Case Study on Damage and Recovery of Water Supply Related Facilities Damaged by Recent Flood Disasters

Abstract

In recent years, several large-scale flood disasters occurred in Japan. The large-scale flooding causes not only direct damage but also indirect damage due to the closure of lifelines such as water, electricity, roads, and railways, and both impact the affected region’s resilience. Therefore, it is important to understand the current level of disaster resilience and consider non-structural measures accordingly to prepare for the next disastrous event. To assess current disaster resilience requires understanding how each building or lifeline structure is damaged in a disaster and the recovery time. In this study, water supply related facilities are selected from various kinds of life-lines, and a questionnaire survey was conducted to investigate facility damage and recovery after being affected by major flood events occurring in Japan after 2015. A comprehensive study on the damage and recovery of water supply related facilities due to flood has never been conducted, not only in Japan but also worldwide. This is because of difficulty in collecting enough data from many facilities, and thus, there have been reports of damage and recovery of an individual facility, but not more. However, occurrence of several severe flooding disasters in recent years in Japan made it possible to do so. This study dug into not only facility-level damage and recovery but also component level ones based on the quantity of data collected (97 components from 61 facilities) through the questionnaire survey. We found that control panels are most likely to be damaged by flood, and the number of days required for temporary recovery strongly depends on how quikly replacement equipment/parts for failed equipment can be procured.