Decisive Factors in Sustainable Stormwater Management

Sustainable stormwater management (SSWM) is widely championed for urban sustainability, yet SSWM decisions remain predominantly driven by technical, environmental, and economic data. Growing evidence voices the roles of social dimensions, but insights into their values and benefits remain explorative and theoretical, limiting their uptake to real-world decision-making. Using mixed methods, we traced participant insights in two Swedish cities (1960–2024) through interviews, identifying 40 factors influencing past-and-present stormwater management transitions. These were synthesized into 9 key factors, which participants then ranked; external collaboration emerged as the most decisive for future SSWM. We find these key factors act as adaptive levers, not static barriers or drivers, with their influence shifting across space and time, offering a transferable framework for different urban contexts. Our findings challenge reductionist decision paradigms and strengthen the evidence base for holistic assessment. Future efforts should refine measurement approaches for these factors and explore their fuller integration into decisions, thereby enabling more robust SSWM outcomes.