In the ideological and legal context of Chilean water, oriented towards the efficiency of water use, the existence of urban gardens in the north of the country is surprising. This article analyzes the role of water user organizations in the construction of water scarcity and a hydro-legal security territorialization in the urban gardens of Vicuna. Located in a semi-arid valley in Chile, the case is representative of canal water management and the intervention of irrigation organizations. From the legal geography, the relationships to law and space and the tensions that cross the boards of three water user organizations are analyzed. For this, qualitative methodologies are used (ethnography, interviews, observations, files). The power relations between water user organizations lead to the definition of three geo-legal actions (desmarque, increase in quota, absence of regularization) that produce water scarcity. To confront it, the leaders of the Community use the right to increase control over irrigation practices, leading to the formation of a secure territorialization of water.