Determination of flood vulnerability to climate change is one of the most critical issues for regional water management. Most of the previous studies related to system vulnerabilities to climate change were either a qualitative assessment without the support of hydrological modeling or too complex to apply them to real-world systems. In this study, a modeling and assessment system is proposed to tackle flood vulnerability to the climate change through the incorporation of future climate change scenarios, rainfall-runoff simulation, and vulnerability estimation within an integrated frame. The developed approach is applied to provide decision support for flood management of the Swift Current Creek watershed in Western Canada. The approach not only is useful to determine relative flood vulnerabilities to climate change for supporting flood control planning in the watershed, but also can be extended to estimate vulnerabilities of water quality and water supply to climate change.