Catchment management in the developed world is undergoing a fundamental reconfiguration in which top-down governance is being challenged by local organisations promoting collaborative decisionmaking. Local, participation-based organisations are emerging as mediators of relations between governments and publics. These organisations, defined here as participatory catchment organisations (PCOs), are emergent at a time when developed world catchment management is itself undergoing substantial change. Through in-depth engagement with four PCOs, and using six case studies, we identify the principles associated with successful problem resolution. The findings illustrate the importance of PCOs as two-way bridges between publics and governments. We identify three principles shared by these organisations (i.e. trust brokers, collaborative decisionmaking and win-wins) that show how, through participatory approaches founded on trust, complex problems can be resolved in ways that do not unduly punish groups or individuals. In conclusion, we identify four questions that highlight the need to consider the practicality of evolving relations amongst governments, publics, and the organisations that have come to mediate catchment management.