This article discusses the role and the effects of a consultation committee (called “Local Public Services Consultation Committee”) — composed of representatives of local and consumer associations — on the regulation of the local water service in Lyon. Created in 2003 on the initiative of the metropolitan government — Greater Lyon —, this committee was at the side of administration and metropolitan representatives to enhance their capacity to regulate the local water service, delegated to a private company. The article’s purpose is to show that this committee is less an autonomous participatory body than an instrument of public action, dependent on the metropolitan government’s institutional configurations and political agenda.