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The Qanat: Ancient Antidote to Arid Iran’s Thirst
Anthony Smith (born 1926) is a British author who, as a graduate student in zoology at Balliol College, Oxford, England, spent the summer of 1951 in central Iran studying its famous qanat [also spelled quanat] systems and their fauna. (1) Smith shared his extraordinary experience in Explorations in Persia: Blind White Fish in Persia (1953), which is a valid scientific source and a romping good read for anyone interested in qanats and their meaning in Persian history and culture. (1)
Smith, three friends, and their loyal Land Rover reached Kerman (Kirman), Persia, by traveling across land and sea (Oxford, to Genoa, to Alexandria, to Beirut, to Baghdad, to Tehran, to Qum, to Istafan, to Yazd, to Kerman, and back). Smith studied qanat systems in several outlying villages (e.g., Zangiabad, Jupar) and in Kerman, a city currently numbering a half million residents. Most villages and rural areas on Iran’s mile-high desert plateau depend on water provided by qanat systems. Iran boasts more than 100,000 miles of qanats. (1)
Qanats are artificial underground water channels up to 1,000 feet deep beneath the surface of the earth, which bring a continual stream of water to the earth’s surface for human agricultural and domestic use. The water emanating from qanats “is not lifted to the surface but flow[s] down the channel away from the point of seepage, as if a normal well had been pushed over on its side until the water flowed out of its mouth,” explains Smith. (1) A qanat then is a horizontal, not a vertical, well, which functions in a non-mechanical manner, relying solely on gravity to move the water from its source to its point of use.
The cross-section of qanats is usually elliptical with a height of around 4 feet and a width of around 2 and ½ feet, says Beaumont. (2) Anthony Smith would probably disagree. He describes a high degree of variation in the cross-sectional shapes of the many qanats through which he waded for many miles. Qanats are usually spectacularly unsupported and unlined by timbers or other framework. The one exception is at areas of weakly consolidated material. Here, baked clay rings known as Kavulls strengthen the tunnel to avoid roof and wall collapse. The vertical shafts are approximately three feet in diameter; mudlinings or mud brickwork usually strengthen the upper portions of the shaft, says Beaumont. (2)
To build a qanat, skilled muqannis (specialized qanat diggers) hand excavate a “mother well” high on a talus slope at the foot of a mountain ridge. The techniques used by muqannis have changed little since qanat construction began millennia ago. (2) A talus is a sloping mass of rocky fragments and debris (sand and gravel, or alluvium) that water, wind, gravity, and seismic forces have washed, blown, shook, or otherwise moved down the mountainsides. Once muqannis successfully locate the water table, they dig a gently sloping tunnel downslope from the bottom of the mother well towards the place the qanat builder plans to situate agricultural fields and a new town. Actually, the muqannis dig the tunnel upslope from the field to be irrigated back toward the well. (2-3) ndeed, “[u]pslope construction of the tunnel continues for some distance below the level of the water table and it is in this section that water seeps into the tunnel,” avers Beaumont. (2)
A single qanat may irrigate a hundred acres or more. Once dug, the channels muqannis must continually maintain them; then, qanats may last a long time. Digging a new qanat takes many years. Scholar English noted one qanat near Kerman of around 2 miles that took one team of qanat diggers 17 years to construct. Beaumont compares this to the one to two months required to drill a vertical well. (2) Qanats work by tapping into an aquifer system. Recall that an aquifer is a rock formation saturated with water. (4) French hydrogeologist Jean Margat identifies three structural types of aquifer systems—sedimentary basins (most common), subsidence troughs, and detrital (i.e., rock fragments and alluvial debris) accumulation at the foot of large mountain chains. (4-5) A detrital accumulation type of aquifer system is comprised of mostly unconfined aquifers, meaning the aquifer freely communicates with the atmosphere. An example of the detrital accumulation type of aquifer system is the Ogallala aquifer extending eastward beyond the steep eastern slope of the Rocky Mountains’ massif in the United States. Qanats built in Kerman province rely for their water source on the detrital accumulation type of aquifer system. The Kerman province is located on the Hazaran massif of the Central Iranian Plateau. In geology, a massif is a section of a planet’s crust that is demarcated by faults or flexures. In the movement of the crust
The massif mountains of Kerman province are marked by numerous commanding peaks; the highest is Mount Hezar, just south of Kerman city. Mount Hezar is nearly 15,000 above sea level, while Kerman city sits at about 6,000 feet above sea level on vast sandy plains. The taluses hold the snowmelt emanating from the Hazaran massif mountains. The unconfined aquifers in these taluses are the sources of the water that flows through Iran’s thousands of miles of qanats.
