JAUE2024-006: Reduction of Urban Pluvial Flooding in Saitama City by Smart Rain Barrels

Abstract

In recent years, low-impact development (LID) has been advocated to address urban flooding caused by climate change. Rain barrels (RBs) are effective stormwater management methods to reduce urban flooding. In our previous study in Saitama City, we found that RB did not perform well in the dense residential areas of Saitama City compared to other LID. This study will investigate smart rain barrel (SRB) containing water pumps controlled using smart switches. The SRB can be controlled online with a smart switch, linked to the local weather forecast, to ensure that the RB is empty before rainfall. This study aimed to verify the effectiveness of SRB use in reducing urban pluvial flooding during continuous rainfall in Saitama City using pySWMM. Drain values of the RBs were varied during the simulation to control the opening or closing of the smart switch to verify the effectiveness of SRBs in reducing urban pluvial flooding. SRBs reduced the total runoff volume by 2%–10% compared with RBs. Moreover, the total runoff reduction effect of the RBs was independent of the capacity size; however, the total runoff reduction effect of the SRBs increased proportionally to the capacity size.