During the 40th meeting of the UNESCO World Heritage Committee in Istanbul, eleven Iranian qanats were inscribed on the World Heritage List. Among these works is the oldest qanat in the country, more than 2500 years old .


During the 40th meeting of the UNESCO World Heritage Committee in Istanbul, eleven Iranian qanats were inscribed on the World Heritage List. Among these works is the oldest qanat in the country, more than 2500 years old (the most recent 200 years ago), as well as the longest qanat in Iran, with a length of 100 kilometers. These eleven qanats selected by the UNESCO World Heritage Committee also have technical peculiarities that make them stand out from the current 37,000 qanats of the country.

The eleven qanates selected for inclusion in the World Heritage List are located in six Iranian provinces: Khorasan Razavi, South Koransan, Kerman, Yazd, Isfahan and Markazi.
In the presentation of the Persian qanat file, the UNESCO World Heritage Center offers this description of the Iranian qanats: "In all the arid regions of Iran, agricultural and permanent settlements are supported by the old system. qanats that draw water from aquifer sources upstream of the valleys and circulate it by gravity along underground tunnels, often over many kilometers. The 11 qanats that make up this system include workers' rest areas, water tanks and water mills. The traditional community management system still in place allows for equitable and sustainable water sharing and distribution. The qanats provide an exceptional testimony to cultural traditions and civilizations from desert areas to arid climates. "
To be included on the World Heritage List, sites must be of outstanding universal value and meet at least one of the ten selection criteria. The Persian Qanat file has been submitted to UNESCO for inscription on the World Heritage List under two important UNESCO criteria for selecting natural sites:

"Criterion III: to bring a unique or at least exceptional testimony to a cultural tradition or a living or extinct civilization;

Criterion IV: To provide an outstanding example of a type of building or architectural or technological ensemble or landscape illustrating a significant period (s) in human history. "

 

What is a qanat?

The technique of qanate construction was developed and implemented in Iran over 3,000 years ago. The Iranians then transferred this know-how to the neighboring regions. Some documents suggest that during the Achaemenid period, the Persians taught these techniques to the inhabitants of Oman during the reign of Cyrus the Great (king of the Persians 559-530 BC). At the time of Darius I (522-486 BC), the Persians made qanats in the oases of Egypt.

According to the Greek historian of the fourth century BCE Callisthenes, who accompanied Alexander during his campaign in Asia, the Persians had solved the problem of fair distribution of water qanat using a water clock (clepsydra).

 

Aerial view of the manholes


Many historians agree that the qanat technique was developed in Persia - pre-Islamic Iran - more than three thousand years ago, then spread eastward. Iranian techniques of qanait construction spread east from Afghanistan to India and China, and west to North African countries such as Morocco, Japan. Algeria and Libya. It has even been introduced to Palermo in Sicily. In fact, the Persian learner, the Romans developed it to Tunisia, and the Arabs transmitted it to Spain and Morocco. In the second century BC, the Greek historian Polybius described the Persian qanats and their construction techniques to bring water into the desert.

The qanat is an underground gallery carved in a quasi-horizontal way. It does, however, have a gentle slope so that water can flow from top to bottom. The purpose of the construction of this gallery is to have access to an underground water table and to carry water through this underground tunnel to the outside at a distance quite far from the place where the first well is dug said the "mother well".

Indeed, the construction of a qanat begins with the drilling of the mother well. The purpose of this first drilling is to access the groundwater level. Then, the workers specialized in the digging of the underground tunnels go to work to dig the gallery at the bottom of the mother well in the direction that has been determined in advance for qanat.

