Urban flooding poses a growing threat to society due to the increasing population and more frequent heavy rainfall due to climate change. Stormwater Green infrastructures (GIs) can mitigate flood risk while providing multiple social, economic, and ecological benefits, such as improving water quality, enhancing aesthetics, and increasing biodiversity. Governments and property owners need to collaborate to maximize the effect of GIs in flood mitigation and equip cities with the capacity to absorb shocks from extreme climates. However, promoting property owners to adopt GIs can be challenging due to financial and risk perception barriers. A growing number of cities are establishing stormwater fee programs to fund their stormwater infrastructure investment and credit programs as an incentive to encourage GI adoption. While incentive programs play an important role in promoting GIs and helping cities meet their goals for stormwater and flood mitigation, the optimal design and efficacy of such programs from one city to another is still unclear. Therefore, there is a need for tools that assess and facilitate the design of such incentive programs. This study proposed a coupled modeling framework to quantify effects of these incentive programs in different scenarios. By coupling a hydrologic model (Storm Water Management Model, SWMM) and an Agent-based Model (ABM) that simulates property owners’ GI adoption, this study explores win-win scenarios through incentive program designs and investigates key factors of property owners’ decisions to adopt GIs. The modeling framework is applied to an urban watershed in the Northeastern US as a case study.
