Japan is suitable for hydropower generation because of its varying topology and abundant water resources. The use of natural energy resources has recently gained importance in Japan, and as such the subject of small- and medium-scale hydropower generation has drawn much attention. However, new developments have not advanced significantly. Hydropower has various advantages over other natural energy sources; it provides stable power output, and if construction and maintenance are implemented appropriately, it can provide electricity at low costs and over long timescales. Further, hydropower is environmentally friendly, and can protect and improve the environment when implemented in harmony with natural and social factors. Moreover, it has social benefits; it contributes to aspects such as regional revitalization, local attractiveness, and disaster prevention. The possibilities of hydropower are not fully understood, and methods have not yet been established for its comprehensive practical utilization. Hydropower in Japan has not been in full-scale development for a while. Therefore, there are currently only a few experts on hydropower development. Accordingly, technologies and institutions for the development of small- and medium-scale hydropower generation while ensuring harmony with the natural and social environment are required. Further, a system is also needed to allow experts to promote and support such technologies and institutions in a cross-sectional way.

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