This paper summarises the impact of earthquakes on Christchurch’s storm water network and the recovery strategies that are being applied to restore the performance of the network. Storm water hydraulic models are being used to determine the level of service in the storm water network, and the extent and severity of flooding pre- and post-quake for different extreme weather events. The modelling tools have been used extensively for land-drainage recovery works. To be suitable for use the storm water models must be sufficiently current and accurate to be a good representation of the actual operation of the storm water system. Thousands of earthquakes and earthquake aftershocks are continually changing the ground levels and the condition of different storm water infrastructure in Christchurch. The dynamic response of the surface water network and coastal plains due to earthquake-related topographical changes, lateral spreading, liquefaction, and subsidence posed a number of challenges for the local water authority. A case study on flood modelling for a flood-prone area of Christchurch has been reported in this paper. This paper outlines key challenges during the storm water model-building and updating process for a network which faces continual earthquakes and earthquake-related aftershocks.

Earthquake recovery, Hydraulic model, Restore stormwater network, Storm water, Surface water, Storm water model

[1] Christchurch Quake Live. Retrieved from http://www.canterburyquakelive.co.nz/Browse/
[2] R.R. Biswas, "Importance of Smart Monitoring Systems for Efficient Vacuum Sewer Performance and Modelling the Network", International Journal of Computer Sciences and Engineering, Vol.5, Issue.8, pp.218-222, 2017. (DOI: https://doi.org/10.26438/ijcse/v5i8.218222)
[3] Christchurch City Council (CCC), “About the land drainage recovery programme”, Retrieved from https://ccc.govt.nz/services/water-and-drainage/storm water-and-drainage/storm water-projects/about-the-land-drainage-recovery-programme , May, 2016.
[4] Christchurch City Council (CCC), “Contextual historical overview”, Retrieved from https://ccc.govt.nz/culture-and-community/heritage/heritage-in-the-city/historical-overview/ , June, 2017
[5] K. D. Simpson, “An Earthquake and Recovery of a Stormwater System,” Paper presented at the Water New Zealand Storm Water conference, New Zealand, April 2012. Retrieved from https://www.waternz.org.nz/Attachment?Action=Download&Attachment_id=823
[6] F. McKay, P. Christensen, and T. Parsons, “Where to Start? Christchurch’s Post-quake Land Drainage Recovery Programme”, Paper presented at the Water New Zealand Storm Water conference, Nelson, NZ, May 2016. Retrieved from https://www.waternz.org.nz/Attachment?Action=Download&Attachment_id=2125
[7] Z. Vojinovic, and D. Tutulic, “On the use of 1D and coupled 1D-2D modelling approaches for assessment of flood damage in urban areas”, Urban Water J., Vol. 6, Issue. 3, pp. 183–199, 2009
[8] A.S. Chen et al., “An integrated inundation model for highly developed urban area” , Water Sci. Technol. J. , Int. Assoc. Water Pollut. Res. , Vol. 51, pp. 221–229, 2005
[9] A. Pan et al. “Hydrologically Enhanced Distributed Urban Drainage Model and Its Application in Beijing City.”, J. Hydrol. Eng. Vol. 17, Issue. 6, pp. 667–678, 2012
[10] O. Mark et al. “Potential and limitations of 1D modelling of urban flooding.”, J. Hydrol. Vol. 299, Issue. 3-4, 284–299, 2004
[11] S. Djordjevi´ et al. “Simulation of interaction between pipe flow and surface overland flow in networks.” Water Sci. Technol. Vol 52, Issue. 5, pp. 275–283, 2005.
[12] T. Chng. Et al., “A novel approach to model dynamic flow interactions between storm sewer system and overland surface for different land covers in urban areas”, J. Hydrol., Volume 524, pp. 662–679, 2015
[13] T. Preston and T. Parsons, “Christchurch city mega model – Magic or madness?”, Paper presented at the Water New Zealand Storm Water conference, Nelson, NZ, May 2016. Retrieved from https://www.waternz.org.nz/Attachment?Action=Download&Attachment_id=1878
[14] Christchurch City Council, “Waterways, wetlands and drainage guide”, Retrieved from https://ccc.govt.nz/environment/water/water-policy-and-strategy/waterways-wetlands-and-drainage-guide/, June, 2017