The European Union Water Framework Directive (WFD) encourages water managers to implement active stakeholder involvement to achieve sustainable water management. However, the WFD does not describe in detail how member states should operationalize participation. The need for local experience and local understanding of collaborative governance (co-governance) processes remains. The WaterCoG project evaluated 11 local pilot schemes. Building on the participatory, qualitative evaluation of pilot schemes from Sweden, United Kingdom, Denmark, The Netherlands, and Germany, the authors take a closer look at how co-governance can improve water governance, how water managers can make best use of tools and knowledge, and how they can improve process designs. The results reflect how social learning and successful co-governance are linked. Social learning as a shared understanding of complex ecosystem and water-management issues can be supported with active stakeholder involvement and citizen science. As such, in co-governance processes, stakeholders need technical access to data and knowledge and a shared process memory. This enables them to develop a shared understanding and facilitates bringing together competing interests and finding new solutions. Participatory tools became part of successful processes by building trust and knowledge based on commitment. However, proficient process design and facilitation make these tools more effective.