The Nazca people have built more than 40 underground water canals to carry the water from the Andes to the valley.. Even if it never rains in Nazca water descends underground from the Andean Cordillera towards the sea. The aqueducts are 3 to 6 meters deep. These photos are of the breathing holes that were built down in to the aqueducts. They were used as clean outs....