Assessing Sustainable Drainage System Performance in Urban Commercial Districts: A Case Study of Greenfield Shopping Mall

Thesis Abstract

Urban commercial districts are increasingly vulnerable to surface runoff and flooding due to inadequate drainage infrastructure and the intensification of land use, necessitating the implementation and assessment of Sustainable Drainage Systems (SuDS) to mitigate these challenges. This study aims to evaluate the performance of SuDS within Greenfield Shopping Mall, a representative case of urban commercial development, to determine their effectiveness in managing stormwater, reducing flood risk, and promoting environmental sustainability. The specific objectives include (1) identifying the types and configurations of SuDS implemented at Greenfield Shopping Mall; (2) assessing the hydraulic efficiency and water quality performance of these systems; (3) evaluating stakeholder perceptions regarding SuDS functionality and maintenance; and (4) developing a performance evaluation framework tailored to commercial urban settings. The research adopts a mixed-methods approach grounded in a pragmatic philosophical paradigm, integrating quantitative hydrological analysis with qualitative stakeholder insights. The population comprises the mall management, tenants, local government authorities, and urban residents within a 2-kilometer radius, totaling approximately 150 stakeholders. A stratified random sampling technique selected 50 stakeholders for interviews and surveys, ensuring representation across stakeholder groups. Data collection instruments include structured questionnaires, semi-structured interview guides, on-site hydraulic monitoring using flow meters, water quality sampling, and photographic documentation. The validity and reliability of survey instruments are enhanced through pilot testing and Cronbach’s alpha analysis, achieving a reliability coefficient of 0.85. Hydraulic performance data are analyzed via regression analysis to establish the relationships between rainfall intensities and runoff reduction, while thematic analysis is employed to interpret qualitative stakeholder feedback. Data analysis is conducted using SPSS and NVivo software, with the hydraulic performance model specified based on the Rational Method and SWMM (Storm Water Management Model). The study hypothesizes that properly designed and maintained SuDS significantly enhance stormwater management efficiency in urban commercial settings. Expected findings include quantifiable improvements in runoff attenuation, water quality, and stakeholder satisfaction levels, along with identification of operational and maintenance factors influencing system performance. This research is anticipated to contribute to existing knowledge by providing empirical evidence on the effectiveness of SuDS in the context of high-density commercial districts, thereby bridging a notable gap in the literature that predominantly focuses on residential or highway applications. The performance evaluation framework developed herein offers a practical tool for urban planners, engineers, and policymakers to assess and optimize SuDS configurations in similar settings. The study concludes that well-designed SuDS can substantially mitigate flood risks and improve urban water resilience when integrated into commercial developments. It highlights the importance of stakeholder engagement, ongoing maintenance, and system adaptability. Based on these findings, recommendations include implementing standardized performance monitoring protocols, fostering stakeholder education on SuDS benefits and maintenance, and scaling successful design principles across comparable urban commercial districts. Future research avenues suggested involve longitudinal studies to assess long-term system performance, cost-benefit analysis of different SuDS configurations, and the application of innovative green infrastructure solutions suited for dense urban environments.