Water Supplier Warns: “Water Pipes with Advanced Corrosion Are Still Left Unattended” – Astonishing Internal Photographs to be Released

If a Nankai Trough earthquake were to occur now…” Mr. A warned, citing his own disaster experience.

Mr. A sounded the alarm, citing his own disaster experience.

In the Great Hanshin-Awaji Earthquake, broken water pipes caused delays in firefighting activities, resulting in extensive damage. We should quickly replace water pipes that have deteriorated over time, as well as those that do not meet earthquake resistance standards. If a Nankai Trough earthquake were to occur now, firefighting would not be able to take place properly and Osaka would become a sea of fire. ……”

Why has the total distance of water pipes installed been decreasing? The Engineering Department of the Osaka Municipal Waterworks Bureau responded, “The most common reason is the aging of the pipes.

We are giving top priority to the elimination of the “ordinary and high-grade cast iron pipes,” which are the most aged and have suffered a very high rate of damage in past earthquakes. In particular, we are working to increase the pace of renewal of large-diameter backbone pipelines. For distribution branch pipes with smaller diameters, we have calculated the future renewal demand based on the usable years of the pipes based on the results of past surveys, and have set the immediate renewal pace at an average of approximately 45 km per year.
In the future, we plan to renew a total of approximately 53 km of pipelines per year on average.

Mr. A, however, refuted the plan, saying, “Fifty-three kilometers is not enough at all.

Yoshiharu Yokoyama, director of the Daichi Disaster Risk Research Institute, points out that, “The Yashio line, where the cave-in accident occurred, is a major roadway in the city.

Yashio City, where the sinking accident occurred, is located in an area with soft ground. When the ground is weak, sewer pipe breakage causes soil and sand to flow into the water pipes, creating a cavity under the road. As a result, it is believed that the road could not withstand the weight and vibration of cars and other vehicles, causing it to cave in. Osaka Prefecture has a lot of reclaimed land, and because the sea used to extend inland, the ground is soft in many areas. The Expo site is also reclaimed land. Osaka must be even more prepared than other prefectures for the risk of aging water pipes.”

How will Mayor Hideyuki Yokoyama (43) and Governor Hirofumi Yoshimura (49) listen to the urgent warnings from the field?

From the March 7, 2025 issue of FRIDAY