Comprehensive evaluation of trade-offs in vegetation planting strategies for stormwater management practices: A city-wide assessment of triple bottom line Co-benefits, life cycle costs, and water quality performance

• Trade-offs among lifecycle costs, co-benefits, and stormwater quality are optimized. • Vegetation type and extent are considered as distinct decision variables. • Diverse surface vegetation boosts co-benefits but increases life-cycle costs. • Trees paired with sand filters yield higher co-benefits at lower cost. • Citywide optimization identified phased investment strategies for urban resilience. Despite the widespread implementation of green stormwater infrastructure (GSI), systematic optimization of vegetation strategies across urban scales remains unexplored. This study bridges the gap by evaluating and optimizing the life cycle costs (LCC), triple bottom line (TBL) benefits, and water quality performance of stormwater management practices (SMP) using public SMPs in Philadelphia, focusing on optimal vegetation planting strategies at a city-wide scale. The results indicate that trees combined with sand filters substantially promote TBL benefits with lower LCC than systems with surface vegetation, leading to a higher benefit-cost ratio. The results of multi-objective optimization suggest that an optimal strategy involves prioritizing tree planting, followed by incorporating highly diverse surface vegetation based on available budgets and water quality considerations. This study provides municipalities with a systematic approach for optimizing green infrastructure investments across the city while achieving both performance requirements and community benefits, advancing the development of more sustainable urban stormwater management strategies.