The characteristic openings of qanats look like molehills or bomb craters in a line trending toward a village or city. These openings speckle the land and stretch for many miles before disgorging their water onto the surface. The openings are the top aspect of the many shafts of the qanat. Through these openings, air rushes downward to ventilate the qanat. Muquannis use the openings to lift out excavated material (spoil) for deposition in piles surrounding the opening. (8)
Smith writes: At the top of each shaft a mound is formed which gives the land above a qanat its characteristic appearance. These shafts are also used when repair work or removal of silt is being carried out, and as we [three friends went with Smith] drove along, we occasionally saw a large wooden wheel erected above one of them. By means of the wheel two men raise the little goat skin bag and then empty it of its contents. Down below, the excavators crawl along the channels and with short handled picks and shovels fill up the bag once more. As there are shafts along the length of the qanat and as the water eventually flows out of its lower end, the depth of the shafts lessen towards the exit. The final shaft may be only 6 feet deep, but at the other end the water channel is often 300 feet from the surface of the land. An exceptional case is at G[o]nabad [a UNESCO World Heritage site in Khorasan (8)] where the deepest well is 1,000 feet. In spite of the obvious labor and expense in excavating each shaft, it is generally considered economic to make a fresh one for every 150 feet of channel. The bad ventilation down in the channel and the difficulties of dragging the full bag along it to the base of the shaft make this necessary.
Yet, although 150 feet separated one gaping hole from the next, and one pile of mud from its neighbor, the medley of qanats that converged upon a town made the dotted lines become indistinct. As with birds before an island, the qanat wells warned you of the approach of a town; they are the ramifying tendrils which are responsible for its livelihood, the arteries of its existence and, as with arteries, their breakdown causes that existence to cease. Herodotus, in describing the wars with in Persia, writes of the simple procedure of filling in the wells of a town in order to destroy it. Nowadays, lines of qanat wells often lead to nothing more than a few old walls; the qanat has dried up and the people have been forced to move elsewhere. The extraction of water from a desert is not only a costly but [also] a chancy business. (9) Qanats have existed on the mile-high plateau of Iran for at least two millennia. (2) English stated in 1968 that qanats appear to have originated in the vicinity of Armenia more than 2,500 years ago (circa 500 B.C.) and spread rapidly throughout southwest Asia and north Africa during Achaemenid times (550 to 331 B.C.). (10) Beaumont continues: Certainly by 209 B.C. qanats were an important feature of the Persian landscape and were described by Polybius [Greek historian, ca, 203-120 B.C.] during the campaign of Antiochus [III, the Great, sixth ruler of the Seleucid Empire, ca. 241-187 B.C.] against Arsaces [I, King of Parthia, ca. 250-211 B.C.]. In his description, Polybius records how Arsaces tried to destroy the qanats and so cut off the water supply in order to halt the advance of Antiochus towards the lost Parthian captial of Hecatompylos. Althouth the methods of qanat constuction were carried westwards into the Mediterranean and subsequently into Latin Amierca, qanat and qanat systems attained their maximum development in Iran. (2) Anthony Smith adds, “Qanat is a word of Assyrian or Akkadian origin and came via the Hebrew and Aramaic languages to be used in Persia. But this type of water channel is definitely Persian in origin and was origianlly called kariz; somehow the word qanat has ousted the word kariz, which is now used only in Afghanistan. Polybius makes the first reference to them in describing the wars of 209 B.C. But although the word qanat may have originated well prior to this date, it is not known when it acquired its present meaning. It is probable that qanats are as old as the towns in those parts of Persia where water does not flow either on or just beneath the surface.” (11) “The real principle behind all qanats is that if a man constructs one then he owns the land which its water irrigates,” declares Smith. “This dictum is very old and still applies.” (11) However, building a new qanat requires much capital. A wealthy person typically finances the building of a qanat system. In Jupar, for example, an old man told Smith, “Many years ago there was no Jupar in the whole world…One of the soldiers guarding the road to India [if one continues eastward on the road connecting Istafan, Yazd, and Kerman, one will reach Bam and then India], in that fort over there, thought that there would be water near this place. Many people believed this, because at one time there was a small stream in the summer time…The soldier, who was a poor man, managed to persuade a rich man to build a qanat. That qanat is still flowing and still gives water; but the fort fell down many years ago.” (12)
