![Pont du Gard BLS](https://upload.wikimedia.org/wikipedia/commons/4/42/Pont_du_Gard_BLS.jpg)
The
Romans constructed
aqueducts throughout their
Republic
A republic () is a " state in which power rests with the people or their representatives; specifically a state without a monarchy" and also a "government, or system of government, of such a state." Previously, especially in the 17th and 18th ...
and later
Empire
An empire is a "political unit" made up of several territories and peoples, "usually created by conquest, and divided between a dominant center and subordinate peripheries". The center of the empire (sometimes referred to as the metropole) ex ...
, to bring water from outside sources into cities and towns. Aqueduct water supplied
public baths
Public baths originated when most people in population centers did not have access to private bathing facilities. Though termed "public", they have often been restricted according to gender, religious affiliation, personal membership, and other cr ...
,
latrine
A latrine is a toilet or an even simpler facility that is used as a toilet within a sanitation system. For example, it can be a communal trench in the earth in a camp to be used as emergency sanitation, a hole in the ground ( pit latrine), or ...
s, fountains, and private households; it also supported mining operations, milling, farms, and gardens.
Aqueducts moved water through gravity alone, along a slight overall downward gradient within conduits of stone,
brick
A brick is a type of block used to build walls, pavements and other elements in masonry construction. Properly, the term ''brick'' denotes a block composed of dried clay, but is now also used informally to denote other chemically cured cons ...
,
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wid ...
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.
Sluice
Sluice ( ) is a word for a channel controlled at its head by a movable gate which is called a sluice gate. A sluice gate is traditionally a wood or metal barrier sliding in grooves that are set in the sides of the waterway and can be considered ...
s, ''castella aquae'' (distribution tanks) and
stopcock
A stopcock is a form of valve used to control the flow of a liquid or gas. The term is not precise and is applied to many different types of valve. The only consistent attribute is that the valve is designed to completely stop the flow when cl ...
s regulated 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 a state honour. In cities and towns, clean run-off water from aqueducts supported high consumption industries such as
fulling
Fulling, also known as felting, tucking or walking ( Scots: ''waukin'', hence often spelled waulking in Scottish English), is a step in woollen clothmaking which involves the cleansing of woven or knitted cloth (particularly wool) to eli ...
and
dying, and industries that employed water but consumed almost none, such as
mill
Mill may refer to:
Science and technology
*
* Mill (grinding)
* Milling (machining)
* Millwork
* Textile mill
* Steel mill, a factory for the manufacture of steel
* List of types of mill
* Mill, the arithmetic unit of the Analytical Engine early ...
ing. 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 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 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
Vitruvius (; c. 80–70 BC – after c. 15 BC) was a Roman architect and engineer during the 1st century BC, known for his multi-volume work entitled '' De architectura''. He originated the idea that all buildings should have three attribut ...
in his work ''
De architectura
(''On architecture'', published as ''Ten Books on Architecture'') is a treatise on architecture written by the Roman architect and military engineer Marcus Vitruvius Pollio and dedicated to his patron, the emperor Caesar Augustus, as a guide ...
'' (1st century BC). The general
Frontinus
Sextus Julius Frontinus (c. 40 – 103 AD) was a prominent Roman civil engineer, author, soldier and senator of the late 1st century AD. He was a successful general under Domitian, commanding forces in Roman Britain, and on the Rhine and Danube ...
gives more detail in his
official report on 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
la, Constantinopolis ota, قسطنطينيه
, alternate_name = Byzantion (earlier Greek name), Nova Roma ("New Rome"), Miklagard/Miklagarth (Old Norse), Tsargrad ( Slavic), Qustantiniya (Arabic), Basileuousa ("Queen of Cities"), Megalopolis (" ...
.
Background
Before 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
Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit ...
from privately or publicly owned wells, and by seasonal rain-water drained from rooftops into storage jars and
cistern
A cistern (Middle English ', from Latin ', from ', "box", from Greek ', "basket") is a waterproof receptacle for holding liquids, usually water. Cisterns are often built to catch and store rainwater. Cisterns are distinguished from wells by ...
s. Such localised sources for fresh water – especially wells – were intensively exploited by 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
The Tiber ( ; it, Tevere ; la, Tiberis) is the third-longest river in Italy and the longest in Central Italy, rising in the Apennine Mountains in Emilia-Romagna and flowing through Tuscany, Umbria, and Lazio, where it is joined by the Riv ...
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
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
allies – but they proved conspicuously successful. By 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.
Rome's aqueducts
![Aqua Anio Vetus, Tivoli - 51072576848](https://upload.wikimedia.org/wikipedia/commons/9/99/Aqua_Anio_Vetus%2C_Tivoli_-_51072576848.jpg)
The city's aqueducts and their dates of completion were:
*312 BC
Aqua Appia
*272 BC
Aqua Anio Vetus
*144-140 BC
Aqua Marcia
The Aqua Marcia ( it, Acqua Marcia) is one of the longest of the eleven aqueducts that supplied the city of Rome. The aqueduct was built between 144–140 BC, during the Roman Republic. The still-functioning Acqua Felice from 1586 runs on long ...
*127-126 BC
Aqua Tepula
The Aqua Tepula is an ancient Roman aqueduct completed in 125 BC by censors Gnaeus Servilius Caepio, who had served as consul in 141 BC, and Lucius Cassius Longinus Ravilla.
The water from the Aqua Tepula was, as implied in the na ...
*33 BC
Aqua Julia
The Aqua Julia (or Iulia) is a Roman aqueduct built in 33 BC by Agrippa under Augustus to supply the city of Rome. It was repaired and expanded by Augustus from 11–4 BC.
Route
The source of the Aqua Iulia is situated approximately a ...
