How wetlands encroachment is endangering Kenya's future

This year’s theme, “Protecting Wetlands for Our Common Future,” underscores the urgent need for stronger conservation efforts amid growing environmental threats. It is a reminder of how closely our lives are tied to these fragile ecosystems. But with another rainy season approaching, Kenya’s wetlands – and the well-being they support – are in grave danger.

Wetlands – swamps, marshes, and riverine floodplains – are nature’s own flood defence system. They act like giant sponges, absorbing excess rainwater, slowing down runoff, and reducing flood risks.

It is estimated that Kenya has more than 12,000 wetlands, covering about three to four per cent of the country’s total land area. They provide water for agriculture, drinking, and industry, while also acting as flood buffers and biodiversity sanctuaries. Yet, only six Kenyan wetlands are recognised as sites of international importance.

Reports show that 68 biodiversity hotspots, including crucial wetlands, have been degraded over time. In cities like Nairobi, these ecosystems were once natural drainage zones, ensuring water had a place to go even in the heaviest storms.

But today, much of this protection is gone. Over 60 per cent of Nairobi’s wetlands have been encroached upon by real estate developments, illegal settlements, and industrial expansion. Concrete has replaced marshes, leaving the city vulnerable every time the rains come.

One of the most glaring examples is South C and Lang’ata, where riparian land along the Ngong River has been swallowed by high-rise apartments. Satellite images from last year showed that nearly 30 per cent of the river’s natural floodplain has been lost in these areas. During the March floods, water had nowhere to go, and roads became rivers within minutes.

Similarly, Mathare and Mukuru slums, which sit along the Nairobi River, have expanded into areas that were once floodplains. Every rainy season, residents are forced to evacuate as their homes are submerged, yet little is done to restore these crucial wetlands.

The situation is just as dire beyond Nairobi. Yala Swamp, Kenya’s largest freshwater wetland, has been carved out for large-scale agriculture, reducing its ability to regulate water levels in Lake Victoria. Lake Ol’ Bolossat, the only freshwater lake in Central Kenya, has shrunk dramatically due to human settlement. In Mombasa, mangrove wetlands that protect the coastline from rising sea levels are being cleared for infrastructure projects.

A 2023 Kenya Wetlands Forum report warned that at least 50 per cent of the country’s wetlands could be lost by 2050 if urgent conservation measures are not taken. The impact? Increased flooding, water shortages, and biodiversity loss.

With the rainy season around the corner, Nairobi and other parts of Kenya are once again bracing for floods. The question is: Will we keep treating flooding as an unavoidable disaster, or will we finally address the root cause?

Countries like Singapore and the Netherlands have shown that integrating wetlands into urban planning reduces flooding and improves water management. Kenya must follow suit by restoring urban wetlands and demolishing illegal structures on riparian land; enforcing riparian protection laws, which exist but are rarely implemented; and creating artificial wetlands to absorb stormwater in flood-prone areas.

World Wetlands Day should not just be a date on the calendar; it should be a wake-up call. If Nairobi continues to build over its natural flood defences, the next flood won’t just be an inconvenience; it could be catastrophic. The choice is ours.

-The writer is the CEO of The Kenya Alliance of Resident Associations