In the early nineties, drinking water became an object of public attention. A new regulatory and institutional framework reshaped relations between elected officials, private operators, state services, and users. Associations were also set up, forming publics in the sense of Dewey, that is to say sets of individuals affected by a problem and engaging in a “social inquiry” about it. Their activity takes the form of what we will call organized civic regulation: interventions aimed at putting the service and its actors under surveillance in order to detect and correct any shortcomings. Mobilizing the results of a study conducted on two main sites, the Rhone and the Orléanais, the article first of all describes the trajectory of engagement of water activists, and distinguishes two typical ideal trajectories, one predominantly political and militant, the other primarily associative and managerial. It then highlights the dynamics of the constitution of associations and their mutual coordination, and characterizes the nature of their activity around a triptych: the politicization of water, assuming a dimension of conflict; the exercise of a competent vigilance that results in a careful follow-up of all the activities of the services; the resolution of problematic cases brought to their attention. Finally, the article sheds light on the tensions and fragilities of this civic regulation, which are likely to cast doubt on its long-term durability.