The Romans didn't invent the aqueduct. According to the Oxford Classical Dictionary, 3rd ed. rev., hydraulic engineering "was quickly adopted by the nascent cities of the Greek world and their leaders: ground-level aqueducts bringing water from extramural [outside the community] springs into Greek cities were at least as old as the 6th cent. BC: notable late-Archaic examples are at Athens, using clay piping, and on Samos, where the water was channeled by rock-hewn tunnel through the acropolis..."
Note: "Most aqueducts did not draw their water from a reservoir. They drew it from a river or a spring that fed water into the system as fast as it was used at the other end. Like an electric grid, the system worked on the principle of constant throughput, with no provision anywhere for storage worth mentioning. The water was supplied as needed and used as supplied -- immediately." -- Roman Aqueducts & Water Supply, A. Trevor Hodge (a classic, massively-detailed studies of aqueducts).