A pre-lslamic poet sang long ago of verdant Oman as "a goodly land, a land abounding in fields and groves, with pastures and unfailing springs." But in the region at the desert’s margin, where no natural rivers flow and where farming is impossible without irrigation, it is the splendidly-engineered aflaj , the system of underground and surface canals, that have watered the country's agriculture for millennia.
Ancient aflaj (singular: falaj ) still course like arteries beneath the hills and plains of Oman, twisting along precipitous cliffs and threading villages and date-palm groves, bringing to the parched land water and coolness and life itself. Today, the aflaj of Oman deliver a total of 900,000,000 cubic meters of water per year - 730,000 acre-feet or 238 billion US gallons - which is more than 70 percent of the country's total water use. Water from aflaj irrigates about 55 percent of Oman's farmed land.
Debate continues to swirl over the origin of this irrigation system, which is at least 2700 years old: Sargon II of Assyria recorded the destruction of the aflaj of the Urartian city of Ulhu in 714 BC.
The word aflaj itself denotes not only the water canals but also the irrigation network that relies on them and the social system that apportions water to the owners of water-shares. The aflaj have helped to shape the history and settlement patterns of Oman, and they continue even now to tie together each community that draws upon the falaj's flow. As part of traditional greetings, an Omani will invariably ask about the condition of the aflaj, which evokes the reply, "Insha'allah, they are full." As concern expands over the best use of Oman's precious water resources, the state of the aflaj will undoubtedly continue to affect Omani life in the oil age and beyond.
The aflaj constitute an elegant and relatively efficient system for tapping underground water in the wetter mountain areas and delivering it to flatter areas where agriculture is possible. Since water flows in the canals by gravity, no outside energy is needed for transport. Beyond the initial investments of capital and effort to build the network, the aflaj require comparatively little labor to maintain. A further advantage - though a two-edged one - is that, unlike wells, the self-regulating aflaj system does not exhaust the aquifer, or underground water-bearing layers, that it taps: In times of drought, for example, all farmers receive proportionately less water.
"We have no rivers and our underground reservoirs are very limited," points out Kamal Abdurredha Sultan, a prominent Omani businessman and farm-owner concerned about the future of agriculture in Oman. "The rainfall on the whole, throughout the country, is unreliable. The past generations, perhaps realizing the circumstances, used the available water resources as efficiently as possible.... The wonderful and intricate falaj system was in complete harmony with the water circumstances, and responded well to the wet and dry periods, each lasting several years, that were a feature of Oman's climate - and still are."
Different types of aflaj were built to suit the water sources available. Some 90 percent of precipitation falling on Jabal Akh-dar, northern Oman's mountainous core, percolates down to the underground water table. Those canals, known as qanat aflaj, collect water in the rock, sand, and gravel aquifers skirting the mountains' edge, and run beneath the land surface for kilometers to emerge at an oasis. The supposed length of aflaj is, in fact, grist for fables: A camel stick, dropped by the Caliph of Baghdad into the Euphrates, is said to have surfaced in an Omani well called Ain Sariq.
Other aflaj exploit shallow or surface waters. Most mountain wadis, or valleys, are lined with gravel and silt, which overlie consolidated rock in the valley floor. Water flows perennially through the surface layers of the wadi deposits, and this may be tapped by a ghayl falaj, which collects and conveys the water in an open channel to an oasis. Still other aflaj simply conduct water above-ground from a spring, such as those channeling the hot springs welling up from diaphanous, calcite-encrusted pools near the towns of Nakhle and Rustaq.
The skills of falaj construction and repair are preserved today in Oman by the Awamir, a partly settled, partly nomadic tribe based near Izki, whose falaj specialists still travel throughout Oman, carrying out their trade. They have a respected reputation for water divining.
To begin a new qanat falaj, a diviner generally scrutinizes the topography, soils, and vegetation at a promising site for a mother well, or umm al-falaj, the vertical shaft down to the aquifer. Some Omani diviners are said to use less orthodox methods: A hydraulic engineer recently observed one enter a prolonged trance, during which he called upon Sulayman ibn Da'ud - Solomon, the son of David - and summoned a jinn from Africa to assist his search.
The shaft of a mother well averages 20 meters (66 feet) deep, but some mother wells descend as much as 60 meters (200 feet). At the bottom, the horizontal channel or gallery that is excavated downslope from the well is left unlined, so that the water can seep into it from surrounding porous layers.
