An increasing number of dams have been in operation for several decades, and so at more dams it will be difficult to maintain dam functions, as a result of progressive deterioration and the cost of maintaining these dams will rise.

In the past, maintenance has been based on trend management through daily management plus inspections and surveys based on periodical examinations to evaluate the degree of soundness of facilities (constituent elements), and countermeasures have been taken when repairs are judged necessary. In contrast, for more efficient and effective maintenance to prolong the service lifetime of dams, it is necessary to study the mechanisms of damage and deterioration of constituent elements such as the dam body, gates, and electrical equipment, to evaluate the degree of impact on dam functions in order to set the management levels, to organize the concepts of maintenance based on these levels (preventive maintenance/corrective maintenance), and then to judge the need to take countermeasures by combining the management level and soundness evaluation categories.

Also, since flood control must continue as normal, large-scale diversion of flood water is performed during the work period. Thus, efficient construction execution requires complex planning.

The Japan Dam Engineering Center is meeting the rising demand for redevelopment by providing technological assistance and preparing execution plans to ensure the reliability of surveying, design, and execution of redevelopment while attaining simple maintenance and dam safety. The JDEC accumulates redevelopment design and execution technologies while preparing for unprecedented large-scale dam redevelopment by carrying out surveys and research to design new redevelopment-related technologies.