TYPOLOGY | Irrigating
SYSTEM | Qanat
PEOPLE | Persian

A line of evenly spaced spoil craters snake along the surface of the desert from the high mountains to the plains of Iraq. They are the only evidence of an invisible subterranean man-made stream called a qanat, which will surface kilometers away in a fanned oasis of agricultural land that appears alien in the arid alluvial plain. Qanats were meticulously designed tunnels and channels constructed by the Persians during the early years of the first millennium BCE, to source, direct and transport underground water from the mountains of present day Iran. Qanat tunnels are hand-dug up to several kilometers long, with vertical shafts sunk at intervals of twenty to thirty meters, to remove excavated material and to provide ventilation and access for repairs. The main qanat tunnel slopes gently down from deep within the mountain side, through pre-mountainous alluvial fans to villages and beyond, eventually distributing irrigation water to fields. This ancient innovation allowed Persian farmers to succeed despite long, dry periods when surface water was unavailable.

Illustrations by Brittany Roy