Ecosystem-based Flood Risk Management in Sub-Saharan Cities Summary Paper

This executive summary describes a scoping study on Ecosystem-based Flood Risk Management in five Sub-Saharan cities: Accra, Cape Town, Durban, Nairobi, and Mombasa. It evaluates the integration of nature-based solutions (NbS) and Ecosystem-based Adaptation (EbA) alongside traditional grey infrastructure to address urban flooding exacerbated by climate change, rapid urbanization, and poor urban planning.

• Urban flooding in Sub-Saharan cities is driven by a combination of climate change, which increases precipitation extremes, and rapid urbanization that creates more impervious surfaces and leads to construction on floodplains. These issues are compounded by poor urban planning and insufficient solid waste management, which often clogs drainage systems.
• Integrated Flood Risk Management (IFRM) utilizes a mix of structural and non-structural elements. Structural elements include both 'grey' hard-engineered solutions like flood defences and 'soft' natural measures such as wetlands. Non-structural measures focus on planning, emergency warning systems, and land use planning to avoid floods.
• Ecosystem-based Adaptation (EbA) and nature-based solutions (NbS) provide co-benefits beyond flood reduction, including improvements to public health, the protection of livelihoods, and the creation of new income-generating opportunities for communities.
• The study identifies specific nature-based interventions across five cities: Accra uses vegetation planting on slopes to prevent erosion; Cape Town focuses on the restoration of sand dunes and protection of kelp beds; Durban implements river rehabilitation and cleaning of waterways; Nairobi focuses on wetland restoration; and Mombasa rehabilitates mangroves.
• Effective flood governance requires multi-actor collaboration across different levels of government—municipal, district, state, and national—because water catchment areas often extend beyond municipal boundaries.
• There is a disparity in the maturity of climate responses between the studied regions; South African cities show more maturity in policy and action frameworks, while Kenyan cities (Nairobi and Mombasa) are still in the process of climate-proofing urban planning and have historically shown a bias toward grey infrastructure.

APA

Gajjar, S. P., Wendo, H., Polgar, A., & Hofemeier, A. (2021). Ecosystem-based Flood Risk Management in Sub-Saharan Cities Summary Paper. Climate and Development Knowledge Network. https://cdkn.org/sites/default/files/files/ecosystem-based-flood-risk-management-summary-Final.pdf

Chicago

Gajjar, Sumetee Pahwa, Hausner Wendo, Ana Polgar, and Alannah Hofemeier. Ecosystem-based Flood Risk Management in Sub-Saharan Cities Summary Paper. Climate and Development Knowledge Network, 2021. https://cdkn.org/sites/default/files/files/ecosystem-based-flood-risk-management-summary-Final.pdf.

Wikipedia

{{cite report |last1=Gajjar |first1=Sumetee Pahwa |last2=Wendo |first2=Hausner |last3=Polgar |first3=Ana |last4=Hofemeier |first4=Alannah |title=Ecosystem-based Flood Risk Management in Sub-Saharan Cities Summary Paper |publisher=Climate and Development Knowledge Network |date=2021 |url=https://cdkn.org/sites/default/files/files/ecosystem-based-flood-risk-management-summary-Final.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{gajjar2021ecosystembased, author = {Gajjar, Sumetee Pahwa and Wendo, Hausner and Polgar, Ana and Hofemeier, Alannah}, title = {{Ecosystem-based Flood Risk Management in Sub-Saharan Cities Summary Paper}}, institution = {Climate and Development Knowledge Network}, year = {2021}, url = {https://cdkn.org/sites/default/files/files/ecosystem-based-flood-risk-management-summary-Final.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }