The Sahel sits atop some of the largest aquifers on the continent. Recent research estimates that the volume of continental groundwater storage is in the order of 0.66 million km3, which is approximately 100 times the volume of annual renewable freshwater resources on the continent. The people living in the Sahel are heavily dependent upon groundwater, directly or indirectly, for their livelihoods. Groundwater in the Sahel region is under threat from a variety sources including urban expansion and rapid development of agriculture. Unsustainable extraction of groundwater is compounded by the impacts of climate change. Furthermore, there are real risks of the unsustainable ‘mining’ of deeper aquifers which are either fossil groundwater, or aquifers with such a long replenishment rate that they are effectively nonrenewable. Sustainable development of groundwater, in order to increase the climate resilience of communities, represents an opportunity for innovative investments and management choices that can also contribute to improved livelihoods and fighting poverty among dryland communities.
Currently there are several gaps in knowledge regarding groundwater. These include lack of:
- Information on the groundwater resource base at suitable scale for planning and coordination, management and development
- Clarity over current levels of extraction and use, and anticipated level of demand given national and regional agendas
- Understanding of exploitation pressures and its implications
- Technical capacity gaps (e.g., in surface-groundwater linkages, groundwater assessment capacity)
- Economics of developing transboundary aquifers
- Institutional cooperation to address management and development of groundwater
- Monitoring and data sharing (national/regional)
The aim of this activity is to enhance understanding of groundwater resources and identify opportunities for investing in collaboration in groundwater resources management and development in the Sahel. This activity, in close coordination with activities associated with the Sahel Initiative of the Bank, will focus on enhancing knowledge regarding groundwater usage. This activity would first identify critically vulnerable areas within the Sahel where growth could be supported by groundwater abstraction from transboundary aquifers and where either; cooperative agreements are not in place or transboundary aquifer characteristics are unknown. Once the project areas had been identified this activity would support cooperation on transboundary aquifers by:
- Drawing on ongoing work (e.g., drylands work and others) that examine the availability of groundwater and will help estimate the practicality and cost of accessing groundwater resources for agriculture.
- Complementing the ongoing work by conducting a rapid assessment of the demand (current and project) for groundwater (e.g., for drinking, industry and agriculture).
In addition to the rapid assessment, the activity will include:
- A rapid appraisal of level of compliance with the draft articles of the UN Law of Transboundary Aquifers and capacity needs of existing institutions. The appraisal would also assess capacity to monitor groundwater extraction and potential for cooperation.