A Roman aqueduct carried water across valleys using raised arches and carefully graded channels.
Most Roman aqueducts were networks of underground conduits, tunnels, bridges, settling tanks, and distribution systems. The water usually flowed by gravity from a spring, river, or reservoir toward a city. Raised arcades were used only where the terrain required an elevated channel or where a steady gradient had to be maintained.
Aqueduct water supplied fountains, baths, latrines, workshops, and some private homes. Rome itself was served by multiple aqueducts, beginning with the Aqua Appia in 312 BCE. The system required surveying, maintenance, inspection, and legal controls to prevent illegal tapping.
The Pont du Gard in southern Gaul is one of the best-preserved examples of Roman aqueduct architecture. It carried water to Nemausus, modern Nîmes, and combined practical engineering with monumental construction.