The Senegal River basin

The Senegal River drains an area of 337000 km2 in western Africa. The basin is shared by four countries: Guinea, Mali, Mauritania and Senegal. The headwaters are located in Guinea, the water tower of the basin, where the Bafing River runs north until it merges with the Bakoye in Mali. From there, the Senegal River runs north-west through a series of falls and gorges before arriving in Kayes. Downstream of Kayes, the hydraulic gradient is much lower and the river meanders through the plain while forming the boundary between Mauritania and Senegal until it discharges into the Atlantic Ocean.

The work in the Senegal started in 2015 with the MSc thesis of Mrs. Ndèye Aïda Thiam who studied the optimal flow allocation in the basin. The work was quickly extended through a project funded by the Food and Agriculture Organization of the United Nations (FAO): “Enhanced cross-boundary water resource management in the Senegal River Basin“. The main results were published as a policy brief and as a scientific paper submitted to the Journal of Hydrology.

Between 2018 and 2020, the impacts of climate change on flow allocation policies and on trade-offs between competing uses were investigated in a follow-up project also funded by FAO. In terms of vulnerability, our simulation results show that (i) hydropower and navigation are high climate-sensitive sectors, (ii) flood recession agriculture and fisheries are instead highly sensitive to changes in allocation policies, while (iii) irrigated agriculture remain fairly robust vis-à-vis natural and anthropogenic factors.

The Gouina Falls on the Senegal River

Our work in the Senegal River basin is now done through the GoNEXUS project. Using the nexus approach and tools that will be developed within this project, we will assess the regional, national and local impacts of alternative water, food, energy security policies on the energy, agricultural and transportation sectors as well as on the economically and politically-marginal communities in downstream riparian countries. Ultimately, that information should contribute to the design of robust water institutions capable of handling the challenges posed by the rapidly changing hydro-socio-economic environment, and to reduce the social cost of achieving water security. Building such institutions will be key in mitigating outmigration and conflict in the region.


  • Espanmanesh, V. and A. Tilmant, 2022. Optimizing the management of multireservoir systems under shifting flow regimes. Water Resources Research58, https://doi. org/10.1029/2021WR030582
  • Guilpart, E., Espanmanesh, V., Tilmant, A., and F. Anctil, 2021. Combining split-sample testing and hidden Markov modelling to assess the robustness of hydrological models, Hydrol. Earth Syst. Sci., 25, 4611–4629,
  • Tilmant A., J. Pina, M. Salman, C. Casarotto, F. Ledbi and E. Pek, 2020. Probabilistic trade-off assessment between competing and vulnerable water users – The case of the Senegal River basin. Journal of Hydrology 587. DOI: 10.1016/j.jhydrol.2020.124915
  • Salman M., C. Casarotto, A. Tilmant and J. Pina, 2018. Hydro-economic modelling for basin management of the Senegal River. Food and Agriculture Organization of the United Nations, Rome, Italy.