Groundwater: a resource for resilience in Southern Africa

Because it is available in different seasons and often of good quality, groundwater provides the opportunity to respond to droughts and climatic variations. These ideas underlie phase II of the new SADC groundwater management programme for 2031, following the one completed in 2021.  The Southern Africa Development Community (SADC)’s Groundwater Management Institute (GMI) secured funding from the World Bank and Global Environmental Facility for phase II of the Sustainable Groundwater Management Project.

It is estimated that 70% of the SADC population depends on groundwater for its daily needs. Statistics also show that 40% of SADC's 280 million inhabitants do not have access to an adequate supply of drinking water, and 60% do not have access to adequate sanitation services.

Groundwater is a fundamental resource to achieve a balance between social, economic and environmental, but groundwater is still poorly understood and insufficiently integrated into legal and policy frameworks. This is urgent in view of the increased demand for water in teh region, driven by population growth, inadequate water infrastructure and, above all, climate variability. For example, to increase resilience, three new boreholes have been drilled in Zambia in a project that will help the population of Chongwe to benefit from the necessary access to water. These boreholes will improve access to drinking water for almost 12,000 inhabitants.

This result was made possible by the Southern African Development Community Groundwater Management Institute (SADC-GMI). This pilot project launched by SADC-GMI in Chongwe complements existing boreholes in the region, while alleviating water scarcity. The project also aims to identify and describe a local aquifer in the region with sufficient production capacity for village water supply. The three boreholes will supply an additional 100 m3/hour to the existing water distribution network. It should also be noted that 70% of SADC's rural population depends on groundwater supplies

A resource to be preserved  

Because it is widely available and often of good quality, groundwater has an intrinsic capacity to absorb episodes of drought and climatic variations. Some SADC member states are therefore actively integrating groundwater into their water resource management policies and legislation. These resources are particularly important for building climate resilience and reducing poverty by improving human well-being, livelihoods, food production, ecosystems, industries and urban growth in SADC. Despite varying dependence on groundwater in SADC member states, it generally provides an essential buffer between dry and rainy seasons.  Groundwater is also resilient to climatic variations and changes.

There is increasing evidence for the importance of groundwater in climate adaptation. A study coordinated by researchers from University College London, Cardiff University (UK) and IRD, published in the journal Nature shows that groundwater renewal depends on heavy rainfall and flooding events, which could be amplified by climate change. In arid zones such as Tanzania, groundwater is generally renewed from localized seepage beneath temporary streams and lowland ponds.This is why Jean-Michel Vouillamoz, hydrogeologist and geophysicist at IRD, who coordinated data analysis in Benin in 2019, insisted that "a better understanding of the processes that control the renewal of groundwater stocks is of great importance to better estimate the impacts of climate change and thus develop appropriate adaptation strategies". Previous studies have, according to Richard Taylor (UCL), one of the coordinators of the study in question, quoted in Nature magazine, "underestimated their renewal and resilience in the face of climate change".