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Volume 15, Issue 2, April - June 2026
CONTENT
Chair's Foreword
Urban Flood Mitigation in West Africa 2026
Earth Science Events
References and selected reading
Chair's Foreword*
In this issue we face head on, the problem of urban flood mitigation in West Africa. Recent heavy rains in urban West African coastal regions has led to at least 72 deaths and thousands of people displaced in Ghana, Ivory Coast and Nigeria. In 2021, as chair of SAES, I attended a post-doctoral review of research work that was being conducted by young African scientists on climate change and mitigation, under the auspices of the African Climate Policy Centre (ACPC). One of the presentations at this closing workshop, was on Flood Risk Reduction for three West African capital cities (Abidjan, Ouagadougou and Dakar) by Evelyne Toure [1]. In the main article, we look at proposals for flood mitigation in the light of the 2021 ACPC closing workshop [2] and the urgency now motivated by the recent flooding emergencies in West Africa.
Urban Flood Mitigation in West Africa 2026
Urban planners across West Africa broadly recognise the core factors driving extreme weather events. However, recent floods in urban regions in West Africa which have claimed the lives of at least 72 people and displaced thousands[3], bring the need to urgently implement measures addressing these flood risk factors, into sharp focus.
Floods in Ivory Coast have claimed the highest number of lives with a death toll of 59 people since May 2026. These death toll figures may still rise as local rescuers continue their search for missing flood victims.[4]
It is the regional rainy season (usually May to July); and coastal West Africa is experiencing exceptionally heavy rains probably due to climate warming. In 2022, the World Meteorology Organisation reported that rains in West Africa had led to extreme events that were 80% more likely to occur as a result of climate change[5]. Extreme rainfall events that were once visiting the region every decade or every few years are now seen as a yearly occurrence. The experience of the populace is that floods in West Africa are becoming a more frequent geohazard, along with the other geohazards it brings, such as landslides and mudslides. Continentally, Africa is already witnessing extreme weather events due to global warming in spite of the fact that the continent only contributes about 4% of global carbon emissions.
In neighbouring Ghana in the Accra region, 13 deaths resulted from floods due to rainy season precipitation where 140mm of rain fell in a single day. This equates approximately to two months of rain in a day. In fact in 2025, the highest rainfall in a single day was at a peak of 56 mm.
Nearly all of the reports of urban regional floods acknowledge the role played by the impact of poor waste management and urban population growth on existing infrastructure. In the case of Ghana, the president himself acknowledged the likely impact of unplanned urban development. President Mahama cited the special case of Accra which lies between the Akwapim mountain range and the coast facing the Atlantic Ocean.
Nigeria was also affected - as it was in 2025. Apart from recent flooding in the Lekki area of Lagos, parts of northern Nigeria also experienced floods in 2025 which were their worst in 60 years [6] and which left 150 people dead and displaced thousands after destroying their dwellings. This year, the Nigerian Meteorological Association (NiMet) predicts rainfall increases in the capital territory, Abuja, as well as 9 other states, with many in the north.
Recent reports of urban regional flooding in West Africa broadly recognise the factors that contribute to extreme urban flood events. They recognise
1) poor waste management impact on existing infrastructure
2) growing urban population impact on existing infrastructure
But in addition to these, a major setback in flood mitigation in Africa is the pattern of
3) unregulated and unplanned construction on actual wetlands
Wetlands - Their Role in West African Flood Mitigation
To appreciate the seriousness of setback of factor 3) above, we must appreciate the definition and function of a wetland. A wetland by definition is: "...a distinct semi-aquatic ecosystem, whose ground covers are flooded or saturated in water either permanently, for years or decades, or only seasonally".[7] In simple terms, it is an area of marsh land capable of absorbing large amounts of water. It serves as a basin where the city flood excess water can drain. For this reason it is a great obstacle to progress when residents build dwellings and structures on wetlands which are supposed to serve as the regional storm basin. For the sake of community safety, building on wetlands should be strictly prohibited, as wetlands should ideally receive the excess floodwater from the city.
It is encouraging that virtually all major cities in West Africa have significant wetland areas, which can readily be incorporated into every West African city's flood defence plans:- For example
Owerri, capital of Imo state, Nigeria - Owerri wetlands
Accra, capital of Ghana - Densu and Sakumonoh wetlands
Abidjan, capital of Cote d'ivoire, Ebrie and Aghien Lagoons
and many other examples. However, their purpose is defeated if unregulated buildings and settlements are located within them.
