How to find out how much damage the dewatering could cause to your house . . .
Look on the map to see which subsidence Zone your house is in. The Zones are labeled in roman numerals from 1 to 5, plus there are special Zones 2A, 2B, 3A and 3B. Then read the subsidence predictions for that Zone and a description of the damage that is associated with that amount of subsidence.

Zone 1 : Subsidence of 5 to 15 mm.
Zone 2 : Subsidence of 5 to 35 mm.
Zone 2A : Subsidence of 50 to 70 mm.
Zone 2B : Subsidence of 70 to 190 mm.
Zone 3 : Subsidence of 10 to 20 mm.
Zone 3A : Subsidence of 40 to 60 mm.
Zone 3B : Subsidence of 35 to 55 mm.
Zone 4 : Subsidence of 5 to 15 mm.
Zone 5 : Subsidence of less than 5 mm.

Typical damage for Zones 1, 2, 3, 3A, 3B, and 4 :
Cracks easily filled. Redecoration probably required. Several slight fractures inside building. Exterior cracks visible; some repainting may be required for weather-tightness. Doors and windows may stick slightly.

Typical damage for Zone 2A :
Cracks may require cutting out and patching. Recurrent cracks can be masked by suitable linings. Tuck-pointing and possibly replacement of a small amount of exterior brickwork may be required. Doors and windows sticking. Utility services may be interrupted. Weather tightness often impaired.

Typical damage for Zone 2B :
Extensive repairs involving removal and replacement of sections of walls, especially over doors and windows required. Windows and door frames distorted. Floor slopes noticeably. Walls lean or bulge noticeably, some loss of bearing in beams. Utility services are disrupted.

Tonkin & Taylor Report
All this information is taken directly from the Tonkin & Taylor Report that was prepared for Winstone Aggregates and submitted to the Auckland Regional Council to support their request for continued dewatering. The map is copied from Figure 7 in the Report and the subsidence and damage details are copied from Table 6, from the text at the foot of page 31 and from Appendix F Table 1.

What you should do now
To avoid possible damage to your house, you should fill in the Submission Form that was sent to you by the Auckland Regional Council (ARC).

You should tell the ARC that you want the dewatering and pumping stopped and the Resource Consent Permit cancelled because you do not want your house to be damaged in any way.

If you do not convey your wishes to the ARC, they are likely to assume that you agree with the amount of land subsidence that the dewatering will cause to your property and the possible damage resulting from it.

The existing Resource Consent Permit expires in the year 2030. This Public Review will almost certainly be your last opportunity to have your say on the matter.

Need Help?
The most important things to put on the Submission Form are your name, address, signature and an instruction to the ARC that you want the dewatering stopped and the Resource Consent Permit cancelled. We can help you with everything else, including posting the Form to the ARC and sending a copy to Winstones. Please phone Corinne 625 7782, or Austen 625 9664, or Iain 625 8303. We have spare Submission Forms if you need one.

Our Committee have collated the following comments that are typical of what people are writing on their Submission Form. Please feel free to use any of them that help you with your submission.

The desired outcome I would like is that the commissioners cancel the Resource Consent.

We have no confidence in the ARC's ability to impose conditions in the future to avoid this happening again.

We feel insecure and feel that we cannot rely on the ARC to protect us from such massive risk to our property.

This is not good resource management practice to expose innocent residents to such huge risks.

Conditions should be that there is no further groundwater drawdown.

The whole Consent is a nullity. The Council should use its powers under the RMA to cancel the Consent.

It now turns out that the original Consent was based on information that was unreliable and possibly blatantly incorrect. How do we know that the new information is reliable.

Resource Consent conditions are there for the protection of the residents of the area, to safeguard them from adverse effects of the dewatering operations. Residents should be able to rely on such conditions. It now turns out that the conditions are meaningless because the zone of influence is much larger than Winstones claimed back in 1997.

How can the ARC assess the potential adverse effects? It tried to do this last time and assured everyone that the conditions were robust. It now appears that they were not and that more appropriate conditions are to be imposed. How will the ARC assure us that there will be no future risks; how can we have confidence in the ARC; and what happens if the ARC gets it wrong (again)?

We are a community in shock! This new revelation is hugely worrying to our community. Of course the Consent can be cancelled, and should be, because no amount of modeling can assure us that "more appropriate conditions" can be dreamt up.

No-one can accurately predict what is going to happen in the next twenty-seven years.

The value of the 8000 plus properties and the peace of mind of the residents, far outweighs the value of the scoria yet to be mined.

I would like the Council to stop the dewatering and pumping and to use its powers under the Resource Management Act to cancel the resource consent.

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