This work is an empiric – theory revision which evidences the existence of two irrigation sectors in the Andean countries: a formal one, mainly located in plain low lands, controlled by the government, mostly directed to agribusiness producers and, in a smaller proportion, to small holders; the other sector, informal irrigation, is directly managed by the producers, usually family farmers, without government control and without being reported in national statistics; this second sector is principally located in the Andean mountains. Nowadays there are several institutions for the access to water which are associated to different stakeholders, so conflicts between different kinds of users emerge.