Water pollution is a growing concern in Asian urban areas, necessitating cost-effective and sustainable solutions. This study advances the field by proposing Nature-based Solutions (NbS), such as Constructed Wetlands, Constructed Floating Wetlands, and Green Roofs, for treating septic tank effluents, canals, and lakes. The research contributes practical insights beyond theoretical discussions by drawing on six case studies in the Philippines, Sri Lanka, and Vietnam. Guides for NbS construction were implemented, enhancing understanding of their real-world performance. Stakeholder engagement was crucial in providing data on public acceptance, policy influence, and governance structures in NbS implementation. The APN project produced 27 diverse products, including articles, chapters, a comprehensive book, perspectives, resources, and videos, accessible on the project website. To further NbS replication, a strategic approach is recommended, leveraging project progress to establish knowledge hubs and fostering living labs. Comprehensive toolkits encompassing guidelines, case studies, and practical insights are proposed to facilitate NbS adoption in urban water treatment. Short courses and training sessions are suggested to equip professionals, policymakers, and communities with the necessary knowledge and skills for effective NbS implementation.