*19 BC
Aqua Virgo
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 Agri ...
*2 BC
Aqua Alsietina
*38-52 AD
Aqua Claudia
*38-52 AD
Aqua Anio Novus
*109 AD
Aqua Traiana
*226 AD
Aqua Alexandrina
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 the
censor Appius Claudius Caecus
Appius Claudius Caecus ( 312–279 BC) was a statesman and writer from the Roman Republic. The first Roman public figure whose life can be traced with some historical certainty, Caecus was responsible for the building of Rome's first road (t ...
. The Aqua Appia was one of two major public projects of the time; the other was a military road between Rome and
Capua
Capua ( , ) is a city and ''comune'' in the province of Caserta, in the region of Campania, southern Italy, situated north of Naples, on the northeastern edge of the Campanian plain.
History
Ancient era
The name of Capua comes from the Etrus ...
, the first leg of the so-called
Appian Way
The Appian Way ( Latin and Italian: ''Via Appia'') is one of the earliest and strategically most important Roman roads of the ancient republic. It connected Rome to Brindisi, in southeast Italy. Its importance is indicated by its common name ...
. 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 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
3 of water each day into a fountain at Rome's cattle market, the
Forum Boarium
The Forum Boarium (, it, Foro Boario) was the cattle '' forum venalium'' of ancient Rome. It was located on a level piece of land near the Tiber between the Capitoline, the Palatine and Aventine hills. As the site of the original docks of R ...
, 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
Pyrrhus (; grc-gre, Πύρρος ; 319/318–272 BC) was a Greek king and statesman of the Hellenistic period.Plutarch. '' Parallel Lives'',Pyrrhus... He was king of the Greek tribe of Molossians, of the royal Aeacid house, and later he be ...
. Its flow 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
The Aqua Marcia ( it, Acqua Marcia) is one of the longest of the eleven aqueducts that supplied the city of Rome. The aqueduct was built between 144–140 BC, during the Roman Republic. The still-functioning Acqua Felice from 1586 runs on long ...
, Rome's longest aqueduct and high enough to supply the
Capitoline Hill
The Capitolium or Capitoline Hill ( ; it, Campidoglio ; la, Mons Capitolinus ), between the Forum and the Campus Martius, is one of the Seven Hills of Rome.
The hill was earlier known as ''Mons Saturnius'', dedicated to the god Saturn. ...
. As demand grew still further, more aqueducts were built, including the
Aqua Tepula
The Aqua Tepula is an ancient Roman aqueduct completed in 125 BC by censors Gnaeus Servilius Caepio, who had served as consul in 141 BC, and Lucius Cassius Longinus Ravilla.
The water from the Aqua Tepula was, as implied in the na ...
in 127 BC and the
Aqua Julia
The Aqua Julia (or Iulia) is a Roman aqueduct built in 33 BC by Agrippa under Augustus to supply the city of Rome. It was repaired and expanded by Augustus from 11–4 BC.
Route
The source of the Aqua Iulia is situated approximately a ...
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 the building of the
Aqua Virgo
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 Agri ...
, and the short
Aqua Alsietina. The latter supplied
Trastevere
Trastevere () is the 13th '' rione'' of Rome: it is identified by the initials R. XIII and it is located within Municipio I. Its name comes from Latin ''trans Tiberim'', literally 'beyond the Tiber'.
Its coat of arms depicts a golden head of a li ...
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 Aqua Alsietina was also known as "Aqua Augusta"; Frontinus distinguishes its "unwholesome" supply from the "sweet waters" of the Aqua Augusta that fed into the Aqua Marcia. On the one hand, he says the Naumachia's supply is "nowhere delivered for consumption by the people... ut the surplus is allowedto the adjacent gardens and to private users for irrigation". On the other hand, "It is customary, however, in the district across the Tiber, in an emergency, whenever the bridges are undergoing repairs and the water supply is cut off from this side of the river, to draw from Alsietina to maintain the flow of the public fountains." Frontinus, ''The Aqueducts of Rome'' 1, 6–20.] The emperor
Caligula
Gaius Julius Caesar Augustus Germanicus (31 August 12 – 24 January 41), better known by his nickname Caligula (), was the third Roman emperor, ruling from 37 until his assassination in 41. He was the son of the popular Roman general Germani ...
added or began two aqueducts completed by his successor
Claudius
Tiberius Claudius Caesar Augustus Germanicus (; 1 August 10 BC – 13 October AD 54) was the fourth Roman emperor, ruling from AD 41 to 54. A member of the Julio-Claudian dynasty, Claudius was born to Drusus and Antonia Minor ...
; 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.
[Sextus Julius Frontinus, ''The Aqueducts of Rome'', 6–20](_blank)
/ref>
Most of Rome's aqueducts drew on various springs in the valley and highlands of the Anio, the modern river Aniene
The Aniene (; la, Aniō), formerly known as the Teverone, is a river in Lazio, Italy. It originates in the Apennines at Trevi nel Lazio and flows westward past Subiaco, Vicovaro, and Tivoli to join the Tiber in northern Rome. It formed the p ...
, east of 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, 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
Trajan ( ; la, Caesar Nerva Traianus; 18 September 539/11 August 117) was Roman emperor from 98 to 117. Officially declared ''optimus princeps'' ("best ruler") by the senate, Trajan is remembered as a successful soldier-emperor who presi ...
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 is estimated between 780 and a little over 800 km, of which approximately 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 m3 per day to a more conservative 520,000–635,000 m3 per day, supplying an estimated population of 1,000,000.
Aqueducts in the Roman Empire
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, in length, was built in the 2nd century AD to supply Carthage
Carthage was the capital city of Ancient Carthage, on the eastern side of the Lake of Tunis in what is now Tunisia. Carthage was one of the most important trading hubs of the Ancient Mediterranean and one of the most affluent cities of the classi ...
