Aqueduct. An aqueduct is a watercourse constructed to carry water from a source to a distribution point far away. In modern engineering, the term aqueduct is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose. The term aqueduct also often refers specifically to a bridge carrying an artificial watercourse. Aqueducts were used in ancient Greece, ancient Near East, and ancient Rome. The simplest aqueducts are small ditches cut into the earth. Much larger channels may be used in modern aqueducts. Aqueducts sometimes run for some or all of their path through tunnels constructed underground. Modern aqueducts may also use pipelines. Historically, agricultural societies have constructed aqueducts to irrigate crops and supply large cities with drinking water. The word aqueduct is derived from the Latin words and. Further information: History of water supply and sanitation Although particularly associated with the Romans, aqueducts were devised much earlier in Greece, the Near East, Nile Valley, and Indian subcontinent, where peoples such as the Egyptians and Harappans built sophisticated irrigation systems. Roman-style aqueducts were used as early as the 7th century BC, when the Assyrians built an 80 km long limestone aqueduct, which included a 10 m high section to cross a 300 m wide valley, to carry water to their capital city, Nineveh. Although particularly associated with the Romans, aqueducts were likely first used by the Minoans around 2000 BCE. The Minoans had developed what was then an extremely advanced irrigation system, including several aqueducts. Medieval Deccan aqueduct in Hampi The Indian subcontinent is believed to have some of the earliest aqueducts. Evidence can be found at the sites of present-day Hampi, Karnataka. The massive aqueducts near Tungabhadra River supplying irrigation water were once 15 miles long. The waterways supplied water to royal bath tubs. There are three types of falaj: Daudi with underground aqueducts. Ghaili requiring a dam to collect the water. Aini whose source is a water spring. These enabled large scale agriculture to flourish in a dry land environment. This technique: taps into subterranean water in a manner that delivers water to the surface without the need for pumping. The water drains relied on gravity, with the destination lower than the source, which is typically an upland aquifer. allows water to be transported long distances in hot dry climates without losing a large proportion of the source water to seepage and evaporation. Nabataean aqueduct in Petra, Jordan Throughout Petra, Jordan, the Nabataean engineers took advantage of every natural spring and every winter downpour to channel water where it was needed. They constructed aqueducts and piping systems that allowed water to flow across mountains, through gorges and into the temples, homes, and gardens of Petra's citizens. Walking through the Siq, one can easily spot the remains of channels that directed water to the city center, as well as durable retention dams that kept powerful flood waters at bay. On the island of Samos, the Tunnel of Eupalinos was built during the reign of Polycrates. It is considered an underground aqueduct and brought fresh water to Pythagoreion for roughly a thousand years. The multiple arches of the Pont du Gard, in Roman Gaul. Its lower tiers carry a road across the river, and the upper tiers support an aqueduct conduit that carried water to Nimes Main article: Roman aqueduct Roman aqueducts were built in all parts of the Roman Empire, from Germany to Africa, and especially in the city of Rome, where they totalled over 415 kilometres. The aqueducts supplied fresh water to public baths and for drinking water, in large cities across the empire, and set a standard of engineering that was not surpassed for more than a thousand years. Bridges, built in stone with multiple arches, were a distinctive feature of Roman aqueducts and hence the term aqueduct is often applied specifically to a bridge for carrying water. Underground aqueducts of Cantalloc, Nazca, Peru Near the Peruvian town of Nazca, an ancient pre-Columbian system of aqueducts called Puquios were built and are still in use today.