INTEGRATING INFILTRATION-BASED NATURE-BASED INFRASTRUCTURE IN COASTAL AREAS FOR SUSTAINABLE STORMWATER MANAGEMENT

Coastal floodplain systems face heightened flood risks due to climate change, urbanization, and limitationsof conventional stormwater practices. Existing infrastructure often lacks the adaptability and ecological benefits required to manage elevated water tables, storm surges, and heavy rainfall. This study evaluates infiltration-based strategies, focusing on Green Infrastructure (GI) and Conventional Infrastructure (CI) in St. Marys, Georgia—a coastal city vulnerable to tidal and rainfall flooding exacerbated by sandy soils and shallow groundwater. Using StormWise hydrological modeling, baseline, GI-enhanced, and CI-only scenarios are assessed for peak flow reduction, infiltration rates, flood extent, and groundwater recharge under varying rainfall intensities and tidal effects. Sensitivity analyses explore factors like soil permeability and vegetation coverage. Results indicate that GI systems improve infiltration, delay runoff peaks, and offer ecological co-benefits compared to CI. These findings address knowledge gaps, supporting sustainable flood management and resilient urban design in flood-prone coastal areas.