PM Key says no one knows how much final quake damage will cost, as overall bill rises toward NZ$25 billion and bad news keeps coming for EQC

Based on your overall mastery of science as evidenced by what you write in here I can only assume that you were a poor student with low, quite possibly marginal grades.

Deviating from the subject, kunst? Gee talk about the kettle calling the pot black! Correct me if I'm wrong but this thread is about the cost of the Christchurch earthquake. And who began rattling on about climate change and pollution as though that had something to do with it. Why of course, kunst, it was you!

Ms de Meanor

You are right I am not am engineer, however I have 15 years experience in property development in Christchurch, plus a Physics degree which included a number of engineering and geophysics papers.  I have also read numerous papers on geological formations in the Canterbury area and of course have been involved in many projects involving groundwork engineering and piling.  I also experienced first hand the effects of liquifaction and lateral movement in September, February and June.

Unless you have specific knowledge of this site, you are probably not aware of the risks.

It is an unfortunate fact that geotechnical "experts" often bring contradictary views depending on who is paying them (remember the Opuha dam).  One recent report I read on the "Prestons" development, essentially stated that the site wasn't at risk of liquifaction because none had been evident in any of the recent events, I would suggest that such reports are not helpful and failed to consider the relative variation in ground motion.  For instance the area of Avondale/Burwood between New Brighton Rd and Travis Rd had very little liquifaction in September when ground shaking was around 20% of gravity but had in February and June had significant liquifaction (now red zone) when ground motion was around 80% of gravity.  Indeed on those above mentioned sites, new homes were started after September with absolutely no greater engineering design than pre-September.

But back to the Kaiapoi site.  I have not seen reports for the specific site, however the area has characteristics that make it unsuitable for building on.

Firstly it is the old river bed.  Only the stopbanks and diversions built from the late 19th Century onwards actually prevent this area from being underwater.  In the event of a large earthquake involving uplift  on one of the many known faults in the area (we know of a fault at the Waimak mouth which ruptured with an M5.2 (March 1987), we also know of faults in north ChCh and around Waimari Beach) there is the risk of the banks failing and the possiblility of uplift to the river beds causing the area to flood (prior to those flood banks being completed the area routinely flooded in the early 20th Century).

Secondly the soils are mainly fluvial deposits.  Not unbuildable but more susceptible to liquifaction.  Even if they overlay river gravels the real risk to the site has to be lateral spread into the river (former north branch of the Waimak) which runs through the site.  There is clear evidence along this river branch of minor ground cracking, which those in the eastern suburbs of ChCh know well, forebodes future damage. 

The proposal to put dense residential on this land less than 20m from the river bank is not logical.  There is historical evidence that this land has not been considered suitable for development as the site has not been split into smaller blocks at any stage despite it's proximity to a sizable town.

Thirdly there was liquifaction on nearby sites with ground accelerations at around 35% of gravity.  As we know ground accelerations can get up to well over 100% of gravity even tens of kilometres from an epicentre of a large quake.  If we look historically we know that there was considerable liquifaction in Kaiapoi during the 1901 M6.8 Cheviot earthquake (although this was forgotten by the time it was developed in the 1970s).  Note that the closer 1922 M6.4 Motanau quake did not cause liquifaction.

http://docs.google.com/viewer?a=v&q=cache:dkkcOTlSPQsJ:db.nzsee.org.nz:…

Now personally I think houses could be built on this land.  However definitely not in the format proposed by the developer.

The site could handle larger lifestyle blocks of perhaps 4000m2 minimum with a 50m setback to the river, but the foundations would need to be well engineered and whether it would be worth developing the site to that intensity at all when there are better quality sites nearby is question of economics.  I would suggest that developing the land with a 1 ha minimum may be more appropriate (the current zoning allows a 4ha minimum). 

As a comparison similar land a few hundred metres away of 4ha size (with a more prestigious Ohoka address) has sat on the market for 5 years priced at around $270k +GST, so any intention of achieving close to $200k for 600m2 (which I understand was the developers intention) seems a nonsense anyway.

Ralph, I am trying to raise issues that are clearly you do not comprehend.

I assume from your comments that you have no first hand experience of the insanity of the current disorganisation.

Insurance and EQC issues are so extensive that it would be fair to say that probably less than 10% of claims are totally sorted (which would mainly be the very minor and the very severely damaged that cash settled).

The CBD is still in lock down.  Our Heritage has been unnecessarily bulldozed.  Whole suburbs swept away without consultation. 

It would have been so simple to get things sorted, instead lots of busy bodies are trying to get their pet projects looked at rather than actual property and business owners having their issues resolved.

It could have been kept simple, instead it's all a dog's breakfast.

Simple ways to fix things would have been:

1. Sort EQC assessment for the most damaged properties with a single assessor who sees it through to payment within a few weeks.

2.  Put pressure on private insurers to have a required timeframe to settle claims.  (Use a large stick if necessary - ie threaten intervention or law changes).

3.  It's too late now, but a plan to get the CBD open to owners should have made within a month of the Feb quake.  Some areas could have and should have been opened months ago. 

4. Plan's needed to made to preserve heritage - too late now.

5. Demolition did not have to be rushed, many buildings could have been repaired and operational now.

6. Red zoning should have been in consultation with land owners.  Many areas could have been "phased out" rather than abandoned.

7. Offers should have been made at market value.  This would have cost no more.

8.  No time frame should have been put on people accepting offers. 

9.  The "big" buildings should have been taken down much quicker.  The Grand Chancellor is incredibly dangerous and is holding up the opening of a large area of the CBD.

10. The public should have been given confidence things were getting sorted, instead we have had nonsensical or plain wrong information fed out by John Key and Gerry Brownlee.  (just today he said only 10,000 people had left ChCh, unfortunately electoral rolls suggest we have 25,000 less persons than 2010, add in 7,000 fewer school age students and a few thousand fewer other young people and non citizens then we have 35,000.  But those numbers also show few have left the most damaged low income areas which suggests that maybe those just haven't sorted their enrollments and that in fact the number who have left could be as high 45,000). 

11.  This list could be endless, but the proof is in the facts:

How many houses built since September 2010?  Less than half of normal.

How many replacement commercial buildings started?  Just a handful.

How many insurance claims settled?  Only the very minor or total losses that cash settled.

How many people have left?  Perhaps 15% of the population.