A Framework for Evaluating the Integration of Green Infrastructure into Stormwater System Design

Flash flood events are significant natural hazards that increasingly affect urban systems. Due to the growing impacts of climate change, urban areas—particularly in arid environments—are becoming more vulnerable to flash floods, with intensified rainfall and rising temperatures making extreme weather events more frequent and severe. However, traditional stormwater systems in urban areas are often expensive and less adaptable, with limited resilience to extreme weather events. This problem points to a growing need for more research on adaptive stormwater management strategies—like green infrastructure (GI)—that can better respond to the evolving challenges of climate change and urbanization, especially in arid environments. This study proposes a framework and introduces novel metrics for integrating GI practices into stormwater management systems, illustrated through a case study in the Kingdom of Saudi Arabia (KSA). Additionally, the resiliency, economic, and environmental impacts were quantified and integrated into a single assessment value. The results demonstrated that implementing GI practices achieved various environmental and resiliency benefits but with higher construction and maintenance costs compared to a conventional stormwater system. Permeable pavement had the highest normalized benefits; however, the integrated assessment index showed that applying three GIs had the highest index, while conventional stormwater systems had the lowest index, resulting only from economic benefits.