There is a crucial need for sustainable water management practices to ensure water security and equity in West Africa’s Senegal river basin, according to a new report.
The Senegal River Basin (SRB) spreads across the nations of Guinea, Mali, Mauritania, and Senegal. It comprises nine sub-basins, including the Lower Senegal River Valley, the Middle Senegal River Valley, and the tributary watersheds of the Bafing, Baoule-Bakoye, Faleme, Ferlo, Terekole Magui Kolimbine, Karakoro, and Gorgol rivers.
The report is a collaboration between the Food and Agriculture Organization (FAO) and the Organization for the Development of the Senegal River (OMVS).
Water stress is a growing problem in the basin, driven by increasing demand from rapid urbanisation and agriculture, combined with the threat of climate change and its associated extreme events.
The report provides a detailed analysis of water stress in the basin.
High stress
Surface and groundwater resources are facing over-extraction in Senegal.
Current water withdrawals are projected to increase by 30 to 60 per cent by 2035.
Demand for surface water is highest in Senegal, primarily for agriculture. Agriculture accounts for 93 per cent of total water demand compared to domestic (4.4 per cent) and industrial uses (2.6 per cent). Approximately 70 per cent of the population is engaged in agriculture and around 30 per cent of agriculture is irrigated, of which 73 per cent is in the Senegal River Valley.
According to the report, by 2050, it is projected that total irrigated land would increase from 195,000 hectares to 430,000 hectares in the SRB.
Using an integrated hydrological model built with Water Evaluation and Planning (WEAP) software, the report monitors Sustainable Development Goal indicator 6.4.2, which measures freshwater withdrawal against available resources, including environmental flows.
By combining a hydrological approach, spatial disaggregation, and scenario analysis, this tool provides a detailed and contextualised understanding of water resource stress.
The calculation and analysis of water stress in the current situation covered the period 2020-2024 to account for the natural inter-annual variability of hydrological conditions.
The results obtained reveal marked heterogeneity in water stress between the sub-basins.
While some, such as the Bafing and the Faleme, exhibit structural water resilience, others, such as the Lower Valley and the Middle Valley, display chronic vulnerability, accentuated by the seasonality of flows and the concentration of agricultural and domestic uses. The other sub-basins (Faleme, Ferlo, and Gorgol) exhibited moderate water stress during the dry season.
Current water stress (from 2020 to 2024) was assessed based on three climate change scenarios — stable wet climate conditions, stable dry climate conditions, and very dry climate conditions.
Comparing water stress across climate scenarios shows that the stable wet climate condition exhibits higher annual water stress than the stable dry climate condition, which in turn is higher than the stable dry climate condition.
These contrasts underscore the importance of designing differentiated management strategies, adjusted to local realities.
The report’s detailed data on water stress at national and sub-national levels supports policymakers and stakeholders in making informed decisions and developing effective water management plans.