Gruppo CAP, the public utility managing the Integrated Water Service of the Metropolitan City of Milan, operates 40 wastewater treatment plants and returns more than 350 million cubic meters of treated water to the environment each year, over 45% of which is reclaimed for reuse in agriculture and other applications. To further scale up water reuse, CAP has joined the international system of voluntary water credits (WTR), becoming the first water utility in Italy and among the first in Europe to apply this sustainable finance instrument to reclaimed water. Through this model, reclaimed water is converted into certified water credits, transforming a technical and environmental activity into one with measurable economic and social value. Credits are generated from a share of the effluent treated at the Bresso–Niguarda WWTP, which undergoes additional treatment to meet EU Regulation 741/2020 Class A standards. The reclaimed water is conveyed via a dedicated 3.5-km pipeline to Parco Nord Milano, a large peri-urban public park. A €250,000 investment increased reuse capacity from 50,000 to over 500,000 m³ per year, reducing groundwater and surface water withdrawals. Each certified cubic meter reused generates one WTR token, tracked on a blockchain-based platform and integrated into ESG reporting. Credits can be purchased by water-intensive companies to reduce or offset their water footprint through a transparent and verifiable system. Part of the revenues is reinvested locally to strengthen infrastructure and promote reuse. This initiative explores innovative financial and technological pathways to overcome long-standing barriers to large-scale water reuse.