The World Resources Institute (WRI) has raised alarms over Nairobi’s susceptibility to severe flooding as the El Niño weather phenomenon intensifies, despite government assurances of preparedness.

El Niño, predicted to peak between October and December 2026, is expected to bring above-average rainfall to East Africa, heightening flood risks. The U.S. Climate Prediction Center reports an 81% chance this El Niño will rank among the strongest since 1950, while the World Meteorological Organization estimates over a 90% likelihood the event will persist through November.

Underlying Causes of Flood Vulnerability

WRI’s recent report, Flooding in Nairobi’s Informal Settlements: Advancing Equitable and Resilient Solutions, attributes Nairobi’s flood challenges not solely to heavy rains but to decades of unplanned urban growth and environmental degradation. Key factors include:

  • Rapid expansion into floodplains and river corridors reducing natural stormwater absorption
  • Loss of wetlands, forests, and green spaces replaced by impermeable surfaces
  • Ageing drainage infrastructure designed for a much smaller population
  • Poor waste management leading to blocked drains
  • Weak enforcement of planning and environmental regulations
  • Fragmented coordination among government agencies responsible for urban planning, water, and environment

Consequences and Urgent Needs

Recent floods underscore the city’s vulnerabilities. The 2024 long rains caused 11 deaths, displaced over 20,000 families, and damaged critical infrastructure. Similarly, floods in March 2026 resulted in 37 fatalities and widespread disruption.

The report warns that without addressing structural issues, Nairobi’s disaster risk management remains inadequate for a changing climate, as extreme rainfall events expected once every 50 years may now occur several times per decade.

Recommendations emphasize a multi-faceted approach, including:

  • Strict enforcement of land-use and environmental laws
  • Protection and restoration of wetlands and river corridors
  • Investment in resilient drainage and nature-based solutions
  • Improved waste management to prevent drain blockages
  • Enhanced inter-agency coordination and resource allocation

As Kenya braces for the upcoming El Niño season, the report stresses that mitigating flood disasters hinges on correcting long-standing urban planning failures rather than relying solely on emergency responses.