The BONUS MIRACLE project focuses on the analysis of the impact of climate change on water environments, including hydrological regimes and nutrient concentrations. The Reda catchment is the pilot catchment for this project in Poland. The overall objective of MIRACLE is to initiate a social learning process that is able to identify new configurations for governance (conceptual, institutional, and practice based) in order to reduce nutrient enrichment and flood risk in the Baltic Sea Region. These configurations should be understood as new solutions in the field of water protection, developed with the participation of stakeholders. They also include ecosystem services and win-win solutions. To achieve this goal, environmental modeling constituted the main part of the project. Mathematical models that specify the detailed processes associated with water cycles for the determination of interconnections, as well as the quantification of variables characteristic to the assessment of the quantity and quality of water resources, were found to be useful. The launching of the models, entering the appropriate data in the appropriate formats and the calibration process proved to be difficult, particularly in the case of complex models. The development of the water management sector in the future should concentrate more on specific local catchment areas where the application of integrated water resource management principles and the adaptation to climate change are easier and can be merged with local spatial planning. However, this requires a larger number of measuring points and increasing the frequency of the measurements themselves.