This is an accepted version of this page
114-705: 41°16′56″N 73°40′04″W / 41.282317°N 73.667908°W / 41.282317; -73.667908 The Delaware Aqueduct is an aqueduct in the New York City water supply system . It takes water from the Rondout , Cannonsville , Neversink , and Pepacton reservoirs on the west bank of the Hudson River through the Chelsea Pump Station, then into the West Branch , Kensico , and Hillview reservoirs on
228-582: A groma , a relatively simple apparatus that was eventually displaced by the more sophisticated dioptra , a precursor of the modern theodolite . In Book 8 of his De architectura , Vitruvius describes the need to ensure a constant supply, methods of prospecting, and tests for potable water. Greek and Roman physicians were well aware of the association between stagnant or tainted waters and water-borne diseases, and held rainwater to be water's purest and healthiest form, followed by springs. Rome's public baths, ostensibly one of Rome's greatest contributions to
342-510: A "never failing" spring, stream or river; but acknowledges that not every farm did. Farmland without a reliable summer water-source was virtually worthless. During the growing season, a "modest local" irrigation system might consume as much water as the city of Rome; and the livestock whose manure fertilised the fields must be fed and watered all year round. At least some Roman landowners and farmers relied in part or whole on aqueduct water to raise crops as their primary or sole source of income but
456-533: 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. The Indian subcontinent is believed to have some of the earliest aqueducts. Evidence can be found at
570-425: A cash income through the sale of surplus foodstuffs, and an increase in the value of the land itself. In the countryside, permissions to draw aqueduct water for irrigation were particularly hard to get; the exercise and abuse of such rights were subject to various known legal disputes and judgements, and at least one political campaign; in 184 BC Cato tried to block all unlawful rural outlets, especially those owned by
684-436: A commensurate water-fee. Some individuals were gifted a right to draw overflow water gratis , as a State honour or grant; pipe stamps show that around half Rome's water grants were given to elite, extremely wealthy citizens of the senatorial class. Water grants were issued by the emperor or State to named individuals, and could not be lawfully sold along with a property, or inherited: new owners and heirs must therefore negotiate
798-576: A continuous water-flow and the inevitable deposition of water-borne minerals within the pipes somewhat reduced the water's contamination by soluble lead. Lead content in Rome's aqueduct water was "clearly measurable, but unlikely to have been truly harmful". Nevertheless, the level of lead was 100 times higher than in local spring waters. Most Roman aqueducts were flat-bottomed, arch-section conduits, approximately 0.7 m (2.3 ft) wide and 1.5 m (5 ft) high internally, running 0.5 to 1 m beneath
912-520: A distinctive feature of Roman aqueducts and hence the term aqueduct is often applied specifically to a bridge for carrying water . 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
1026-556: A dry land environment. In Persia , starting around 3000 years ago 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
1140-534: 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
1254-458: A legal landscape at least as daunting as the physical one". In the aftermath of the Second Punic War , the censors exploited a legal process known as vindicatio , a repossession of private or tenanted land by the state, "restoring" it to a presumed ancient status as "public and sacred, and open to the people". Livy describes this as a public-spirited act of piety, and makes no reference to
SECTION 10
#17328519762971368-455: A local level, particularly when ager publicus was understood to be common property, to be used for whatever purpose seemed fit to its user. After ager publicus , minor, local roads and boundaries between adjacent private properties offered the least costly routes, though not always the most straightforward. Sometimes the State would purchase the whole of a property, mark out the intended course of
1482-415: A low "venter" bridge, then rose to a receiving tank at a slightly lower elevation. This discharged into another conduit; the overall gradient was maintained. Siphon pipes were usually made of soldered lead, sometimes reinforced by concrete encasements or stone sleeves. Less often, the pipes were stone or ceramic, jointed as male-female and sealed with lead. Vitruvius describes the construction of siphons and
1596-550: A maximum gradient of about 1:700) and Las Medulas in northern Spain . Where sharp gradients were unavoidable in permanent conduits, the channel could be stepped downwards, widened or discharged into a receiving tank to disperse the flow of water and reduce its abrasive force. The use of stepped cascades and drops also helped re-oxygenate and thus "freshen" the water. Some aqueduct conduits were supported across valleys or hollows on multiple piered arches of masonry, brick or concrete, also known as arcades . The Pont du Gard , one of
1710-426: A minor branch of the main aqueduct supplied a local suburb via a lead siphon whose "belly" was laid across a riverbed, eliminating any need for supporting bridgework. Some aqueducts running through hilly regions employed a combination of arcades, plain conduits buried at ground level, and tunnels large enough to contain the conduit, its builders and maintenance workers. The builders of Campana's Aqua Augusta changed
