Pressure on groundwater in growing African cities in the face of climate change: challenges and opportunities learned from Lusaka and Windhoek

ABSTRACT Groundwater plays a critical role in urban water security across African cities, yet its management is often fragmented amid rapid urbanization, population growth and climate variability. This study provides an overview of groundwater development approaches in Lusaka (Zambia) and Windhoek (Namibia), two cities with contrasting hydrogeological settings but similar water security challenges. Through a comparative review of literature and secondary data, the study identifies knowledge gaps and transferable strategies. In Lusaka, over 50% of potable water is drawn from a vulnerable karst aquifer increasingly stressed by population growth. In contrast, Windhoek manages its aquifer as a strategic storage reserve by incorporating artificial recharge systems that inject over 2.8 million m3 annually. The city further strengthens water security through potable water reuse which contribute about 30% of supply. This integrated approach has enabled Windhoek to diversify water sources, enhance resilience to climatic and population pressures, and optimise the use of water resources in a semi-arid environment. Key lessons include the need for aquifer protection in rapidly urbanizing areas, the role of managed aquifer recharge, efficient water use, source diversification, and robust regulatory frameworks. The findings underscore the importance of regional knowledge exchange and climate-adaptive groundwater policies to safeguard urban groundwater sustainability.