
Scientists have stated that vast reservoirs of groundwater exist under the surface of much of Africa.

A detailed map of its location has been produced for the first time. Much of the water is under traditionally parched areas – indeed the volume is thought to be as much as an equivalent of 75m of water in thickness.
With sustainable use it seems that these reserves could offer an opportunity to both alleviate present needs, and increase food production, via irrigation, to provide for the continents growing population.
http://geographyblog.eu/wp/?p=9284