PPT Slide
Qanats are astounding feats of engineering,
especially considering that some may be
hundreds, even thousands of years old. Once
qanats sustainably harvested mountain runoff
that had seeped into the watertable, trans-
porting the water in underground tunnels over
as many as 50 km to surface irrigation canals.
Borehole wells now have lowered watertables
across Iran, and most qanats are abandoned.
Qanat spoil heaps march across the Dasht-e-Lut desert.
Digging underground horizontal canals required that
engineers also dig vertical shafts to remove material.
These heaps accumulated around the vertical shafts.