Résumé
Concerted and participative management has emerged in recent years in the French water policy to respond to the current projections of climate change, and an increasing demand for water in response to population growth. Therefore water management needs to move towards more sustainable practices. In France decentralization caused legislative changes. The Water Act of 1992 and the establishment of SAGE (Local Water Management Plan) and river contracts have generated the need for people facilitating them. We consider here a new category of people named boundary worker which will be part of what some authors call intermediary people (Mauz, Granjou, Billaud, Moss, and Medd). This new approach to public policies is not completely stabilized. Its implementations on the ground are very diverse. Little is known on their efficiency. Our work aims at providing means to improve the assessment of this aspect of participatory governance for public policies. In this paper we propose a model to represent consequences of the involvement of a boundary worker in river basin governance, taking in account the context (social, institutional, physical) of this involvement. To achieve this we will particularly relate and articulate an analysis of several interviews with the boundaries worker. Final aim of this model is exploration of various conditions of involvement of boundary workers and consequences on the evolution of socio-hydrosystems they are attached to.