(in modern Tunisia
)
, image_map = Tunisia location (orthographic projection).svg
, map_caption = Location of Tunisia in northern Africa
, image_map2 =
, capital = Tunis
, largest_city = capital
, ...
). Surviving provincial aqueduct bridges include the Pont du Gard
The Pont du Gard is an ancient Roman aqueduct bridge built in the first century AD to carry water over to the Roman colony of ''Nemausus'' ( Nîmes). It crosses the river Gardon near the town of Vers-Pont-du-Gard in southern France. The Po ...
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, 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
Naples (; it, Napoli ; nap, Napule ), from grc, Νεάπολις, Neápolis, lit=new city. is the regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 909,048 within the city's adm ...
and Misenum
Miseno is one of the ''frazioni'' of the municipality of Bacoli in the Italian Province of Naples. Known in ancient Roman times as Misenum, it is the site of a great Roman port.
Geography
Nearby Cape Miseno marks the northwestern end of the Ba ...
; sea voyages by traders and Rome's Republican and Imperial navies required copious on-board supplies of fresh water.
Planning, surveying and management
Planning
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 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 increase the aqueduct's length, and thus its cost.[Taylor, Rabun, M., "Public Needs and Private Pleasures" in: ''Water Distribution, the Tiber River and the Urban Development of Ancient Rome'', (Studia Archaeologica), L'ERMA di BRETSCHNEIDER, 2000, pp. 54-60]
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 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.[Frontinus, Book 2, 128] Regulations and restrictions necessary to the aqueduct's long-term integrity and maintenance were not always readily accepted or easily enforced at 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 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 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 a legal landscape at least as daunting as the physical one".
In the aftermath of the Second Punic War
The Second Punic War (218 to 201 BC) was the second of three wars fought between Carthage and Rome, the two main powers of the western Mediterranean in the 3rd century BC. For 17 years the two states struggled for supremacy, primarily in Ital ...
, the censors exploited a legal process known as ''vindicatio
''Rei vindicatio'' is a legal action by which the plaintiff demands that the defendant return a thing that belongs to the plaintiff. It may be used only when the plaintiff owns the thing, and the defendant has wrongly claimed or assumed possession ...
'', 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 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, the Aqua Marcia
The Aqua Marcia ( it, Acqua Marcia) is one of the longest of the eleven aqueducts that supplied the city of Rome. The aqueduct was built between 144–140 BC, during the Roman Republic. The still-functioning Acqua Felice from 1586 runs on long ...
, 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
The Capitolium or Capitoline Hill ( ; it, Campidoglio ; la, Mons Capitolinus ), between the Forum and the Campus Martius, is one of the Seven Hills of Rome.
The hill was earlier known as ''Mons Saturnius'', dedicated to the god Saturn. ...
, but the ''decemviri'' had consulted Rome's main written oracle, the ''Sibylline Books
The ''Sibylline Books'' ( la, Libri Sibyllini) were a collection of oracular utterances, set out in Greek hexameters, that, according to tradition, were purchased from a sibyl by the last king of Rome, Tarquinius Superbus, and were consulted at ...
'', and found there a warning against supplying water to the Capitoline. This brought 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
Praetor ( , ), also pretor, was the title granted by the government of Ancient Rome to a man acting in one of two official capacities: (i) the commander of an army, and (ii) as an elected '' magistratus'' (magistrate), assigned to discharge vari ...
Quintus Marcius Rex, who had championed its construction.
Sources and surveying
Springs were by far the most common sources for aqueduct water; most of Rome's supply came from various springs in 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
''Dammed: The Politics of Loss and Survival in Anishinaabe Territory'' is a 2020 book by Brittany Luby, Associate Professor of History at the University of Guelph. The book charts the impacts of the damming of the Winnipeg River in the Lake of ...
reservoirs, such as the two (still in use) that supplied the aqueduct at the provincial city of Emerita Augusta
Emerita may refer to:
* ''Emerita'' (crustacean), a genus of crustaceans
* Emerita Augusta, an ancient city of Spain
* Saint Emerita, 3rd-century martyr; see Digna and Emerita
* Emerita, the feminine form of the adjective "emeritus
''Emeritus ...
.
The territory over which the aqueduct ran had to be carefully surveyed to ensure the water would flow at a consistent and acceptable rate for the entire distance.[Taylor, R. M., (2012). Rome's Lost Aqueduct. (Cover story). Archaeology, 65(2), 34–40.] 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 a '' groma'', a relatively simple apparatus that was eventually displaced by the more sophisticated dioptra
A dioptra (sometimes also named dioptre or diopter, from el, διόπτρα) is a classical astronomical and surveying instrument, dating from the 3rd century BC. The dioptra was a sighting tube or, alternatively, a rod with a sight at b ...
, a precursor of the modern theodolite
A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building and ...
. In Book 8 of his ''De architectura
(''On architecture'', published as ''Ten Books on Architecture'') is a treatise on architecture written by the Roman architect and military engineer Marcus Vitruvius Pollio and dedicated to his patron, the emperor Caesar Augustus, as a guide ...
'', Vitruvius
Vitruvius (; c. 80–70 BC – after c. 15 BC) was a Roman architect and engineer during the 1st century BC, known for his multi-volume work entitled '' De architectura''. He originated the idea that all buildings should have three attribut ...
describes the need to ensure a constant supply, methods of prospecting, and tests for potable water.
Water and health
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 the health of its inhabitants, were also instrumental in the spread of waterborne diseases. In his ''De Medicina
''De Medicina'' is a 1st-century medical treatise by Aulus Cornelius Celsus, a Roman encyclopedist and possibly (but not likely) a practicing physician. It is the only surviving section of a much larger encyclopedia; only small parts still survi ...
