Infrastructure installed during periods of rapid economic growth has exceeded its service life, and problems owing to deterioration have occurred in many fields, such as highway bridges, road surfaces, water supply facilities, power transmission facilities, and power plants. In particular, we focus on the deterioration of buried water pipes. Buried water pipes are exceeding their service life, and the number of leakages and burst accidents is increasing. However, replacing all the deteriorated pipes is difficult because this is costly and time-consuming. Therefore, the conditions of water pipes must be quantified, and efficient maintenance management is required.