Wellington is making good progress in improving its ability to restore essential services after a severe earthquake, but there is still some years’ work ahead, says the chair of a group of the region’s infrastructure providers.
The Wellington Lifelines Group, which comprises 20 utility operators and civil defence authorities from local and central government, released a report today examining the restoration of key infrastructure after a major rupture of the Wellington Fault.
Greater Wellington Chair Fran Wilde, who chairs the group, says the report is the result of six months’ work by members and shows progress in all critical areas of the region’s infrastructure.
“We’re by no means fully prepared, but every utility provider has either begun or is well into preparations for getting key services back on line after a serious rupture of the Wellington Fault,” she said.
“This report has taken a worst-case scenario - a Wellington Fault rupture measuring 7.5 on the Richter scale - and the work on this possibility puts us in a better position not just for ‘the big one’ but also for smaller earthquakes.
“It is important to stress that the chances of a quake of this magnitude in the near future are small. A major rupture is predicted to occur approximately every 840 years, and since the last one was 300 years ago, hopefully we have some time to build our resilience.
“As you’d expect, the report shows we are better organised in some areas of infrastructure than others, but doing a comprehensive audit of our efforts to date is vital to improving overall preparedness.”
A rupture of the size envisaged in the report could shift ground alongside the fault sideways by as much as five metres and lift one side by as much as a metre.
Ms Wilde said work had been going on across a host of different areas for some years, much of it unreported to the public. Strengthening work was invariably low-key and carried out in conjunction with routine maintenance work. A small but typical example cited was a programme to replace ageing cast iron mains pipes – both for water and gas – with flexible polyethylene piping.
She said the experience in Christchurch had brought home to everyone in quake-prone areas of the country just how important it was to invest today to save lives and property tomorrow.
“It’s an unfortunate fact, however, that unless you have a limitless budget there is no quick fix. The seismic strengthening of infrastructure is a huge and costly undertaking and must be approached in a methodical way over many years.”
She said Wellington faced particular difficulties because its topography funnelled roads, pipes and other key infrastructure into bottlenecks vulnerable to disruption.
“All our planning assumes that the disruption of one service would impede the recovery of others, so untangling the web of damage would be a big challenge. We might get off more lightly, but we’re not planning on it.”
Ms Wilde said the region’s residents and businesses should not be alarmed by the report because it sketched a scenario that had only a one-in-10 chance of happening in the next 100 years.
“Nonetheless, people should not be complacent. The length of time it would take to restore essential services underlines the importance of individuals taking responsibility for their own preparedness, whether at work or at home, as well as getting involved in Civil Defence efforts in the wider community.”
Living on a fault meant no amount of strengthening work could remove all risk, she said.
Jenny Rowan, chair of the Wellington Region Civil Defence Emergency Management joint committee, to which the report will be presented on Friday, said that residents needed to take heed of the report and understand its implications for them and their families.
“This report raises the bar for individual responsibility and preparedness,” she said. “People and organisations need to be aware of the catastrophic disruption of a major earthquake and ensure that their planning takes it into account. A few bottles of water scattered round the house are no longer enough.”
The Wellington Lifelines Group will continue to monitor and co-ordinate planning and quake-strengthening work in the years ahead.
The aftermath of a 7.5-magnitude rupture:
Key upgrading work:
Significant seismic-strengthening projects completed, under way or planned include:
Capacity Infrastructure Services Ltd
Council-controlled Capacity operates the water, wastewater and stormwater networks on behalf of the cities of Wellington, Lower Hutt and Upper Hutt. Seismic-strengthening of these networks is carried out as part of regular infrastructure spending, which amounts to more than $60 million a year. Construction of a reservoir with a capacity of 35 million litres near Wellington hospital is an example of this work. Installation of automatic shut-off valves at reservoirs is another. There is about 25 days’ supply in city reservoirs.
Finding and fixing leaks after a big earthquake will first require water to be back on. Repair work must extend from the source outwards to the furthest points, which would be Wellington City’s eastern and southern suburbs (hence the new reservoir near the hospital). Work goes on to secure back-up sources such as artesian wells, emergency storage tanks and the collection of surface water. People are likely to be on their own in the days immediately after an earthquake, making it vital they have their own potable supplies (20 litres per person a day). The same goes for waste disposal, because restoration of the water network will take priority over the wastewater network.
CentrePort, as the infrastructure and service provider facilitating the berthing of vessels and working of cargoes, is a major contributor to the economic wellbeing of the region and acknowledges the role that it will need to play in any post-disaster recovery. As an active participant in the Wellington Lifelines Group, CentrePort has contributed to the activities and objectives of the group and is currently reviewing its disaster recovery plan to better position itself in addressing a post-disaster situation.
The Earthquake Commission funds natural hazards research that assists in land use planning, building design and infrastructure strengthening. EQC has been funding the It’s Our Fault research programme since its launch in 2006. The value of this kind of work was amply demonstrated by the robust performance and quick recovery of key lifeline utilities in Christchurch after the Canterbury earthquakes. This was possible as a result of seismic mitigation prompted by an EQC-commissioned report by the Christchurch Engineering Lifelines Group in 1997.
