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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. [1] The term aqueduct also often refers specifically to a bridge carrying an artificial watercourse. [1] Aqueducts were used in ancient Greece, the ancient Near East, ancient Rome, ancient Aztec, and ancient Inca. 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 aqua (water) and ductus (led or guided).
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. The Aztecs and Incans also built such systems independently later. 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. [2]
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. [3]
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 (24 km) long. [4] The waterways supplied water to royal bath tubs.
In Oman from the Iron Age, in Salut, Bat, and other sites, a system of underground aqueducts called falaj or qanāts were constructed, a series of well-like vertical shafts, connected by gently sloping horizontal tunnels.
There are three types of falaj:
These enabled large scale agriculture to flourish in a dry land environment.
In Persia, starting around 3000 years ago [5] a system of underground aqueducts called qanāts were constructed, a series of well-like vertical shafts, connected by gently sloping tunnels. This technique:
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 (538–522 BC). It is considered an underground aqueduct and brought fresh water to Pythagoreion for roughly a thousand years.
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 (258 mi). 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. [1]
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. [6]
The Guayabo National Monument of Costa Rica, a park covering the largest archaeological site in the country, contains a system of aqueducts. The complex network of uncovered and covered aqueducts still functions well. [7] The aqueducts are constructed from rounded river stones, which are mostly made of volcanic rock. [8] The civilization that constructed the aqueduct system remains a mystery to archaeologists; it is suspected that Guayabo's aqueducts sat at a point of ancient cultural confluence between Aztecs, Mayans, and Incas.
When Europeans saw the Aztec capital Tenochtitlan, early in the 16th century, the city was watered by two aqueducts. One of these, Chapultepec aqueduct, built c. 1420, was rebuilt by the Spanish almost three hundred years later. Originally tracing part of its path over now-gone Lake Texcoco, only a fragment remains in Mexico City today.
Extensive usage of elaborate aqueducts have been found to have been used in ancient Sri Lanka. The best example is the Yoda Ela or Jaya Ganga, an 87 kilometres (54 mi) long water canal carrying excess water between two artificial reservoirs with a gradient of 10 to 20 cm per kilometer during the fifth century AD. However, the ancient engineering methods in calculating the exact elevation between the two reservoirs and the exact gradient of the canal to such fine precision had been lost with the fall of the civilization in 13th Century. [9]
The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject.(July 2012) |
Modern aqueducts are a central part of many countries' water distribution infrastructure.
The United States' aqueducts are some of the world's largest. 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 242-mile (389-km) Colorado River Aqueduct, which supplies the Los Angeles area with water from the Colorado River nearly 250 miles to the east and the 701.5-mile (1,129.0 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.
An aqueduct in New Zealand, "the Oamaru Borough Race", was constructed in the late 19th century to deliver water (and water-power) about 50 km from the Waitaki River at Kurow to the coastal town of Oamaru.
In Spain, the Tagus-Segura Water Transfer system of aqueducts opened in 1979 and transports water 286 kilometres (178 mi) from north to south. [10]
In China, the South–North Water Transfer Project aims to connect the Yangtze River basin to Beijing through three separate systems. The project will reuse part of the Grand Canal of China.
The simplest aqueducts are small ditches cut into the earth. Much larger channels may be used in modern aqueducts, for instance the Central Arizona Project uses 7.3 m (24 ft) wide channels. [11] A major factor in the design of all open channels is its gradient. A higher gradient allows a smaller channel to carry the same amount of water as a larger channel with a lower gradient, but increases the potential of the water to damage the aqueduct's structure. A typical Roman aqueduct had a gradient of about 1:4800. [12]
A constructed functional rill is a small canal or aqueduct of stone, brick, concrete, or other lining material, usually rectilinear in cross section, for water transportation from a source such as a river, spring, reservoir, qanat, or aqueduct for domestic consumption or agricultural irrigation of crop land uses.
Rills were traditionally used in Middle Eastern and Mediterranean climate cultures of ancient and historical eras; and other climates and continents worldwide. They are distinguished from a 'water ditch' by being lined to reduce absorption losses and to increase durability. The Falaj irrigation system at the Al Ain Oasis, in present-day Abu Dhabi Emirate, uses rills as part of its qanat water system. Sometimes in the Spanish language they are called Acequias .
Rills are also used for aesthetic purposes in landscape design. Rills are used as narrow channels of water inset into the pavement of a garden, as linear water features, and often tiled and part of a fountain design.
