Qanat-e Zarch – Longest Qanat in Iran
قنات زارچ · Zarch Qanat · Yazd Zarch Aqueduct · Eastern Central Plateau Qanat
Achaemenid to present (2,500 years continuous)·Persian qanat engineers (Achaemenid, Sassanian, Safavid)·🇮🇷 Yazd Province, Iran
About
About Qanat-e Zarch – Longest Qanat in Iran
World's longest qanat (71 km, possibly 90 km historically) and collective UNESCO property (Persian Qanat 1506) with 2,115 vertical shafts tapping a 90-m-deep mother well at the Shirkouh alluvial fan, built over millennia with Achaemenid origins (≈500 BCE) and Sassanian–Safavid re-cuttings. Its double-gallery technique splits upper active and lower abandoned gallery sections, enabling maintenance without supply interruption. Qanat-e Zarch still delivers 100 L/s servicing Zarch town and Yazd orchards, demonstrating 2,500-year gravity-groundwater technology with 1:1,000 gradient precisely levitated via oil-lamp mirroring (ayeneh) during hand-dig—blurs engineering with artisanal tradition.
Eleven qanats inscribed collectively 2016.
Why it mattersExemplar of world's longest single qanat demonstrating unbroken Persian indigenous water management sustaining desert civilization for 2,500 years; model for sustainable gravity groundwater.
Open questions
Mysteries & theories
Mysteries
- 01Absolute dating of initial Achaemenid cut vs Sassanian re-cut dominance
- 02Whether double-gallery contemporaneity or sequential collapse response
Theories
- 01Zarch as Safavid demonstration that qanat commons governance outlasts dynasties
- 02Gradient precision 1:1,000 as proof of Achaemenid surveying applied to Khwarizm
Theories are interpretations, not findings. The seal above tells you how much scholarly weight the place carries.
History
How it came to be
- Built
- c.500 BCE (Achaemenid) with Sassanian and Safavid re-cuttings—continuously maintained
- Period
- Achaemenid to present (2,500 years continuous)
- Culture
- Persian qanat engineers (Achaemenid, Sassanian, Safavid)
- Builders
- Shirkouh–Yazd qanat builders successive dynasties
- Purpose
- Gravity-fed groundwater delivery from mountain aquifer to desert oasis town—year-round supply without pump
- Rediscovered
- Continuously in use; 2016 UNESCO Persian Qanat documentation
- Excavation
- Excavation ongoing
500 BCE
Achaemenid mother-well sinking at Shirkouh fan
224 CE
Sassanian second gallery cut
1500
Safavid re-lining with baked brick collars
2016
UNESCO inscription Persian Qanat (1506) including Zarch
On the ground
Structures & features
32.0200° N · 54.0700° E · 1220 m · 3 mapped features
Mother Well at Shirkouh Fan
shaft90-m-deep apex shaft tapping mountain aquifer
31.8200° N · 54.1100° EMid-line Shaft Cluster (km 35)
shaft fieldLine of 100 shafts crossing desert piedmont
32.0200° N · 54.0700° EZarch Oasis Outflow Mazhar
outflowGravity outflow pond feeding Zarch gardens
32.0800° N · 54.2500° E
Gallery