Karez systems in Turkmenistan

Eurasia.Travel > Turkmenistan > Karez systems in Turkmenistan

How the Persian Water Collection System Worked

Look at these strange holes in the ground—what do you think they are? These structures, nearly 3,000 years old, were built long before the Persian-Greek wars, about three centuries earlier.

This system, called a karez or qanat, is located in Gonabad, present-day Iran.

The karez is considered one of the greatest inventions of its time. This water management system could collect water from underground aquifers and transport it to cities and irrigation channels. Thanks to this, Persia thrived and developed despite its arid climate.

The hydraulic system includes a main well that taps into the aquifer, a network of tunnels transporting water, and vertical shafts along the route for ventilation, which also allow for moisture condensation. Additionally, the underground channels minimize evaporation of precious water.

The Gonabad karez stretches 33,113 meters and contains 427 water shafts. Built using knowledge of physics, geology, and hydraulics, it exemplifies the advanced engineering skills of the Persians. In 2007, this karez was added to the UNESCO World Heritage List.

This method of water collection was adopted by other nations, including Morocco, Algeria, Libya, and Afghanistan.

Irrigated agriculture began 8,000 years ago in the foothills of the Kopet Dag mountains, using streams flowing from the mountains. As agriculture developed and water demands increased, karez systems became a vital solution.

Researchers believe the first karez systems in southern Turkmenistan and northern Iran appeared in the mid-1st millennium BCE. Turkmen legends attribute their construction to the time of Alexander the Great. Ancient historian Polybius wrote about karez systems in southern Parthia, noting that whoever brought “key water to unwatered lands” was granted the use of the area for five generations—a testament to the importance of these systems.

Building karez systems was labor-intensive and dangerous. Wells, reaching depths of several hundred meters and galleries spanning kilometers, were dug from the bottom up. Collapses were frequent, and constructing one karez could take years, even decades. Yet the water irrigated tens of hectares of fertile land.

The chief builder, known as the karezgen, led a team of 4–5 assistants. They used simple tools like picks, small shovels, protective boards, lamps, specialized headgear, leather bags, and wooden pulleys for lifting workers, soil, tools, and more.

The depth of a well was determined by the karezgen using a basic level (a rope with a weight). The well diameter did not exceed 1 meter, while gallery heights ranged from 1.3 to 1.5 meters and widths reached 80 cm. If air was insufficient, a forge at the wellhead would pump air into the gallery through reed tubes. The distance between wells, typically 20–30 meters, was also determined by the karezgen.

Building and maintaining karez systems required skill, strength, and determination. For instance, some stones used in gallery construction measured 120x70x50 cm—lifting and placing them would require a modern crane. How ancient builders managed this remains a mystery.

As hydrologist G. Kurtovezov notes, the uniqueness of the karez lies in its ability to extract water from deep underground through complex systems of galleries and vertical shafts, bringing water to the surface using gravity, without external energy sources.

In arid and desert regions, karez systems were often the sole source of drinking water. Turkmens protected wells with felt coverings to shield them from sand and enemies. In medieval Turkmenistan, karez systems were widespread. Abdullah ibn Tahir, a ruler of Khorasan (830–840 CE), even commissioned religious scholars to compile a guide on karez systems. An 11th-century author, Gardizi, mentioned this book, “Kitab al-Kuniy” (“The Book of Wells”), which was still in use 200 years later but has since been lost.

The durability and scale of karez systems are astonishing. For example, the underground gallery of the Kone Murcheh karez reaches a height of 4 meters with a width of 2 meters, while the Durun karez systems are remarkable for their length, supplying water through brick channels extending tens of kilometers from the foothills to the city of Shehr-Islam, on the desert’s edge.

Karez water powered mills and water-raising devices (chigirs). One chigir is mentioned in the 10th century in the Ferawa region, likely referring to the karez of Janahyr in modern Serdar. According to al-Khwarizmi, medieval Khorasan used various chigir types, such as dulab, daliya, garraf, zurnuk, naura, and mandjanun, often powered by animals. Even in the 1920s, 15,000 chigirs operated along the Amu Darya, irrigating about 30,000 hectares of land.

The Turkmen also had a patron deity for karez builders, Shahyzenna. Offerings were made to him to prevent accidents during construction. From selecting the site to completing the project, the karezgen prayed for Shahyzenna’s blessings.

The Gonabad system, built 2,700 years ago, still operates today, supplying water to approximately 40,000 people—a testament to its enduring utility and significance.