access to water resources has gained extensive scientific and political relevance over the last three decades. the french modern experience has become a reference point for the institutionalization of new management practices. in brazil, this experience provided a basis for establishing not only new state management apparatuses, but also the water resources national policy itself. this article seeks to examine relevant social disputes concerning water management technocracy over the establishing period of the new management apparatus. thus, we have reviewed the sociopolitical net involving agents, groups, and social institutions towards the definition of a new regulatory frame. this frame has resulted in a symbolic re-designation of the resource (reaching the category of natural capital) and a 'scientification' of politics as a principle for legitimating competence in water governance.