Cylindrical water towers like this historic example in Jesup are also known as standpipes.
Water Tower, 1912, Jesup
Vanishing Georgia: Photographs by Brian Brown
Since 2008. A visual survey of Georgia's historic architecture and culture. 9,000 locations. 30,000 images.
Are you sure that this is a water tower? We have a VERY similar structure in our town that is or was an incenterator.