Auckland  Regional  Council    -    Officers  Report    -    Review of the Dewatering at Three Kings Quarry

Section 4 of the Officers Report


The service of the Notice of Review and a summary of its contents was publicly notified on 21 May 2003 in accordance with Section 93 of the RMA. Submissions closed on 19 June 2003 and 574 submissions were received. 193 of these submitters asked to be heard at the hearing. A list of submitters is provided in Appendix D.

There was considerable support for the review being undertaken by the ARC. The majority of submissions did not support continued dewatering at Three Kings Quarry. There were 26 submissions which supported continued dewatering at the quarry. A number of submitters did not elaborate on reasons for their submission. The following is a list of the points raised by submitters. Because of the large number of submissions it is necessary to summarise the issues raised.

1.         Increased Zone of Dewatering and Settlement

A large number of submitters were concerned that the zone of dewatering is now predicted to be significantly larger than that predicted in the original application, and that ground settlement is occurring and is predicted to occur in areas where it was not identified previously.

2.         Cancellation of Consent

The majority of submitters asked for the consent to be cancelled and/or for the taking of water to cease. Several wanted groundwater to return to its natural levels. Many stated that they wanted the consent cancelled due to inaccuracies in the original application, and that new conditions will not provide enough certainty for landowners.

3.         Dewatering to Cease

As an alternative many submitters asked that dewatering (further lowering of the water table) should cease and/or the groundwater level should be maintained where it is now and no lower. Some submitters asked that the take quantity on the consent be reduced.

4.         Damage to Property

The major concern is damage to property, houses, services, and public buildings from subsidence/settlement. One submitter was worried about the stability of Big King. Several submitters were concerned that lives may be endangered. Comparisons were made by some submitters with Waihi and Huntly. Some submitters were worried about the effect on gardens and trees. One submitter was concerned about effects on historic buildings and stonewalls.

5.         Reported Damage

A small number of submitters reported potential damage to their property that could be related to ground or foundation movement. The submitters attributed this to ground settlement caused by the dewatering.

6.         Loss of Value

A major concern of submitters is the potential loss of property value. A number were concerned that Auckland City Council (ACC) would place comments regarding settlement on LIM reports and this would further add to loss of value.

7.         Insurance

Many submitters are concerned that their house insurance and the Earthquake and War Damages Commission does not cover damage to their properties from ground settlement caused by dewatering. Many asked who was responsible, and that there was a lack of an accountable agency. Others stated that Winstones and the ARC should be made more accountable. There was a general lack of confidence in the present Winstones insurance scheme. Some stated that Winstones should make good any damage or loss of value to property. It was suggested a fund should be set up to pay for any damage or other financial assurances should be put in place.

8.         Standard of Investigations

There was considerable concern about the standard and completeness of investigations undertaken on behalf of the Consent Holder. It was stated that the geological investigations were not complete or comprehensive enough. In particular, there is poor understanding of the Tauranga Group sediments. Many submitters stated that they had little confidence in the latest investigations, based on inaccuracies in the original application. Some submitters noted that groundwater drawdown and ground settlement calculations are not an exact science. Others stated that no further dewatering should occur until further, more comprehensive investigations, are undertaken. One submitter stated that there were two few ground settlement monitoring sites and that there were flaws in the statistical methodology in the analysis of such data. Several submitters noted that no baseline survey of all properties, in terms of a detailed structural analysis, has been undertaken. One submitter added that the walk-by survey’s undertaken to date were inadequate. Another submitter stated that the added effects of seismic activity had not been taken into account.

9.         Support for Dewatering

A number of submitters (26) supported the continuing dewatering of the quarry. These submitters were companies or individuals who used the scoria product from the quarry. They noted that scoria is a valuable product, for several construction purposes, and that it is becoming rare in the Auckland Region. It was also stated that there was an advantage in having this product close to the markets where it was used.

10.       The ARC has failed to look after the interests of the community, and it must look after its ratepayers. ACC is not representing its ratepayers as it should.

11.       Ground settlement should be within the bounds of seasonal soil movement. Any ground settlement is an adverse effect and there should be no settlement outside the quany boundary. There is already excessive subsidence occurring.

