FAQs

1. Who are McCallum Bros. Ltd® (MBL)?

McCallum Bros Limited® (MBL) is a family-owned company that has been operating since 1904.

Based in Auckland, MBL forms part of the wider McCallum Group, which includes Clevedon Coast Oysters®, The McCallum Residence® in Clevedon, and Excelsior Poultry Grit.

MBL specialises in supplying the Auckland construction market with essential sand and quarried rock products, as well providing maritime and road bulk cargo transport services.

MBL has been extracting high-quality sand from the Mangawhai-Pākiri embayment for more than 75 years, which it primarily supplies to concrete manufacturers in the greater Auckland area.

2. What is the sand extracted from Mangawhai-Pākiri used for?

Sand is a critical building material and is essential to producing concrete. The sand extracted from the Mangawhai-Pākiri embayment supplies approximately 45 percent of the construction sand requirements for the Auckland region.

The sand extracted by MBL is essential for both Auckland’s infrastructure and housing development. It has been used in some of the city’s largest construction projects, most recently in the Waterview Tunnel, City Rail Link, the Central Wastewater Interceptor and the Newmarket Viaduct.

Pākiri sand extracted by MBL has also been used in the construction of the Sky Tower, the Auckland War Memorial Museum, the Harbour Bridge and numerous other infrastructure projects and landmark buildings in the greater Auckland region.

Outside of the construction industry, Pākiri sand is used for landscaping and industrial applications, sports field renovations, equestrian arenas and beach replenishments – including at Mission Bay, Kohimarama, St Heliers and Eastern Beach.

3. Are there alternatives to using sand to make concrete?

Concrete has been used in construction since it was first used in Ancient Rome.

Sand is critical to concrete production because it fills the voids between the aggregates used. This minimises the requirement for cement while maintaining the dimensional stability required to produce good quality concrete.

A typical mix of concrete is approximately 80-90 percent sand and aggregates.

4. What are manufactured sands and could they be used as a replacement for Pākiri sand?

Manufactured sands are made by crushing up quarry rock to a sand sized particle. Particle size can range from 6-7mm down to fines of 0.75mm.

Manufactured sands are currently being produced and sold as PAP type products. These products make up approximately 50 percent of the fines used in Auckland’s concrete, with the other 50 percent being natural sand such as Pākiri sand.

So, while manufactured sands are already being produced, quarries are running at capacity and cannot produce extra fines. This means there is an inability for quarries to make finer manufactured sand in adequate quantities to replace natural sands.

CO2 emissions are also increased using manufactured sands due to the energy expended to produced them as well as the increased amount of cement required to make comparable strength concrete as using Pākiri sand.

Internationally, demand for manufactured sand is mixed. The production of a fine manufactured sand is expensive and produces more ultra-fines which need to be removed and disposed of. In fact, the further crushing of PAP products to make a manufactured sand of similar particle size distribution to natural sand has been calculated to add another $14 per tonne.

5. What are the environmental and social costs from sourcing sand from alternative sources?

While there are alternative sources of sand available to replace Pākiri sand, using these sands comes at a higher environmental and social cost. This is because Pākiri sands are barged directly into the centre of Auckland and distributed and distributed efficiently to local concrete plants. This minimises truck and trailer movements on Auckland’s roads. In fact, there would be an estimated 22,000 extra truck and trailer movements on Auckland’s motorways if Pākiri sand was replaced with sources outside of Auckland.

Waikato sand also requires more cement to make comparable strength concrete to Pākiri sands, and this would result in increased CO2 emissions if these sands were used.

 

EXTRA TRUCKING KM’S

 

EXTRA CO2 EMISSIONS (Tonnes/annum)

KAIPARA HARBOUR 1,418,000 7,400
TOMARATA 2,138,000 11,200
WAIKATO 3,000,000 30,000

In addition to increased CO2 and trucking kilometres, there are other pollutants released into the environment from running trucks, including noxious gases, heavy metal residues from brakes. There are also increased social costs of having and extra 22,000 truck and trailer movements on the roads, including an increased risk of vehicle accidents causing deaths and injuries.

6. Has McCallum Bros Limited® consulted with iwi?

MBL have a long term relationship with iwi in the Mangawhai Pākiri Embayment, which has been ongoing for years.