'', the encyclopaedist Celsus warned that public bathing could induce gangrene
Gangrene is a type of tissue death caused by a lack of blood supply. Symptoms may include a change in skin color to red or black, numbness, swelling, pain, skin breakdown, and coolness. The feet and hands are most commonly affected. If the gan ...
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 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
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanic ...
and alder
Alders are trees comprising the genus ''Alnus'' in the birch family Betulaceae. The genus comprises about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few sp ...
as particularly durable, when kept wet and buried. Examples include pipes of alder, clamped at their joints with oak, at Vindolanda fort and alder in Germany. Where lead pipes were used, 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.
Conduits and gradients
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 the ground surface, with inspection-and-access covers at regular intervals. Conduits above ground level were usually slab-topped. Early conduits were ashlar
Ashlar () is finely dressed (cut, worked) stone, either an individual stone that has been worked until squared, or a structure built from such stones. Ashlar is the finest stone masonry unit, generally rectangular cuboid, mentioned by Vitruv ...
-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 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
Vitruvius (; c. 80–70 BC – after c. 15 BC) was a Roman architect and engineer during the 1st century BC, known for his multi-volume work entitled '' De architectura''. He originated the idea that all buildings should have three attribut ...
recommends a low gradient of not less than 1 in 4800 for 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
In vector calculus, the gradient of a scalar-valued differentiable function of several variables is the vector field (or vector-valued function) \nabla f whose value at a point p is the "direction and rate of fastest increase". If the gr ...
of the Pont du Gard
The Pont du Gard is an ancient Roman aqueduct bridge built in the first century AD to carry water over to the Roman colony of ''Nemausus'' ( Nîmes). It crosses the river Gardon near the town of Vers-Pont-du-Gard in southern France. The Po ...
is only 34 cm per km, descending only 17 m vertically in its entire length of : it could transport up to 20,000 cubic metres a day. The gradients of temporary aqueducts used for hydraulic mining
Hydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment.Paul W. Thrush, ''A Dictionary of Mining, Mineral, and Related Terms'', US Bureau of Mines, 1968, p.560. In the placer mining of ...
could be considerably greater, as at Dolaucothi
The Dolaucothi Gold Mines (; cy, Mwynfeydd Aur Dolaucothi) (), also known as the Ogofau Gold Mine, are ancient Roman surface and underground mines located in the valley of the River Cothi, near Pumsaint, Carmarthenshire, Wales. The gold min ...
in Wales
Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...
(with a maximum gradient of about 1:700) and Las Medulas in northern Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
. 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.
Bridgework, siphons and tunnels
Some aqueduct conduits were supported across valleys or hollows on multiple piered arches of masonry, brick or concrete, also known as arcade
Arcade most often refers to:
* Arcade game, a coin-operated game machine
** Arcade cabinet, housing which holds an arcade game's hardware
** Arcade system board, a standardized printed circuit board
* Amusement arcade, a place with arcade games
* ...
s. The Pont du Gard
The Pont du Gard is an ancient Roman aqueduct bridge built in the first century AD to carry water over to the Roman colony of ''Nemausus'' ( Nîmes). It crosses the river Gardon near the town of Vers-Pont-du-Gard in southern France. The Po ...
, one of the most impressive surviving examples of a massive masonry multiple-piered conduit, spanned the Gardon
The Gardon or Gard ( Occitan and French: ''Gardon, Gard'', , ) is a river in southern France. It is the namesake of the department of Gard. Several of its tributaries are also called ''Gardon''. It is long, and takes its source in the commu ...
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 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 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
The Aqueduct of the Gier (French ''Aqueduc du Gier'') is an ancient Roman aqueduct probably constructed in the 1st century AD to provide water for Lugdunum (Lyon), in what is now eastern France. It is the longest and best preserved of four Roman ...
was ramped up on bridgework to clear a navigable river, using nine lead pipes in parallel, cased in concrete. Modern hydraulic engineers
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 mov ...
use similar techniques to enable sewers and water pipes to cross depressions. At Romano-Gallic Arles, 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 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.
Inspection and maintenance
Roman aqueducts required a comprehensive system of regular maintenance. On 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
( en, On aqueducts) is a two-book official report given to the emperor Nerva or Trajan on the state of the List of aqueducts in the city of Rome, aqueducts of Rome, and was written by Sextus Julius Frontinus at the end of the 1st century AD. It ...
'', Frontinus
Sextus Julius Frontinus (c. 40 – 103 AD) was a prominent Roman civil engineer, author, soldier and senator of the late 1st century AD. He was a successful general under Domitian, commanding forces in Roman Britain, and on the Rhine and Danube ...
describes 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
Travertine ( ) is a form of terrestrial limestone deposited around mineral springs, especially hot springs. It often has a fibrous or concentric appearance and exists in white, tan, cream-colored, and even rusty varieties. It is formed by a pro ...
) in systems fed by hard water
Hard water is water that has high mineral content (in contrast with "soft water"). Hard water is formed when water percolates through deposits of limestone, chalk or gypsum, which are largely made up of calcium and magnesium carbonates, bicarbo ...
sources; modern research has found that quite apart from 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 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 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 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 a restoration by Vespasian
Vespasian (; la, Vespasianus ; 17 November AD 9 – 23/24 June 79) was a Roman emperor who reigned from AD 69 to 79. The fourth and last emperor who reigned in the Year of the Four Emperors, he founded the Flavian dynasty that ruled the Empi ...
and another, later, by his son Titus
Titus Caesar Vespasianus ( ; 30 December 39 – 13 September 81 AD) was Roman emperor from 79 to 81. A member of the Flavian dynasty, Titus succeeded his father Vespasian upon his death.
