The shift from government to governance in European water policies conveys a pluralist conception of stakeholder participation in planning. This article argues that the current Driving forces-Pressures-State-Impact-Response (DPSIR) approach to the planning of natural resource use, developed by the Organisation for Economic Cooperation and Development (OECD) and the European Environmental Agency (EEA) is at odds with a pluralistic conception. The DPSIR approach consists in constructing a single socio-environmental model to address a specific problem in water management, while paying no attention to the existence of conflicts surrounding the definition of the issue at hand, the social, political and spatial delimitation of that issue, and the translation of stakes in terms of quantitative variables. Scenarios produced in this process therefore explore a limited range of policies, i.e. those defining the problem in the same way, as illustrated here with the case of the Garonne River in France. This article presents an alternative method, combining knowledge in social science and natural determinisms to build contrasting socio-hydrological scenarios that do not share the same hypotheses regarding their respective key issues.