Water resources management has to deal with complex real life problems under uncertain framework conditions. One possibility for encountering such challenges is integrated water resources management (IWRM). However, IWRM is often understood as prescriptive manual, not acknowledging the need for adaptive solutions and capacity development (CD). These challenges demonstrate that sustainable water resources management requires transdisciplinarity, i.e. the integration of several scientific disciplines, as well as the collaboration between science and local actors. Transdisciplinarity is inherently related to CD since it facilitates collaboration and provides mutual learning and knowledge on complex interrelationships. This correlates with the evidence that CD can be seen as a key factor for water resources management (Alaerts et al. 1991, Alaerts 2009). Consequently, the objective of this thesis is to strengthen water resources management by connecting processes of IWRM and CD in a transdisciplinary sense, i.e. (i) interrelating disciplinary research within an interdisciplinary research team that collaborates with local actors, and (ii) conducting a political process for knowledge and capacity development. Based on general insights, an embedded case study in the Western Bug River Basin, Ukraine, was conducted to evaluate the concept. It is shown that CD is essential for shifting from IWRM theories towards implementation and accordingly advantages of harmonizing CD into the IWRM process are presented (Leidel et al. 2012). Next to capacity issues, also other coordination gaps were assessed. River Basin Organisations are frequently proposed as a response to the administrative gap; however, coordination efforts cannot be simply reduced by transferring tasks from jurisdictional institutions to a river basin authority, because they will always need to coordinate with organizations from within or outside the water sector (von Keitz and Kessler 2008). Thus, coordination mechanisms across the boundaries of relevant policy fields are essential. Therefore, a management framework is established linking technical development and capacity development that describes interrelations between environmental pressures and capacity and information gaps for different levels of water management (Leidel et al. 2014). The developed model-based and capacity-based IWRM framework combines model-based systems analysis and capacity analysis for developing management options that support water management actors. This is aligned with a political process for capacity development. It constitutes a boundary object for approaching cross-scale challenges that converges analyses, assessments and participation into one strategy. As concluded by Mollinga (2008), this can improve the performance of sustainable resources management by approaching transdisciplinarity. Within the model and capacity-based IWRM framework, the results of the integrated analysis are made explicit and transparent by introducing a matrix approach. Technical issues, institutional challenges, organizational and human resources development, and information needs are jointly assessed and interrelated by confronting pressures and coordination gaps on a subsystem basis. Accordingly, the concept supports a transparent decision making process by identifying knowledge and capacities required for the implementation of technical intervention options and vice versa. The method is applied in the International Water Research Alliance Saxony (IWAS) model region ‘Ukraine’. It could be shown that the approach delivers management options that are scientifically credible and also accepted by and relevant for the actors. The case study revealed that technical intervention measures for the urban and rural water management have to be jointly implemented with appropriate CD measures and an accompanying political process on (i) strengthening the institutional framework and interministerial collaboration, (ii) fitting RBM into the existing institutional framework, (iii) setting up prerequisites for realistic RBM (Monitoring, information management, legal enforcement), (iv) a revision of effluent standards and a differentiated levy system, (v) cost covering tariffs, (vi) association work. For the Western Bug River Basin (WBRB), the strengthening of the collaboration between actors on all levels has to be continued. For increasing the usability, the approach needs to be institutionalized and become more practice relevant, e.g. by extending it to a water knowledge management system. Developing a roadmap for establishing transboundary water management is a subsequent step. For strengthening future water management actors, IWRM curricula development at uni-versities in Ukraine was supported. And we developed the e-learning module IWRM-education that links interactively different aspects of water management to comprehend the complexity of IWRM (Leidel et al. 2013). The evaluation showed that participants under-stand the content, appreciate this way of learning, and will use this module for further activities. The case study showed that technical cooperation can be a facilitator for political processes and that it can support decision making in a transparent way. Yet, it also showed that IWRM is highly political process and that the developed approach cannot cover all obstacles. In summary, exploring and reducing simultaneously environmental pressures and capacity and information gaps is essential for water sector evolution worldwide. Accordingly, transdisciplinarity as a means for capacity development can support the implementation of real integrated water resources management.