Although many projects have already been executed, it seems that most of them do not yet have a concrete concept of people's participation in the planning process of improving the waterside. We aim to construct a whole planning methodology for evaluation of the waterside. The study in this paper is just one of the processes of the overall planning methodology and takes into account people's participation through their impression of the waterside. This is because people have various kinds of feelings through their different uses of the waterside. In this study we focus on people's impression, which is captured qualitatively, instead of valuing quantitatively. Impression is described, for example, as ‘friendly, or not friendly', so impression is considered to be an integrated value which is composed of some elements. The authors aim to clarify the environmental valuation of a waterside area through people's impressions. A social survey focusing on impressions and their components regarding Geo-, Eco-, and Socio-environments taking into account seasons or time, and place or space was first implemented. From the results of simple aggregation data, it was shown that there were differences of response to the Eco items for each season, to the Geo items and to the utilization of space in the Socio items for sub-areas. Secondly, it was clarified that the elements which constitute impression differ depending on season and sub-area by Cramer's coefficient of contingency. Further, it was shown that response and sensitivity to the GES impression differs depending on the season, even in the same sub-area. Finally, applying a factor analysis to the GES impression items (defined to be the integrated value), common factors have been derived that describe the characteristics of each sub-area. Thus, it was shown that the people value the waterside, and the elements that constitute the valuation were demonstrated. Though derived common factors are the same among sub-areas, they are composed of different elements. JEL Classification: Q51, R10, R53