The man who believes he has enough money to build a qanat first calls for water-finding experts, explains Smith. “They arrive and inspect the neighborhood. Partly by intuition and partly by intelligence in connection with the lie of the land, the proximity of any springs and the abundance of plants in the summer, they estimate where there will be water beneath the surface. Their decision is never discussed with the landlord, for the secret is a jealous one; instead, they point to a spot, collect their money and go,” continues Smith. (11) Then surveyors come, dig a well at the indicated spot, and continue down until they strike water; “if no water is arrived at before a depth of 300 feet has been dug, then the well is abandoned and a fresh party of diviners is summoned. However, if water is found, then the well is deepened until a depth of two meters accumulates overnight: this quantity not only makes further deepening unpractical but shows that there is a sufficiency of water at that level.” The ancient, but quite scientific method, used by muqannis to lay out the qanat system is described elsewhere. (11) Building qanats has occurred during boom periods in history. For example, Bulliet describes the economic basis of one building boom of qanats in Iran during the ninth and tenth centuries A.D., following the Muslim Arab conquest in the seventh and eighth centuries A.D. (13) Arab conquerors preferred cotton textiles, which were not readily available in Iran, because people there preferred wool (e.g., sheep wool, camel wool), linen and even silk transported to Iran via the Silk Road from Central Asia and China. The new Arab elite thus oversaw the development of qanats to bring more Iranian land under cultivation to grow the cotton plant. The boom in the production and export of cotton made possible by constructing thousands of qanats that supported thousands of small villages inhabited by peasants who tilled the fields of cotton across Iran, made Iran the richest region of the Islamic caliphate in the ninth and tenth centuries AD. The cotton boom ended, theorizes Bulliet, because of a significant cooling of the climate that lasted for more than a century. Cotton needs heat and water to grow. (13)
Anthony Smith waxed eloquently on the meaning of the qanat stream for villagers: it is “the life of the village; without it the village would be as dust. Although mainly used for irrigation it also provides all the drinking water; and the first duty of a Persian day is to go and collect this water from the mouth of the qanat before too many other Persians have paddled in it or the animals have come down to drink from it.” He continues: Drinking water is free; not because of any benevolence on the part of the owners [of the qanat system] but because of the impossibility of charging for it. As it is, there is much disregard for the private ownership of the qanat; a second duty of the Persian day is to cover up the traces of any robbing of water he may have made during the night; for a man who has no money, who has a stream flowing near his garden and who has an unscrupulous bent, in short a Persian peasant, the gurgling of that stream provides too great a temptation. (14) The water robbers grab their shovels and remove a large chunk from the bottom of their own, or their neighbors’, garden walls. “There is never any question of the water not flowing correctly; with the passage of time the unlawful channel has become too deep.” Smith was amazed: Once, when I was returning late at night from a walk into the mountains along a route that I knew quite well, I suddenly found myself wading through a small stream that had never been there before; the odd thing was that it flowed straight under a garden door…I strode on. I was soon splashing down a path which had previously, as I remembered it, been a dry and dusty way; many streams had dried up but more had been born in the night. It chanced that I should pass that way again the next morning and there was the dust I knew, the dust of ageless time, the dust as old as the desert itself. Sometimes, of course, the diverter is so fatigued by the night’s work that he falls asleep when the warmth of the day beings to seep into his system; then it is that the stream continues on its unnatural course. Its owner will hastily put things right, but the tell tale dampness will be there for [the village bailiff] to see, even if the owner hadn’t gone bounding off to find him. All three then argue until the heat of the day becomes too oppressive: the argument swells to a climax and finally all is forgotten under the beneficence of sleep. (14) Anthony Smith described his first experience hiking a qanat—the Gauhariz (the qanat of the flowing jewels in Kerman province) described above by the old man. The Gauhariz irrigates an area of two square miles and has five channels, each three miles long and leading from a depth of 150 feet (as of 1951, when Smith studied the qanat). Smith and a muqanni left their shoes at the entrance to the qanat, stepped into the water and began to walk upslope toward the mother well. “At the beginning it [the qanat] was about six feet wide and six feet high,” wrote Smith, “with the water reaching up to our knees.” He continued, Sometimes the roof was less than four feet high, in other places it was many yards above. Occasionally there were great caverns where many roof falls had occurred and also, as a relief, would come