The relevance of sewer deterioration modelling to support asset management strategies

Abstract

Deterioration modelling can be a powerful tool to support utilities in planning efficient sewer rehabilitation strategies. However, the benefits of using deterioration models are still to be demonstrated to increase the confidence of utilities toward simulation results. This study aims at assessing the performance of a statistical deterioration model to estimate the current condition and predict the future deterioration of a sewer network. The prediction quality of the deterioration model GompitZ has been assessed using the extensive data-set of 35,826 inspections performed in the city of Braunschweig, Germany. The performance of the statistical model has been compared with the performance of a simple model based only on the condition of observed sewers. Results show that the statistical model performs much better than the simple model for simulating the deterioration of the network. The findings highlight the relevance of using modelling tools to simulate sewer deterioration and support strategic asset management.

Keywords:

• Asset management
• statistical modelling
• sewer condition
• CCTV inspection
• sensitivity analysis

Acknowledgements

We would like to thank all colleagues involved in the project, especially Michael Timm from SE|BS for the preparation of CCTV and sewer data in Braunschweig.