JAUE2022-026: Efficacy of Infiltration Facilities to Prevent Urban Pluvial Flooding

Abstract

In recent years, the risk of urban pluvial flooding has increased due to the climate change and development of urbanization. The purpose of this study is to verify the effectiveness of small-scale decentralised rainwater infiltration facilities in preventing urban pluvial flooding by using SWMM simulation. Singular and mixed usage of green roofs, permeable pavement, and infiltration trenches, and two types of rainfall scenarios (short and long duration torrential rains) are used to examine their effectiveness. Furthermore, an 'Existing Potential Scenario' and the 'Maximum Potential Scenario' are investigated to elucidate current and future implementation possibilities of small-scale decentralised rainwater infiltration facilities within the available urban infrastructure. The results show that small-scale decentralised stormwater infiltration facilities are highly effective in reducing urban pluvial flooding for short duration torrential rains under the scenarios considered. However, their effectiveness is significantly reduced for long duration heavy rainfall events. Furthermore, the Maximum Potential Scenario is found to be more effective in reducing urban pluvial flooding not only for short duration torrential rains, but also for long duration torrential rains. This outcome reiterates the need to further develop urban stormwater infiltration technologies and investigate urban planning guidelines for an effective implementation of these small-scale decentralised infiltration facilities.