Before becoming emperor, Titus gained renown as a mili ...
. 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
The Flavian dynasty ruled the Roman Empire between AD 69 and 96, encompassing the reigns of Vespasian (69–79), and his two sons Titus (79–81) and Domitian (81–96). The Flavians rose to power during the civil war of 69, known as ...
, father and son, and exaggerate the negligence of their disgraced imperial predecessor, Nero
Nero Claudius Caesar Augustus Germanicus ( ; born Lucius Domitius Ahenobarbus; 15 December AD 37 – 9 June AD 68), was the fifth Roman emperor and final emperor of the Julio-Claudian dynasty, reigning from AD 54 un ...
, whose rebuilding priorities after Rome's Great Fire were thought models of self-indulgent ambition.
Distribution
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 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 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 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 a new grant, in their own name. In the event, these untransferable, personal water grants were more often transferred than not.
Frontinus
Sextus Julius Frontinus (c. 40 – 103 AD) was a prominent Roman civil engineer, author, soldier and senator of the late 1st century AD. He was a successful general under Domitian, commanding forces in Roman Britain, and on the Rhine and Danube ...
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
( en, On aqueducts) is a two-book official report given to the emperor Nerva or Trajan on the state of the List of aqueducts in the city of Rome, aqueducts of Rome, and was written by Sextus Julius Frontinus at the end of the 1st century AD. It ...
'' can be read as a useful technical manual, a display of persuasive literary skills, and 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.[Keenan-Jones, (2015) pp. 1-4] 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 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 was measured in quinaria
A quinaria (plural: quinariae) is a Roman unit of area, roughly equal to . Its primary use was to measure the cross-sectional area of pipes in Roman water distribution systems. A "one quinaria" pipe is in diameter.
In Roman times, there was c ...
(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 the public at large, including public baths and fountains.
Management
In the Republican era, aqueducts were planned, built and managed under authority of the censors, or if no censor was in office, the aedile
''Aedile'' ( ; la, aedīlis , from , "temple edifice") was an elected office of the Roman Republic. Based in Rome, the aediles were responsible for maintenance of public buildings () and regulation of public festivals. They also had powers to enf ...
s. 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
The ''Curator Aquarum'' was a Roman official responsible for managing Rome's water supply and distributing free grain. Curators were appointed by the emperor. The first curator was Agrippa. Another notable ''Curator Aquarum'' was Frontinus, a Ro ...
''); this was a high status, high-profile Imperial appointment. In 97 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
Nerva (; originally Marcus Cocceius Nerva; 8 November 30 – 27 January 98) was Roman emperor from 96 to 98. Nerva became emperor when aged almost 66, after a lifetime of imperial service under Nero and the succeeding rulers of the Flavian dy ...
.
Particular sections of Campania's very long, complex, costly and politically sensitive ''Aqua Augusta'', constructed in the early days of the Augustan principate
The Principate is the name sometimes given to the first period of the Roman Empire from the beginning of the reign of Augustus in 27 BC to the end of the Crisis of the Third Century in AD 284, after which it evolved into the so-called Dominate.
...
were supervised by wealthy, influential, local ''curatores''. They were drawn from local elites by the local electorate, or by Augustus himself. The entire network relied on just two mountain springs, shared with a river that supported freshwater fish, a free food source for all classes. The ''Augusta'' supplied 8 or 9 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
Miseno is one of the ''frazioni'' of the municipality of Bacoli in the Italian Province of Naples. Known in ancient Roman times as Misenum, it is the site of a great Roman port.
Geography
Nearby Cape Miseno marks the northwestern end of the Ba ...
and the merchant port of Puteoli
Pozzuoli (; ; ) is a city and ''comune'' of the Metropolitan City of Naples, in the Italian region of Campania. It is the main city of the Phlegrean Peninsula.
History
Pozzuoli began as the Greek colony of ''Dicaearchia'' ( el, Δικα ...
. Its delivery is unlikely to have been wholly reliable, adequate or free from dispute. Competition would have been inevitable.
Under the emperor Claudius
Tiberius Claudius Caesar Augustus Germanicus (; 1 August 10 BC – 13 October AD 54) was the fourth Roman emperor, ruling from AD 41 to 54. A member of the Julio-Claudian dynasty, Claudius was born to Drusus and Antonia Minor ...
, 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
Procurator (with procuracy or procuratorate referring to the office itself) may refer to:
* Procurator, one engaged in procuration, the action of taking care of, hence management, stewardship, agency
* ''Procurator'' (Ancient Rome), the title o ...
aquarium''. The ''curator aquarum'' had magisterial powers in relation to 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 ''lictor
A lictor (possibly from la, ligare, "to bind") was a Roman civil servant who was an attendant and bodyguard to a magistrate who held ''imperium''. Lictors are documented since the Roman Kingdom, and may have originated with the Etruscans.
Orig ...
s'' 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 the water within the conduit, or allowing one's slave to do the same.
Uses
Civic and domestic
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 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
Public baths originated when most people in population centers did not have access to private bathing facilities. Though termed "public", they have often been restricted according to gender, religious affiliation, personal membership, and other cr ...
. The first was probably built in the next century, based on precursors in neighbouring Campania
Campania (, also , , , ) is an administrative Regions of Italy, region of Italy; most of it is in the south-western portion of the Italian peninsula (with the Tyrrhenian Sea to its west), but it also includes the small Phlegraean Islands and the i ...
; 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 the baths, in particular, became important social centres.
The majority of urban Romans lived in multi-storeyed blocks of flats (''insulae
The Latin word ''insula'' (literally meaning "island", plural ''insulae'') was used in Roman cities to mean either a city block in a city plan, i.e. a building area surrounded by four streets, or, later, a type of apartment building that occup ...
