It is important that residents do river environmental management, because reducing governmental burden, minimization of the psychological distance of residents and river and strengthening regional social network. Recently, these activities by cooperation of residents and administration are done. The purpose of this study is to create the assessment model for potential of resident activities considering with social capital and usefulness, and to make the potential maps of various kinds of activity.
 Firstly, the changing process of management activities are analyzed of class A river. The activity began in the East Japan and spread through the whole country in the 1990s. Most of old activity contents were cleaning, but in late years a variety of activity including the river environment study. Secondly, linear discriminant analysis about doing activity or not was done in Chugoku, Shikoku and Kyushu districts. The river where activity is done has an elementary school near and an own house rate is high. Thirdly, the activity potential evaluation by the logistic regression analysis is done. It is shown to be high activity potential in the river where basin cooperation is carried out. It is thought that the basin cooperation functions as the bridging type social capital. An activity potential map is made using this evaluation model. The potential evaluation model about individual activity contents are made. The effect of the basin cooperation was shown quantitatively by making an evaluation model.

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 Partridge showed that a group was formed of three or more and the leader did not exist. However, swimming behavior of changing the number of fish in running water has not been investigated. In this study, the swimming behavior of isolated or couple or trio or quintet or dectet of ayu in running water was investigated. It was found that the top change rate, the ground speed and swimming speed increases with an increase of the number of fish and also that the ground distance and swimming distance decreases with an increase of the number of fish. And, it was found that the change for swimming behavior of ayu became slow of three or more.

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 The combined sewer improvement works addressed in sewer advanced areas have had a task in the interception accuracy of sewerage flowing into an intercepting pipe, and its countermeasures have also been pointed out in terms of a low improvement effect and complicated maintenance and management. With regard to the flowing water diversion function, a hydraulic phenomenon of an overflow weir and an orifice is organically combined, and in the conventional technology, flow quantity is directly controlled by overflow in a single tank, but this study proposed an indirect control with several tanks to regulate the water level in the diversion chamber. This study was to verify technical theories of the conventional technology and the new technology with regard to the interception accuracy of sewerage flowing into the intercepting pipe, and scrutinized data of a numerical analysis of a diversion phenomenon and a hydraulic model experiment to judge the validity from a management practice point of view. Results of this study showed that an excessive interception error of sewerage by the conventional technology, 45% become to 3% or less by the new technology with three regulating tanks in the diversion chamber.

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