Appropriate knowledge management is recognized as a crucial success factor in the domain of IWRM planning, decision making and related capacity building efforts. In this respect it is especially the aspect of efficient and reproducible knowledge transfer between the actors in the IWRM process, from research to planning and finally decision making, which is hardly supported by available decision support strategies. To address these challenges in the framework of an integrated water resources management concept for the Lower Jordan Valley (SMART-Project), we follow a novel approach based on Web 2.0 technology. By adapting a semantic wiki system to organize information and knowledge within the IWRM process, we allow all members of our research and stakeholder community to contribute to a long term knowledge base and to succeed on the need of collaborative scenario building and response planning. In contrast to conventional wiki systems, the demonstrated semantic wiki system has the potential for automated links with databases and models (e.g. WEAP) through the definition of a common semantic structure.