Aqueducts are older than Rome by well over a thousand years
Aqueducts call to mind Roman arches, but the Minoans of Crete were probably building them around 2000 BC. By the 7th century BC the Assyrians had run an 80-kilometre limestone channel to Nineveh, lifted 10 metres high to cross a valley 300 metres wide, long before Rome's engineers made the idea famous.
The name joins the Latin aqua, water, and ductus, led. Today it covers any system of ditches, canals, tunnels and pipes carrying water from a source to a distant point, and often the bridge that carries such a channel. The simplest are shallow trenches in the soil; bigger ones use huge channels, underground tunnels or pipelines. Farming societies built them both to water crops and to supply large cities with drinking water.
Egyptians and Harappans devised sophisticated irrigation in the Nile Valley and the Indian subcontinent, and the Aztecs and Incas later arrived at similar systems on their own. Near the Tungabhadra River at Hampi, in Karnataka, great irrigation aqueducts once ran 24 kilometres and fed royal baths.
Dry lands produced an especially clever design. In Persia, starting roughly 3,000 years ago, builders dug qanats: lines of vertical shafts like wells, linked at the bottom by gently sloping tunnels. They tap groundwater in upland aquifers and let gravity bring it to the surface lower down with no pumping, and because the water travels underground, far less is lost to seepage and evaporation in the heat. Oman had its own version, the falaj, at Iron Age sites such as Salut and Bat. Some drew on underground channels, some needed a dam to gather water and others started at a spring, and together they let large-scale farming thrive in the desert.
At Petra in Jordan, Nabataean engineers made use of every spring and every winter storm. Their aqueducts and pipes carried water over mountains and through gorges into temples, homes and gardens. Visitors walking the narrow gorge of the Siq can still see channels that led water to the city centre, along with sturdy dams that held back flash floods.
Source: Aqueduct (water supply)
