Climate change events, such as droughts and floods, are affecting water availability and the global economy. Decentralized water management (DWM) systems can enhance water reuse by treating wastewater near its source and repurposing it for suitable uses. However, widespread adoption requires greater awareness of its benefits, technical demonstrations, and policy adaptation. The WATERSENS project aims to demonstrate the benefits of six DWM technologies and provide an integrated decision framework to help water authorities and stakeholders select, design, and integrate these systems. The selected technologies cover diverse water resources and uses, addressing various geographic and economic contexts. They include floating wetlands for wastewater and stormwater treatment, biofilters for river pollution removal, phototrophic bacteria and biofilters for urban wastewater, green walls for greywater treatment, and green roofs and cisterns for stormwater collection. Quality control procedures will be followed, and emerging contaminants will be characterized. The impacts will be evaluated through LCA, LCC, and social LCA, supported by a risk management model to provide data-driven evidence of the benefits. WATERSENS will also identify barriers in different regions and propose a governance framework based on a cost-benefit analysis and the evaluation of administrative challenges. This will be integrated into a Decision Support System (DSS) platform, driven by AI, which will also include a DWM catalogue, GIS tools, and climate change models, aiding water management stakeholders in making informed decisions.