Streamlining facility management for Osaka city sewage conduits Efficient maintenance, management, renovation, and renewal using deterioration prediction technology

The City of Osaka has a sewer network with a total length of approximately 4,900 km. About 30% of all sewer pipes, namely about 1,500 km, have already exceeded their standard useful life of fifty years. In order to control this vast stock of sewer pipes effectively and provide the sewerage service consistently, Osaka city employed a new high-accuracy deterioration prediction method based on a Markov deterioration hazard model. The method utilizes long accumulated onsite inspection data of sewer pipes in Osaka city. It can reflect degrees of deterioration speeds varying according to individual pipes’ characteristics. The method enabled the city to establish a more sensible and versatile risk evaluation system. Thanks to the new evaluation system, Osaka city managed to make a more efficient maintenance plan and a more practical long-term investment plan for sewer pipes than before, which leads to a sustainable sewerage management.