Aqueduct

Constructions either above or under ground employed to conduct water. Aqueducts of Roman construction, some of which are still in existence, are absolute monuments of art, and in some cases harmonise wonderfully with the lines of the landscape. In modern times aqueducts are built from the designs of engineers, and are as a rule nothing more than waterpipes of immense girth. They are generally carried underground that they may escape the frost in winter and that the water they convey may be kept cool in summer. (1891a1)

Structure any channel or artificial conduit constructed to supply water to an area from a source some distance away. The term is most commonly applied to large arched bridges built by the Romans to carry water over valleys and through ravines and used for the baths, for street cleaning, and for public mains. Aqueducts generally entered a city near its gateway and terminated at a distribution junction (castellum) where the public and private supplies would be drawn. There are some remains, such as Pont-du-Gard near Nismes, France, and Segovia in Spain. The longest was 82 miles (132 km) at Carthage. Aqueducts often discharged into reservoirs.

Any channel constructed for the supply of water, but most commonly applied to the massively engineered arched bridges built by the Romans both to carry water supplies over valleys and ravines, and also to maintain correct height and fall across open spaces. The most famous examples are the Pont du Gard outside Nimes (Roman Nemausus) in southern France, and the colossal double-tiered example at Segovia in Spain. Building costs were high (Aqua Marcia cost 180,000,000 sesterces) and maintenance was also expensive and demanding. Leakage was a dominant problem, and it is likely that a typical installation operated with high water losses. An aqueduct would usually terminate at a distribution junction (castellum) whence public and private supplies would be drawn, with non-essential consumers taking the overflow water, and time limits being generally applied.