Aqueduct

This article is about conduits used for water supply. For bridges used by boats, see navigable aqueduct. For other uses, see aqueduct (disambiguation).

Pont du Gard, France, a Roman aqueduct built circa 19 BC. It is one of France's top tourist attractions and a World Heritage Site.

An aqueduct is a water supply or navigable channel constructed to convey water. In modern engineering, the term is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose. In a more restricted use, aqueduct (occasionally water bridge) applies to any bridge or viaduct that transports water—instead of a path, road or railway—across a gap. Large navigable aqueducts are used as transport links for boats or ships. Aqueducts must span a crossing at the same level as the watercourses on each end. The word is derived from the Latin aqua ("water") and ducere ("to lead").

Ancient aqueducts

Nabataean aqueduct in Petra (Jordan)

Mathur Aqueduct, India

Although particularly associated with the Romans, aqueducts were devised much earlier in Greece and the Near East 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 BCE, when the Assyrians built an 80 km long limestone aqueduct, 10 m high and 300 m wide, to carry water across a valley to their capital city, Nineveh.

India

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 river Tungabhadra supplying irrigation water were once 15 miles (24 km) long. The waterways supplied water to royal bathhouses.

Oman

Main article: Falaj

In Oman from the Iron Age Period (found in Salut, Bat and other sites) a system of underground aqueducts called Falaj were constructed, a series of well-like vertical shafts, connected by gently sloping horizontal tunnels. There are three types of Falaj

• Daudi (داوودية) with underground aqueducts
• Ghaili (الغيلية ) requiring a dam to collect the water
• Aini (العينية ) whose source is a water spring

These enabled large scale agriculture to flourish in a dry land environment

Persia

Main article: Qanat

In Persia from early times a system of underground aqueducts called Qanat were constructed, a series of well-like vertical shafts, connected by gently sloping tunnels. This technique:

• taps into subterranean water in a manner that delivers water to the surface without need for pumping. The water drains relying 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.

Greece

On the island of Samos, the Tunnel of Eupalinos was built during the reign of Polycrates (538-522 BC). It is considered an underground aqueduct and brought fresh water to Pythagoreion for roughly a thousand years.

Roman

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 totaled over 415 km. The aqueducts supplied 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.

Ancient Indian aqueduct in Hampi

South America

Near the Peruvian town of Nazca, an ancient pre-Columbian system of aqueducts called Puquios were built and are still in use today. They were made of intricately placed stones, a construction material widely used by the Nazca culture. The time period in which they were constructed is still debated, but some evidence supports circa A.D. 540–552, in response to drought periods in the region. When European explorers arrived in the Aztec capital of Tenochtitlán early in the 16th century CE the city was found to be watered by two aqueducts.

Sri Lanka

Extensive usage of elaborate aqueducts have been found to have been used in Ancient Sri Lanka.

Modern aqueducts

In modern times, the largest aqueducts of all have been built in the United States to supply the country's biggest cities. The Catskill Aqueduct carries water to New York City over a distance of 120 miles (190 km), but is dwarfed by aqueducts in the far west of the country, most notably the Colorado River Aqueduct, which supplies the Los Angeles area with water from the Colorado River nearly 400 km to the east and the 701.5 mi (1,129 km) California Aqueduct, which runs from the Sacramento-San Joaquin River Delta to Lake Perris. The Central Arizona Project is the largest and most expensive aqueduct constructed in the United States. It stretches 336 miles from its source near Parker, Arizona to the metropolitan areas of Phoenix and Tucson. A modern version of aqueduct is a pipeline bridge.

Uses

Segovia, Spain. Roman aqueduct

Historically, agricultural societies have constructed aqueducts to irrigate crops. Archimedes invented the water screw to raise water for use in irrigation of croplands.

Another use for aqueducts is to supply large cities with drinking water. Some of the Roman aqueducts still supply water to Rome today. In California, United States, three large aqueducts supply water over hundreds of miles to the Los Angeles area. Two are from the Owens River area and a third is from the Colorado River.

In more recent times, aqueducts were used for transportation purposes to allow canal barges to cross ravines or valleys. During the Industrial Revolution of the 18th century, aqueducts were constructed as part of the boom in canal-building.

In modern civil engineering projects, detailed study and analysis of open channel flow is commonly required to support flood control, irrigation systems, and large water supply systems when an aqueduct rather than a pipeline is the preferred solution.

In the past, aqueducts often had channels made of earth or other porous materials but significant amounts of water are lost through such unlined aqueducts. As water gets increasingly scarce, these canals are being lined with concrete, polymers or impermeable soil. In some cases, a new aqueduct is built alongside the old one because it cannot be shut down during construction.

Notable aqueducts

Ancient Greek aqueducts

• The Eupalinian aqueduct on the Greek island of Samos.

