Urban regions face compounding challenges from climate change, environmental injustice, and aging infrastructure, requiring planning frameworks that align social and environmental vulnerabilities with ecological processes and future climate-related risk. This paper presents the Urban Watershed Vulnerability Index (UWVI), a forward-thinking geospatial framework that evaluates vulnerability using hydrologically defined sub-watersheds rather than political boundaries. Applied to 1,198 urban sub-watersheds in Los Angeles County, the UWVI integrates environmental, social, and climateprojection variables to reveal correlations and identify vulnerability hotspots. To bridge geospatial analysis and design, the UWVI overlays vulnerability scores with infrastructure datasets to identify strategic opportunities for implementing Nature-based Solutions and offers a replicable method for equitable, climate-resilient landscape planning.