1824-494: A more conservative 520,000–635,000 m per day, supplying an estimated population of 1,000,000. Hundreds of aqueducts were built throughout the Roman Empire. Many of them have since collapsed or been destroyed, but a number of intact portions remain. The Zaghouan Aqueduct , 92.5 km (57.5 mi) in length, was built in the 2nd century AD to supply Carthage (in modern Tunisia ). Surviving provincial aqueduct bridges include
1938-476: A new aqueduct is built alongside the old one because it cannot be shut down during construction. Roman aqueduct 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. Aqueducts moved water through gravity alone, along
2052-429: A new grant, in their own name. In the event, these untransferable, personal water grants were more often transferred than not. Frontinus thought dishonest private users and corrupt state employees were responsible for most of the losses and outright thefts of water in Rome, and the worst damage to the aqueducts. His De aquaeductu can be read as a useful technical manual, a display of persuasive literary skills, and
2166-438: A public aqueduct could draw, under license, a specified quantity of aqueduct water for irrigation at a predetermined time, using a bucket let into the conduit via the inspection hatches; this was intended to limit the depletion of water supply to users further down the gradient, and help ensure a fair distribution among competitors at the time when water was most needed and scarce. Columella recommends that any farm should contain
2280-412: A pull-through device. In Rome, where a hard-water supply was the norm, mains pipework was shallowly buried beneath road kerbs, for ease of access; the accumulation of calcium carbonate in these pipes would have necessitated their frequent replacement. Full closure of any aqueduct for servicing would have been a rare event, kept as brief as possible, with repair shut-downs preferably made when water demand
2394-930: A restoration by Vespasian and another, later, by his son Titus . To many modern scholars, the delay seems implausibly long. It might well have been thought politic to stress the personal generosity of the new Flavian dynasty , father and son, and exaggerate the negligence of their disgraced imperial predecessor, Nero , whose rebuilding priorities after Rome's Great Fire were thought models of self-indulgent ambition. Aqueduct mains could be directly tapped, but they more usually fed into public distribution terminals, known as castellum aquae ("water castles"), which acted as settling tanks and cisterns and supplied various branches and spurs, via lead or ceramic pipes. These pipes were made in 25 different standardised diameters and were fitted with bronze stopcocks. The flow from each pipe ( calix ) could be fully or partly opened, or shut down, and its supply diverted if necessary to any other part of
SECTION 20
#17328519762972508-636: A slight overall downward gradient within conduits of stone, brick , concrete or lead; the steeper the gradient, the faster the flow. Most conduits were buried beneath the ground and followed the contours of the terrain; obstructing peaks were circumvented or, less often, tunneled through. Where valleys or lowlands intervened, the conduit was carried on bridgework , or its contents fed into high-pressure lead, ceramic, or stone pipes and siphoned across. Most aqueduct systems included sedimentation tanks, which helped to reduce any water-borne debris. Sluices , castella aquae (distribution tanks) and stopcocks regulated
2622-508: 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
2736-408: A state honour. In cities and towns, clean run-off water from aqueducts supported high consumption industries such as fulling and dyeing , and industries that employed water but consumed almost none, such as milling . Used water and water surpluses fed ornamental and market gardens, and scoured the drains and public sewers. Unlicensed rural diversion of aqueduct water for agriculture was common during
2850-635: 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,
2964-503: 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
3078-439: A warning to users and his own staff that if they stole water, they would be found out, because he had all the relevant, expert calculations to hand. He claimed to know not only how much was stolen, but how it was done. Tampering and fraud were indeed commonplace; methods included the fitting of unlicensed or additional outlets, some of them many miles outside the city, and the illegal widening of lead pipes. Any of this might involve
3192-511: 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 , the ancient Near East , ancient Rome , ancient Aztec , and ancient Inca . The simplest aqueducts are small ditches cut into
3306-646: Is called a qanat. One historic example found in Syria, the Qanat Firaun, extends over 100 kilometers. 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
3420-570: 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
3534-653: Is estimated between 780 and a little over 800 km, of which approximately 47 km (29 mi) were carried above ground level, on masonry supports. Most of Rome's water was carried by four of these: the Aqua Anio Vetus, the Aqua Marcia, the Aqua Claudia and the Aqua Anio Novus. Modern estimates of the city's supply, based on Frontinus' own calculations in the late 1st century, range from a high of 1,000,000 m per day to
Delaware Aqueduct - Misplaced Pages Continue
