This study sought to find a new diagnostic method. The drain hole temperature and the upstream water temperature change were measured for 1 year. The purpose of this study was to analyze the correlation between the temperature of the drain hole and the upstream temperature.

In this study, in order to survey the concrete dam leakage use the Thermal Line Sensor (TLS) temperature monitoring instruments. The temperature monitoring locations are two drain hole of concrete dam and the upsteam water temperature of dam.

Various methods were investigated to confirm the clogging of the drain hole of the concrete dam and recover it. The effects of drainage holes were investigated through re-drilling at the two locations.

Various methods were investigated to confirm the clogging of the drain hole of the concrete dam and recover it. The effects of drainage holes were investigated through re-drilling at the two locations.