Aging water mains and sewage pipes have become a major concern among municipalities across Japan, particularly after
a fatal sinkhole incident last year in Yashio, Saitama Prefecture, near Tokyo. In the incident, a truck and its driver were swallowed by a large, expanding sinkhole that opened up after a sewer pipe collapsed under an intersection. Much of the water piping in Osaka dates back to the postwar era, during which Japan registered rapid economic growth. According to the waterworks bureau, it had 92 cases of water leaks under roads in the one-year span through March 2025.