See inside a qanat

For those of you who are claustrophobic, here is a rare chance (for the next few days ONLY: don’t delay, the BBC will take it off the internet soon) to see inside a qanat – a traditional Iranian underground irrigation canal.  Click here for the film – to see the qanat section, watch from 15 mins. There are then 7 minutes of film from a qanat near Bam (where the big earthquake was in 2003).

You can see from my photos at left that the qanat I have been down (near Natanz) is much (much!) smaller than the one in the BBC film.  The muqanni (qanat digger) is considerably shorter than me, and I only just fitted in, crouched on my heels, with my bum in the running water, my shoulders slanted sideways, and my head tucked right down.  I was so tightly squeezed that I couldn’t walk at all, and had to flick each knee in turn to move my feet at all.

The BBC presenter explains qanats as being cut through solid rock, and as related to fault lines, with natural clay dams cut through by the muqannis.  This is not usually the case in Iran: the figure shows how they much more commonly work (read the image from right to left).

The initial ‘mother-well’ is cut in foothills down to an aquifer or water-bearing layer of rock. Then a gradually sloping tunnel is dug between access or ventilation shafts to the village or fields where the water is going to be used.  The tunnel is usually not through solid rock at all – but in loose alluvial material.  This is easier to dig, but prone to collapse – and baked clay (or, now, concrete) rings are commonly used to support the walls, as you can see in my photos. Of course, the muqannis can’t simply dig from the mother-well to the village at the lower end of the tunnel – or else they would drown.  They have to dig upwards to the mother well.  They also have to get the gradient exactly right – if it’s too steep, the water washes the bottom of the channel out; and if it’s too shallow, the water is not fresh.  This makes the surveying job they do truly impressive – especially when you remember that their traditional tools were a knotted rope (for the depth of the ventilation shafts) and lit candles (to check that the tunnel is straight).

You can see some of the lines of qanat ventilation shafts in the landscape around Ghuriyan, if you click here.

The BBC presenter descends his qanat using a machine-winch and a tractor.  More traditionally, though, the muqannis use hand-windlasses (čark-e čāh) for both the men and the spoil.  I didn’t have to go quite so deep, so I abseiled down and was hauled out.