Dear Canterbury Earthquake Recovery Authority,

SOUTHSHORE RED ZONE NORTH BOUNDARY:
I would like data for the criteria, 'tipping points' or parameters for each criterion, the weighting given to the various criteria within the decision framework, the margins of error for each and how these margins of error were factored in to the decision.

SOUTH NEW BRIGHTON TC3 AREAS:
I would also like the same data relating to the areas along Kibblewhite Street and estuary end of Beatty Street in South New Brighton to explain why these areas were zoned TC3.

BACKGROUND:
My previous request for this information was partially (slightly)successful in that I had a short discussion with Jan Kupec and I did get access to the geotechnical database and technical reports from GNS etc. While this has provided some of the previously 'missing data', I still have not had an explanation of the parameters used to determine where the boundary should go.

Explanations to date for the Southshore red zone boundary have been subjective: 'I didn't draw the boundary', 'the boundary has to go somewhere' and 'there's probably some buffer zones'. And various vague responses to my earlier request do not make sense in explaining why the northern boundary was drawn where it is. For example, Cera said in 30 Sept "the location of those properties zoned green in Southshore were done so on the basis that damage to land and homes can be addressed on an individual basis by homeowners working with EQC and their insurance company. This is in contrast to the properties on that Southshore boundary that ended up being zoned red. To fix the damage to land and properties in this area would have required area-wide engineering works (such as deep and wide zone of ground improvements along the estuary coastline) to address the potential for extensive area-wide lateral spread." This is true of houses immediately bordering the estuary along the spit. However, given that the TC3 house to the north of the red zone boundary is only 1 m from the fenceline (the boundary), I cannot see that explanation makes sense. The 4-6 houses in last block of Estuary Road before Halsey Street are some distance from the estuary. The lateral spread is concentrated along the estuary margins as was obvious on the ground and as is shown in the GNS Lidar report.

This weekend (15th & 16th Dec 2012) had higher tides than normal, which was interesting for the end of Kibblewhite Street ... TC3. The land inside the stopbank (which had to have emergency repairs to raise it considerably after Feb 2011) is lower than the high tide so river / estuary water pours up through the stormwater system and ponds behind the stopbank. Water was almost to the door of the last house. The houses along Kibblewhite St are very close to the estuary, and houses / drives show obvious lateral spread etc. Drilling indicates shallow aquifers at 26m.

Flooding, liquefaction and cracks were severe around the bridge after the earthquakes. The area around Beatty Street also showed very severe land cracking and lateral spreading after all the quakes. These areas are TC3.

I have been through a lot of the geotechnical database, GNS reports & T&T reports ... and the boundary decisions for both Southshore and South New Brighton seem to make less sense than ever.

SUBJECTIVE OR OBJECTIVE DECISIONS?:
Please inform me whether there were subjective decisions.

If not subjective, then please provide the information on which the decsions were made ... the criteria, 'tipping points' or parameters for each criterion, the weighting given to the various criteria within the decision framework, the margins of error for each and how these margins of error were factored in to the decision.

I look forward to your explanations so that I (and others) can see the clear evidence for your decisions and decision processes.

Yours faithfully,
Judy Grindell

Dear Cera

Thank you for your reply. Alas, it does not provide the information I requested.

Your response is merely a rehash of the general, area-wide information already provided and which is in the public domain. I had already been through all that information but it does not provide the data I am seeking. For example, nowhere have a seen a definition or criteria explaining ‘potential for future lateral spreading’. Given that the CPTs for the end of Kibblewhite Street area seem to hit a shallow aquifer at 26m and given the proximity to the estuary / river, the land subsiding and flooding at high tides plus the lateral spreading that was and is still apparent, I would have expected that area (TC3) would have greater ‘potential for lateral spreading’. I have asked for the data (as per my OIA request) so that I can better understand the zoning processes and criteria used.
I did have a meeting with Jan Kupec (I did appreciate this), which was useful for seeing the information previously missing (e.g., CPT testing for the last block of Estuary Rd, and LiDAR data for the maps that, in the published reports, had been covered by the map legend or the map did not extend as far as the red / TC3 boundary. Jan went over the same general ‘area-wide’ decision stuff again but would not (or could not) provide any specific explanation as to how the boundaries were drawn where they are; his responses were ‘I did not draw the boundary’, ‘the boundary has to be somewhere’, and ‘there’s probably a buffer in there’.
I have been through the Project Orbit Database (I do have access) and the various reports (T&T, GNS etc) … and while it provided access to much interesting data, it provides no judgement or evidence as to how boundary decisions were made based on what data.
The first house after the red /TC3 boundary for the Southshore north area is only 1 metre from the red zone boundary and the property extends all the way back to the campground. There are two properties in the red zone at the red / green boundary; one of which backs on to the campground and one nearest the road obviously does extend to the campground. I would like to be able to understand how your data and evidence-based decision-making process justify the differences over 1 metre.
The various criteria relating to lateral spreading (existing or potential, whatever that might be), land elevation or subsidence appear to be applied inconsistently across the areas. So I repeat again, I would like an explanation and evidence explaining the rationale for the different areas as I requested.
I repeat, I have asked for the data (as per my OIA request) so that I can better understand the zoning processes and criteria used. While a number of residents in the Southshore and South New Brighton areas are satisfied with general, area-wide information, there are many others who would like to understand more.

Please provide the data and explanations as requested.

Yours sincerely,

Judy Grindell

Dear oce (CERA),

my letter of 18 Jan was not a new request. It was clarification as to why your response (18 Jan) to my 19 December request did not meet that request and clarification that I still do want the information as requested. I am still seeking that information and am expecting this will be provided within 20 working days of 20 December.

Yours sincerely,

Judy Grindell

Dear Roger (CERA),

I am very disappointed in your response and your unwillingness to provide the data as requested.

Given that no CPT testing had been done at all in that block of Estuary Road when the zoning decision was made, I cannot see how you can state "the key factor in declaring an area as green zone was whether individual foundation solutions were feasible for the particular ground conditions".

Ground conditions can, in some circumstances, change over a few metres but no drilling had been done anywhere near the red/green boundary to check this. There is no surface indication of a drastic change in soil type in this area and one would not expect it.

There are inherent margins of error in the accuracy of the original DTMs and the LiDAR data so you need to be very cautious in claiming how definitive that data is for decisions.

You recommendation that I seek independant advice from a qualified geotechnical engineer is unhelpful and really rather silly ... how is that going to provide me with the detailed evidence as to how CERA decided where boundaries should go and how CERA decided what was red and what was green for the areas I am seeking clarification for?????

Besides, I already have access to (and regularly discuss these issues with)some of the country’s best remote sensing and LiDAR scientists,pedologists and geomorphologists. I also have access to a retired geotechnical engineer who worked overseas on such issues.

While CERA have made it abundantly clear they will not overturn any zoning decision, I do believe a public decision-making body has an incumbent responsibility to explain how and why the decision has been made in a particular situation. This is particularly so when people and communities are so significantly affected. Moreover, I also believe that CERA should have provided
data as requested when first requested rather than go through these nebulous explanations wasting your time and mine.

Yours sincerely,

Judy Grindell