Quantifying the Performance of a Post-Earthquake, Post-Rebuild Wastewater Network using Hydraulic Models

Objectives: This paper demonstrates how hydraulic models were built and calibrated for the 2018 post-rebuild hydraulic model and the 2018 no-earthquake hydraulic model for Christchurch’s wastewater network to evaluate the success of the post-earthquake rebuild work in returning the Level of Service (LoS) of the wastewater network to the no-earthquake level. Methods: Info works ICM (Integrated Catchment Management) and Infonet hydraulic modeling tools were used for this investigation. The models were developed taking Christchurch’s sewer network information such as the network survey files, GIS sewer network files, Closed Circuit Television (CCTV) inspection information and flow-monitoring data. Findings: Wastewater network hydraulic models were found to be very powerful tools that can combine different network information (GIS, CCTV inspection data, surveys and flow-monitoring data) into a meaningful platform and predict the performance of the network for different development scenarios. This paper successfully demonstrates how hydraulic models were developed and used to assess and compare the performance of the rebuilt sewer network with the no-earthquake sewer network of Christchurch. As per the model simulation results, there will be less wastewater overflow in the post-rebuild network when compared with the no-earthquake network. Application/Innovation: Sewer network hydraulic modelling is traditionally used for concept design and future planning, or programming for wastewater network. In this research, hydraulic models were developed and used in an innovative way to assess the success of multimillion dollar rebuild works.