Decades-old water pipes present problems local govts can’t ignore

Financial difficulties related to population decline have made it difficult to maintain water supply services in various parts of the country. As the water infrastructure also is aging, the central and local governments must speed up their efforts to deal with the issue.

Last month, a bridge carrying a water main across a river in Wakayama City collapsed, cutting off water to 60,000 households for about a week. The bridge, which was completed in 1975, is believed to have fractured due to the corrosion of parts connecting the bridge and the water pipes.

The city government had planned to build additional pipes to create redundancy in the supply lines as an anti-disaster measure, but it had postponed the project because it could not manage to raise the needed funds.

Drinking water supply is a service mostly run by municipalities. Many local governments’ drinking water supply operations are in the red due to declining revenue from users, mainly because of a shrinking population. The incident in Wakayama can be said to have exposed structural problems facing the nation’s water supply businesses.

The aging of water pipes that were installed during the nation’s high economic growth period is serious. According to the Health, Labor and Welfare Ministry, nearly 20% of all water pipes in Japan have exceeded their 40-year service life.

Every time a big earthquake happens, old water pipes burst, but due to financial difficulties, local governments cannot keep up with replacing them. The quake-resistance rate of key conduits, meaning those that distribute water to a wide range of areas, is only 40%.

There are concerns that large earthquakes could directly hit the Tokyo metropolitan area or occur in the Nankai Trough in the Pacific Ocean. Securing water in the event of these large earthquakes is of paramount importance, and local governments must expedite work to renew water pipes.

To this end, it is necessary to improve the efficiency and profitability of the water supply services.

In 2018, Kagawa Prefecture integrated its water supply operations in 16 municipalities — eight cities and eight towns — covering almost the entire area of the prefecture, and is proceeding with the integration and closure of water purification plants, and the unification of its water supply operations. The prefecture estimates that the efforts will slow the increase of water charges by about 10% in 10 years.

The central government has also recommended such efforts, and the expansion of water supply operations to cover wider areas can be regarded as an effective measure.

It may also be effective to use leak sensors and other digital technology to reduce the workload of water supply operations.

Promoting cooperation between the public and private sectors is also worth considering. The revision of the Water Supply Law in 2019 made it easier for local governments to introduce so-called concession contracts, under which they sell their operation rights to private businesses.

Using this system, Miyagi Prefecture will hand over its management of drinking water, sewage and industrial water to the private sector next spring. The prefecture expects to thereby reduce its total project costs by ¥33.7 billion over the next 20 years mainly by reducing personnel costs.

However, some local governments have dropped the idea of selling their water supply operations to the private sector for reasons such as concerns among residents about the stable supply of water and the problem of profitability. It is hoped that each local government will seriously discuss an overall vision of its water supply, looking 50 or 100 years into the future, while taking actual local conditions into account.

— The original Japanese article appeared in The Yomiuri Shimbun on Nov. 18, 2021.