Managing Flood Risks Using Nature-Based Solutions in Nouakchott, Mauritania

Abstract

Whether or not exacerbated by climate change, flood risks are becoming more frequent in the capital city of Nouakchott in Mauritania. Flooding in Nouakchott is due to a combination of both natural factors and human activities. The extreme fragility of the barrier beach that protects the city from the sea, the accelerated exploitation and inadequate infrastructure built along the coast have made this barrier beach highly vulnerable to wave action, exposing the city to a high risk of flooding. Flooding is further exacerbated by rising groundwater levels in several neighborhoods of the city. Cartographic analysis of flood risk indicated that socio-economic impacts associated with floods could be high. In the case of sea water intrusion, up to 30 % of the city could be potentially submerged. This would directly affect nearly 300,000 people and entail high risks of casualties. Associated economic losses due to flooding could be as high as USD 7 billion (Senhoury, Aménagements portuaires et urbanisation accelerée des côtes basses sableuses d’Afrique de l’Ouest dans un contexte de pejoration climatique, cas du littoral de Nouakchott (Mauritanie). Thesis state, University of Dakar, April 29, 2014, 157 pp, 2014).

The following measures based on nature-based approaches are recommended to tackle flood risks in Nouakchott:

• Restore and consolidate the barrier beach through reforestation of degraded areas;

• Put in place an appropriate drainage system for rain and marine waters and a sewage sanitation system;

• Optimize a solution to safeguard the harbor of Nouakchott; and

• Transform wetlands created by the permanent flooding of low-lying areas in the city into urban protected areas.