The Value of Lifeline Seismic Risk Mitigation in Christchurch – June 2012 Executive Summary
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June 2012 This electricity substation had been decommissioned prior to the earthquakes and was unstrengthened Nearby strengthened electricity substation See inside front cover for additional information Document Information Prepared by: Tony Fenwick Contractor / Consultant 228 Ngatiawa Road RD 1 Waikanae 5391 [email protected] Reviewer: Dave Brunsdon Chair, New Zealand Lifelines Committee Kestrel Group Ltd Level 1, 114 Lambton Quay, Wellington http://www.kestrel.co.nz [email protected] Date: June 2012 This report was commissioned by the New Zealand Earthquake Commission under its ‘Science-to- Practice’ Programme. The terms ‘lifeline utility’ and ‘lifeline engineering’ are used in this report. Lifeline utilities are defined in the Civil Defence and Emergency Management Act 2002. Broadly, lifeline utilities are companies and publicly owned entities delivering infrastructure services in energy, telecommunications, transport and water / sewerage. Lifeline engineering describes collaborations between lifeline utility representatives and scientists, emergency managers and other professionals aimed to reduce service outage risks and minimise restoration times when outages occur. Regionally based lifeline groups undertake collaborative projects to reduce vulnerabilities (regional group activity commenced in the early 1990s). The New Zealand Lifelines Committee was formed in 1999 to foster regional activity and provide a link to government. DISCLAIMER This high-level overview has been compiled from available documented information, responses to numerous enquiries made to lifeline utilities, and ideas offered by representatives of the utilities at a meeting of the Canterbury Lifeline Utilities Group (August 2011) and at the National Lifelines Forum (November 2011). Effort has been taken to summarise the information accurately. However, the parties involved in preparing this report do not accept liability for losses arising from use of, or gaps in, the information it contains. Cover Photos: The photos illustrate the value of seismic mitigation, in this case, strengthening unreinforced masonry structures, many of which serve as substations in Christchurch’s electricity network. The substation on the left had been decommissioned prior to the earthquakes and was therefore excluded from Orion’s mitigation programme (it is no longer owned by Orion). The building was severely damaged in the September 2010 earthquake. The substation on the right, approximately 500 metres away, had been seismically strengthened and was largely undamaged. Strengthening work of this nature greatly assisted electricity restoration in Christchurch following the earthquakes. (Photo source: Orion New Zealand Ltd.) ISBN 978-0-473-21630-6 (Paperback) ISBN 978-0-473-21631-3 (PDF) Contents Foreword ..................................................................................................................................................i Executive Summary .................................................................................................................................ii Introduction ............................................................................................................................................ 1 The 2010 and 2011 Earthquakes ........................................................................................................ 1 History ............................................................................................................................................... 2 The Present Report ........................................................................................................................... 4 Risks and Realities – Main Mitigation Measures .................................................................................... 5 Risk Reduction................................................................................................................................... 5 Readiness .......................................................................................................................................... 6 Seismic Mitigation Work Immediately Following Risks and Realities ................................................ 6 Mitigation Work Undertaken Following Risks and Realities .................................................................... 7 Risk Reduction Measures.................................................................................................................. 8 Readiness Measures ........................................................................................................................14 Assessing the Merits of Mitigation ...................................................................................................... 21 The Economic Costs of a Disaster .................................................................................................. 21 The Cascade Effect – Interdependencies of Lifeline Utilities .......................................................... 23 Issues in Measuring the Benefits of Seismic Mitigation ................................................................. 24 Research on the Benefits of Seismic Risk Mitigation ...................................................................... 25 Conclusion ............................................................................................................................................ 30 Attachment 1: National Lifelines Forum 2011: Key Learnings to Inform Earthquake Resilience Planning ..................................................................... 32 Works Cited .......................................................................................................................................... 33 Foreword Christchurch has shown us that sometimes things go wrong and, unfortunately, we sometimes experience significant emergencies. This just serves to highlight that risk is a constant companion in all that we do. Some risks are minor but others can be catastrophic. The purpose of this report is to show from Christchurch that steps can be taken to manage risk, but that these efforts need to focus on the things that really matter. The way we think about managing risk depends on the way we define it – we can’t do anything about the likelihood of an earthquake, but we can do a lot about whether the consequences of an earthquake will be costly. This report helps us learn that many of these mitigation steps are not difficult to do, and that they are not always costly. But the time to act is now – before we experience an emergency. The Ministry of Civil Defence & Emergency Management is working hard to do what it can to manage risks. Our contribution is in setting emergency management frameworks covering the ‘four Rs’– risk reduction, readiness, response and recovery – and in promoting healthy arrangements to deliver good outcomes through the sector. While we can’t ourselves ensure good outcomes, it is our responsibility to encourage local communities to adopt good mitigation practices. This report is about the substantial range of risk reduction and readiness steps taken by lifeline utilities in Christchurch over recent years to reduce the impact of earthquakes. The work leading to the report of the Christchurch Engineering Lifelines Group in the 1990s, Risks and Realities, is the foundation for much of the measures adopted. As the report notes, seismic mitigation undertaken by Christchurch lifelines since Risks and Realities has served Christchurch well in reducing losses that would otherwise have been much greater. The mitigation work also helped facilitate improved emergency responses and recovery. The report shows that the costs of seismic risk mitigation in Christchurch will have been repaid many times over. It is therefore a most worthwhile investment. Christchurch, and New Zealand, owes a debt of gratitude to the Christchurch lifeline community for its pre-earthquake preparation. It has set an example and it was most pleasing to see the lifelines across the many sectors step up to the plate, in challenging circumstances, and play their part in the immediate post-earthquake responses. I would like to acknowledge that very substantial contribution this made to the well-being of Christchurch citizens and businesses. I also acknowledge EQC’s historical and continuing support for these risk reduction activities and its sponsorship of this report. Lastly, thanks go too to the New Zealand Lifelines Committee for making arrangements for the report’s preparation and release. I commend this review to all agencies and individuals who have an interest in helping their communities prepare effectively for an emergency. John Hamilton Director Civil Defence June 2012 i The Value of Lifeline Seismic Risk Mitigation in Christchurch – June 2012 Executive Summary Christchurch and Canterbury suffered damaging earthquakes in September 2010 and February 2011. Underground infrastructure assets (pipes and cables) were severely impacted; unreinforced masonry structures and a number of reinforced concrete structures, including many owned by lifeline utilities, were also damaged. Lifeline vulnerability to natural hazards including earthquakes had been given prominence in a comprehensive project undertaken by the Christchurch Engineering Lifelines Group in the first half of the 1990s. The project report Risks and Realities records the processes, findings and mitigation steps (risk reduction and readiness) identified at the time (Christchurch Engineering Lifelines