The main part of a check dam installed in the Shigekurazawa, a tributary of the Tone River, was removed in November2009. The dam was removed to restore the stream ecosystem and develop a new method and technology for stream conservation. Removal of a check dam in the ecological context was unique implementation in Japan. The stream is in the forest area of the Akaya Project, a project that has been conducted through discussion and collaboration among the Kanto Regional Forest Office, the Nature Conservation Society of Japan, and a council organized by the local people in order to recover the ecosystem of the area. The participants engaged in consultation with professionals regarding disaster prevention and specific ecological and engineering problems and designed a basic plan for engineering and monitoring based on the concept of adaptive management that was then executed by the Kanto Regional Forest Office. Forest conservation engineering conventionally focuses on disaster prevention; however, the current plan would give ecological contents in Japanese forest conservation plan and engineering.

Key wordsFforest conservation, restoration of stream ecosystem, collaboration, adaptive management, Akaya project