Abstract
The urbanization of basin increases the impermeable area and decreases the infiltration of rainwater in the subsoil, and as the result the heavy rainfall is liable to cause the urban storm. This paper deals with a new residential area at the developed basin and discusses the characteristics of runoff discharge before or after development and with or without underground storage tank installed in the residential zone. The runoff analysis is used by the kinematic wave method and the peak cut of runoff discharge was ascertained to be effective by the underground storage tank. Long-term runoff analysis also brought a good result as to keeping the nine-month flow which means the condition that the discharge or the water level keeps the amount higher than one observed in nine months in a year. Anyway, the installation of underground tank at the residential area works preferably both for the flood control and for the improvement of the acquirement of water in the stream in the dry season.
