Komori Dam (小森ダム, Komori damu) is a gravity dam located in Gunma Prefecture in Japan. The dam is used for power production. The catchment area of the dam is 406 square kilometres (157 sq mi). The dam impounds about 10 hectares (25 acres) of land when full and holds up to 855 thousand cubic metres (30.2 million cubic feet) of water. The construction of the dam was started on 1956 and completed in 1958.