After the collection gallery for the mother well is dug, the builders move down slope. Here they dig another vertical shaft and begin burrowing back almost horizontally toward the mother well. Crouching in the tunnel, they excavate with hammer and chisel. Successive vertical shafts extend the underground tunnel toward the point at which it surfaces kilometers away. The Awamir are particularly accomplished at excavating aflaj through hard rock - a daunting task, for a tunnel one kilometer (1100 yards) long and one-half meter (20 inches) in diameter requires removing between 3000 and 4000 tons of rock.
From the air, Oman's landscape, particularly the mountainous heartland, is dotted with holes that look like chains of bomb craters. These holes mark the successive vertical shafts sunk to excavate the horizontal tunnel of a falaj, and they indicate its course from source to the oasis. The original builders left the holes open after the underground canal was completed, so that their access shafts could be used for subsequent inspection and repair.
The hazards of falaj work are legion. In Iran, excavators baldly call the qanat falaj "the murderer" in Persian. An Oman Ministry of Agriculture engineer marvels at the skills of the original builders, who worked without air pumps or safety equipment. In an access shaft, a worker may be struck by falling stones, while tunnels pose the danger of collapse. Added to this, the stifling heat and poor air circulation within a falaj may allow work for only 20 minutes at a time. The worker faces particular danger when, tunneling uphill, he nears the mother-well gallery where water has collected. Many have drowned in the onrush of water as the final rock gives way between the tunnel and the gallery.
Oman's rugged topography tested the ingenuity of ancient planners, who produced engineering solutions that are part of Oman's architectural heritage. Some aflaj run along the contour lines, tracing the curves of wadis or valleys, like the falaj near Tanouf in the Jabal Akhdar that hugs the cliff wall high above the wadi floor. Parallel abandoned channels, cut into the wadi wall some distance above the flowing falaj, probably testify to past changes in water level or flow.
Where a falaj crossed wadis, such as near Rustaq and Nakhle on the Jabal's coastward slopes, architects bridged the valleys with arched aqueducts often more graceful than the sturdy poured-concrete ones built today. Wherever the torrential flood of a wadi was strong enough to wash away an aqueduct, engineers built inverted siphons - closed U-shaped tunnels. In these, the horizontal falaj flow disappears down a vertical shaft on one side of the wadi, tunnels straight across beneath the wadi floor, and reemerges up a second vertical shaft on the other side. Because the lip of the second shaft is slightly lower than the siphon entrance, the head of water forces the flow through the structure.
Oman's numerous aflaj are the best known of those in Arabia, but similar underground channels can be found under various local names from China to the western Sahara - in Afghanistan, Pakistan, Iraq, Iran, the Levant, Cyprus and northwest Africa - as well as in Sicily, Spain, South America and even Korea and Japan.
Such a widespread distribution complicates the question of who invented the falaj. The word itself is quite ancient, stemming from a Semitic root (plg) that denotes division. The related Arabic three-consonant root flj signifies the division of property, suggesting the falaj's purpose as a system for dividing or distributing water.
Many investigators cite ancient Persia as the home of the aflaj, which are called kariz in Persian. As geographer Paul Ward English writes, "The core area of qanats [aflaj] ... lies in the realm of the Persians, whose language is rich in words relating to qanat technology and where qanats are very old, very numerous, and constniction techniques are fully developed."
This theory postulates that the Persians carried qanat technology with them to the lands they colonized in Achaemenid times during the sixth century BC; indeed, one measure of a Persian leader at the time was the number of qanats he had built in the lands he ruled. Commercial incentives were used - the builder of a qanat was granted the profit from it for five generations, like a patent - and they were apparently successful: Iran is still home to perhaps 40,000 qanats stretching some 161,000 kilometers (about 100,000 miles) altogether; they still supply many cities, including Tabriz, Tehran and Yazd.
Recent archeological investigations, however, may suggest an indigenous origin for the aflaj of Oman. The country's oldest aflaj are said to be those of the al-Jauf region near Nizwa, in the interior. Tradition identifies the most ancient as Falaj al-Malaki, which still supplies the town of Izki in the region (See Aramco World, January-February 1989). Mining and hydraulic techniques were developed in the Arabian Peninsula by 1000 BC, and sophisticated mining techniques - related to those of falaj builders - were employed in Oman even in the third millennium BC.
