NAIROBI, Kenya, Jul 31— Nairobi’s worsening flood crisis is being driven as much by decades of poor urban planning and environmental degradation as by heavy rainfall, according to new research by the World Resources Institute (WRI), which is urging authorities to shift from reactive disaster response to long-term climate resilience.
The report, Flooding in Nairobi’s Informal Settlements: Advancing Equitable and Resilient Solutions, argues that while intense rainfall triggers flooding, underlying structural problems, including unplanned development in flood-prone areas, inadequate drainage systems, shrinking wetlands and green spaces, weak enforcement of land-use regulations, fragmented governance and limited investment in resilience, are amplifying the impacts.
The findings come after successive devastating flood events that have exposed the capital’s vulnerability.
According to the report, nearly 21,000 families were displaced during the 2024 floods, more than 90 kilometres of roads and nine bridges were damaged, while over 147,000 cases of waterborne diseases were recorded.
In March 2026 alone, flooding claimed 37 lives in less than three weeks.
WRI says the repeated disasters demonstrate that flooding should no longer be viewed solely as a weather-related emergency but as a broader urban planning, housing and public health challenge.
The study draws on flood modelling and mapping alongside surveys and discussions with 98 households in Kibera, Mukuru Viwandani and Mathare.
Residents reported losing homes, livelihoods and personal belongings while highlighting shortcomings in early warning systems, emergency preparedness and community participation in flood risk management.
The research found that women, children, older persons and persons with disabilities are disproportionately affected because they often face additional barriers in accessing flood warnings, evacuation support and post-disaster recovery assistance.
To help address these challenges, WRI and the Nairobi Rivers Commission (NRC) jointly launched the Nairobi Rivers Nature-based Solutions Strategic Framework, designed to guide the planning, financing and implementation of projects that reduce flood risks while restoring degraded ecosystems.
The framework focuses on four major climate risks facing Nairobi: flooding, urban heat, biodiversity loss and air pollution, and outlines interventions aimed at restoring wetlands and river corridors while improving biodiversity, public health, gender equity, social inclusion and overall quality of life.
“Nairobi’s rivers cannot be restored through isolated projects or short-term interventions,” said Nairobi Rivers Commission Chairperson Bishop Margaret Wanjiru.
“Through this Framework, the Commission and its partners now have a shared, evidence-based roadmap to coordinate action across the river basin, direct investment to priority areas and track results. Our ambition is to restore river corridors that reduce flood risk, improve public health, support livelihoods and become safe, productive assets for the people of Nairobi.”
As part of the initiative, WRI also signed Memoranda of Understanding with the Nairobi City County Government and the Kenya Forestry Research Institute to strengthen collaboration on climate action, research, data sharing, nature-based solutions, landscape restoration, stakeholder engagement, resource mobilisation and sustainable livelihoods.
Wanjira Mathai, Managing Director for Africa and Global Partnerships at WRI, said the evidence shows that climate resilience must be integrated into housing, infrastructure and basic service delivery.
“The evidence from Nairobi’s floods is clear: climate resilience cannot be separated from housing and basic services,” Mathai said.
“Safer communities require risk-informed planning, reliable drainage and sanitation, healthy rivers and wetlands, and residents who are partners in designing and stewarding solutions. This launch connects evidence, public leadership, local knowledge and finance so Nairobi can move from repeated emergency response to investable action that protects both people and nature.”
WRI said the report, the new strategic framework and the partnerships together provide a roadmap for Nairobi to transition from responding to floods after they occur to proactively managing disaster risks through coordinated planning, resilient infrastructure and nature-based solutions.
