aqueduct

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 (conduit) 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.^[1] 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 side. The word is derived from the Latin aqua ("water") and ducere ("to lead").

Ancient aqueducts

Mathur Aqueduct, India

Although particularly associated with the Romans, aqueducts were devised much earlier in 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 BC, 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.

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

An entrance to the ancient Puquios, near Nazca

In the new world, when the Aztec capital of Tenochtitlán was discovered in the middle of the second millennium, it was watered by two aqueducts. Water ran down to the city from the mountains through one while the other was cleaned and maintained.

India

The Indian subcontinent had some of the earliest aqueducts. Evidence can be found at the sites of present day Hampi. The massive aqueducts near river Tungabhadra supplying irrigation water were once 15 miles (24 km) long^[2]. The water ways supplied water to royal bath houses.

Persia

In Persia from early times^[vague] 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.

Roman

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 km. The aqueducts supplied water to 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 are 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.^[3]

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 714.5 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.

Uses

Segovia, Spain. Roman aqueduct

Roman aqueduct supplying Carthage, Tunisia

Valens Aqueduct, Istanbul, Turkey

Traditional homes built between the arches of the Aguas de Prata aqueduct in Evora,Portugal.

Roman-era aqueduct near Skopje, Macedonia.

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, USA, 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

• The Pont du Gard in southern France
• Barbegal aqueduct, France
• Aqueduto de São Sebastião, in Coimbra, Portugal
• Santa Clara Aqueduct, in Vila do Conde, Portugal
• Eifel aqueduct, Germany
• Caesarea Maritima, Israel
• Kavala, Greece
• 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

• 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
• Águas Livres Aqueduct, in Lisbon, Portugal (built 1731-1748)
• Aqueduto de Óbidos, in Obidos, Portugal (built 1570)

An Aqueduct in Vila do Conde, Portugal

• Aqueduto da Amoreira, in Amoreira, Portugal (built 15370)
• Aqueduto de Setúbal in Setubal, Portugal (built 1696)
• Aqueduto dos Pegões in Tomar, Portugal (built 1593)

The Aqueduto dos Pegoes in Tomar, Portugal

Aqueduct in Segovia, Spain

A small disused aqueduct in Leeds, England.

• Água de Prata Aqueduct, in Evora, Portugal (built 1531-1537)
• 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
• 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, Michoacan, built between 1735 and 1738.
  • Aqueduct of Acámbaro, Guanajuato, built in 1528 [1].
  • Chapultepec aqueduct, Mexico D.F
• 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 miles (39.6 km) long tunnel, in Massachusetts, United States.
• Chicopee Valley Aqueduct, 13.1 miles (21.1 km) long, in Massachusetts, United States.
• Central Arizona Project Aqueduct
• California Aqueduct, a 444 miles (approx. 714.5 kilometers) long 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.

See also

Water channel of the Nanzen-ji aqueduct, Kyoto, Japan

• Aztec, the Aztec Empire used aqueducts
• Drought
• Earthquake engineering
• Goldfields Water Supply Scheme
• Irrigation
• Leat
• List of Roman aqueduct bridges
• Pipeline - some used to carry water
• Roman aqueduct
• Roman architecture
• Roman engineering
• Sanitation in Ancient Rome
• Viaduct - a similar structure to carry a road or a railway
• Water resources

References

External links

Wikimedia Commons has media related to: Aqueduct

• Imperial Rome Water Systems
• 600 Roman aqueducts with 25 descriptions in detail
• The Roman aqueduct at Kavala (Greece) - Encyclopedia Britannica

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