Persian Qanat
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How it came to be
A qanat taps the groundwater of alluvial fans at the head of a valley and carries it by gravity through underground tunnels, often over many kilometres. According to most sources the technique was developed in ancient Iran in the early first millennium BCE and spread east and west from there. In Iran's arid regions both farming and permanent settlement have depended on this water.
In 1010 al-Karaji wrote The Extraction of Hidden Waters, a technical book on how to build and repair a qanat, how to find groundwater and how to level a tunnel. In the mid-20th century about 50,000 qanats were in use in Iran; by 2015, 37,000 remained in use.
In 2016 eleven qanats were inscribed together as the Persian Qanat. One of them, the Qasebeh Qanat of Gonabad, is among the oldest and largest in the world: it has 427 wells and still supplies drinking and irrigation water to nearly 40,000 people. The property also includes rest areas for workers, reservoirs and watermills, and a traditional communal system that still shares the water out fairly.
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