The exit of qanat



As the work of digging the gallery progresses, a series of vertical shafts should be drilled at intervals of 50 to 100 meters. The existence of these access shafts allows the technicians who dig the qanat and who will maintain it later to be able to evacuate the debris of the digging and the sediments. It is also a way to ensure the ventilation of the underground gallery, vital for the workers who work at this depth. The length of the gallery can reach several kilometers, even several tens of kilometers. Qanat is a reliable and permanent source of water supply in arid and semi-arid regions. One of the great advantages of qanates is that they resist natural disasters such as earthquakes and floods, and that the change in precipitation rate does not affect them in the short or medium term.
In the past, the construction of a qanat was usually financed by landowners who gathered to recruit skilled workers to first identify a water table. The team then proceeded to dig the wells and the gallery. But since qanat was an undivided property, the great problem raised was that of the equitable distribution of water. In addition, maintenance of qanat could also cause problems.

The ancient Iranians had solved the problem of equitable distribution of qanat water using the efficient system of the water clock or clepsydra. In the villages, the peasants designated one of them to monitor the equitable distribution of qanat water. This person was settling at the water outlet and placing a small, specifically punctured container in a larger container filled with water, and after filling the small container (one or more times according to the quotas), he would change the course of the water and brought it to the stream of another farmer.

But it must be remembered that qanat water was not only used on farms. On their route, the qanats also watered the neighborhoods and ensured the supply of drinking water to the population. They filled the cisterns and supplied mosques or steam rooms with water.

 

Underground Gallery

If the maintenance work is done correctly and consistently, the qanats are works that stand marvelously in the test of time. This sustainability is due to several factors: respect for the nature and capacity of the water tables and moderation in the use of their resources, the use of local building materials, the resistance of the works to natural disasters such as earthquakes , the energy autonomy of the system, and finally its efficiency in the distribution of water.



Ghassabeh qanat


The qanat Ghassabeh, also called "Kai-Khosrow" or Qanat of Gonabad, is probably the oldest and deepest qanat in the world. According to ancient documents such as Nasser Khosrow's travel account (1004-1074), its construction goes back more than 2500 years. The qanat Ghassabeh of the city of Gonabad (Khorassan Razavi province in northeastern Iran) has 427 access wells. Its mother well has a depth of 320 meters and the length of its gallery is 13.1 kilometers. In his book, Nasser Khosrow describes the length of the qanat and the depth of his mother well, adding that it was built on the order of Kai-Khosrow, the mythological king of Iran. According to some research, qanat was built before the Achaemenid era, and developed and maintained during the reign of the founder of the Achaemenid dynasty, Cyrus the Great.

 

Ghassabeh qanat


The qanat of Zartch


The Qanat of Zartch, located in the province of Yazd, is another Iranian qanat inscribed on the UNESCO World Heritage List. At almost 80 kilometers long, Zartch is Iran's longest qanat and has 2,110 access wells for maintenance and renovations. According to the results of scientific research, the qanat of Zartch is as old as the qanat of Ghassabeh. Its construction dates back to around 3000 years ago.
 

The qanat of Zartch


The qanat of Baladeh
 

The construction of the qanat of Baladeh dates back to the time of the pre-Islamic Sassanid dynasty. This qanat is, in fact, made up of a network of 16 qanats. It is located in Ferdows, a small town in South Khorasan Province. He waters the agricultural lands of the region and runs 12 water mills in its path.

 

The qanat of Baladeh

The qanat of Moun


The qanat of Moun is the only qanat with two floors of the world. It is located in Ardestan, in the province of Isfahan. The waters of the two floors of this underground structure never mix. The two parallel galleries of this qanat are located one above the other at different depths of the earth. This while they have common access wells.

 

The twin qanhats of Akbarabad and Qasemaddad
 

The twin qanats of Akbarabad and Qassemabad are in Bam, in the province of Kerman. The two qanats have a parallel route and their flow is greater than all the qanats of Iran.

 


The qanat of Vazvan


The qanat of Vazvan is in the province of Isfahan. The great particularity of this qanat is that part of its underground gallery includes a dam and a reservoir that can hold water for a period of 120 days each year during the season when farmers in the area do not have need this water. In early spring, the dam is up and farmers can use the water.

 

Works on construction of a qanat in the 19th century