Examining the Impact of LID Practices on Mitigating Stormwater Runoff in a Repetitively Flooded Area

The interests on low impact development(LID) practices have been continuously increased as an alternative approach to alleviate the impacts of urban flooding. This study examines the effectiveness of LID practices on stormwater runoffs by employing LIDMOD3. A flood-prone area in Juan-dong, Incheon, South Korea, was selected for the study site. The findings show that LID measures are shown to be effective in managing stormwater runoff in two developed scenarios. While annual runoff depth within the site decreased by 45% and 29%, respectively, peak flow was reduced by 1.38-1.81 ㎥/second and peak time was delayed by up to 0.92-1.55 minute, depending on the scenario. Drainage areas are divided into four sections within the study area, and the drainage area located on the north side of Scenario A had the highest runoff reduction effects. Among three LID practices applied in both scenarios, rain garden captured the greatest amounts of rainfall, followed by porous pavement and infiltration chamber. The study concludes by providing several spatial suggestions to local environmental planners while implementing LID practices in flood vulnerable old city centers.