"The problem of the origin of the falaj, therefore, remains open to further speculation," believes archeologist Paolo Costa. "This must take into consideration the technical skill in water management and mining known to have been acquired by the ancient Arab populations long before [the Persian] Cyrus the Great's conquests."
An Omani falaj of especially elegant construction, Falaj al-Kamel near Rustaq, dates fromYa'ariba Imamate rule of Oman during the 17th and 18th centuries, an era that also bequeathed a number of the country's most spectacular forts (See Aramco World, January-February 1991). Visitors must descend a flight of stone steps into the falaj and wade through the tepid, flowing water to appreciate the artistry of this underground monument, which is said to have extended 32 kilometers (20 miles) in the past. Tiny fish nibble at waders' bare toes, while the sultry gloom is pierced only by light from access shafts, themselves the lairs of snakes and bats. The falaj was not merely tunneled through rock, but is distinctive for the segment lined with an arched vault of local Omani cement.
Nearby, a falaj leading to al-Hazm fort, another notable, demonstrates the Oman's turbulent try to cut a falaj to deprive the comunity and fort of their water supply, but a line of dummy shafts parallels illustrating the imam's craftiness in protecting hjs domain. The phony falaj could be blocked while, unknown to the attackers, the real canal would continue to serve the besieged fort.
In modern Ruwi in the capital area, the historic falaj in the museum-fort of Bay al-falaj has been put to new use watering graceful gardens in the fort's precincts. But to best see aflaj in their traditional setting, one must travel inland to Oman's heartland, which is far less touched by modern development. Here, distant smudges of green against the feet of the mountains resolve upon approach into date-palm groves and villages. Mounds of earth typically surround the oases, left after excavating garden basins to the proper level to receive the falaj's gravity-propelled flow.
A typical qanat falaj surfaces at the head of an oasis, where a time-hallowed hierarchy governs the use of its flow. At the top of the village is a special place for drawing drinking water, which is free to all. Downstream lie the men's bathing facilities, open-roofed bathhouses with private cubicles, and next, the women's; below these is the place for washing the dead. A mosque or an important fort, such as al-Hazm, may have direct access to the falaj, although most private houses do not; however, a house's proximity to the point at which the canal enters the village can indicate its family's prominence. Farther downstream, past sites for washing clothing, dishes, and cooking utensils, the falaj flows on to irrigate the gardens.
Palm trees, goes a traditional saying, "like their heads in fire [sunlight] and their feet in water," making them well-adapted to cultivation on the desert's edge. Date palms.constitute three-quarters of Oman's tree crops, a proportion reaching seven-eighths in the country's interior. Other tree crops include citrus, banana and mango. Fodder-crops, notably alfalfa, are planted along with vegetables and other crops further down the falaj network. Such placement capitalizes upon times of good to-grow a variety of crops, which can sacrificed during drought in favor of the valuable palms.
Falaj water is apportioned to villagers upon an age-old system, and religious authorities arbitrate disputes over water rights. Gardens are irrigated for a certain time period called an athar and commonly half an hour long. Successive plots are irrigated in sequence in the course of a cycle that may last six to eight days before the first plot is watered again. At the designated time, the farmer – or a water-watchman called haris al-bider – diverts the falaj flow into the designated plot with a simple dam, usually a flat stone or section of palm trunk wedged into the channel with scarps of fabric.
Some villagers may own rights to a certain number of athar of water in perpetuity. Others lease their athar at half-yearly auctions. In a village with a complex system of water shares, such as Izki, a falaj book records the owners of water rights, who may number more than 200.
In central Oman, money for maintaining a large falaj usually comes from these auctions of shares of falaj water. During an auction in Izki, for instance, bidders ring the auctioneer, touching him with their camel sticks to indicate a bid, and dropping out from the contest by lifting their sticks until only one bidder remains.
Many villages have a sun clock to measure time periods of irrigation. A smaller village may have a simple clock, a mere patch of flat ground in an area open to the sun, with a wooden or metal post at its center. On either side of the post, a row of parallel lines is scratched into the earth. As the sun passes overhead, the shadow of the stick strikes successive lines at 30-minute intervals. Different plots are designated by small stones embedded at or between the lines; when the shadow falls upon a stone, it is time to water the plot it represents.