Conclusion
The levels of flooding we have witnessed across West Africa is in some instances so tumultuous as to suggest there is an element of climate change-induced flooding that we cannot control. Following basic common sense measures such as mapping the city guttering networks for the sake of maintenance and gutter clearing, West African cities can more effectively discharge excess rain water to a storm basin. Local wetlands in urban regions employed in this way can play a valuable role in mitigating urban flooding; but only if unregulated buildings within them are prohibited.
Policy makers are urged to take note and ensure implementation of this measure protecting city wetlands as essential storm basins, by putting aside the sufficient relocation budgeting. It is better in the long term to bear the the cost of relocating citizens and providing alternative dwellings outside of wetlands or storm basin zones before a catastrophic flood occurs. Waiting until after a flood calamity has occurred, leads to possible loss of life and forced relocation under potentially traumatic circumstances, with the accompanying costs still having to be met.
For a deeper analysis of how urban expansion impacts flood mitigation in West Africa, readers can refer to the study by Enu, K.B, et al, exploring wetlands as nature-based solutions for West African Urban flooding [8].
Earth Science Book Review
- A new publication by Society of African Earth Scientists
"Earth, Water, Energy and Climate - The Collected Newsletters of the Society of African Earth Scientists 2012-2026"
Published by Orisa Press. (c) Society of African Earth Scientists, May 2026.
Edited by Chukwunyere Kamalu
What emerges from these pages is the cumulative weight of knowledge - built issue by issue: detailed reporting on weather disasters and geo-hazard events; reflections on geotourism, geoheritage and scientific heritage such as the Ishango Bone; documentation of workshops from Ghana to Nigeria; and sustained engagement with Africa’s renewable‑energy future. Together, these contributions demonstrate how the Society’s newsletters have matured into a reliable, long-term record of Earth science across the continent—capturing both the scientific realities on the ground and the intellectual currents shaping African responses.
Both print copy and ebooks are available from https://orisapress.blogspot.com
Earth Science Events
6-11 July 2026
5th International Conference on African Rivers: Research Development and Innovation
VENUE: Mohamed V. University, Rabat, Morocco.
21 July 2026
International Conference on Hydraulics and Civil Engineering Solutions
VENUE: Cape Town, South Africa.
21-23 September 2026
African Water Security Conference - Towards and Secure and Resilient Africa
VENUE: Addis Ababa University, Addis Ababa, Ethiopia.
8-11 December 2026
7th International Africa Congress on Hydro environment and engineering Research
- Water Resilience & Innovation
VENUE: Kigali, Rwanda.
25 April 2027
Society of Africa Earth Scientists 15th Year Celebration:
Earth, Water, Energy & Climate
A conference to celebrate 15 years in existence of the Society of African Earth Scientists. It features a key note talk by geophysicist, Henok Tewelde (P.G), On the Role of Exploration Geophysics in Sustainable Groundwater Management in Africa, floor discussions and a book launch of the Society's latest publication: Earth Water Energy and Climate - A collection of its first fourteen years of periodic newsletters from 2012 - 2026.
VENUE: Bernie Grants Arts Centre, London
References and Selected Reading
[1] Toure, E.N., Flood Risk Reduction Under the Paris Agreement for Three West African Cities, CR4D, End of grant workshop, 21-23 June, Nairobi, Kenya, 2021.
[2] SAES Newsletter #39.
[3] Guardian 2 July 2026, Cote d'Ivoire flood kills 59 as west Africa endures torrential rains.
[4] Ibid.
[5] Tandon, A., West Africa's deadly rainfall in 2022 made "80 times more likely" by climate change, Carbon Brief, Nov., 2022.
[6] Guardian - Faye Hulton (Met desk), Weather tracker: Nigeria hit by deadly flooding described as worst in 60 years, 2 Jun 2025.
[7] Wikipedia, en.wikipedia.org/wiki/wetland
[8] Enu, K.B., Merk, F., Su, H., Rauch, M., Zingraff-Hamed, A., Broich, K., Forster, K., Pauleit, S., and M. Disse, A scenario based analysis of wetlands as nature-based solutions for flood risk mitigation using the TELEMAC-2D model, Science Direct, Nature-Based Solutions, Vol. 7June 2025, 100236, https://doi.org/10.1016/j.nbsj.2025.100236
*Board of the Society of African Earth Scientists: Dr Enas Ahmed (Egypt), Osmin Callis (Secretary - Guyana), Dr Stanley Echebima (Nigeria), Mathada Humphrey (South Africa), Damola Nadi (Nigeria), Dr Chukwunyere Kamalu (Chair - Nigeria).
