A majority of people in sub-Saharan Africa lack access to reliable, safe water.
But a British researcher said her latest research shows part of the solution to this massive human development problem lies right under their feet.
Helen Bonsor, a hydrologist for the British Geological Survey, said her research shows that groundwater – underground water sources – is available across the continent in huge quantities: "over 100 times the annual renewable freshwater resource available in Africa, and 20 times that stored in Africa's freshwater lakes."
Bonsor led a team from the BGS and the University College London in crafting a comprehensive map of the groundwater sources across Africa, complete with details about exactly how much water can be found.
"Previously, groundwater was discussed in terms of high potential, low potential, and no potential. And that was the extent of the information," Bonsor explained.
Her team took data from small-scale local studies and compiled them on a continent-wide scale to produce the map. So now, instead of generalities, Bonsor said, "we're talking about, well in this area, with careful exploration and siting of boreholes, you are likely to get a yield of one to five liters per second."
Because that quantitative data had been missing, Bonsor said, groundwater had "often been left out of discussions on water scarcity and water security."
She hopes her new map will help change that, and prompt governments to focus on developing groundwater sources.
"It's a huge resource sitting there," Bonsor said. "This work demonstrates that if it's managed appropriately, and with proper governance and technology to access the water source, and with the proper governance, it could alleviate water poverty."
The World Health Organization says a growing number of people lack access to safe, reliable water sources; as the population increases, a larger proportion move to cities, and domestic and industrial demands rise.
The WHO says water scarcity poses serious health risks, both from people drinking and irrigating with contaminated water and from people storing water in their homes, which can become breeding grounds for disease-carrying mosquitoes.
Bonsor noted that water scarcity also contributes to poverty because it forces people to spend time in search of water that they could have otherwise used to go to school or develop their business.
Her research was funded in part by the UK Department for International Development.