3648-640: Is provincial Italy's Aqua Augusta . It supplied a great number of luxury coastal holiday-villas belonging to Rome's rich and powerful, several commercial fresh-water fisheries, market-gardens, vineyards and at least eight cities, including the major ports at Naples and Misenum ; sea voyages by traders and Rome's Republican and Imperial navies required copious on-board supplies of fresh water. Aqueducts were built to supply Roman military bases in Britain. The sites of permanent fortresses show traces of fountains and piped water, which were probably supplied by aqueducts from
3762-468: Is still debated, but some evidence supports circa A.D. 540–552, in response to drought periods in the region. 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. The aqueducts are constructed from rounded river stones, which are mostly made of volcanic rock . The civilization that constructed
3876-664: 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
3990-638: The Aqua Marcia , was at first legally blocked on religious grounds, under advice from the decemviri (an advisory "board of ten"). The new aqueduct was meant to supply water to the highest elevations of the city, including the Capitoline Hill , but the decemviri had consulted Rome's main written oracle, the Sibylline Books , and found there a warning against supplying water to the Capitoline. This brought
4104-562: The Capitoline Hill . As demand grew still further, more aqueducts were built, including the Aqua Tepula in 127 BC and the Aqua Julia in 33 BC. Aqueduct building programmes in the city reached a peak in the Imperial Era; political credit and responsibility for provision of public water supplies passed from mutually competitive Republican political magnates to the emperors. Augustus' reign saw
4218-911: 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
4332-778: The Pont du Gard in France and the Aqueduct of Segovia in Spain. The longest single conduit, at over 240 km, is associated with the Valens Aqueduct of Constantinople. "The known system is at least two and half times the length of the longest recorded Roman aqueducts at Carthage and Cologne, but perhaps more significantly it represents one of the most outstanding surveying achievements of any pre-industrial society". Rivalling this in terms of length and possibly equaling or exceeding it in cost and complexity,
4446-658: 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. A major factor in
4560-481: The censor Appius Claudius Caecus . The Aqua Appia was one of two major public projects of the time; the other was a military road between Rome and Capua , the first leg of the so-called Appian Way . Both projects had significant strategic value, as the Third Samnite War had been under way for some thirty years by that point. The road allowed rapid troop movements; and by design or fortunate coincidence, most of
4674-518: 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
Delaware Aqueduct - Misplaced Pages Continue
4788-531: The "positively unwholesome" waters of the Aqua Alsietina were used to supply Trastevere's public fountains. The situation was finally ameliorated when the emperor Trajan built the Aqua Traiana in 109 AD, bringing clean water directly to Trastavere from aquifers around Lake Bracciano . By the late 3rd century AD, the city was supplied with water by eleven state-funded aqueducts. Their combined conduit length
4902-515: The 69 km (42.8 mile) Aqua Claudia , which gave good quality water but failed on several occasions; and the Anio Novus , highest of all Rome's aqueducts and one of the most reliable but prone to muddy, discoloured waters, particularly after rain, despite its use of settling tanks. Most of Rome's aqueducts drew on various springs in the valley and highlands of the Anio, the modern river Aniene , east of
5016-413: The Anio valley and its uplands. Spring water was fed into a stone or concrete springhouse, then entered the aqueduct conduit. Scattered springs would require several branch conduits feeding into a main channel. Some systems drew water from open, purpose-built, dammed reservoirs, such as the two (still in use) that supplied the aqueduct at the provincial city of Emerita Augusta . The territory over which
5130-630: The Aqua Appia ran within a buried conduit, relatively secure from attack. It was fed by a spring 16.4 km from Rome, and dropped 10 m over its length to discharge approximately 75,500 m of water each day into a fountain at Rome's cattle market, the Forum Boarium , one of the city's lowest-lying public spaces. A second aqueduct, the Aqua Anio Vetus , was commissioned some forty years later, funded by treasures seized from Pyrrhus of Epirus . Its flow
5244-520: The City of Rome's aqueducts, suffered at least two serious partial collapses over two centuries, one of them very soon after construction, and both probably due to a combination of shoddy workmanship, underinvestment, Imperial negligence, collateral damage through illicit outlets, natural ground tremors and damage by overwhelming seasonal floods originating upstream. Inscriptions claim that it was largely out of commission, and awaiting repair, for nine years prior to
5358-522: The Claudian period on. Permanent auxiliary forts were supplied by aqueducts from the Flavian period, possibly co-incident with the regular demand for dependable water supplies by provincial military settlements equipped with bathhouses, once these were introduced. The plans for any public or private aqueduct had to be submitted to scrutiny by civil authorities. Permission was granted only if the proposal respected
