European wastewater systems are increasingly challenged by tightening nutrient discharge consents, climate-driven hydraulic variability, and ageing infrastructure, while planning decisions often lack integrated, transparent tools to balance technical performance, environmental impact, and long-term resilience. The core problem addressed is the absence of a practical, evidence-based framework that enables utilities to systematically evaluate and justify resilient wastewater solutions under uncertain future conditions. This research proposes a GIS-based, multi-criteria decision support framework that integrates spatial analysis, process performance indicators, climate stress testing, and analytic hierarchy process (AHP) weighting to assess decentralised and hybrid wastewater and resource recovery options. The approach supports decision-making for achieving low total nitrogen and phosphorus compliance, enabling water reuse fit-for-purpose, and enhancing asset resilience under variable flows and temperature stress. By translating complex technical, environmental, and policy trade-offs into transparent and defensible planning outputs, the proposed solution supports zero-pollution ambitions and future-ready operation while maximising the potential of existing assets. The framework provides European wastewater stakeholders with a transferable, robust tool to support resilient, sustainable, and compliant system performance.