targets outlying, vulnerable neighborhoods, where flooding historically had the heaviest social impact on residents.
The Agla neighborhood, in western Cotonou along Lake Nokoué, has long been among the city's most flood-exposed areas. Drainage work there is now largely complete. Drainage and road resurfacing projects have also covered the neighborhoods of Kouhounou, Akplomey, Ménontin, and parts of Godomey, including the construction of retention basins using gabion and Reno mattress techniques to stabilize the banks of these structures.
Other parts of the municipal territory, particularly in the north and east of Cotonou, are covered by later lots of the program, with an execution timeline stretching over several years beyond 2026.
4. Concrete impact for residents
An already-measurable reduction in flooding
According to feedback from local authorities and observations on the ground, neighborhoods where PAPC work is finished or well advanced see a clear drop in how long and how badly water stands after heavy rain. Events haven't disappeared entirely, as the temporary overload seen in May 2026 showed, but the speed at which water drains away has improved considerably compared to before.
Temporary construction inconveniences
The scale of the program inevitably means construction-related disruption for people living near active work sites: disrupted traffic, dust, noise from earth-moving equipment, and sometimes temporary blocked access to certain properties while collectors are being laid. These inconveniences are generally limited to the duration of work on a given stretch, with the road resurfaced once the pipe-laying is finished.
An impact on property value and insurability
For anyone house-hunting or considering a real estate investment in Cotonou, whether a neighborhood's PAPC work is finished or not is an increasingly important factor. Properties in historically flood-prone areas that are now protected by the new drainage network are becoming more attractive, while plots still waiting for the work remain exposed to seasonal risk during the rainy season, generally between April and July and again in September-October.
5. What to do during heavy rain in a neighborhood not yet connected
While work continues across the rest of the municipal territory, a few precautions can limit the impact of heavy rainfall for residents of neighborhoods still vulnerable.
Raising ground-floor electrical equipment that's sensitive to water, avoiding parking in known low points of the neighborhood during heavy rain warnings, and reporting blocked gutters to local authorities (the district town hall, or SIRAT) before the rainy season are all useful habits. Preventive gutter clearing by municipal services ahead of seasonal peaks plays a decisive role in how fast standing water drains away, as confirmed by the May 2026 event.
6. PAPC and the SONEB network: two separate projects
It's worth not confusing the PAPC with SONEB (Société Nationale des Eaux du Bénin, the national water utility) infrastructure, which handles drinking water distribution to homes through a network of pipes and individual meters. The PAPC deals exclusively with citywide rainwater drainage, through collectors, gutters, and retention basins that are entirely separate from the drinking water network. A home can be perfectly well connected to the SONEB network for running water while still sitting in a neighborhood still vulnerable to flooding because its stormwater collectors aren't finished yet — or vice versa.
This distinction matters for future residents assessing a neighborhood before moving in: the quality of the drinking water supply and vulnerability to flooding are two entirely separate infrastructure networks, managed by different bodies, and shouldn't be confused when viewing a home during the dry season, when signs of flood vulnerability aren't very visible.
7. What's next: the program after 2026
The remaining PAPC lots mainly cover parts of the north and east of the metropolitan area, where urbanization continues to outpace the historic drainage infrastructure. The official timeline calls for the remaining sections to be completed gradually in the years after 2026, with ongoing environmental and social monitoring funded by the program's international backers.
For residents of areas still waiting on the work, staying vigilant during every rainy season remains important, with preventive clearing of existing gutters still, as things stand today, the main immediate lever for limiting how long water stands.
FAQ: stormwater drainage and the PAPC in Cotonou
Will the PAPC completely eliminate flooding in Cotonou?
The program aims for a drastic reduction in how often and how long flooding occurs, not a total elimination of weather-related risk. Exceptionally heavy rain can still temporarily overwhelm the new infrastructure, as seen in May 2026, but drainage is much faster in areas the program has already covered.
Which Cotonou neighborhoods are furthest along in PAPC work?
The Agla neighborhood, particularly exposed to flooding due to its proximity to Lake Nokoué, is among the areas where work is most advanced. Kouhounou, Akplomey, and Ménontin have also benefited from drainage and road resurfacing projects under the program.
How can I find out if my future home is in an area already covered by the PAPC?
There's no publicly accessible, continuously updated interactive map yet. The most reliable approach is to ask directly at the relevant district town hall, or to check the condition of the neighborhood's gutters and collectors in person during a viewing, ideally during or right after a rainfall event.
Who funds the PAPC and how long does the program run?
The program is funded by several international backers, including the World Bank, the European Investment Bank, and the French Development Agency, for a total cost of around 264 billion FCFA. The execution timeline spans several years, with the first lots starting in 2022 and some work continuing beyond 2026.
Does the PAPC cover household wastewater too, or only rainwater?
The program specifically targets stormwater — draining off rainfall runoff. Managing household wastewater (individual sanitation, septic tanks, sewer networks) falls under a separate framework, largely handled at the household level in Cotonou in the absence of a widespread collective sewer network.