5472-709: The NYCDEP. "About two-thirds of it, $ 1 billion, will actually go into constructing a bypass tunnel around the location with the most significant leakage in Roseton, and to do additional concrete grouting in the Wawarsing section." The new bypass tunnel is the largest construction project in NYCDEP's history. Construction of the tunnel, 500 feet (150 m) under the Hudson, was completed in 2019. The project involved digging two shafts measuring 700 and 900 feet (210 and 270 m) deep. To complete
5586-506: The Roman Empire emulated this model, and funded aqueducts as objects of public interest and civic pride, "an expensive yet necessary luxury to which all could, and did, aspire". Most Roman aqueducts proved reliable and durable; some were maintained into the early modern era, and a few are still partly in use. Methods of aqueduct surveying and construction are noted by Vitruvius in his work De architectura (1st century BC). The general Frontinus gives more detail in his official report on
5700-581: The Romans throughout their history, but reliance on the water resources of a small catchment area restricted the city's potential for growth and security. The water of the River Tiber was close at hand, but would have been polluted by water-borne disease. Rome's aqueducts were not strictly Roman inventions – their engineers would have been familiar with the water-management technologies of Rome's Etruscan and Greek allies – but they proved conspicuously successful. By
5814-625: 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
SECTION 50
#17328519762975928-882: The Rondout, Cannonsville, Neversink and Pepacton reservoirs with the Delaware and Neversink tunnels. (The latter three reservoirs are within the Delaware River watershed. Rondout is considered by the New York City Department of Environmental Protection (NYCDEP) to be part of the Delaware system despite being firmly within the Hudson River watershed.) Combined, the four reservoirs account for 1,012 square miles (2,620 km) of watershed and 320.4 billion US gallons (1.2 billion cubic metres) of capacity, 890 million US gallons (3.4 million cubic metres) of which goes to
6042-511: The Tiber. A complex system of aqueduct junctions, tributary feeds and distribution tanks supplied every part of the city. Trastevere, the city region west of the Tiber, was primarily served by extensions of several of the city's eastern aqueducts, carried across the river by lead pipes buried in the roadbed of the river bridges, thus forming an inverted siphon . Whenever this cross-river supply had to be shut down for routine repair and maintenance works,
6156-810: 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. In China,
6270-436: The aqueduct ran had to be carefully surveyed to ensure the water would flow at a consistent and acceptable rate for the entire distance. Roman engineers used various surveying tools to plot the course of aqueducts across the landscape. They checked horizontal levels with a chorobates , a flatbedded wooden frame some 20 feet long, fitted with both a water level and plumblines. Horizontal courses and angles could be plotted using
6384-595: 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
6498-438: The aqueduct's eventual length, and thus to its cost. On rural land, a protective "clear corridor" was marked out with boundary slabs ( cippi ) usually 15 feet each side of the channel, reducing to 5 feet each side for lead pipes and in built-up areas. The conduits, their foundations and superstructures, were property of the State or emperor. The corridors were public land, with public rights of way and clear access to
6612-417: The aqueduct, and resell the unused land to help mitigate the cost. Graves and cemeteries, temples, shrines and other sacred places had to be respected; they were protected by law, and villa and farm cemeteries were often deliberately sited very close to public roadways and boundaries. Despite careful enquiries by planners, problems regarding shared ownership or uncertain legal status might emerge only during
6726-418: The basins and carried the water to their apartments; the better-off would have sent slaves to perform the same task. The outlet's elevation was too low to offer any city household or building a direct supply; the overflow drained into Rome's main sewer, and from there into the Tiber. Most inhabitants still relied on well water and rainwater. At this time, Rome had no public baths . The first was probably built in
6840-462: The baths, in particular, became important social centres. The majority of urban Romans lived in multi-storeyed blocks of flats ( insulae ). Some blocks offered water services, but only to tenants on the more expensive, lower floors; the other tenants would have drawn their water gratis from public fountains. During the Imperial era, lead production (mostly for pipes) became an Imperial monopoly, and
6954-448: The bore of pipe that led from the public water supply to their property – the wider the pipe, the greater the flow and the higher the fee. Some properties could be bought and sold with a legal right to draw water attached. Aqueduct officials could assign the right to draw overflow water ( aqua caduca , literally "fallen water") to certain persons and groups; fullers , for example, used a great deal of fresh water in their trade, in return for
SECTION 60
#17328519762977068-484: The bribery or connivance of unscrupulous aqueduct officials or workers. Archaeological evidence confirms that some users drew an illegal supply but not the likely quantity involved, nor the likely combined effect on supply to the city as a whole. The measurement of allowances was basically flawed; officially approved lead pipes carried inscriptions with information on the pipe's manufacturer, its fitter, and probably on its subscriber and their entitlement; but water allowance