In a large and complex oasis watered by several aflaj, such as Rustaq, the sun clock is an expansive rectangular platform set with many large stones of different colors. The smaller sun clock in the town of Adam, with lines carved into a fallen tree trunk, is also still used, although a local farmer admits to consulting his watch on cloudy days. But the falaj flows day and night, so a timing method is needed for nighttime use as well.
Nighttime irrigation in Oman was formerly timed by the movement of designated stars. In Mudayrib, a village north of the Wahiba Sands (See Aramco World, January-February 1988), watchers traditionally observed the night sky from the Reckoning Mosque (Masjid Al-Hisab).
In Iran, instead of a sun clock, a water clock is used that consists of a brass bowl with a small hole in its bottom, set in a larger container of water. The irrigation time unit is the length of time it takes for the brass bowl to fill and sink - a period that is the same for a given bowl, day or night.
As John C. Wilkinson demonstrates in his landmark study of the aflaj of Oman, the geographic distribution of water resources and aflaj help explain the pattern of scattered small habitations in the country's heartland. A falaj can support only a limited number of people, and even the largest towns supplied by several aflaj, such as Rustaq and Nizwa, have fewer than 10,000 inhabitants. Since the falaj system demands cooperation for its maintenance and operation, it has helped to organize life in the isolated, tightly-knit communities of Oman's interior.
Aflaj also play a role in local legend. One spring-fed falaj called Ma'awil, near Ibri in the interior, is wreathed in myth because of its intermittent flow. Local belief holds that long ago, a girl of the Maqrashi tribe descended to the falaj to collect water, and disappeared. Legend maintains that she was taken by the head of the jinn, who to this day releases water only when her tribesmen visit the falaj, to compensate them for the kidnaping of one of their daughters. Hydrogeologists, more prosaically, attribute the spring's stops and starts to a natural siphon effect, which allows the spring to fill only under certain conditions.
The aflaj that animate legend and life in the villages of Oman suffered various mishaps throughout history. Evidence of abandoned aflaj indicates that Oman's agriculture was considerably more extensive in former times; indeed, Wilkinson believes that the cultivated area of the country may be only half as large today as it was at the end of the sixth century. Floods swept away many aflaj, while others were destroyed during civil wars - a calamity that provides the dramatic backdrop for Hammond Innes' 1960 novel The Doomed Oasis. In the oil era, the migration of populations and modern development, including the introduction of new agricultural techniques such as mechanical pumping, have all contributed to the decline of the aflaj. It is a sign of change that the Awamir falaj experts are called upon increasingly to excavate mechanical wells as well as aflaj.
As part of its demonstrated and increasing concern for the viability of the country's agriculture and water resources, the Omani government launched an effort in recent years to document all the country's aflaj, and has spent millions of riyals on repairing the systems. Ministry of Agriculture staff estimate that they renovate sections of approximately 150 aflaj every year, building new concrete channels to numerous ancient villages, and constructing such works as the concrete inverted siphon to carry a falaj beneath a new road near Rustaq.
As agriculture has been modernized, some observers believe that mechanical pumping in the new wells poses a particular threat to the falaj system, through lowering the water table in some areas. The government prohibits new wells within 3.5 kilometers (two miles) of a falaj's mother well - at least in those cases where its location has not been lost to history.
A longer-term consideration is identified by a Ministry of Water Resources scientist who has assessed Muscat's rainfall pattern over the past century. The area has enjoyed higher than average precipitation during the past three decades or so, he notes; if pumping is now depleting the aquifer during a time of favorable rainfall, the aflaj may suffer if rainfall again decreases below the norm.
"Some of the aflaj have been permanently destroyed, others have stopped flowing," observes Kamal Sultan. "Among them are the famous falaj of Jabrin, and those in Wadi Naam, Ibra, and so on. The level of most of them is gradually falling.... When they are restored, it will be wonderful to see people back in the dead villages that were perhaps deserted when their aflaj fell into disuse or couldn't be repaired."
During what is clearly a time of reckoning for the remaining aflaj of Oman, experts and officials are now engaged in a broad effort to preserve this venerable institution, along with the way of life it has so long made possible.
Washington-based free-lance writer and photographer Lynn Teo Simarski specializes in Middle Eastern topics. She wrote on Oman's forts in an earlier issue ofAramco World.