The historical origins are from paradise garden religious images that first translated into ancient Persian Gardens. Rills were later exceptionally developed in the Moorish (Spanish) Gardens of Al-andalus, such as at the Alhambra in Granada; and also in other Islamic gardens, cultures, and countries. Early 20th century examples are in the María Luisa Park gardens in Seville, Spain; and at the Casa del Herrero gardens in Montecito, California.
Aqueducts sometimes run for some or all of their path through tunnels constructed underground. A version of this common in North Africa and Central Asia that has vertical wells at regular intervals is called a qanat. One historic example found in Syria, the Qanat Firaun, extends over 100 kilometers. [13]
Modern aqueducts may also make extensive use of pipelines. Pipelines are useful for transporting water over long distances when it needs to move over hills, or where open channels are poor choices due to considerations of evaporation, freezing, pollution, or environmental impact. They can also be used to carry treated water.
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. They also help drought-prone areas with water supply. 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 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.
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(help)Canals or artificial waterways are waterways or engineered channels built for drainage management or for conveyancing water transport vehicles. They carry free, calm surface flow under atmospheric pressure, and can be thought of as artificial rivers.
Hydraulics is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concerns gases. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on applied engineering using the properties of fluids. In its fluid power applications, hydraulics is used for the generation, control, and transmission of power by the use of pressurized liquids. Hydraulic topics range through some parts of science and most of engineering modules, and they cover concepts such as pipe flow, dam design, fluidics, and fluid control circuitry. The principles of hydraulics are in use naturally in the human body within the vascular system and erectile tissue.
Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive use of gravity as the motive force to cause the movement of the fluids. This area of civil engineering is intimately related to the design of bridges, dams, channels, canals, and levees, and to both sanitary and environmental engineering.
A qanat or kārīz is a system for transporting water from an aquifer or well to the surface through an underground aqueduct; the system originated approximately 3,000 years ago in Iran. The function is essentially the same across the Middle East and North Africa, but the system operates under a variety of regional names: qanat or kārīz in Iran, karez in Afghanistan and Pakistan, foggara in Algeria, qanat in Malta, khettara in Morocco, falaj in Oman and the United Arab Emirates, and uyūn in Saudi Arabia, etc. The largest extant and functional qanat systems are located in Afghanistan, Algeria, Iran, Oman, Pakistan, and the oases of the Turfan region in Xinjiang, Northwestern China.
The Cloaca Maxima or, less often, Maxima Cloaca, was one of the world's earliest sewage systems. Its name is related to that of Cloacina, a Roman goddess. Built during either the Roman Kingdom or early Roman Republic, it was constructed in Ancient Rome in order to drain local marshes and remove waste from the city. It carried effluent to the River Tiber, which ran beside the city. The sewer started at the Forum Augustum and ended at the Ponte Rotto and Ponte Palatino. It began as an open air canal, but it developed into a much larger sewer over the course of time. Agrippa renovated and reconstructed much of the sewer. This would not be the only development in the sewers. By the first century CE all eleven Roman aqueducts were connected to the sewer. After the Roman Empire fell the sewer still was used. By the 19th century, it became a tourist attraction. Some parts of the sewer are still used today. Whilst still being used, it was highly valued as a sacred symbol of Roman culture, and Roman engineering.
Navigable aqueducts are bridge structures that carry navigable waterway canals over other rivers, valleys, railways or roads. They are primarily distinguished by their size, carrying a larger cross-section of water than most water-supply aqueducts. Roman aqueducts were used to transport water and were created in Ancient Rome. The 662-metre (2,172 ft) long steel Briare aqueduct carrying the Canal latéral à la Loire over the River Loire was built in 1896. It was ranked as the longest navigable aqueduct in the world for more than a century, until the Magdeburg Water Bridge in Germany took the title in the early 21st century.
The ancient Romans were famous for their advanced engineering accomplishments. Technology for bringing running water into cities was developed in the east, but transformed by the Romans into a technology inconceivable in Greece. The architecture used in Rome was strongly influenced by Greek and Etruscan sources.
The Aqua Appia was the first Roman aqueduct, constructed in 312 BC by the co-censors Gaius Plautius Venox and Appius Claudius Caecus, the same Roman censor who also built the important Via Appia.
