Assessment of urban drainage system using SWMM and GIS: a case study on SUST campus

In response to the urgent need to mitigate frequent flooding during the rainy season, particularly in urbanized areas, this study provides a comprehensive analysis and strategic recommendations for enhancing the stormwater drainage system. Urban flooding poses significant challenges to infrastructure resilience and public safety, necessitating proactive measures for effective management. Focusing on the SUST campus, which has experienced persistent flooding issues over the past two years, this investigation proposes a systematic enhancement of the stormwater drainage system. Leveraging Geographic Information System technology and the Storm Water Management Model (SWMM), a Digital Elevation Model was developed and validated, facilitating the delineation of sub-catchment areas and identification of outside contributing sub-catchments. The study incorporates Low Impact Development controls to simulate ponding effects and collects detailed cross-sectional data on drainage channels and networks. Additionally, dry weather flow data from 4 different inlets at the SUST boundary along with outfall discharge of the study area were collected and used for model simulation and calibration of Manning’s roughness coefficient of the drainage system. Moreover, the subcatchment parameters (i.e., width, imperviousness, Manning’s roughness coefficient, and depth of the depression storage) were calibrated using recent rainfall data. The calibrated model's simulations underpin recommendations for crosssectional changes to the drainage system, aiming to prevent flooding in extreme rainfall events. By emphasizing the critical role of advanced modeling and simulation in informing infrastructure enhancements, this study offers valuable insights for engineers and urban planners globally, providing a replicable methodology for urban flood risk management in the context of evaluating and enhancing urban drainage capacity for flood mitigation.