''). Some blocks offered water services, but only to tenants on the more expensive, lower floors; the rest would have drawn their water ''gratis'' from public fountains. During the Imperial era, lead production (mostly for pipes) became an Imperial monopoly, and 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 33BC, Marcus Agrippa
Marcus Vipsanius Agrippa (; BC – 12 BC) was a Roman general, statesman, and architect who was a close friend, son-in-law, and lieutenant to the Roman emperor Augustus. He was responsible for the construction of some of the most notable build ...
built or subsidised 170 public bath-houses during his aedile
''Aedile'' ( ; la, aedīlis , from , "temple edifice") was an elected office of the Roman Republic. Based in Rome, the aediles were responsible for maintenance of public buildings () and regulation of public festivals. They also had powers to enf ...
ship. In Frontinus's time (c. 40 – 103 AD), around 10% of Rome's aqueduct water was used to supply 591 public fountains, among which were 39 lavishly decorative fountains which Frontinus calls ''munera
Munera is a town and municipality in the province of Albacete, Spain; part of the autonomous community
eu, autonomia erkidegoa
ca, comunitat autònoma
gl, comunidade autónoma
oc, comunautat autonòma
an, comunidat autonoma
ast, comuni ...
''. 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.
Farming
Between 65 and 90% of the Roman Empire's population 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 naturally 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 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
Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire.
His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the wo ...
recommends that any farm should contain 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, the water demand of 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 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, 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 the landed elite. This may be connected to Cato's diatribe as censor against the ex-consul Lucius Furius Purpureo Lucius Furius Purpureo was a Roman politician and general, becoming consul in the year 196 BC. Lucius Furius was from the '' gens Furia'' patrician family in Rome.
Military tribune
Purpureo was a military tribune in 210 BC during the Second Punic ...
: "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 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 ( 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
Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic '' ...
, 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 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.
Industrial
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 leat
A leat (; also lete or leet, or millstream) is the name, common in the south and west of England and in Wales, for an artificial watercourse or aqueduct dug into the ground, especially one supplying water to a watermill or its mill pond. Other ...
s were designed to operate at the steep gradients that could deliver the high water volumes needed in mining operations. Water was used in hydraulic mining
Hydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment.Paul W. Thrush, ''A Dictionary of Mining, Mineral, and Related Terms'', US Bureau of Mines, 1968, p.560. In the placer mining of ...
to strip the overburden and expose the ore by hushing
Hushing is an ancient and historic mining method using a flood or torrent of water to reveal mineral veins. The method was applied in several ways, both in prospecting for ores, and for their exploitation. Mineral veins are often hidden below ...
, to fracture and wash away metal-bearing rock already heated and weakened by fire-setting
Fire-setting is a method of traditional mining used most commonly from prehistoric times up to the Middle Ages. Fires were set against a rock face to heat the stone, which was then doused with liquid, causing the stone to fracture by thermal sh ...
, 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
The Dolaucothi Gold Mines (; cy, Mwynfeydd Aur Dolaucothi) (), also known as the Ogofau Gold Mine, are ancient Roman surface and underground mines located in the valley of the River Cothi, near Pumsaint, Carmarthenshire, Wales. The gold min ...
in south-west Wales
Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...
.
Mining sites such as Dolaucothi and Las Medulas in northwest Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
show multiple aqueducts that fed water from local rivers to 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, as well as drop chutes for diversion of water supplies. The remaining traces (see palimpsest
In textual studies, a palimpsest () is a manuscript page, either from a scroll or a book, from which the text has been scraped or washed off so that the page can be reused for another document. Parchment was made of lamb, calf, or kid skin an ...
) of such channels allows the mining sequence to be inferred.
A number of other sites fed by several aqueducts have not yet been thoroughly explored or excavated, such as those at Longovicium
Longovicium (or Lanchester Roman Fort) was an auxiliary fort located on Roman Dere Street, in the Roman province of Britannia Inferior. It is located just southwest of Lanchester () in the English county of Durham, roughly to the west of the ...
near Lanchester south of Hadrian's wall
Hadrian's Wall ( la, Vallum Aelium), also known as the Roman Wall, Picts' Wall, or ''Vallum Hadriani'' in Latin, is a former defensive fortification of the Roman province of Britannia, begun in AD 122 in the reign of the Emperor Hadrian. R ...
, in which the water supplies may have been used to power trip-hammers for forging iron.
At Barbegal
The Barbegal aqueduct and mills is a Roman watermill complex located on the territory of the commune of Fontvieille, Bouches-du-Rhône, near the town of Arles, in southern France. The complex has been referred to as "the greatest known concentra ...
in Roman Gaul
Roman Gaul refers to GaulThe territory of Gaul roughly corresponds to modern-day France, Belgium and Luxembourg, and adjacient parts of the Netherlands, Switzerland and Germany. under provincial rule in the Roman Empire from the 1st century ...
, a reservoir fed an aqueduct that drove a cascaded series of 15 or 16 overshot water mills, grinding flour for the Arles region. Similar arrangements, though on a lesser scale, have been found in Caesarea
Caesarea () ( he, קֵיסָרְיָה, ), ''Keysariya'' or ''Qesarya'', often simplified to Keisarya, and Qaysaria, is an affluent town in north-central Israel, which inherits its name and much of its territory from the ancient city of Caesare ...
, Venafrum
Venafrum was an ancient town of Molise, Italy, close to the boundaries of both Latium adiectum and Samnium. Its site is occupied by the modern Venafro, a village on the railway from Isernia to Vairano, 25 km southwest of the former, 201 m ...
and Roman-era Athens
Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital and largest city of Greece. With a population close to four million, it is also the seventh largest city in the European Union. Athens dominates ...
