In 2000, the European Parliament and Council passed the directive 2000/60/EC establishing a framework for Community action in the field of water policy, known as the Water Framework Directive. It aims to deliver 'good ecological status' for all rivers through the adoption of basin-based Integrated Water Resources Management. Identifying and implementing a programme of measures, encapsulated in River Basin Management Plans, will achieve this. To support the Water Framework Directive implementation, much research has been commissioned at both national and European levels. CatchMod is a cluster of these projects, which is focusing on the development of computational catchment models and related tools. Models are seen as essential for evaluating the various possible programmes of measures. However, the Water Framework Directive creates new challenges for modellers, particularly because it requires models not only to represent individual processes from many domains but also how they interact. Some projects, therefore, target the development of frameworks for model linking, while other projects aim at specific issues such as 'transboundary challenges', 'participatory tools', transitional waters and climate change effects. A Concerted Action promotes collaboration, disseminating results and active use during the implementation. CatchMod is co-funded by the European Commission's Directorate General Research. This paper presents an overview of the results of the CatchMod cluster to date. Based on the result it is clear that the joint CatchMod projects have addressed a large number of issues in integrated modelling. Due to the parallel execution of the projects, the results do require further integration. This integration is picked up in follow-up projects, in which many researchers from different projects have joined forces. Separate initiatives are brought forward to achieve true integration. This largely would not have happened if key partners of various projects hadn't gotten the chance to meet, discuss and learn about the broadness of European research. Now that almost all the results are available, Harmoni-CA will facilitate discussions on the various products, providing crosscutting state of the art with advice to further integration and use within the WFD implementation.