Nazca
The Nazca constructed a highly sophisticated irrigation system, specialy designed for their surroundings. Between January and April the rainy season started on the plateau. Rivers brought water to the valley. A large part of it disappered into the soil and flowed by way of geological fractures to another territory. Where the Nazca lived it was very dry. That's why they dug trenches and tunnels (puquios) to get to the water under ground (water would be drawn off and stored for irrigation purposes). Nowadays there are still some 29 in use, in the Nazca time there were surely more than that. These "aqueducts" were about 1 km long.

The walls of the tunnels were at that time lined with pebbles and grit; nowadays with concrete. Onze above ground the canals were covered with stone plates or tree trunks to prevent the water from evaporating.

The canals and tunnels were cleaned each year. For this purpose they made funnelshaped holes (ojos) in the canals.

The first puquios are probably constructed in the 4th century aD, after the great draught.