Roman aqueducts

See also: List of aqueducts in the Roman Empire

Aqueduct of Segovia

Aqueduct Santiago de Queretaro, Mexico

• The Pont du Gard in southern France
• Barbegal aqueduct, France
• Aqueduto de São Sebastião, in Coimbra, Portugal
• Eifel aqueduct, Germany
• Caesarea Maritima, Israel
• Patras, Greece
• Aqueduct of Segovia, Spain
• Acueducto de los Milagros, Mérida, Spain
• Tarragona, Spain
• Almuñécar, Spain (5 aqueducts – 4 still in use)
• Valens Aqueduct, Istanbul, Turkey
• Aqua Augusta, Italy
• Aqua Claudia and the Anio Novus, as part of the Porta Maggiore, Rome, Italy
• Skopje Aqueduct, Skopje, Republic of Macedonia

Other aqueducts

An Aqueduct in Vila do Conde, Portugal

The Aqueduto dos Pegoes in Tomar, Portugal

• Wignacourt Aqueduct, Malta. Built in the 16th century to transport water from the old capital city of Malta, Mdina to the new capital city Valletta. Today, only part is visible in the localities of Balzan, Birkirkara and Santa Venera.
• Aqueduct St-Clément, Montpellier, France – 17th century
• Bar Aqueduct, Montenegro - 16th century
• Águas Livres Aqueduct, in Lisbon, Portugal (built 1731–1748)
• Aqueduto de Óbidos, in Óbidos, Portugal (built 1570)
• Aqueduto de Setúbal in Setúbal, Portugal (built 1696)
• Aqueduto dos Pegões in Tomar, Portugal (built 1593)
• Água de Prata Aqueduct, in Évora, Portugal (built 1531–1537)
• Santa Clara Aqueduct, in Vila do Conde, Portugal
• Carioca Aqueduct in Rio de Janeiro, Brazil (built 1744–1750)
• Aqueduct of Teruel, Spain
• Roquefavour aqueduct, France – built between 1842 and 1847
• Winnipeg Aqueduct, Manitoba, Canada – built between 1915 and 1919
• Canal de l'Aqueduc, Quebec, Canada
• Päijänne Water Tunnel, a 120-kilometer long underground aqueduct (continuous tunnel) connecting lake Päijänne to Greater Helsinki.
• Wan Mat Saman Aqueduct, Kedah, Malaysia – built between 1900 and 1909
• Mathur Aqueduct in Tamilnadu state, India
• Pontcysyllte Aqueduct in Wales
• Surviving Spanish aqueducts in Mexico:
  • Aqueduct of Querétaro, Mexico – built between 1726 and 1738, 1.3 km long and featuring 74 arches.
  • Aqueduct of Morelia, Michoacán, built between 1735 and 1738.
  • Aqueduct of Acámbaro, Guanajuato, built in 1528.
  • Chapultepec aqueduct, Mexico D.F
• Kavala aqueduct, 16th-century Ottoman aqueduct in Kavala, Greece
• Levadas, 1,350 miles (2,170 km) of 17th century aqueducts on the Portuguese island of Madeira.
• Espada Aqueduct, built 1735, in San Antonio, Texas, United States.
• Quabbin Aqueduct, 24.6-mile (39.6 km) long tunnel, in Massachusetts, United States.
• Chicopee Valley Aqueduct, 13.1-mile (21.1 km) long, in Massachusetts, United States.
• Central Arizona Project Aqueduct
• California Aqueduct, a 715 mi (1,151 km) combination of canals, pipelines and tunnels, United States.
• Delaware Aqueduct, in New York State, United States – at 85 miles (137 km) long, the world's longest continuous underground tunnel.
• High Bridge, part of the former Croton Aqueduct, built in 1848, is the oldest surviving bridge in New York City.
• Sooke Flowline located on Vancouver Island, Canada, is a 44 kilometres long, gravity fed concrete pipe which provided water to the City Of Victoria for 55 years.
• National Water Carrier of Israel located in Israel, is a 130 km long system of giant pipes, open canals, tunnels, reservoirs and large scale pumping stations to transfer water from the Sea of Galilee in the north of the country to the highly populated center and arid south, built between 1953 and 1964.

Gallery

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  View from inside a Roman aqueduct from the Pools of Solomon to Jerusalem

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  An entrance to the ancient Puquios, near Nazca

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  Aqueduct in Segovia, Spain

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  Roman aqueduct supplying Carthage, Tunisia

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  Valens Aqueduct, Istanbul, Turkey

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  Traditional homes built between the arches of the Água de Prata Aqueduct in Évora, Portugal

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  Roman-era Skopje Aqueduct near Skopje, Macedonia

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  A small disused aqueduct in Leeds, England

See also

• Earthquake engineering
• Goldfields Water Supply Scheme
• Leat
• List of Roman aqueduct bridges
• Pipeline – some used to carry water
• Roman architecture
• Roman engineering
• Sanitation in Ancient Rome
• Water resources

References

• Sextus Julius Frontinus, De Aquaeductu Urbis Romae (On the water management of the city of Rome), Translated by R. H. Rodgers, 2003, University of Vermont
• Aqueduct entry from Encyclopædia Britannica Eleventh Edition
• Chanson, H. (2002). Certains Aspects de la Conception hydrauliques des Aqueducs Romains. ('Some Aspect on the Hydraulic Design of Roman Aqueducts.') Journal La Houille Blanche, No. 6/7, pp. 43–57 (ISSN 0018-6368)
• Chanson, H. (2008). "The Hydraulics of Roman Aqueducts: What do we know? Why should we learn ?" in Proceedings of World Environmental and Water Resources Congress 2008 Ahupua'a, ASCE-EWRI Education, Research and History Symposium, Hawaii, USA, Invited Keynote lecture, 13–16 May, R.W. Badcock Jr and R. Walton Eds., 16 pages (ISBN 978-0-7844-0976-3)

External links

• Imperial Rome Water Systems
• 600 Roman aqueducts with 25 descriptions in detail