Irrigation is a determining element for agricultural production in highly populated mountainous catchments of the Ecuadorian Andes. Since the Spanish colonization, the control of water sources and water distribution has been subject to many conflicts or to many alliances. The study of the evolution of the main irrigation canals in the area of Santa Rosa- Pilahuin allows us to analyze the various forms of water control used by the different groups of stakeholders. From the large haciendas under the Spanish colonization, water control went to small Mestizo farmers and is currently in the hands of Indian communities. The history of water control has been closely linked to the agricultural development in the studied area for the last four centuries.