Flooding in Nairobi, Kenya due to Climate Change
Nairobi City, my home, is increasingly vulnerable to flooding as a direct and indirect effect of climate change, with poor drainage of stormwater runoff being one of the most visible and damaging outcomes. Climate change has intensified rainfall events in the city, increasing both the frequency and intensity of heavy downpours. According to Abuje et al. (2020), Nairobi experienced a significant rise in average rainfall between 1984 and 2016, combined with rapid urban expansion. This combination has dramatically increased surface runoff, overwhelming existing drainage systems and causing recurrent flooding during rainy seasons. The problem is worsened by extensive urban sprawl, which the study identifies as having increased by over 160% in the same period. Natural surfaces that once absorbed rainwater—such as wetlands, riverbanks, forests, and open soil—have been replaced by impermeable materials like concrete, asphalt, and roofing sheets. As a result, rainwater flows rapidly over surfaces instead of infiltrating the ground, placing immense pressure on drains and river channels.
Several factors make Nairobi’s flooding challenges more severe. Inadequate and poorly maintained drainage infrastructure, frequent blockage of drains by solid waste, informal settlements built along riparian reserves, and encroachment on natural waterways all reduce the city’s capacity to manage runoff. The study highlights that urban land-cover change is a key driver of increased runoff volumes, meaning that even moderate rainfall now produces flood conditions. Climate change acts as a multiplier, intensifying rainfall patterns in a city already structurally unprepared for them.
This challenge can be in mitigated, in addition to improvement of drainage infrastructure and depopulation, is by reforestation in the city and its environs. Tress, plants and grass can be planted on rooftops, balconies and along walkways in the city. The neighbouring forests of Karura, Ngong and John Michuki Park should be protected from encroachment by urban construction. Additionally, reduced usage of glass walls in the construction of high-rise buildings and skyscrapers in the key areas including CBD, Westlands, Kilimani and Upperhill will improve the evaporation and drainage of runoff rainwater to prevent flooding.
References
Abuje, S. J., Otoki, B. M., Njuguna, B. M., & Munala, G. (2020). The Vulnerability of Nairobi to the Effects of Climate Change Between 1984 and 2016. Landscape Architecture and Regional Planning.
UN-Habitat. Climate Change and Cities in Africa.
Nairobi City County. Integrated Urban Development and Drainage Plans.