Abstract Water was a key element in the Inca civilization ( c . ad 1438–1534), both for their crops and as part of their vision of the cosmos. According to myths on the origin of the Incas, their civilization arose from the sea through one of its main manifestations, Lake Titicaca. Throughout the period of Inca dominance, as in some of the cultures that preceded them, water was a sacred element. This vision of the cosmos can be regarded as a hydrogeological model with similarities to the beliefs in force in Europe from the classical period until the end of the seventeenth century. Because of their excellent intuitive understanding of water, the Incas developed a complex irrigation system to channel water to their agricultural lands. Coinciding with the distribution of water, they organized periodical thanksgiving festivals, when farming communities gathered to celebrate the beginning of a new agricultural cycle with songs, dances and festivities. However, the centralized control of water resources introduced in the twentieth century led to the disappearance of many of these traditions and to the replacement of an irrigation system that had proved acceptable, by one that was alien to the customs and history of the country people. This led to the first conflicts over water control. As a result, the vision of the cosmos based on water and rooted in agricultural communities has been lost.