7182-492: The building of the Aqua Virgo , and the short Aqua Alsietina . The latter supplied Trastevere with large quantities of non-potable water for its gardens and was used to create an artificial lake for staged sea-fights to entertain the populace. Another short Augustan aqueduct supplemented the Aqua Marcia with water of "excellent quality". The emperor Caligula added or began two aqueducts completed by his successor Claudius ;
7296-558: The channel, presumably to prevent damage to the structure through erosion and water pressure. This value agrees well with the measured gradients of surviving masonry aqueducts. The gradient of the Pont du Gard is only 34 cm per km, descending only 17 m vertically in its entire length of 50 km (31 mi): it could transport up to 20,000 cubic metres a day. The gradients of temporary aqueducts used for hydraulic mining could be considerably greater, as at Dolaucothi in Wales (with
7410-810: The city — 50% of daily demand. All this water is fed from the Rondout to West Branch Reservoir in Putnam County (part of the Croton River watershed , which includes the flow of the upstream Boyds Corner Reservoir ), then to the Kensico, and Hillview reservoirs in southern Westchester County , before continuing on to distribution within New York City. Leaks were first discovered in the Delaware Aqueduct in 1988, with water losses up to 36 million US gallons (140,000 m) per day. The city took many years to analyze
7524-417: The conduit depended on the catchment hydrology – rainfall, absorption, and runoff – the cross section of the conduit, and its gradient; most conduits ran about two-thirds full. The conduit's cross section was also determined by maintenance requirements; workmen must be able to enter and access the whole, with minimal disruption to its fabric. Vitruvius recommends a low gradient of not less than 1 in 4800 for
7638-469: The conduits for maintenance. Within the corridors, potential sources of damage to the conduits were forbidden, including new roadways that crossed over the conduit, new buildings, ploughing or planting, and living trees, unless entirely contained by a building. The harvesting of hay and grass for fodder was permitted. Regulations and restrictions necessary to the aqueduct's long-term integrity and maintenance were not always readily accepted or easily enforced at
7752-493: 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. 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
7866-406: The development of aqueduct technology, Romans, like most of their contemporaries in the ancient world, relied on local water sources such as springs and streams, supplemented by groundwater from privately or publicly owned wells, and by seasonal rain-water drained from rooftops into storage jars and cisterns . Such localised sources for fresh water – especially wells – were intensively exploited by
7980-459: The early Imperial era, the city's aqueducts helped support a population of over a million, and an extravagant water supply for public amenities had become a fundamental part of Roman life. The city's aqueducts and their dates of completion were: The city's demand for water had probably long exceeded its local supplies by 312 BC, when the city's first aqueduct, the Aqua Appia , was commissioned by
8094-528: 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
8208-545: The east bank, ending at Hillview in Yonkers, New York . The aqueduct was constructed between 1939 and 1945, and carries approximately half of New York City's water supply of 1.3 billion US gallons (4,900,000 m) per day. At 13.5 feet (4.1 m) wide and 85 miles (137 km) long, the Delaware Aqueduct is the world's longest tunnel . The Delaware Aqueduct carries water from the 95-square-mile (250 km), 49.6-billion-US-gallon (188-million-cubic-metre) watershed using
8322-430: 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. 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
8436-513: The fraction of aqueduct water involved can only be guessed at. More certainly, the creation of municipal and city aqueducts brought a growth in the intensive and efficient suburban market-farming of fragile, perishable commodities such as flowers (for perfumes, and for festival garlands), grapes, vegetables and orchard fruits; and of small livestock such as pigs and chickens, close to the municipal and urban markets. A licensed right to use aqueduct water on farmland could lead to increased productivity,
8550-443: The granting of rights to draw water for private use from state-funded aqueducts was made an imperial privilege. The provision of free, potable water to the general public became one among many gifts to the people of Rome from their emperor, paid for by him or by the state. In 33 BC, Marcus Agrippa built or subsidised 170 public bath-houses during his aedileship . In Frontinus's time (c. 40–103 AD), around 10% of Rome's aqueduct water
8664-426: The ground surface, with inspection-and-access covers at regular intervals. Conduits above ground level were usually slab-topped. Early conduits were ashlar -built but from around the late Republican era, brick-faced concrete was often used instead. The concrete used for conduit linings was usually waterproof , with a very smooth finish. The flow of water depended on gravity alone. The volume of water transported within
8778-455: The growing season, but was seldom prosecuted as it helped keep food prices low; agriculture was the core of Rome's economy and wealth. Rome's first aqueduct was built in 312 BC, and supplied a water fountain at the city's cattle market. By the 3rd century AD, the city had eleven aqueducts , sustaining a population of over a million in a water-extravagant economy; most of the water supplied the city's many public baths. Cities and towns throughout
