Japan's aging water pipes will take 140 years to be replaced at current pace

OSAKA -- Deteriorating water infrastructure has become a serious problem across Japan, and it will take about 140 years to replace all the pipes that need it at the current pace.

In the city of Wakayama, a water pipe bridge over the Kinokawa River collapsed on Oct. 3, hugely affecting residents' daily lives and shedding light on the importance of basic infrastructure and the difficulty of maintaining it.

Networks of underground pipes send water from purification plants to households. When they get older and corrode, they cause water outages and leaks. There has been a spate of instances nationwide of water bursting from the ground due to broken underground pipes.

According to Japan's Ministry of Health, Labor and Welfare, there are about 720,000 kilometers of water pipes in the country. At the end of fiscal 2006, 6% of pipes were older than 40 years -- the legally mandated useful life period. By the end of fiscal 2018 it had risen to 17.6%. In contrast, 0.97% of water pipes were replaced in fiscal 2006, with the proportion falling to 0.68% in fiscal 2018. About 5,000 kilometers of pipes are replaced annually, meaning it would take some 140 years to update the entire stock.

There are also some rural, sparsely populated municipalities where maintaining the water supply has become difficult due to the deterioration of waterworks business management caused by falling water demand and the decreasing number of specialist workers. According to the welfare ministry, there were some 50,000 employees involved in supplying water in fiscal 2000 in Japan, but the number had decreased to between 30,000 and 40,000 in fiscal 2017. The central government is calling for measures such as regional partnerships among multiple municipalities and tapping the private sector to keep the water flowing.

Takuya Urakami, a professor of public utility theory at Kindai University and an expert in the aging water infrastructure issue, pointed to the changing times, saying, "While the technical requirements of building new water pipes put the government to the test in the 20th century, the test of this century is managing the maintenance of the system."

Urakami added, "First, it's necessary to make people understand how serious the water issue is. It will be too late to do that after the water network breaks."

(Japanese original by Mirai Nagira, Osaka City News Department; Video by Takao Kitamura, Osaka Photo Department)