If a person who has passed the dam operation and maintenance engineer examination which aims to confirm the knowledge and skills necessary for dam management, applies to the Japan Water resource Environment Center (hereinafter referred to as "Center"), one will be registered in the dam management engineer inventory, be certified as a dam operation and management engineer, and get the title of CEDOM （Certified Engineer for Dam Operation and Maintenance). The number of CEDOM is more than 1000 in Japan. Registration is renewed every 5 years by attending the registration renewal course held by Center. Many of the CEDOM are involved in dam management work at dams managed by river managers and are active on the front lines.