8892-521: The health of its inhabitants, were also instrumental in the spread of waterborne diseases. In his De Medicina , the encyclopaedist Celsus warned that public bathing could induce gangrene in unhealed wounds. Frontinus preferred a high rate of overflow in the aqueduct system because it led to greater cleanliness in the water supply, the sewers, and those who used them. The adverse health effects of lead on those who mined and processed it were also well known. Ceramic pipes, unlike lead, left no taint in
9006-406: The landed elite. This may be connected to Cato's diatribe as censor against the ex-consul Lucius Furius Purpureo : "Look how much he bought the land for, where he is channeling the water!" Cato's attempted reform proved impermanent at best. Though illegal tapping could be punished by seizure of assets, including the illegally watered land and its produce, this law seems never to have been used, and
9120-454: The leak problem and devise a solution. In 2010 it announced a plan for a major repair project. The NYCDEP is building a 2.5-mile (4.0 km) Rondout-West Branch Bypass Tunnel beneath the Hudson River, which will allow it to bypass the leak. Construction began in November 2013. "The number's going to be $ 1.5 billion to do the entire program to make the fix," said Paul Rush, Deputy Commissioner of
9234-507: The likely legal conflicts arising. In 179 BC the censors used the same legal device to help justify public contracts for several important building projects, including Rome's first stone-built bridge over the Tiber and a new aqueduct to supplement the city's existing – but, by now, inadequate – supply. A wealthy landowner along the aqueduct's planned route, M. Licinius Crassus, refused it passage across his fields, and seems to have forced its abandonment. The construction of Rome's third aqueduct,
9348-418: The local electorate, or by Augustus himself. The entire network relied on just two mountain springs, shared with a river that supported freshwater fish, providing a free food source for all classes. The Augusta supplied eight or nine municipalities or cities and an unknown number of farms and villas, including bathhouses, via branch lines and sub-branch lines; its extremities were the naval port of Misenum and
9462-675: The merchant port of Puteoli . Its delivery is unlikely to have been wholly reliable, adequate or free from dispute. Competition would have been inevitable. Under the emperor Claudius , the City of Rome's contingent of imperial aquarii (aqueduct workers) comprised a familia aquarum of 460, both slave and free, funded through a combination of Imperial largesse and the water fees paid by private subscribers. The familia aquarum comprised "overseers, reservoir‐keepers, line‐walkers, pavers, plasterers, and other workmen" supervised by an Imperial freedman, who held office as procurator aquarium . The curator aquarum had magisterial powers in relation to
9576-423: The mine head. The channels may have deteriorated rapidly, or become redundant as the nearby ore was exhausted. Las Medulas shows at least seven such leats, and Dolaucothi at least five. At Dolaucothi, the miners used holding reservoirs, as well as hushing tanks and sluice gates to control flow, and drop chutes were used for the diversion of water supplies. The remaining traces (see palimpsest ) of such channels allows
9690-514: The most impressive surviving examples of a massive masonry multiple-piered conduit, spanned the Gardon river-valley some 48.8 m (160 ft) above the Gardon itself. Where particularly deep or lengthy depressions had to be crossed, inverted siphons could be used, instead of arcades; the conduit fed water into a header tank, which fed it into pipes. The pipes crossed the valley at lower level, supported by
9804-417: The narrowing of apertures, even slight roughening of the aqueduct's ideally smooth-mortared interior surface by travertine deposits could significantly reduce the water's velocity, and thus its rate of flow, by up to 1/4. Accretions within siphons could drastically reduce flow rates through their already narrow diameters, though some had sealed openings that might have been used as rodding eyes , possibly using
9918-411: The next century, based on precursors in neighbouring Campania ; a limited number of private baths and small, street-corner public baths would have had a private water supply, but once aqueduct water was brought to the city's higher elevations, large and well-appointed public baths and fountains were built throughout the city. Public baths and fountains became distinctive features of Roman civilization, and
10032-401: The penetration of conduits by tree-roots as particularly damaging. Working patrols would have cleared algal fouling, repaired accidental breaches or accessible shoddy workmanship, cleared the conduits of gravel and other loose debris, and removed accretions of calcium carbonate (also known as travertine ) in systems fed by hard water sources; modern research has found that quite apart from
10146-426: The physical construction. While surveyors could claim ancient right to use land once public, now private, for the good of the State, the land's current possessors could take out a legal counterclaim for compensation based on their long usage, productivity and improvements. They could also join forces with their neighbours to present a united legal front in seeking higher rates of compensation. Aqueduct planning "traversed
