Description based on the latest issueFrequency variesSupervisor: River Department, Kanto Regional Construction Bureau, Ministry of Construction, Japan...
Supervisor: River Department, Kanto Regional Construction Bureau, Ministry of Construction, Japan (no. 1-no. 9) ; River Department, Ministry of Construction, Japan (no. 10-no. 15) ; River Bureau, Ministry of Land, Infrastructure and Transport, Japan (no. 16-)