. Rome's Aqua Traiana drove a flour-mill at the Janiculum
The Janiculum (; it, Gianicolo ), occasionally the Janiculan Hill, is a hill in western Rome, Italy. Although it is the second-tallest hill (the tallest being Monte Mario) in the contemporary city of Rome, the Janiculum does not figure among th ...
, west of the Tiber. A mill in the basement of the Baths of Caracalla
The Baths of Caracalla ( it, Terme di Caracalla) in Rome, Italy, were the city's second largest Ancient Rome, Roman public baths, or ''thermae'', after the Baths of Diocletian. The baths were likely built between AD 212 (or 211) and 216/217, durin ...
was driven by aqueduct overspill; this was but one of many city mills driven by aqueduct water, with or without official permission. A law of the 5th century forbade the illicit use of aqueduct water for milling.
Decline in use
During the fall of the Western Roman Empire
The fall of the Western Roman Empire (also called the fall of the Roman Empire or the fall of Ancient Rome, Rome) was the loss of central political control in the Western Roman Empire, a process in which the Empire failed to enforce its rul ...
, some aqueducts were deliberately cut by enemies. In 537, the Ostrogoths
The Ostrogoths ( la, Ostrogothi, Austrogothi) were a Roman-era Germanic peoples, Germanic people. In the 5th century, they followed the Visigoths in creating one of the two great Goths, Gothic kingdoms within the Roman Empire, based upon the larg ...
laid siege to Rome, and cut the aqueduct supply to the city, including the aqueduct-driven grist-mills of the Janiculum
The Janiculum (; it, Gianicolo ), occasionally the Janiculan Hill, is a hill in western Rome, Italy. Although it is the second-tallest hill (the tallest being Monte Mario) in the contemporary city of Rome, the Janiculum does not figure among th ...
. Belisarius
Belisarius (; el, Βελισάριος; The exact date of his birth is unknown. – 565) was a military commander of the Byzantine Empire under the emperor Justinian I. He was instrumental in the reconquest of much of the Mediterranean terri ...
, defender of the city, had mills stationed on the Tiber instead, and blocked the conduits to prevent their use by the Ostrogoths as ways through the city defences. In time, some of the city's damaged aqueducts were partly restored, but the city's population was much reduced and impoverished. Most of the aqueducts gradually decayed for want of maintenance, creating swamps and marshes at their broken junctions. By the late medieval period, only the Aqua Virgo still gave a reliable supply to supplement Rome's general dependence on wells and rainwater cisterns.[Deming, David, "Decay and Renaissance Revival": in ''The Aqueducts and Water Supply of Ancient Rome,'' The Groundwater Association, Online version, Volume 58, issue 1, January/February 2020, 30 October 2019 https://doi.org/10.1111/gwat.12958 (accessed April 26, 2021)]
In the provinces, most aqueducts fell into disuse because of deteriorating Roman infrastructure and lack of maintenance, such as the Eifel aqueduct (''pictured right''). Observations made by the Spaniard Pedro Tafur
Pedro Tafur (or Pero Tafur) (c. 1410 – c. 1484) was a traveller, historian and writer from Castile (modern day Spain). Born in Córdoba, to a branch of the noble house of Guzmán,He dedicated his manuscript to Don Fernando de Guzmán, Chief Co ...
, who visited Rome in 1436, reveal misunderstandings of the very nature of the Roman aqueducts:
During the Renaissance
The Renaissance ( , ) , from , with the same meanings. is a period in European history marking the transition from the Middle Ages to modernity and covering the 15th and 16th centuries, characterized by an effort to revive and surpass ideas ...
, the standing remains of the city's massive masonry aqueducts inspired architects, engineers and their patrons; Pope Nicholas V
Pope Nicholas V ( la, Nicholaus V; it, Niccolò V; 13 November 1397 – 24 March 1455), born Tommaso Parentucelli, was head of the Catholic Church and ruler of the Papal States from 6 March 1447 until his death in March 1455. Pope Eugene IV, Po ...
renovated the main channels of the Roman ''Aqua Virgo
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 Agri ...
'' in 1453. Many aqueducts in Rome's former empire were kept in good repair. The 15th-century rebuilding of an aqueduct at Segovia
Segovia ( , , ) is a city in the autonomous community of Castile and León, Spain. It is the capital and most populated municipality of the Province of Segovia.
Segovia is in the Inner Plateau (''Meseta central''), near the northern slopes of th ...
in Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
shows advances on the Pont du Gard
The Pont du Gard is an ancient Roman aqueduct bridge built in the first century AD to carry water over to the Roman colony of ''Nemausus'' ( Nîmes). It crosses the river Gardon near the town of Vers-Pont-du-Gard in southern France. The Po ...
by using fewer arches of greater height, and so greater economy in its use of the raw materials. The skill in building aqueducts was not lost, especially of the smaller, more modest channels used to supply water wheel
A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel (usually constructed from wood or metal), with a number of blades or buckets ...
s. Most such mills in Britain were developed in the medieval period for bread production, and used similar methods as that developed by the Romans with leat
A leat (; also lete or leet, or millstream) is the name, common in the south and west of England and in Wales, for an artificial watercourse or aqueduct dug into the ground, especially one supplying water to a watermill or its mill pond. Other ...
s tapping local rivers and streams.
See also
* List of Roman aqueduct bridges
* Roman architectural revolution
* Roman architecture
Ancient Roman architecture adopted the external language of classical Greek architecture for the purposes of the ancient Romans, but was different from Greek buildings, becoming a new architectural style. The two styles are often considered on ...
* Roman engineering
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 ...
* Roman technology
Roman technology is the collection of antiques, skills, methods, processes, and engineering practices which supported Roman civilization and made possible the expansion of the economy and military of ancient Rome (753 BC – 476 AD).
