Osaka, Oct. 14 (Jiji Press)–Public infrastructure and equipment essential to daily life are rapidly deteriorating in Osaka Prefecture, western Japan, which is home to the country’s second-largest metropolitan area and has a population of about 8.75 million. Much of the infrastructure was developed within a relatively short period during Japan’s era of rapid economic growth and is now aging simultaneously. The deterioration of water supply and sewage systems is of particular concern because of its potentially serious consequences, underscoring the need for prompt action. Replacement Work Lags Aging pipes that carry wastewater and rainwater from homes and factories pose a challenge across much of Osaka Prefecture. The regional sewage network managed by the prefectural government spans several municipalities and extends for a total of 573 kilometers. It includes the Neyagawa River basin, where work began in fiscal 1965 on Japan’s first regional sewage project. About 86 kilometers of the network, or roughly 15 pct of the total, has exceeded the standard service life of 50 years, making the repair or replacement of these pipes an urgent priority. A further 171 kilometers, or about 30 pct, has been in service for at least 40 years but less than 50 years. Consequently, the burden of inspections and other maintenance work continues to grow. Even if replacement work moves forward, completing it quickly would be nearly impossible, primarily due to staffing and financial constraints. “Replacing even 8 kilometers a year over a 10-year period would be very difficult,” an official with the construction group of the prefectural government’s sewage office said. Osaka Prefecture is also grappling with aging pipes used to supply tap water. As of fiscal 2024, more than 9,000 kilometers of water pipes had exceeded their statutory service life of 40 years. Such pipes accounted for about 36 pct of the network still in service, the highest figure among Japan’s 47 prefectures. Although pipes do not necessarily fail or begin leaking immediately after exceeding their statutory service life, cast-iron pipes, which are particularly vulnerable to seismic shocks, remain widely used, raising the risk of leaks in the event of an earthquake. These pipes need to be replaced with ductile-iron or steel pipes fitted with earthquake-resistant joints, which are better able to withstand seismic shocks and are less likely to rupture. In the city of Osaka, however, only about 35 pct of the network had been upgraded as of the end of fiscal 2023. Flooded Pumping Station The deterioration of infrastructure is being compounded by increasingly frequent and severe natural disasters, including torrential rains. At the Suminoe pumping station in Osaka’s Suminoe Ward, all six large pumps were submerged on June 26 during intense rainfall caused by the approach of Typhoon Mekkhala, the seventh of the year. The facility discharges rainwater collected in underground floodways into a river, helping prevent urban flooding. A city government investigation found that water entered the facility after a rubber joint connecting an underground floodway to the pump room ruptured. Full restoration is expected to cost about 30 billion yen and take three and a half years, with completion projected for the end of fiscal 2029. Until then, the risk of flooding will remain elevated in areas including Ikuno, Abeno, Hirano, Higashisumiyoshi, Sumiyoshi and Suminoe wards. The city recorded rainfall exceeding 80 millimeters per hour that day. Osaka Mayor Hideyuki Yokoyama said the city’s infrastructure was designed to handle rainfall of up to 60 millimeters per hour. “Even increasing (that capacity) to 66 millimeters per hour would require the city to invest several hundred billion yen,” he said. Meanwhile, some critical facilities, including pumping stations operated by the prefectural government, have yet to undergo necessary seismic upgrades. Completing the work is expected to take considerable time. But time is running short, particularly given the threat of a massive earthquake along the Nankai Trough, which lies beneath the Pacific Ocean off central and western Japan. END [Copyright The Jiji Press, Ltd.]
