Located 70 km from Dakar in Senegal, the city of Thiès faces recurrent flooding that is aggravated by rapid urbanization, unregulated land management, and the increasing impacts of climate change. These floods particularly affect low-lying areas in the communes of Thiès-Nord and Thiès-Est. Against this backdrop, nature-based solutions (NbS) are emerging as a relevant and complementary alternative to conventional infrastructure for strengthening urban resilience to climate change.
The potential of NbS in the urban context of Thiès
Nature-based solutions refer to approaches that use or draw inspiration from natural ecosystems to meet environmental and social challenges. NbS can play a crucial role in achieving sustainable development and reducing climate risk, while simultaneously enhancing biodiversity, maintaining ecosystem services, and providing co-benefits to people and nature.
In urban environments, they help to regulate runoff, restore vegetation cover, limit erosion, and reduce heat islands, while providing additional economic and social benefits. NbS are often designed and implemented in partnership with communities to ensure that their needs are prioritised and that the solutions are sustainable and provide multiple co-benefits such as supporting livelihoods, improving health, and reducing risk to natural hazards.
Using the Climate Resilience Measurement for Communities approach, a project funded by the Zurich Climate Resilience Alliance identified how a lack of natural resources and assets (i.e., natural capital) is increasing flood risk in Thiès. The assessment, published as a report in 2024, revealed that the city’s vegetation cover remains below 15%, that natural riverbanks are poorly managed, and that undeveloped urban spaces- which provide natural drainage and water retention capacity – are undervalued in flood risk reduction policies. In response, the Alliance-funded project encouraged the promotion of NbS to restore urban ecosystems, build community resilience to flood risk, and integrate nature as a strategic lever for climate resilience.
Practical Action’s work, in partnership with the École Polytechnique de Thiès (EPT), explored the role and potential of NbS to address urban flooding and environmental challenges in Thiès. This research identified 139 NbS initiatives across the city and surrounding area that provide social and economic benefits for residents. These initiatives, which are linked to over 930 formal and informal jobs, cover a range of sectors including urban market gardening, aquaculture, reforestation, waste management, renewable energy, and the creation of green spaces. The findings from this research demonstrate the growing importance of integrating ecological solutions into sustainable urban development strategies to strengthen the resilience of urban communities.
Local practices contributing to flood risk reduction
The NbS initiatives identified in Practical Action’s 2024 study in Thiès have direct and indirect impacts on flood risk reduction. Agriculture and floriculture, which is particularly widespread in the wetlands of Thiès, extracts groundwater for irrigation, which helps to reduce soil saturation and increase the ability of the soil to absorb water in the event of floods. Agriculture and floriculture activities also encourage the revegetation of urban areas, which support the livelihoods of urban residents, generating income for over 500 people.
Aquaculture in flood-prone areas, notably in Nguinth, illustrates the innovative capacity of local actors. The accumulated water is used to raise fish, irrigate gardens, and provide water to animals, in an integrated solar-powered irrigation system. This approach enhances community resilience while making sustainable use of water resources.
Sand dykes and stone barriers implemented on the Thiès plateau, with the support of local NGOs, help to slow runoff, limit erosion and promote water infiltration. These low-cost ecological engineering techniques are particularly well suited to local conditions.
Finally, urban green spaces, which are still underdeveloped, play a crucial role in absorbing rainwater and regulating heat. However, their contribution to flood prevention remains insufficiently recognized and assessed in local policies and urban planning.
Integrating the principles of NbS into urban flood management
Practical Action’s work to strengthen community resilience to urban flood risk using NbS will continue, through an ambitious project called PRECABE, launched in January 2025. Led by Practical Action, in partnership with EPT and the Group for Initiatives for Social Progress/West Africa Region, this project aims to integrate principles of ecosystem-based adaptation into urban flood management. Lasting two years, the project is structured around four components:
- Strengthening the technical and institutional capacities of local authorities and communities;
- Integrating NbS into urban planning documents;
- Targeted support for women involved in urban agriculture and natural resource management; and
- Knowledge-sharing through multi-stakeholder workshops and ongoing training.
In the start-up phase, the project team organized a workshop bringing together local authorities, technical services, researchers, and community organizations. A preliminary assessment of flood risks and ecosystem services will be carried out to guide the design of interventions. The aim of these initial steps is to lay the foundation for a sustainable transformation of urban flood risk management in Thiès, with the potential for replication in other Senegalese cities.
Urban flooding is not inevitable. Through NbS driven by communities themselves, practical and sustainable responses are emerging to build more resilient and inclusive cities. The project in Thiès embodies this ambition, placing local knowledge, ecological innovation, and social justice at the heart of the fight against climate change.
To find out more about the work in Senegal to build resilience to flood and climate risk, visit our Senegal country page.