10260-565: The problems of blockage, blow-outs and venting at their lowest levels, where the pressures were greatest. Nonetheless, siphons were versatile and effective if well-built and well-maintained. A horizontal section of high-pressure siphon tubing in the Aqueduct of the Gier was ramped up on bridgework to clear a navigable river, using nine lead pipes in parallel, cased in concrete. Modern hydraulic engineers use similar techniques to enable sewers and water pipes to cross depressions. At Romano-Gallic Arles,
10374-451: The problems, uses and abuses of Imperial Rome's public water supply. Notable examples of aqueduct architecture include the supporting piers of the Aqueduct of Segovia , and the aqueduct-fed cisterns of Constantinople . "The extraordinary greatness of the Roman Empire manifests itself above all in three things: the aqueducts, the paved roads, and the construction of the drains." Dionysius of Halicarnassus , Roman Antiquities Before
10488-479: The project to a standstill. Eventually, having raised the same objections in 143 and in 140, the decemviri and Senate consented, and 180,000,000 sesterces were allocated for restoration of the two existing aqueducts and completion of the third, in 144–140. The Marcia was named for the praetor Quintus Marcius Rex , who had championed its construction. Springs were by far the most common sources for aqueduct water; most of Rome's supply came from various springs in
10602-490: The public at large, including public baths and fountains. In the Republican era, aqueducts were planned, built and managed under authority of the censors , or if no censor was in office, the aediles . In the Imperial era, lifetime responsibility for water supplies passed to the emperors. Rome had no permanent central body to manage the aqueducts until Augustus created the office of water commissioner ( curator aquarum ); this
10716-504: The repairs, the aqueduct was supposed to shut down temporarily in 2022, but this was postponed. The shutdown was rescheduled for 2024–2025; completion of the project is dependent on potential drought conditions and associated demand levels for water from the Delaware system. The northern section of the tunnel was shut down in September 2024. At the time, the closure was planned to last eight months. Aqueduct (water supply) An aqueduct
10830-405: The rights to a spring and its water from his neighbour, and access rights to a corridor of intervening land, then built an aqueduct of just under 10 kilometres, connecting the springhead to his own villa. Some aqueducts supplied water to industrial sites, usually via an open channel cut into the ground, clay-lined or wood-shuttered to reduce water loss. Most such leats were designed to operate at
10944-622: The sites of present-day Hampi, Karnataka . The massive aqueducts near Tungabhadra River supplying irrigation water were once 15 miles (24 km) long. 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
11058-745: The so-called "corn dole" ) and the army. Rather than seek to impose unproductive and probably unenforcable bans, the authorities issued individual water grants and licenses, and regulated water outlets though with variable success. In the 1st century AD, Pliny the Elder , like Cato, could fulminate against grain producers who continued to wax fat on profits from public water and public land. Some landholders avoided such restrictions and entanglements by buying water access rights to distant springs, not necessarily on their own land. A few, of high wealth and status, built their own aqueducts to transport such water from source to field or villa; Mumius Niger Valerius Vegetus bought
11172-567: The standard, buried conduits, inspection and access points were provided at regular intervals, so that suspected blockages or leaks could be investigated with minimal disruption of the supply. Water lost through multiple, slight leaks in buried conduit walls could be hard to detect except by its fresh taste, unlike that of the natural groundwater. The clear corridors created to protect the fabric of underground and overground conduits were regularly patrolled for unlawful ploughing, planting, roadways and buildings. In De aquaeductu , Frontinus describes
11286-595: The steep gradients that could deliver the high water volumes needed in mining operations. Water was used in hydraulic mining to strip the overburden and expose the ore by hushing , to fracture and wash away metal-bearing rock already heated and weakened by fire-setting , and to power water-wheel driven stamps and trip-hammers that crushed ore for processing. Evidence of such leats and machines has been found at Dolaucothi in south-west Wales . Mining sites, such as Dolaucothi and Las Medulas in north-west Spain , show multiple aqueducts that fed water from local rivers to
11400-399: The supply to individual destinations, and fresh overflow water could be temporarily stored in cisterns. Aqueducts and their contents were protected by law and custom. The supply to public fountains took priority over the supply to public baths, and both took priority over supplies to wealthier, fee-paying private users. Some of the wealthiest citizens were given the right to a free supply, as
11514-434: The system in which water-demand was, for the time being, outstripping supply. The free supply of water to public basins and drinking fountains was officially prioritised over the supply to the public baths, where a very small fee was charged to every bather, on behalf of the Roman people. The supply to basins and baths was in turn prioritised over the requirements of fee-paying private users. The last were registered, along with
11628-536: 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
