Moving towards Europe-wide freshwater restoration through model-based integration of policy objectives

• Integrating HD and WFD data and indicators for pan-EU freshwater screening • Framework to identify where, when and which restoration meets policy targets • Bayesian network approach for data-driven decisions under WFD, HD and NRR • Continental-scale zoning for freshwater conservation, restoration and mitigation • Uncertainty-aware data tool to maximize ecological impact of restoration In Europe, ecological restoration efforts remain restricted and fragmented, with limited success and coordination across policies. The newly adopted Nature Restoration Regulation aims to address these challenges by setting ambitious, legally binding restoration targets. For freshwater ecosystems, its success depends on better integration of existing legislative frameworks, particularly the Habitats Directive (HD) and the Water Framework Directive (WFD). We present a novel European-scale modeling framework that for the first time, combines HD and WFD-related indicators, and applies specific Bayesian Network features, to achieve: i) a Europe-wide status prediction to identify areas with potential for restoration, conservation or mitigation measures, including spatially explicit information on uncertainty and data gaps, and iii) spatially explicit restoration targets, such as lateral and longitudinal connectivity improvements, derived through backward inference. Model validation demonstrated acceptable performance for six of twelve HD groups, including Bogs, Mires, Fens, and Amphibia, Fish, Plants, while sensitivity analysis indicated that taxon-specific responses were primarily driven by pressures from hydrology, morphology, and organic pollution. We provide a large-scale data-driven tool to maximize the ecological impact of restoration efforts across Europe, support efficient resource use, and help policymakers to direct efforts where they are most likely to succeed.