The Roma ...
References
Bibliography
*Bannon, Cynthia, ''Fresh Water in Roman Law: Rights and Policy'', Cambridge University Press, p. 219: 18 August 2017, vailable online, accessed 14 April 2021*Bannon, Cynthia, ''Gardens and Neighbors: Private Water Rights in Roman Italy''. University of Michigan Press, 2009.
*Blackman, Deane R., Hodge, A. Trevor (2001). "Frontinus' Legacy". University of Michigan Press.
*Bossy, G.; G. Fabre, Y. Glard, C. Joseph (2000). "Sur le Fonctionnement d'un Ouvrage de Grande Hydraulique Antique, l'Aqueduc de Nîmes et le Pont du Gard (Languedoc, France)" in ''Comptes Rendus de l'Académie des Sciences de Paris''. Sciences de la Terre et des Planètes. Vol. 330, pp. 769–775.
*Bruun, C., (1991). "The Water Supply of Ancient Rome, a Study of Roman Imperial Administration". Helsinki, Finland: Societas Scientiarum Fennica. oogle Scholar
A gutter punk is a homeless or transient individual who displays a variety of specific lifestyle traits and characteristics that often, but not always, are associated with the punk subculture. Attributes may include unkempt dreadlocks, nose ri ...
*Bruun, C., (2013). "Water supply, drainage and watermills", In: ''The Cambridge Companion to Ancient Rome'', editor, Erdkamp, Paul, pp. 297–313. New York: Cambridge University Press.
*Carcopino, J. (1940). Daily Life in Ancient Rome, translated by E. O. Lorimer. New Haven, Connecticut: Yale University Press.
*Chanson, H. (2002).
Certains Aspects de la Conception hydraulique des Aqueducs Romains
. ''Journal La Houille Blanche''. No. 6/7, pp. 43–57.
*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 ()
*Coarelli, Filippo (1989). ''Guida Archeologica di Roma''. Milano: Arnoldo Mondadori Editore.
*Claridge, Amanda (1998). ''Rome: An Oxford Archaeological Guide''. New York: Oxford University Press
Oxford University Press (OUP) is the university press of the University of Oxford. It is the largest university press in the world, and its printing history dates back to the 1480s. Having been officially granted the legal right to print books ...
.
*Fabre, G.; J. L. Fiches, J. L. Paillet (2000). ''L'Aqueduc de Nîmes et le Pont du Gard. Archéologie, Géosystème, Histoire''. CRA Monographies Hors Série. Paris: CNRS Editions.
*Gebara, C.; J. M. Michel, J. L. Guendon (2002). "L'Aqueduc Romain de Fréjus. Sa Description, son Histoire et son Environnement", ''Revue Achéologique de Narbonnaise'', Supplément 33. Montpellier, France.
*Hodge, A.T. (2001). ''Roman Aqueducts & Water Supply'', 2nd ed. London: Duckworth.
* Kamash, Zena (2010). ''Archaeologies of Water in the Roman Near East''. Gorgias Press.
*Keenan-Jones, Duncan, "The Aqua Augusta and control of water resources in the Bay of Naples", ''Australasian Society for Classical Studies Conference 31,'' Perth, Australia 2010, Macquarie University.
*Keenan-Jones, Duncan; Motta, Davide; Garcia, Marcelo H; Fouke, Bruce, W. "Travertine-based estimates of the amount of water supplied by ancient Rome's Anio Novus aqueduct", ''Journal of Archaeological Science: Reports'', Science Direct, Volume 3, September 2015, pp. 1 – 10 (accessed online January 30, 2021)
*Leveau, P. (1991). "Research on Roman Aqueducts in the Past Ten Years" in T. Hodge (ed.): ''Future Currents in Aqueduct Studies''. Leeds, UK, pp. 149–162.
*Lewis, P. R.; G. D. B. Jones (1970). "Roman gold-mining in north-west Spain". ''Journal of Roman Studies'' 60 : 169-85.
*Lewis, P. R.; G. D. B. Jones (1969). "The Dolaucothi gold mines, I: the surface evidence". ''The Antiquaries Journal'', 49, no. 2: 244–72.
*Martínez Jiménez, J. (2019). ''Aqueducts and Urbanism in post-Roman Hispania''. Gorgias Press.
*Mango, C. (1995). "The Water Supply of Constantinople". In C. Mango, G. Dagron, et al. (eds) ''Constantinople and its Hinterland.'' pp. 9–18. Aldershot.
*Taylor, Rabun, M., "Public Needs and Private Pleasures", in: ''Water Distribution, the Tiber River and the Urban Development of Ancient Rome'', (Studia Archaeologica) L'ERMA di BRETSCHNEIDER, 2000.
*Taylor, Rabun, M., (2002),
Tiber River bridges and the development of the ancient city of Rome
, in ''The Waters of Rome'', 2, published online by virginia edu2,
*Tucci, Pier Luigi (2006). "Ideology and technology in Rome’s water supply: castella, the toponym AQVEDVCTIVM, and supply to the Palatine and Caelian hill". ''Journal of Roman Archaeology'' 19 : 94-120.
External links
* Sextus Julius Frontinus.
De Aquaeductu Urbis Romae
' (''On the water management of the city of Rome''). Translated by R. H. Rodgers. University of Vermont
The University of Vermont (UVM), officially the University of Vermont and State Agricultural College, is a Public university, public Land-grant university, land-grant research university in Burlington, Vermont. It was founded in 1791 and is amon ...
. 2003.
Lacus Curtius
– entry on Roman waterworks, uchicago.edu
{{Ancient Rome topics
Ancient Roman architecture
Water
History of construction