The Canterbury earthquake in New Zealand demonstrated the enormous economic and social impact natural events have on a modern city. Key to minimising both financial and social effects of such events is infrastructure resilience planning and delivery as an integral part of managing assets.
The Canterbury earthquake in New Zealand demonstrated the enormous economic and social impact natural events have on a modern city. Key to minimising both financial and social effects of such events is resilience planning and delivery as an integral part of managing assets.
40,000 homes in Christchurch were without power, wastewater and water services as a result of a devastating earthquake on 22 February 2011. Residents were living with boiling water restrictions and an unstable power supply for over six weeks.
Four years on there remains hundreds of demolished buildings and a CBD that is still not functional. Is this the resilience we desire in our cities? Is building for improved resilience a luxury we can afford?
The infrastructure and building assessment response crews did an amazing job during the Canterbury Earthquake Sequence (CES) but have we learned the lessons around the importance of infrastructure, business and community resilience? If not, it is only a matter of time before another urban centre in New Zealand will face the same calamity as Christchurch.
Numbers around the total cost of the CES will never be truly known as some areas of infrastructure and redevelopment will take 20 to 30 years to fully restore as the new city emerges. Considering resilience as a key analysis factor in the development of projects and renewal or strengthening of existing assets will go a long way to improving how fast the next community will recover from a natural disaster of similar magnitude.
Integral to demonstrating the value of resilience is having an understanding of the consequences of large low frequency events. While other natural disasters have devastating effects, earthquakes are often considered the controlling event because:
- they occur without warning and can strike at any time
- predicting their magnitude and location is very difficult
- they have an instant devastating effect on manmade structures which in reality can never be totally designed for
Put into context this means almost every area of New Zealand should have a strong focus on building resilient communities.
So how do we move forward? A lot of work has been done in this space and has manifested itself in a myriad of reports and changes in design codes. However, a very important work element is around building resilience rationale into asset renewal, project thinking and making our communities aware of the magnitude of risk to the community in an open and transparent manner.
Simulation technologies and graphical software systems give us the platforms to simulate earthquake events and their impacts on building stock and infrastructure. We have the capability to visually demonstrate loss of services, and commercial site activity.
Sharing this knowledge between business, infrastructure and community civil defence groups will help people make decisions around the ability of their business and homes to continue through such events. Having businesses able to operate in an existing location keeps people employed, maintains economic output and reduces government aid.
While it is impractical to move from a status quo position to one of strong resilience in a short timeframe, the embedding of resilience performance and economic assessment in asset renewal decision making will significantly improve resilience over time.
Economic consequences of asset failure can be built into renewal decision making processes by looking over a 25 to 30 year timeframe and integrating earthquake probability, magnitude and cost consequences into business case models.
The simulation tools available to us today should allow an improvement in resilience to be constantly measured and assist in the targeting of infrastructure funding to the area of highest impact (reduced consequence and shortening of service restoration time). This level of sophistication in asset planning is still developing in many infrastructure areas and should be an area of focus for utility providers.
The use of prediction, consequence and investment tools will help essential services governance bodies to invest in a manner that will reduce the frequency of a future "Canterbury Earthquake Sequence.