Abstract
Recently, cause of localized torrential rain especially in urban area, numbers of city flood is increasing. In such situation, it is encouraging to introduce detention tank not only in public facilities but also in conventional home in SUMIDA ward in Tokyo-met, but the diffusion rate of them are only 2%. In this point of view, the questionnaire survey was implemented and it is pointed out that “awareness to the risks of city flood” and “understandings to the effectiveness of rain water utilization” are both relevant factors to the awareness for introduction, but these factors have influence only in concurrent presence.
