The Water Framework Directive institutionalises participatory processes in river basin planning across the European Union. This paper reports on three case studies from southern Europe where conflicts over water exist. In each a different method for participation was experimentally employed: scenario workshops, mediated modelling, and social multicriteria evaluation. Scenario workshops and mediated modelling proved well suited to the early stages of a planning process (problem solving and identification of goals and alternatives) and to be good at educating participants and supporting capacity building. Their performance was less satisfactory with respect to resolving long-standing conflicts and achieving consensus. In comparison, social multicriteria evaluation was better able to address the evaluation of alternatives, reveal trade-offs, and aid convergence between divergent stakeholders' views, but it relied more heavily on experts and allowed less participation and deliberation in goal-setting than the other two methods. These results show complementarities amongst methods which imply that hybrid or combined approaches would be best for aiding the water planning process. They also reveal problems confronting the use of participatory approaches and constraints which prevent theoretical promise from being converted into practical results.