Programme background

Groundwater storage for Africa based on the effective porosity and saturated aquifer thickness. Panel (a) shows a map of groundwater storage expressed as water depth in millimetres with modern annual recharge for comparison (Döll and Fiedler 2008). Panel (b) shows the volume of groundwater storage for each country; the error bars are calculated by recalculating storage using the full ranges of effective porosity and thickness for each aquifer, rather than the best estimate. Annual renewable freshwater availability (FAO 2005) generally used in water scarcity assessments is shown for comparison
Groundwater storage for Africa based on the effective porosity and saturated aquifer thickness. Panel (a) shows a map of groundwater storage expressed as water depth in millimetres with modern annual recharge for comparison (Döll and Fiedler 2008). Panel (b) shows the volume of groundwater storage for each country; the error bars are calculated by recalculating storage using the full ranges of effective porosity and thickness for each aquifer, rather than the best estimate. Annual renewable freshwater availability (FAO 2005) generally used in water scarcity assessments is shown for comparison

Water resources are critical to economic growth and social development. Groundwater provides most of the domestic water supply in parts of rural Africa and supports poverty reduction through access to clean drinking water and irrigation[1]. In 2015, only 23 of the 52 countries in Sub-Saharan Africa (SSA) met the UN Millennium Development Goals target for drinking-water provision[2] and Target 6.1 of the Sustainable Development Goals is to achieve universal access to safe, affordable water by 2030. Groundwater has the potential to provide an improved source of drinking water for those in SSA who are currently without access. It is also a relatively safe source of water for drinking and agriculture/livestock – it is naturally protected from contamination, so is generally of excellent quality and needs no treatment.

Yet water is not only an important resource for the poor living in rural SSA, but is also central to most industries and a vital commodity for tourism. Industry is an important source of income for several African countries and a lack of water supply could constrain opportunities for development, including better services and improvements to poor people’s livelihoods. Groundwater sources are often resistant to drought, acting as a natural buffer against rainfall variability. However, groundwater is already intensively used in certain parts of Africa and in some cases it is being extracted faster than it can be replenished. As the population grows, water security in SSA will become increasingly important and demands on groundwater resources are likely to surge. To ensure sustainability, greater understanding of groundwater resources and how to manage their use effectively will be required.

A recent study on groundwater in Africa has shown that there is possibly 20 times more water available as groundwater compared with that available in lakes and rivers[3]. Droughts are currently a major cause of humanitarian disaster in SSA, often leading to mass population movements and considerable health, social and economic stress on many developing nations. These humanitarian disasters are likely to grow in scale as populations increase and climate and land-use change accelerate. With these increasing pressures on water resources, the potential pressure on groundwater as the solution to the water security challenge in SSA is high.

Without addressing some of the core gaps in the evidence and data, it will be hard to identify and manage the full implications of increased groundwater use. Abstraction of groundwater could accelerate out of control and bring with it some of the harm experienced in other regions. The sinking of bore holes is likely to remain ad-hoc and costly without data to help guide their placement and management of how much can be extracted, so the likelihood remains that boreholes and hand-pumps may fail after limited use.

To maximise the sustainable use of groundwater for the benefit of the poor and reduce the risk of damage to the environment, a number of questions need to be asked, such as:

  • Where is the groundwater, how and at what rate is it recharged, and how can it be more effectively and efficiently abstracted to meet local needs?
  • What is the state of the resource – quality and quantity – and how will it respond to abstraction, impact of growing population, climate change etc.?
  • What management and institutional arrangements are needed to support this access in an inclusive and sustainable way, and in particular to reach the poorest and most marginalised groups?
  1. Hunter et al. 2010. Water Supply and Health PLoS Med7 (11): e1000361
  2. JMP
  3. MacDonald et al. 2012. Quantitative maps of groundwater resources in Africa. Environ. Res. Lett. 7. 024009

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