Hissaeni Abdoulaye, 46, center, washes his face with water from an animal trough, after using a donkey to pull it up from a well which took twenty men a week to dig by hand, in a wadi near Tchyllah, a desert village in the Sahel belt of Chad, Thursday, April 19, 2012. UNICEF estimates that 127,000 children under 5 in Chad’s Sahel belt will require lifesaving treatment for severe acute malnutrition this year. (AP Photo/Ben Curtis)

Access to clean water remains a problem for millions in Africa, but new research suggests that there may be hope. Researchers from the British Geological Survey and University College London have mapped the quantity and potential yield of groundwater across the entire continent, explained PhysOrg—–.

They estimate that Africa’s groundwater totals about 0.66 million cubic kilometers, which means the continent has over 100 times more water underground than on the surface. The study’s authors calculated the groundwater using a database they compiled of “existing national hydrogeological maps as well as 283 aquifer studies from 152 publications.”

The vast quantity of water could mean the potential for relief for the estimated 300 million Africans lacking access to safe drinking water, but it may not be easy. Reuters notes that the groundwater reserves are “no panacea” for Africa, but they could help “to cope with an expected sharp increase in demand for water as the continent’s population increases.”

Published this week in Environmental Research Letters, the study cautions that not all the groundwater may be accessible. A senior adviser for Global Water Partnership told Reuters, “It is not as simple as drilling big bore holes and seeing rice fields spring up everywhere. In some places it could be economically and technically feasible to use groundwater to reduce crop loss, but I would question whether that is true everywhere.”

A spokesman for the United Nations Environment Program Nairobi, Kenya explained to Reuters, “The discovery of substantial water reserves under parts of Africa may well be good news for the continent but it may prove hard to access in the near term and, if not sustainably managed, could have unforeseen impacts.”

Instead, the researchers explain, small-scale development of the water resources may be the best option. Study co-author Helen Bonsor told the BBC, “Our work shows that with careful exploring and construction, there is sufficient groundwater under Africa to support low yielding water supplies for drinking and community irrigation.”

She also explained that if appropriately developed, the groundwater may help Africans deal with water fluctuations as a result of climate change. Bonsor said, “So at present extraction rates for drinking and small scale irrigation for agriculture groundwater will provide and will continue to provide a buffer to climate variability.”

The research comes as experts warn that increasing water scarcity is likely to contribute to political instability in Africa and elsewhere. John Kufuor, a former president of Ghana and current head of the Sanitation and Water for All partnership, recently told Bloomberg, “People migrate to find water anywhere if there’s a scarcity situation. People have fought wars to access water.”