Groundwater resources in sub-Saharan Africa are more substantial than many people realise. However, groundwater use for agriculture is relatively low, especially compared to Asia. What use there is may be underappreciated by development researchers.

Understanding groundwater use, and the challenges of using this more extensively, can demonstrate how this resource could contribute to future agricultural development and poverty alleviation in sub-Saharan Africa (SSA). However, research from the International Water Management Institute highlights the lack of information on agricultural groundwater in SSA and raises several questions. What contribution does groundwater make to the agricultural economy and rural development? How much groundwater is used? How much groundwater is available? 

Farmers in SSA have used groundwater for centuries. It is primarily used to ease the effects of erratic rainfall and drought on agricultural production. This is particularly important in SSA, a region with the highest rainfall variability in the world. Groundwater has three main agricultural functions: crop production, livestock watering and drought mitigation. Using groundwater to reduce poverty depends on understanding more about these. The research shows:

• Groundwater is used for both traditional subsistence crops and large-scale commercial crops.
• Agricultural groundwater use probably contributes to the livelihoods of over 1 million people.  
• Large areas of Africa have livestock-based economies – approximately 10 percent of Africa’s population depends directly on livestock and a further 60 percent is partially dependent. A large proportion of livestock is watered from wells that yield too little water for irrigating crops.

However, a lack of further information and data has made it difficult to fully value these uses. Even when considering these existing activities, groundwater use is still low compared to other regions, especially considering the size of SSA’s groundwater resources.

There are several reasons why groundwater is not used more widely:

• Most groundwater resources are located in high rainfall areas, where it is least needed.
• Physical and policy factors lead to relatively high development costs for extracting groundwater.
• National and donor policies have often given greater focus to developing surface irrigation resources, which can reduce groundwater use.

Future research and policies in SSA should aim to understand where additional groundwater development is possible and, of equal importance, where it is not and why. This will require further research to overcome the information gaps on agricultural groundwater use and potential in SSA. The research recommends:

• Policymakers need more basic information on current agricultural groundwater use and its value to African economies so that groundwater and its development can be better prioritised.
• Policies for future groundwater development must consider appropriate and feasible technology for developing groundwater resources, as well as political and economic situations that can restrict groundwater use.

Source(s):
‘Agricultural groundwater use in sub-Saharan Africa: what do we know and where should we go?’ Water Policy 7:6, 613 – 626, by Mark Giordano, December 2005 Full document.

Funded by: Government of the Netherlands and the Organisation of the Petroleum Exporting Countries’ Fund for International Development. The research is part of the Comprehensive Assessment of Water Management in Agriculture.

id21 Research Highlight: 11 May 2006

Further Information:
Mark Giordano
International Water Management Institute
PO Box 2075
Colombo
Sri Lanka

Tel: +94 11 2787404
Fax: +94 11 2786854
Contact the contributor: mark.giordano@cgiar.org

International Water Management Institute

Other related links:
'Managing groundwater for dry season irrigation'

'Efficient water use tackles food insecurity'

'Can South Africa’s rural poor be guaranteed water?'

'Efficient water use tackles food insecurity'

See id21's links for Water