Coastal areas globally, including Europe, face mounting pressures from population growth, rising standards of living, and climate change-induced sea level rise. These stressors increase vulnerabilities such as microplastic pollution, saltwater contamination, chemical spills, and flood risks. Consequences include damage to structures, infrastructure, and tourism revenue, as well as broader societal impacts like poor water quality, biodiversity loss, and crop failures. RESCUER is a MSCA Doctoral Network funded by the European Commission Pillar 1 Excellence, aiming to educate the next generation of researchers combining numerical and modeling experience with and understanding of physical and biological processes, and a keen awareness of the challenges faced by us due to the climate change and subsequent changes in the risk profile of coastal communities. RESCUER integrates four research themes: WP1: Coastal modeling and hazards – focusing on phase-resolved wave forecasting tools and the study of wave processes and hazards related to infragravity waves and waves propagating over steep bed topography; WP2: River and estuary dynamics – focusing on flow and sediment transport in the river/estuary contact area, and to study sediment transport over saturated subsurface flow; WP3: Urban flooding – focusing on the construction of higher oredr models which include floating debris; WP4: Water quality – focusing on the spreading of pollutants and the kinetics of decomposition. In order to address these phenomena, we will leverage a number of novel methods developed in the last few years such as Graphical Processing Unit techniques, new efficient methods for boundary conditions and entropy stability [1] as well as higher-order accurate models for wave generation and propagation. When combined, these techniques will enable us to model the impact of phenomena such as infragravity waves and the influence of steep bathymetry with high accuracy, and also allow the establishment of real-time operational wave forecasting in coastal locations. For river and estuary dynamics, we will focus on coupling hydrodynamic codes with transport/diffusion models which need to interact dynamically in order to provide a complete picture of current and wave conditions as well as spreading of contaminants. For urban flooding, these challenges will be addressed by the utilization of a shallow-water model and the use of high-order DG methods on unstructured grids. References [1] M. Svärd, “Entropy stable boundary conditions for the Euler equations”, Journal of Computational Physics, 426, 2021 . This project has received funding from the European Union's Horizon 2020 research and innovation program under the MSCA grant agreement No 101119437.