1987 年 15 巻 p. 66-71
In the Rokkaku basin, paddy fields have spread over extensively reclaimed lands and the water requirement surpasses the river water utilization capacity. Then many irrigation ponds and deep wells were constracted, and traditional water control systems have been kept for some 400 years by regional inhabitants. The farmland improvement project and constraction of the river mouth reservoir are in effect, and they will change inhabitant consciousness about water quantity and quality. It is necessary to reform the water control system with quantity and quality according to the improvement of irrigation and drainage establishments and the development of rural communities. The water environment in the rural area has to be independently managed by the organization mainly composed of local inhabitants, and the administrative organizations have to provide sewage treatment system at cities for the preservation and improvement of water quality in this basin.