Evolution of water wells focusing on Balkan and Asian civilizations

The provision of water has been a major enterprise in human history. Groundwater was one of the first sources since the prehistoric times to cover human needs. Initially, the exploitation of groundwater has been made by shallow wells and later by boreholes. A water well is constructed through excavation in the ground by digging, driving, boring, or drilling to access groundwater in aquifers. Groundwater wells were used in the Helladic world since Neolithic times. Ancient China developed a sophisticated tool for drilling water wells that is similar to modern machines. Qanat, a system of wells, originated in Iran (Persia), but was adopted by other countries. Moreover, the Indus valley civilization had well-constructed wells mainly for drinking purposes. The construction of wells varied according to local conditions, determined by geology, hydrogeology, and morphology, as well as by local tradition. Furthermore, a well was not just a water source but also became a cultural symbol throughout history, related to local religion and custom. The stepwells in India became not only sources of drinking water, but also holy places (sanctuaries) for bathing, meditation and prayer. In the present review, the evolution of wells through the centuries is examined. The study of water well technologies demonstrates their diachronic evolution and, furthermore, reveals that the ancient people had an outstanding engineering knowledge of water exploitation, which is interesting for water engineering and hydrogeologists, even nowadays.