Why Mombasa’s devastating flash floods persist
Pedestrians cross a flooded street following heavy rains at Kiembeni in Mombasa.
What you need to know:
- A 2024 report has cited settlement on floodplains, inadequate adaptive infrastructure to mitigate flooding, poor management of solid waste and unregulated construction leading to blockage of waterways as some of the challenges that leave the port city vulnerable to flooding.
Mombasa city has long grappled with devastating flash floods whenever heavy rains strike. The problem persists due to a mix of geographical vulnerabilities, climate change, and human-induced factors, compounded by weak mitigation measures from authorities.
Flat terrain
Although conditions common in coastal cities around the world such as a flat terrain, rising sea levels and low elevation of the region can be difficult or even impossible to control, county and national governments have been on the spot for weak mitigation measures.
A 2024 report by the German Corporation for International Cooperation (GIZ) cited settlement on floodplains, inadequate adaptive infrastructure to mitigate flooding, poor management of solid waste and unregulated construction leading to blockage of waterways as some of the challenges that leave the port city vulnerable to flooding.
The report indicated that 9.5 per cent of the county areas are under very high flood risk, 21.3 per cent under high risk and 28.7 per cent under moderate risk.
On the other hand, 27.3 per cent of the county areas are under low risk and 13.2 per cent under very low risk.
“It is evident that high flood risk is faced by over 30 per cent of the county area. This requires detailed strategising and resources mobilisation to support the readiness, survival, and recovery in the event this translates into disaster,” it stated.
For the last two weeks, the familiar scenes during heavy rainfall in Mombasa have been witnessed once again.
Transport in several parts of the county was affected following heavy rainfall that persisted for days.
Some major roads were submerged, homes flooded, while businesses struggled to stay open.
A spot check by Nation painted a grim picture of Nyali, Kisauni, Bamburi and other parts of the North Coast area, where motorists and commuters waded through knee-deep water while matatus were forced to divert or hike fares as roads were flooded.
Along the busy Mombasa-Malindi highway, only a single lane was passable.
“It is risky to drive through this road. Potholes are no longer visible. You can easily hit one and cause a fatal accident,” said Ali Suleiman, a matatu driver who plies the Bombolulu- Likoni Ferry route.
Mr Suleiman added that they were forced to hike fare due to delays caused by traffic snarl-ups.
“Normally we charge Sh70 from Bombolulu to Ferry, but now we have to ask for Sh100 because. It is not greed, its survival," he told Nation.
Commuters like Mary Achieng’, a resident in Mtopanga, decried the doubled fare price.
“I used to pay Sh100. Now it’s Sh150 and still you don’t know if you will make it to your destination since the matatu might get stuck in the mud. The economy is tough,” she said.
It is not just commuters feeling the pinch. Residents are angry at what they see as decades of poor planning and inaction.
Estates that have witnessed heavy investments in construction of cabro-paved roads by the county government as well as through the National Government-Constituency Development Funds in the previous years were not spared.
A survey by Nation around Nyali and Kisauni sub-counties found that although construction of these feeder roads came in handy to ease access into estates, they turn into a nightmare during the rainy season. When it rains, flooding on roads due to inadequate drainage infrastructure makes them impassable for foot traffic, disrupting daily life and potentially posing safety risks.
Existing drains are clogged with plastic waste, silt, and construction debris, making them useless during heavy rains.
“In flat terrains like Mombasa, with insufficient drainage systems and impermeable surfaces, floodwaters may rise slowly and remain exacerbated for extended periods; as evident in Nyali, parts of Maweni, Kongowea, 2nd Avenue Nyali, and Links Roads," the report by German Corporation for International Cooperation stated.
In an earlier interview, Mombasa Governor Abdulswamad Nassir said the flooding was not solely due to a faulty drainage system.
According to Mr Nassir, haphazard construction along waterways exacerbates the situation.
“There are some areas where entire villages are built directly on natural waterways. When the rain pours excessively, there is simply nowhere for the water to go, hence the flooding," he said.
To ease the situation, the county government deployed water bowsers to siphon water from submerged roads in areas like Nyali.
However residents say the move will not solve the crisis since the rains are ongoing, flooding the same areas.
“Using bowsers is a temporary fix, what we need is a modern, comprehensive drainage system that can handle downpour. We face this every year, yet little is being done,” said Charles Okoth, a businessman in Nyali.
They also called on the county government to take action on landlords who have built houses on waterways.
Ms Ester Wamboi from Kisauni said poor planning is to blame for the crisis.
“Many buildings at the Coast have been constructed along natural outlets to the ocean, blocking water from draining freely. This poor planning has made it worse every time it rains,” she said.
She also urged the county government to improve the drainage system to prevent flooding on roads.