GNS Science has been leading a multi-agency project aimed at better understanding the likelihood of big earthquakes in the region and their impact on people and structures. The project, called It's Our Fault, is investigating the Wellington Fault and about three dozen other smaller geological faults in the region. Research emerging from the project is putting solid scientific data before decision-makers and helping them to set priorities for seismic-strengthening work. The project will benefit Wellington, and New Zealand, for decades to come. Improved earthquake resilience is central to the Wellington region’s viability because it will reduce damage and losses and lessen recovery time.
Over the last few years over $550 million has been spent on improving the Wellington rail network and this work is done according to design standards that take into consideration earthquake, flood risk, intense rainfall and other natural disasters. There is a committed funding stream for further infrastructure works over the next eight years and includes lowering the risk of landslides by improving slope stability in those areas of highest risk. At a company-wide level, there is business continuity planning for incidents and natural disasters. Part of this planning includes access to emergency bridging stock and access to resources outside the Wellington region to help recover after an event.
Ministry of Civil Defence & Emergency Management
The Ministry of Civil Defence & Emergency Management will review the Wellington Earthquake National Initial Response Plan in light of the Lifelines Group report. However, the plan’s principles will remain that of directing and co-ordinating the immediate national response to a major Wellington earthquake for the first three to five days. The plan sets out the roles and responsibilities agencies know they must immediately take up, and these would apply until a detailed National Action Plan was in place. The National Action Plan would respond to the specific damage and needs caused by the earthquake. The Lifelines report provides important information to include in the National Action Plan, and for utility providers and WREMO to use in their planning. They are already starting to include that in their planning. The National Crisis Management Centre at Parliament would be the hub of any central government response to a large-scale crisis, and is designed to withstand major earthquakes.
New Zealand Telecommunications Forum Inc
The telephone networks stood up reasonably well after the Christchurch earthquakes, but key lessons were learned and mitigation action has been undertaken to make any response to an event in Wellington more effective. However, the terrain in Wellington and the issues around access will impact on how the response can be delivered.
New Zealand Transport Agency
The report highlights the challenges the region faces in keeping its communities well connected and resourced. Good work has already been completed, such as Wellington City Council’s improvements to the Ngaio Gorge Road and along Churchill Drive, Churton Park, which could both be vital access routes after a major earthquake. The Terrace and Karori tunnels have also recently been strengthened, and further upgrade work is about to begin on the Mt Victoria Tunnel.
Construction of the Wellington Northern Corridor Road of National Significance will provide a huge boost in the security and resilience of routes north by providing a four-lane highway built to modern seismic standards, with the ability to be restored far more quickly than State Highway 1. In particular, the Transmission Gully motorway will provide an improved inland route out of the Wellington metropolitan area, and the MacKays to Peka Peka section of the Kapiti Expressway will extend the secure highway link. Investigating the link between Petone and Grenada will give us an insight into how this route could add to the network’s seismic resilience. It is important investment focuses on those roads that could be critical lifelines for the region. NZTA is working with councils in the region to develop a regionally focused package of investments.
An engineering study for Wellington Airport shows that some areas of the runway will incur damage in a major earthquake. Following any seismic event above MM4.1 on the airport’s accelerometer, an infrastructure assessment is undertaken. Depending on the extent of damage, the runway is expected to be operational for helicopter and military aircraft within hours. Airport engineers are now undertaking further assessment on what is likely to be required to reinstate full operations after a major earthquake.
The Wellington Electricity network is one of the most reliable in New Zealand because 60% of it is located underground. However, this makes it vulnerable in a major earthquake. Electricity is essential to the economy and the community, so Wellington Electricity is developing plans for seismic-strengthening of its substations and related equipment as well as innovative plans for rapid restoration of power supplies after a big earthquake. The Commerce Commission controls Wellington Electricity’s prices, so the company needs to ask residents what level of seismic-strengthening of their local electricity network they would be willing to support. Wellington Electricity recognises it is in everyone's interest to have the lights remain on or get back on quickly in Wellington
Wellington Regional Council
During the past two decades Wellington Regional Council has completed, or has under way, nearly 50 projects to earthquake-strengthen the region’s bulk water infrastructure and enable the network to resume service faster after a serious earthquake. The cost of the projects exceeds $20 million. Projects under way in the current financial year total $5.4 million. Among the most noteworthy are: seismic-strengthening of the Stuart Macaskill storage lakes at Te Marua ($10 million); construction of pumping stations at Karori and Point Howard in more secure locations ($3.9m); rerouting a main supply pipeline near Haywards to avoid earthquake-induced landslides ($3.2m); and a new suction main to Point Howard pumping station ($1m).
The regional council is also responsible for the region’s public transport needs. It has contingency plans in place to restore bus services as speedily as possible if an earthquake disrupts the road network.
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