the light from one of the shafts to the surface. There are many reasons for the irregularities: a blockage may have necessitated a new detour, the thin portions might have been an attempt at economy; the deep parts are proof of the everlasting search for more water when its level in the channel begins to drop. So, sometimes scraping our shoulder, sometimes bumping our heads and always stubbing our toes, this small party waded on towards the source. (15) Gauhariz qanat had many branches flowing down to its single exit. Smith said, “Every now and then we would come to a junction; sometimes one of the channels would be dry but more often they contained water. Whichever it was Abu Ali would shout up it and listen to the tubular noise which it produced…I started writing down which route we had taken but the muqanni saw my map and protested. “Lazim nist,” he said, “It is not necessary”…I continued with my map, but surreptitiously. As no branch of Gauhariz stretched for more than three miles it was after a couple of hours that we reached the end. There was no well from this point to the surface; only 150 feet of desert. The channel was far narrower than it had been all the way along; we crouched on our haunches and got in each other’s way: it was not a pleasant spot down there. I flicked my flashlight about but the beam rested either on solid wall and roof or the muddy water and ourselves….[We] crawled away backwards the way we had come. For most of that day we plunged about in those qanats: always it was exhausting and usually it was cold [typically 65 degrees Fahrenheit, while the temperature of the air outside was 90 degrees (16)]; but certain channels felt quite warm. It was possible to float down them, either face downwards or upwards; you would then push yourself along from the bottom or the roof. It was possible if an occasional submerged and jagged rock was not a deterrent: the fish [there were fish in the qanats] would bump into you whichever way up you were; the bumpings and their numbers increased as we neared the exit. It was good to get out into the open again, to lie in the heat of the sun, and to see nothing but sky above you. Some goats were regarding with disdain the foully muddy water which was now exuding from the qanat…(17) Anthony Smith finally settled on the mechanism whereby fish get into qanats. During times of flooding, mountain rivers (containing some fish) overflow, sending streams of water down the mountainsides and over the openings to the qanats, and deposit fish in them in this manner. The fish that Smith found were not white and blind, but were edible. In 1971, qanat expert Beaumont stated his belief that the future of qanats in Iran is limited. (2) He wrote, “Although the qanat has served Iran over the length of historical record as a supplier of water for irrigation and domestic purposes, its lack of controllability in terms of water discharge has meant that it is now unsuited for uses in schemes aimed at the optimum use of water supplies. At the present time it seems likely that Iran will become increasingly committed to a programme of water supply dependent on large scale surface water schemes and the controlled use of groundwater through pumped wells. In the latter case, in order to obtain higher yields or more water it is necessary to have steeper groundwater gradients and larger drawdowns. The effect of this is a lowering of the groundwater level and the drainage of many of the shallower qanats. In the future it seems likely that the qanat will continue to decline in importance as a supplier of water and may disappear completely in areas of high population density or good quality agricultural land where investment capital for modern integrated water schemes is available. In remote areas of low population density and in areas of low or poor yielding aquifers the qanat will, however, still have an important role to play in the supply of irrigation water for many years to come.” (2) Was Beaumont correct about Iran’s water strategy of departing from qanat irrigation technology and turning to large scale surface water schemes? Apparently, the answer is yes. Most drinking water today in Iran comes from deep wells and newly dammed reservoirs. (18-19) Long-distance water transmission pipelines carry the water to users. About 60,000 qanat systems in the plateau regions of Iran (Yazd, Khorasan and Kerman) remain in use for irrigation and drinking water in small towns and rural areas, as described above. Up to 1990 the water and sanitation sector in Iran was highly decentralized, says one source. (18) “Most water and wastewater service provision was the responsibility of municipalities and provinces. This was changed through a fundamental sector reform in 1990 with the ratification of the Provincial Water and Wastewater Companies Law of September 1990. In September 2003 the Government of Iran and the World Bank agreed on a sector strategy with the targets for improved cost recovery and collection and increased efficiency. [20-21] It is not clear what were the baseline data in 2003 and to what extent progress has been made to reach these targets.” (18) In November 2008, the Government of Iran announced that it will construct 177 dams nationwide. (22) Notes:
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