Adapting Dakar's stormwater retention basin to climate change

Project description

Title: Hydraulic and Landscape Redevelopment of the Stormwater Retention Basin in Grand Yoff, Dakar
Commissioned by: German Federal Ministry for Economic Cooperation and Development (BMZ)
Co-funded by: British Government, United States Agency for International Development (USAID), Children’s Investment Fund Foundation (CIFF)
Country: Senegal, global programme
Lead executing agency: City of Dakar, National Sanitation Office of Senegal (ONAS)
Overall term: 2016 to 2022

Retention basin. Copyright: GIZ.


Dakar has a large flood retention basin for rainwater. The basin, built in the 1990s, captures water from precipitation, prevents flooding and enables targeted irrigation of areas of land. The retention basin is located at the lowest topographical point of the city, so water collects here and frequently leads to flooding. The water is pumped from the basin into the sea.

The basin currently urgently requires renovation. On one hand, a high level of immigration is leading to increased infrastructural demands. On the other, wastewater, rubbish and the poor structural state of the basin cause problems. As a result, there are annual floods after rainfall. This flooding is a risk to the health of the local community and the inhabitants' quality of life, and has significant impacts on adjacent infrastructure, such as the nearby hospital.


The retention basin is adapted to the effects of climate change and protects Dakar's water supply.

Retention basin from another perspective. Copyright: GIZ.


The project supports practical implementation and works in partnership locally with authorities and experts. It also offers training, provides technical support and carries out the topographical and geotechnical studies required for its implementation.

The implementing project partner is the Urban Development Department of the City of Dakar. The studies were undertaken by independent French consultants.

The C40 Cities Finance Facility (CFF) assisted the City of Dakar in getting the project ready for investment. The German Federal Ministry for Economic Cooperation and Development (BMZ), the British Government, the United States Agency for International Development (USAID) and the Children's Investment Fund Foundation (CIFF) are all involved in funding the project.

Last update: July 2022

An inflow carrying rainwater into the retention basin. Copyright: GIZ.