<p>Green Infrastructure (GI) is gaining attention in urban flood management for its ability to reduce peak flow and volume while providing multiple urban and environmental benefits. Climate change and urbanization intensify GI development needs but also amplify design, management, and performance challenges for local governments and stakeholders. Understanding the complex challenges of implementing GI is essential for advancing sustainable urban water management in line with the Sustainable Development Goals (SDGs), particularly SDG 6 (Clean Water and Sanitation), SDG 11 (Sustainable Cities and Communities), and SDG 13 (Climate Action). Previous studies have often focused on specific components of GI systems, but this research provides the first comprehensive work covering it from pre-design to post-installation—of GI implementation in metropolitan Melbourne. Through a targeted survey of local councils and water consultancies, our study bridges the gap between theoretical design and practical application. By incorporating practitioners’ real-world experiences alongside technical modelling challenges, we reveal how factors like limited real-time data and regional parameterization can affect GI performance. Our approach uniquely examines interlinked obstacles, from financial constraints to maintenance protocols, giving decision-makers valuable insights to enhance GI project outcomes. This research addresses critical knowledge gaps, such as the need for community engagement and tailored technical expertise, providing actionable solutions for improving GI planning, implementation, and sustainability. Our findings offer a practical framework for future GI initiatives, helping practitioners pre-emptively tackle challenges, optimize resource use, and establish a resilient urban infrastructure that supports clean water access, sustainable urban growth, and climate adaptation.</p>