748 km of Japan’s Sewers Classified as Requiring Action

Tokyo, April 21 (Jiji Press)–The total length of sewer pipes in Japan that have been judged to require countermeasures due to risks such as cave-ins reached 748 kilometers, the infrastructure ministry said Tuesday. The figure accounts for about 16 pct of the sewer pipes totaling 4,692 km that were inspected by the end of February, according to the results of intensive inspections. The ministry will ask 383 municipalities and organizations managing the sewer pipes to take immediate measures, such as repairs. The survey was conducted after a huge sinkhole was created on a road in the city of Yashio, Saitama Prefecture, north of Tokyo, in January 2025 due to the corrosion of a sewer pipe. In March last year, the ministry requested local governments to inspect about 5,332 km of sewer pipes with diameters of 2 meters or more that have been used for 30 years or over for corrosion, sagging and cracks within about a year. According to the survey results, 201 km in 46 of the country’s 47 prefectures, excluding Yamanashi, were classified as “emergency level I” requiring action within a year, while 547 km in all prefectures were categorized as “emergency level II” requiring full repairs within five years after temporary measures. Based on the results, the ministry will provide technical and financial support to local governments managing the sewer pipes in question, while reviewing inspection standards and the frequency of checks. The ministry will also call on local governments to complete inspections and assessments of the remaining sewer pipes. In the incident that occurred in Yashio on Jan. 28, 2025, the central part of an intersection caved in, causing a passing truck to fall into the hole. The driver’s cabin was left inside a sewer pipe, and the body of the 74-year-old male driver was recovered about three months later. END [Copyright The Jiji Press, Ltd.]