Groundwater plays a fundamental yet often little appreciated role in supporting economic development and human well-being in both urban and rural environments, as well as supporting many aquatic ecosystems in Africa. Thus, groundwater has high relevance to the development and well-being of Africa, if adequately assessed and sustainably exploited. Whilst the potential for groundwater-resources development continues to be reported in the literature, a quantitative understanding of these issues remains poor. The objective of this paper is to highlight the main groundwater issues and problems in Africa and the current and expected opportunities for sustainable groundwater management. This will be done through the review of existing knowledge of groundwater resources and of ongoing and planned groundwater management programs and initiatives. Groundwater resources in Africa face increasing threat of pollution from urbanisation, industrial development, agricultural and mining activities, and from poor sanitation practices and over-exploitation due to increasing demand to meet human and agricultural needs. However, despite the existence of a number of groundwater management challenges, groundwater resources in Africa are still generally under-developed and can meet the various needs in a sustainable manner if better managed. Thus, strategies to ensure sustainable development and management of groundwater resources need to be put in place. These include establishment of groundwater monitoring systems, understanding of the groundwater–aquatic ecosystem relationships, management of transboundary aquifers, addressing climate-change impacts on groundwater, assessing the impact of increased pumping from various types of aquifers on sustainability of groundwater abstraction, and capacity building in groundwater management.

The groundwater resources potential of Ethiopia is estimated to be about 40 billion cubic meters. Groundwater has been used as the main source of water supply since the 1970s for the main cities, towns and dispersed rural communities across the country, where provision of reticulated surface-water schemes is often expensive because of initial project construction costs and poor water quality. The exponential growth of the urban population and agriculture-led industrial development have resulted in greater attention to groundwater as the potentially cost-effective water supply source. As part of the growing focus on the use of groundwater, the Ethiopian government is currently implementing irrigation projects. One plan involves nine irrigation projects covering an estimated area of 8,000 ha, being developed on a pilot scale, with 9,000 test wells, 28,000 monitoring wells and 14,657 spring improvements. If this unprecedented Ethiopian groundwater-centred development plan is implemented successfully at such a scale, it is highly likely that its success will persuade other Sub-Saharan developing nations to put in place the necessary policies, regulations and investment for infrastructure and capacity development for exploring, exploiting and managing their groundwater resources.

In the Bandung basin, Indonesia, excessive groundwater pumping caused by rapid increases in industrialization and population growth has caused subsurface environmental problems, such as excessive groundwater drawdown and land subsidence. In this study, multiple hydrogeochemical techniques and numerical modeling have been applied to evaluate the recharge processes and groundwater age (rejuvenation). Although all the groundwater in the Bandung basin is recharged at the same elevation at the periphery of the basin, the water type and residence time of the shallow and deep groundwater could be clearly differentiated. However, there was significant groundwater drawdown in all the depression areas and there is evidence of groundwater mixing between the shallow and deep groundwater. The groundwater mixing was traced from the high dichlorodifluoromethane (CFC-12) concentrations in some deep groundwater samples and by estimating the rejuvenation ratio (R) in some representative observation wells. The magnitude of CFC-12 concentration, as an indicator of young groundwater, showed a good correlation with R, determined using ¹⁴C activity in samples taken between 2008 and 2012. These correlations were confirmed with the estimation of vertical downward flux from shallower to deeper aquifers using numerical modeling. Furthermore, the change in vertical flux is affected by the change in groundwater pumping. Since the 1970s, the vertical flux increased significantly and reached approximately 15% of the total pumping amount during the 2000s, as it compensated the groundwater pumping. This study clearly revealed the processes of groundwater impact caused by excessive groundwater pumping using a combination of hydrogeochemical methods and modeling.