The Aqua Virgo was one of the eleven Roman aqueducts that supplied the city of ancient Rome. It was completed in 19 BC by Marcus Agrippa, during the reign of the emperor Augustus and was built mainly to supply the contemporaneous Baths of Agrippa in the Campus Martius.
The Romans constructed aqueducts throughout their Republic and later Empire, to bring water from outside sources into cities and towns. Aqueduct water supplied public baths, latrines, fountains, and private households; it also supported mining operations, milling, farms, and gardens.
Aqueduct may refer to:
Sanitation in ancient Rome, acquired from the Etruscans, was very advanced compared to other ancient cities and provided water supply and sanitation services to residents of Rome. Although there were many sewers, public latrines, baths and other sanitation infrastructure, disease was still rampant. The baths are known to symbolise the "great hygiene of Rome".
The Lower Prospect Canal Reserve is a heritage-listed former farm and public water supply canal and now bushy corridor and nature reserve stretching 7.7 kilometres (4.8 mi) through the heart of suburban Sydney, New South Wales, Australia. The lineal corridor stretches from Prospect Reservoir to Sydney Water Pipehead at Albert Street, Guildford with the majority of the reserve located in Greystanes, which is a suburb within the Cumberland Council area.
De aquaeductu is a two-book official report given to the emperor Nerva or Trajan on the state of the aqueducts of Rome, and was written by Sextus Julius Frontinus at the end of the 1st century AD. It is also known as De Aquis or De Aqueductibus Urbis Romae. It is the earliest official report of an investigation made by a distinguished citizen on Roman engineering works to have survived. Frontinus had been appointed Water Commissioner by the emperor Nerva in AD 96.
The Pont d'Aël is a Roman aqueduct located in a village of the same name in the comune of Aymavilles in Aosta Valley, northern Italy. It was built in the year 3BC for irrigation purposes and supplying water for the newly founded colony of Augusta Praetoria, which is now known as Aosta. The water was directed through a neighbouring valley 66 m above the floor of the Aosta valley, through a sophisticated system. The aqueduct is 6 km long in total. In addition to its unusual position, the construction, which was originally thought to be a three-story structure, shows more unique features such as a control corridor below the water line, as well as explicit private funding. Today, the water channel of the aqueduct serves as a public walking trail.
The Gadara Aqueduct, also called Qanatir Fir'awn or Qanat Fir'aun, was a Roman aqueduct supplying water for some of the cities of the Decapolis. It serviced Adraha, Abila, and Gadara. The aqueduct has the longest known tunnel of the Classical era.
The Menua Canal, also known as the Semiramis Canal or as the Shamiram Canal, is a canal joined with a series of hydraulic works such as aqueducts constructed by King Menua of Urartu. It is located to the east of Van, Turkey and runs 56 kilometers, supplying a large region and flowing into Lake Van. It has been continuously used by the local inhabitants for irrigation purposes up to this day, more than 2500 years after its construction. It is considered a masterpiece of hydraulic and architectural engineering by regional and global standards.
Aqueducts are bridges constructed to convey watercourses across gaps such as valleys or ravines. The term aqueduct may also be used to refer to the entire watercourse, as well as the bridge. 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, therefore meaning "to lead water". A modern version of an aqueduct is a pipeline bridge. They may take the form of tunnels, networks of surface channels and canals, covered clay pipes or monumental bridges.
The Aflaj Irrigation Systems of Oman are ancient water channels from 500 AD located in the regions of Dakhiliyah, Sharqiyah and Batinah. However, they represent a type of irrigation system as old as 5,000 years in the region named as qanat or kariz as originally named in Persia.
The Murdock Canal, also known as the Provo Reservoir Canal and the Provo River Aqueduct, is a 23 mile water conveyance system that diverts water from the Provo River and other water storage systems to water users in Utah County. The canal starts at the Murdock Diversion Dam which is located at the mouth of Provo Canyon in Provo, Utah. The canal runs completely underground through Utah Valley and ends at the Jordan Aqueduct in Lehi, Utah. It carries water through the cities of Orem, Lindon, Pleasant Grove, Cedar Hills, American Fork, Highland, and Lehi. The canal is the largest of three primary water conveyance systems in Salt Lake Valley, the other systems being the Jordan Aqueduct and the Salt Lake Aqueduct. The water capacity of the Murdock Canal more than doubles that of either the Jordan Aqueduct or Salt Lake Aqueduct at 612 cfs.