Something we occassionaly come across are free flowing aquifers. When we drill we sometimes penetrate an aquifer that is under pressure and the water starts to flow up the drill pipe to the surface. This indicates we have drilled through a confining clay layer into a body of water that has a hydrostatic head higher than the ground level. Perhaps this water is originating all the way from the Udzungwa Mountains which start around 5-10km from Ifakara. The below is a picture from todays drilling where at 21m the water started to flow freely to the surface.
MSABI driller Cretus admires the free flowing aquifer.