12.       A number of new residents in the area were concerned that they did not know about the dewatering when they bought their property and it was not listed on the LIM report.

13.       A number of submitters took issue with the statement in the Notice of Review that the consent duration could not be reviewed, because it could be cancelled under Section 132 of RMA.

14.       How will adverse effects be assessed in the future by the ARC? Many submitters were concerned that it is difficult to determine whether damage is caused by the exercise of the consent and that proving this was too onerous for residents.

15.       Transit NZ were concerned over potential effects on the 5H20 construction at Mt Roskill.

16.       Several submitters stated that there should be an extension in the timeframes for submissions. In addition, they asked that the ARC use Section 92 of RMA to require the consent holder to gather more data.

17.       One submitter did not want any reduction in groundwater level beneath their property at all. Others stated that dewatering should not occur in residential areas as the risks are too great.

18.       Winstones is doing a "pump and hope" ("suck-it-and-see") experiment which is unacceptable.

19.       New conditions should not be able to be changed without a public resource consent review. There should be opportunity for the public to make further submissions once further investigations are complete.

20.       The original decision did not have regard to Part II and section 104 of the RMA.

21.       What are the effects of the groundwater take (and hence increased dewatering zone) on groundwater flows, stream flows and springs.

22.       Current conditions do not adequately protect historic buildings and stonewalls.

23.       The ARC should take a conservative view, because a large number of residential properties are affected.

24.       Continued dewatering is contrary to the Air, Land and Water Regional Plan.

25.       Settlement could affect water tightness of homes.

26.       There were questions over the way survey data is reported.

27.       Fearon Park

One submitter lives adjacent to Fearon Park (on Fearon Rd) and has submitted that this is an area of fill which is vulnerable to settlement and where there have been settlement related issues in the past. Some houses have already been damaged by settlement in the past and may not take the same degree of further settlement that other houses might before they are damaged. The groundwater and settlement models are general and do not apply to sites such as this. This requires site specific investigations.

28.       The original consent was granted during the drought in the early 1990’s. Auckland is no longer short of water, with the advent of the Waikato pipeline, and no longer needs the Three Kings water for municipal supply. Submitters have suggested that because of the drought the ARC was pressured into granting the original consent.


A number of submissions are considered to be not relevant to this review. These are listed below. The reasons they are not relevant is discussed in Section 6 of this report.

1.         Submissions relating to the use of the water taken for drinking water.

2.         Water discharge to the stormwater system.

3.         Issues relating to dust and blasting.

4.         Issues relating to dust and noise from trucks.

5.         Submissions relating to the quarry in the city, close proximity to houses, the quarry not in keeping with the residential nature of the area.

6.         Issues relating to end use options for the quarry.

7.         Winstones left Lunn Ave because of residents concerns, why not Three Kings.

8.         How much is Winstones paying ACC and ARC to extract scoria from Three Kings Quarry?

9.         ARC should review conditions on all the Treatment Plant permits.

10.       1915 Auckland City Volcano legislation.


In addition to changes in consent conditions generally outlined above, a number of specific changes or additions to conditions were suggested by submitters.

1.         The area monitored for ground settlement should be expanded with more survey points in critical areas.

2.         Financial assurances need to be put in place to cover the cost of property damage should it occur.

3.         There should be no further dewatering (hold water level at 34 mRL) until further investigations are undertaken, including detailed geological surveys.

4.         There should be an annual review of the consent conditions.

5.         Monthly reporting of monitoring.

6.         Formation of an independent disputes tribtmal or similar.

7.         All properties in the zone should be surveyed (structural) and damage recorded for future claims.

8.         Requirement for Winstones to purchase properties of those who do not wish to stay in the area.

9.         Yearly peer reviewed summary of monitoring data.

10.       Staged dewatering (e.g. 3 months on, 6 month off).

11.       Update the existing inadequate Monitoring and Contingency Plan.

12.       Recommendations from the Tonkin and Taylor and Earthtech reports to be added to conditions.

13.       Condition requiring peer review of monitoring data, reporting regularly to ARC.

14.       Bond should be 20% of capital value of all properties, inflation adjusted, and be for a period of 20 years post dewatering.

15.       Reduce take quantity.

16.       A condition requiring Winstones to make good any damage.


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