Abstract The flooding in the Bangkok city became more frequent due to overpopulation, urbanization, unplanned development and climate change. These phenomena was not only damage organisms and environment but also impact economy, health, social and transportation. In urban areas, flooding was caused by several reasons: the rise of the water level in the river through the city high tides for coastal cities, poor operation of drainage system, and each of drainage systems maintenance etc. Flood management required an understanding of the causes and adaptation in order to take appropriate measures by decreasing percentage of imperviousness in urban area. Thus, it could be taken to reduce the impact of floods. The most important tool needed for decreasing percentage of imperviousness in urban area are sustainable urban drainage system tools. These could provide effective tools to reduce impact of floods. The main objective of this study is to analyze the effect of decreasing percentage of imperviousness at Sukhumvit area, Bangkok, Thailand for the latest urban drainage modeling software. Comparing the result of each amount of decreasing percentage for a suitable value of the present condition. These effects of decreasing percentage of imperviousness at Sukhumvit area, Bangkok, Thailand are helpful for the urban pluvial flood control. Moreover, these are solution for the urban development planning in future.