11742-614: The water rights of other citizens. Inevitably, there would have been rancorous and interminable court cases between neighbours or local governments over competing claims to limited water supplies but on the whole, Roman communities took care to allocate shared water resources according to need. Planners preferred to build public aqueducts on public land ( ager publicus ) , and to follow the shortest, unopposed, most economical route from source to destination. State purchase of privately owned land, or re-routing of planned courses to circumvent resistant or tenanted occupation, could significantly add to
11856-413: The water supply, assisted by a team of architects, public servants, notaries and scribes, and heralds; when working outside the city, he was further entitled to two lictors to enforce his authority. Substantial fines could be imposed for even single offences against the laws relating to aqueducts: for example, 10,000 sesterces for allowing a tree to damage the conduit, and 100,000 sesterces for polluting
11970-616: The water they carried, and were therefore preferred over lead for drinking water. In some parts of the Roman world, particularly in relatively isolated communities with localised water systems and limited availability of other, more costly materials, wooden pipes were commonly used; Pliny recommends water-pipes of pine and alder as particularly durable, when kept wet and buried. Examples revealed through archaeology include pipes of alder, clamped at their joints with oak, at Vindolanda fort and pipes of alder in Germany. Where lead pipes were used,
12084-429: The water within the conduit, or allowing one's slave to do the same. Rome's first aqueduct (312 BC) discharged at very low pressure and at a more-or-less constant rate in the city's main trading centre and cattle-market , probably into a low-level, cascaded series of troughs or basins; the upper for household use, the lower for watering the livestock traded there. Most Romans would have filled buckets and storage jars at
12198-424: The water's orientation from an existing northerly watershed to a southerly watershed, establishing the new gradient using a 6 km tunnel, several shorter tunnels, and arcades, one of which was supported more or less at sea level by foundations on the sea bed at Misenum. En route , it supplied several cities and many villas, using branch lines. Roman aqueducts required a comprehensive system of regular maintenance. On
12312-550: Was a high status, high-profile Imperial appointment. In 97 AD, Frontinus, who had already had a distinguished career as consul, general and provincial governor, served both as consul and as curator aquarum , under the emperor Nerva . Particular sections of Campania's very long, complex, costly and politically sensitive Aqua Augusta , constructed in the early days of the Augustan principate were supervised by wealthy, influential, local curatores . They were drawn from local elites by
12426-501: Was involved in some form of agricultural work. Water was possibly the most important variable in the agricultural economy of the Mediterranean world. Roman Italy's natural fresh-water sources – springs, streams, rivers and lakes – were abundant in some places, entirely absent in others. Rainfall was unpredictable. Water tended to be scarce when most needed during the warm, dry summer growing season. Farmers whose villas or estates were near
12540-524: Was lowest, during the winter months. The piped water supply could be selectively reduced or shut off at the castella when small or local repairs were needed, but substantial maintenance and repairs to the aqueduct conduit itself required the complete diversion of water at any point upstream, including the spring-head itself. Frontinus describes the use of temporary leaden conduits to carry the water past damaged stretches while repairs were made, with minimal loss of supply. The Aqua Claudia , most ambitious of
12654-426: Was measured in quinaria (cross-sectional area of the pipe) at the point of supply and no formula or physical device was employed to account for variations in velocity, rate of flow or actual usage. Brun, 1991, used lead pipe stamps to calculate a plausible water distribution as a percentage of the whole; 17% went to the emperor (including his gifts, grants and awards); 38% went to private individuals; and 45% went to
12768-441: Was more than twice that of the Aqua Appia, and supplied water to higher elevations of the city. By 145 BC, the city had again outgrown its combined supplies. An official commission found the aqueduct conduits decayed, their water depleted by leakage and illegal tapping. The praetor Quintus Marcius Rex restored them, and introduced a third, "more wholesome" supply, the Aqua Marcia , Rome's longest aqueduct and high enough to supply
12882-403: Was probably impracticable; while water thefts profited farmers, they could also create food surpluses and keep food prices low. Grain shortages in particular could lead to famine and social unrest. Any practical solution must strike a balance between the water-needs of urban populations and grain producers, tax the latter's profits, and secure sufficient grain at reasonable cost for the Roman poor (
12996-427: Was used to supply 591 public fountains, among which were 39 lavishly decorative fountains that Frontinus calls munera . According to one of several much later regionaries, by the end of the 4th century AD, Rome's aqueducts within the City – 19 of them, according to the regionary – fed 11 large public baths, 965 smaller public bathhouses and 1,352 public fountains. Between 65 and 90% of the Roman Empire's population
#296703