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.
For the people of northern Namibia water is something that they either have too much of or too little.
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
have 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.
On the Namibian side of the border it covers an area roughly 70 km by 40 km (43 miles by 25 miles).
According to project manager Martin Quinger, from the German
federal institute for geoscience and natural resources (BGR), 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, which has about 40 percent
of the nation's population."
"What we are aiming at is a sustainable water supply so we only extract the amount of water that is being recharged.
"What we can say is that the huge amount of stored water is
will always be enough for a back up for an area that is currently
supplied only by surface water."
Water is the world’s most critical strategic resource, and a $470 billion industry.
