A newly discovered water source in Namibia could have a major impact on development in the driest country in sub-Saharan Africa.
Estimates suggest the aquifer could supply the north of the country for 400 years at current rates of consumption.
Scientists say the water is up to 10,000 years old but is cleaner to drink than many modern sources.
However, there are concerns that unauthorised drilling could threaten the new supply.
The 800,000 people who live in the area depend for their drinking water on a 40-year-old canal that brings the scarce resource across the border from Angola.
Over the past decade, the Namibian government has been trying to tackle the lack of a sustainable supply, in partnership with researchers from Germany and other EU countries.
They have now identified a new aquifer called Ohangwena II, which flows under the boundary between Angola and Namibia.
According to project manager Martin Quinger, from the German federal institute for geoscience and natural resources, it’s a substantial body of water.
“The amount of stored water would equal the current supply of this area in northern Namibia for 400 years.
“What we can say is that the huge amount of stored water will always be enough for a back-up for an area that is currently supplied only by surface water,” he said.