The need to maximize a limited access to water for both human consumption and agriculture might explain the fact that both Peruvian cultures - both agricultural civilizations - used underground aqueducts to collect and transport water to reservoirs that were located nearby. For instance, the rivers that supplied the Nazca people did not carry any water during part of the year, so they conceived an innovative system that allowed them to collect the water from the rain that filtered through the ground into underground galleries, which allowed them to prevent the loss of that water - they inhabited a desert area, after all. The Chavin civilization also inhabited arid and extensive coastal areas that required ample and complex irrigation systems, hence the importance of saving and transporting water.
