Current Situation and Future Challenges for Disaster Emergency Wells in Ordinance-Designated Cities in Japan

Abstract

　Securing a minimum volume of water for drinking and domestic purposes is vitally important in the aftermath of an earthquake. Currently, water supply systems across Japan are being reconstructed to ensure that they are earthquake-resistant. Disaster emergency wells are one means of supplementing basic water demand. Such wells are often privately owned, but are used for public purposes such as first-aid water supply in emergency situations. Although some case studies of disaster emergency wells have been reported after major earthquakes, how widely such wells are adopted in municipalities in Japan has not been investigated. This paper conducts a survey of the prevalence of disaster emergency wells in 20 ordinance-designated cities in Japan and describes evaluation of institutional effectiveness using criteria based on experiences following the 2016 Kumamoto earthquake. Survey results reveal that only 12 of those 20 cities have established disaster emergency wells and that Chiba, Kawasaki, Kumamoto, Nagoya, Sagamihara, and Yokohama cities have more effective institutions than other cities do. Finally, this paper presents future challenges for disaster emergency well management, including the need to increase their prevalence and, in combination with land use policy, to ensure their maintenance and their combined use with other water supplies.