Résumé
This paper investigates a participatory process set up in the Drôme river basin to get citizens to support the update of the water management scheme. Some citizens were engaged at an early stage in selecting and structuring their own participatory process. Such co-engineering raised their interest in such decisions, fostered social learning and triggered conditions for an efficient regulation. It clarified the links between participation and institutional governance. But co-engineering was abstract for participants. Co-engineering requires clear participation rules and sufficient awareness of the issues and vocabulary of participation. To conclude, we propose adjustments of the co-engineering of participation according to the expectations and resources available.This document includes the annexes of the article:APPENDIX 1 ● Actors involved in the co-engineering of the Drôme participatory processAPPENDIX 2 ● The six phases for designing a participation plan (PrePar)APPENDIX 3 ● Support matrix for the realization of the PrePar participation planAPPENDIX 4 ● Correspondence between the decision steps proposed within the PrePar methodology, the phases of the decision-making process identified by Simon (1977) and the standard stages for the development of the french river basin management plans (SAGE)APPENDIX 5 ● Quantitative elements on the monitoring-evaluation of the Drôme participatory processAPPENDIX 6 ● Coding of the interviews