Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search


Liquefaction report for Timaru released

25 March 2014

Liquefaction report for Timaru released

Environment Canterbury today released a review of liquefaction information for Timaru District, indicating that only small amounts of liquefaction may happen in a large earthquake.

The review report, commissioned by Environment Canterbury and the Timaru District Council and produced by Geotech Consulting Ltd, summarises and updates liquefaction studies from the last 15 years.

Environment Canterbury Commissioner Donald Couch says the review targets areas that have been identified in the past as potentially liquefiable in a big earthquake and offers guidance about appropriate levels of geotechnical investigation at the time of subdivision or development.

“This comprehensive piece of work gives the community better information for those considering building,” Mr Couch said. “It essentially confirms what was already known – there is very limited liquefiable ground in Timaru District, meaning only small pockets of liquefaction are likely.

“It does not tell individual landowners whether there is a risk of liquefaction on their particular property, but there are ways to get information about their properties and it will show them when liquefaction hazard investigation should be included in consent applications. It will also avoid their being asked for liquefaction hazard investigations in areas where potential for damage is low.”

The report includes the results of new geotechnical testing in specific areas of Timaru and Geraldine. It shows that ground that is more susceptible to liquefaction is in low-lying areas close to the coast, and along rivers and floodplains.

“The most susceptible areas are valley bottoms close to the coast in Timaru City, between Washdyke Lagoon and Saltwater Creek. The area subject to river engineering works at Washdyke Creek is not susceptible, however,” Mr Couch said.

“Timaru Port is an area of low susceptibility. Much of Redruth, including the area currently occupied by the landfill, may need further investigation to make sure the liquefaction hazard is appropriately managed.”

The main purpose of the report is to provide Timaru District Council and the community with general guidance on where geotechnical investigation and engineering assessment of liquefaction potential may or may not be required for plan changes, and for subdivision and building consents. It may also be useful for lifeline utility and emergency management planning.

“The report divides the district into four areas of relative liquefaction susceptibility ranging from ‘nil to extremely low’ potential to ‘moderate’ potential,” Mr Couch said. “Liquefaction assessment is needed in two of these areas. Nowhere has been identified where development may lead to unacceptable economic risk.”

The report identifies potential liquefaction hazards in respect of land use planning for general residential and light commercial development. It does not provide information for major infrastructural and critical facilities.

Mr Couch advises potential purchasers in Timaru District and elsewhere always to get a LIM. “You might also need an investigation for hazards other than liquefaction – for example, for susceptibility to land subsidence,” he said.

“This report will help ensure that costly liquefaction investigations will not be required in areas where they are not needed and will be focused on areas where they can ensure appropriate building solutions.

“This is the way it should be towards making sure our buildings are as safe as possible for the future of Canterbury,” Mr Couch concluded.

For more on the report and related information go to www.ecan.govt.nz/liquefaction


The occurrence of liquefaction depends on whether underlying soils include liquefiable sediments, which have very distinctive characteristics, and whether these sediments are saturated by water (under the water table).

In the report:

• Zone 1 land (“moderate potential”), which covers a very small part of the district, has the highest liquefaction susceptibility and all new development should have appropriate site investigations and liquefaction assessment by a suitably qualified geotechnical engineer or engineering geologist.
• Zone 2 land (“low potential”) may contain areas of liquefiable ground, and liquefaction assessments should be carried out for new subdivisions at consent stage.
• The geological nature of the ground in zones 3 and 4 (“very low” and “nil to extremely low” potential) is such that future earthquakes are unlikely to cause land damage from liquefaction.


© Scoop Media

Parliament Headlines | Politics Headlines | Regional Headlines



Australia Deportations: English Relaxed On Immigration Centre Conditions

Labour's Annette King: “There have been numerous reports from inside these detention centres on just how bad conditions are... If they were being held in any other foreign jail, I imagine Mr English would be somewhat concerned. More>>


Schools: Achievement-Based Funding Would Be A Disaster

The Education Minister’s speech to the PPTA Conference raising the spectre of achievement data driving a new funding system would be disastrous, says NZEI Te Riu Roa. More>>

  • Video Out-Link - PPTA Annual Conference 2015 on Livestream (Q+A dicussion suggests funding would be directed to less successful schools.)

  • ALSO:

    ECE Report:

    Key In NY: Prime Minister Addresses United Nations

    Prime Minister John Key has addressed the United Nations General Assembly in New York, focusing on a call for action in Syria and on other conflicts, reform of the veto process and on the UN’s Sustainable Development Goals. More>>.


    Gordon Campbell: On The Lack Of Accountability Over Philip Smith

    In New Zealand, accountability is an exotic creature rarely glimpsed at ministerial level, or among senior management. The flight to Rio by the paedophile /murderer Philip John Smith/Traynor is no exception. More>>


    More On Corrections

    Gordon Campbell: On Putin’s Diplomatic Coup Over Syria

    There’s a simple historical precedent for what is occurring in Syria. During WWII, the Allies joined forces with a known butcher and tyrant – Joseph Stalin of the Soviet Union – in order to defeat a greater evil, Nazi Germany… More>>


    Key 'Didn't Know': Brownlee Seeks Pandas In China

    While Defence Minister Gerry Brownlee is in China pushing a taxpayer funded deal to bring two pandas to New Zealand, the country’s military look set to be hit with a pay freeze, Opposition Leader Andrew Little says. More>>


    Scoop Business: GCSB Willing To Extend Cyber-Attack Programme To Local ISPs

    The Government Communications Security Bureau’s ‘Cortex’ cyber-security programme has been successful in helping identify and mitigate a series of cyber attacks since its introduction and an extension to cover local internet service providers is still on the cards... More>>


    Get More From Scoop



    Search Scoop  
    Powered by Vodafone
    NZ independent news