The qanats, one of the greatest inventions of mankind

The qanats are an ever-returning and ever-fascinating subject of discussion.

[Picture from klikabol.com]

It is a water supply system that transports water from underground reserves to irrigation canals and even to cities. The qanats are a valuable asset in desert regions. They are known all over the world, from North Africa to Asia, Arabia, the Mediterranean countries such as Spain, Italy, and Greece, and even in the Nazca Valley of Peru and Chili!

My first encounter happened in Libya where I was introduced to the Garamantes, who used this water supply system. It is still visible in the Sahara desert, although the local Berbers called it foggaras (see: Could Alexander have known the Garamantes?). It is impossible to trace its origins back and we don’t know who really invented the system or implemented it first. Persia seems to be a good candidate and it may have traveled from there over the Silk Road.

Since Libya, I did indeed come across repeated qanats all over Iran. According to the statistics, there were approximately 50,000 such qanats still working in Iran last century. In Afghanistan, about 20,000 qanats were still in use at that time.

With the climate change that is affecting our daily use and need for water, the qanats regain their importance. Although the concept is rather simple, it does require regular maintenance. Over the centuries, the local tribes and chiefs were in charge of keeping the system in working order. However, modern construction projects such as cities and barrages on existing rivers often disrupt and/or interrupt the water supply. Since those projects are overseen by a governmental institution, little attention goes to this centuries-old supply system on which many local populations are still relying. In the process, small communities lose their only access to water. They cannot raise their crops and lack water for their own basic needs.

In northeastern Iran, the qanats of Gonabac are among the oldest and the largest in the world. Their origin seems to go back to 700-500 BC, to the days of the Achaemenid kings. My question about Alexander getting his knowledge from the Garamantes in Libya is obviously outdated. The hydraulic system existed way before his arrival in Persia, but he must have seen it at work.

Once you know what to look for, the scars in the landscape are unmistakably clear. The vertical openings reaching down to the horizontal underground aqueduct appear like a string of pearls. Heaps of soil around the shafts are the visible traces of these access columns. For the maintenance operation, men were lowered down those shafts and each one would clear a section of the horizontal water flow at the bottom. These shafts also functioned as wells and contributed to the ventilation along the route. The water comes from a faraway source, often in the mountains. Gravity carries it through these man-made tunnels. An additional advantage is that these underground conduits significantly reduce the evaporation of the water in the hot desert climate.

The Gonabac complex runs over a total length of 33 kilometers and counts 427 wells. The structure has nothing to envy our modern knowledge of geology and hydraulics. After 2700 years, the qanats are still working! Quite an amazing achievement, that teaches us a precious lesson, doesn’t it?

In this context, a previous post on water management may be interesting reading as well (see: Water management in antiquity).