On August 5th 2022, in the middle of the Sahelian country's rainy season, Senegal saw the worst storm of the year. When heavy rain falls, traffic stops, houses flood, cars are carried away by the sandy brown water. Is climate change to blame or lacking infrastructure?
Senegalese Weather
Senegal, a sub-Saharan country of West Africa, is nicknamed "the nose of Africa" by virtue of its location on the western tip of the continent. Senegal (except for the more tropical Casamance region to the south) has two major seasons: a dry, windy season from October to May and a rainy season from June to September. While rain is not a problem most of the year, as soon as the first heavy rain of the rainy season falls, the city and its suburbs become unrecognizable.
Dakar's Infrastructure
Dakar's suburbs were never designed for large-scale habitations and neighborhoods. As urban sprawl expanded, rural populations began to settle closer to the city. They developed neighborhoods and towns without drainage canals, sewage systems, or urban planning. Poorly placed buildings and roads blocked rain-water circulation and drainage to rivers and the sea.
In the early 2000s, Senegal's road infrastructure was in the middle of the quality distribution among West African countries. Road standards were judged adequate and of average quality. The country has a few main highways (the most used being the Dakar-Diamniadio Toll Highway) and created the Second Generation Road Fund (FERA) and the Road Maintenance Executing Agency. Yet, the efforts of the early 2000s are still helpless against water.
Floods of August 2022
While compared to more serious floods--such as those of August 2012 which saw 156mm of water fall in two hours--the floods of August 5th did not count as many casualties, but were still an alarming wake-up call. City streets drowned under 1meter of water, causing damage to roads and buildings, and widespread traffic disruption.
At least four people died; one man lost control of his vehicle in a flooded tunnel; one taxi driver and his two passengers were locked in a flooded car (Senegalese taxis are notoriously old and often defective cars). Roads were blocked for entire days (my family and I spent 7 hours on the highway on what should have been a 15-minute trip) because no cars can move until the water does:
Environmental Concerns
In addition to the many functional problems of flash floods, there are countless environmental issues that arise with rising waters. Because of the lack of reliable sewage systems in Dakar's suburbs, flood water contains dangerous amounts of raw sewage. Such flood water contaminates surface and ground water, endangering aquatic habitats and human drinking water. It also pollutes agricultural fields, increases soil erosion, and decreases yield.
While these effects are undoubtedly a result of lacking water drainage infrastructure, their magnitude is a testament to climate change-induced extreme weather. The map below compares the 1991-2020 average rainfall in early August to the amount that fell in 2022. The darker the green, the more the rainfall exceeded the average.
Sustainable Solutions
The first and most efficient solution--though not particularly environmental--is to improve water drainage infrastructure and roads. To relieve roads, Senegal updated and reopened it's only train, the 'Train Express Regional' (Regional Express Train) last December.
While Senegal already spends around $910 million on infrastructure per year, nearly $312 million of it is lost to inefficiencies such as poor financial management of utilities and inefficient allocation of resources across sectors. In fact, after catastrophic floods in 2012, the Storm Water Management and Climate Change Adaptation Project promised to invest about $2.36 billion to protect communities from floods with more manholes, pipelines, retention basins... Ten years later, still better infrastructure is needed--perhaps management is the problem now.
To boost its infrastructure sector, Senegal could raise tariffs to cost-recovery levels and reduce operational inefficiencies.
The debate over how environmental these solutions would be still rages on, with both sides raising pertinent arguments. Quick solutions that will boost the country's standard of living and economy in the short-term. or sustainable solutions that have high initial costs and only long-term relief?
Dakar's priority for now is for the uniquely eclectic (and frankly quite dangerous) "Car Rapides" to be able to roll freely to the suburbs, without worrying about flooded roads.
Sources:
Senegal Current Climate. World Bank Climate Change Knowledge Portal. https://climateknowledgeportal.worldbank.org/country/senegal/climate-data-historical#:~:text=Two%20distinct%20seasons%20characterize%20Senegal's,average%20of%201200%20mm%2Fyear.
How Does Flooding Affect Humans and the Environment? Internet Geography. https://www.internetgeography.net/topics/how-does-flooding-affect-humans-and-the-environment/
Davies, Richard. (August 8 2022). Senegal--Deadly Flash Floods in Dakar. https://floodlist.com/africa/senegal-deadly-flash-floods-in-dakar
(February 3 2016) Sustainably Managing Flood Risks in Dakar's Outer Suburbs. The World Bank. https://www.worldbank.org/en/news/feature/2016/02/03/sustainably-managing-flood-risks-in-dakars-outer-suburbs
Briceño-Garmendia, Cecilia M.; Torres, Clemencia; Dominguez, Carolina. 2011. Senegal's Infrastructure : A Continental Perspective. Africa Infrastructure Country Diagnostic. World Bank, Washington, DC. https://openknowledge.worldbank.org/handle/10986/27256