As part of the Resource Consent process, MBL has:

  • reached out to 21 Marine and Coastal (Takutai Moana) Act applicants to get their input and comments on the application
  • undertaken direct consultation and engagement with:
    • Ngāti Manuhiri Settlement Trust
    • Te Uri o Hau Settlement Trust
    • Ngāti Wai Trust Board
  • Sought Cultural Impact Assessments from:
    • Ngāti Manuhiri Settlement Trust
    • Te Uri o Hau Settlement Trust

7. What consents are held at the Mangawhai-Pākiri embayment and who extracts from them?

There are two active coastal permits in operation in the Mangawhai-Pākiri embayment – an inshore permit owned and operated by MBL and an offshore permit, which was owned by Kaipara Ltd but was purchased by MBL in October 2021.

8. What are the volumes permitted to be extracted from the Mangawhai-Pākiri embayment?

On its inshore coastal permits extraction of up to 76,000 cubic metres of sand per annum.

The offshore coastal permit permits 150,000 cubic metres of sand to be extracted from between the 25 and 30m depth contours per annum, More sand can be extracted from deeper water. The offshore coastal permit is limited to a total of 2,000,000 cubic metres over the 20-year life of the consent.

9. How long has sand been extracted from the Mangawhai-Pākiri embayment?

Extraction activity has been taking place in the embayment for more than 75-years, since the first consent was granted to MBL in the 1940s.

As Auckland has grown and developed, so has its demand for sand. This has seen extraction activities increase over time.

When sand extraction volumes increased in the 1980’s, enhanced monitoring of the beach was implemented to ensure sand extraction was not causing coastal erosion on the beach or foreshore.

The Mangawhai-Pākiri Sand Study, the previous Environment Court findings for the inshore consent renewal, and recent work undertaken by both MBL and Kaipara Ltd have all concluded that sand extraction can continue in the embayment with little to no effect on the natural coastal processes occurring on the beach.

10. How much sand is McCallum Bros Ltd® extracting from the Mangawhai-Pākiri embayment?

In the last year, MBL has extracted approximately 200,000 cubic metres of sand across both coastal permits. This meets approximately 45% of construction sand requirements for the Auckland region. Some sand is also used in industrial, turf, landscape and equestrian applications.

11. What is unique about the sand in the Mangawhai-Pākiri embayment?

The marine sand in the Mangawhai-Pākiri embayment is amongst the highest quality sand available in New Zealand, providing several benefits to the construction market.

The sand has an ideal mineral content and particle shape and size, which means it can be used to produce very high-quality concrete for use in major infrastructure projects.

Pākiri sand also does not contain the alkali reactive compounds commonly found in sands from other parts of the upper North Island. These alkali compounds, which are the result of volcanic activity on the central plateau over millions of years, can weaken and shorten the life of concrete structures.

12. What happens if the Pākiri consents are not renewed?

If sand could no longer be extracted from the Mangawhai-Pākiri embayment, the construction market would suffer a supply shock.

Initially there wouldn’t be enough sand to keep infrastructure projects progressing. Longer-term supply could be sourced from other sites, but based on where this sand would have to come from, it would drive up the cost of concrete material and thereby projects and housing.

The ability to move sand quickly by barge greatly reduces transport and environmental costs and creates significant savings in greenhouse gas emissions by reducing the need for road transport.

If sand was to be sourced from alternative supplies, such as Kaipara Harbour or the Waikato, an extra 10,000 to 15,000 truck and trailer movements into Auckland would be required from locations either south or west of the city.

13. How much sand is in the Mangawhai-Pākiri embayment and is sand extraction sustainable?

The volume of sand in the Mangawhai-Pākiri embayment is enormous – estimated at between 1.7 and 3 billion cubic metres. Annually MBL proposes to extract ~0.01% of the lower total volume, but the actual figure is far less as there is “new” sand entering the system in greater volumes than is being extracted.

More importantly, the embayment is defined as a partially closed system. This means that new sand is continually entering the system via normal coastal processes, biogenic shell production and wave and current activity.

As a result of these natural processes, sand can continue to be sustainably extracted from the embayment with suitable consent conditions and appropriate monitoring.

Further information can be found in the report by Jacobs: Assessment of Effects on Coastal Processes – New Consent Area.

14. Has extraction activity had an effect on Pākiri Beach?

The Mangawhai-Pākiri Embayment is one of the most monitored beaches in the world, with it being subject to intense monitoring since the mid-1980s. During this period, no detrimental effect has been observed that is attributable to extraction activities.

Pākiri Beach is subject to a constant movement of sand on and off the beach. Storms, particularly in winter, wash sand off the beach and into the nearshore area, where it accumulates on the nearshore bar. During periods of calmer weather, the sand moves off the nearshore bar and accumulates back onto the beach and foredune area.

Aerial photos have found the beach has actually grown in the last 50 years as more sand washes onto the beach than is washed away. In fact, the sand dunes at Pākiri Beach have moved seawards by 22 metres (an average of 0.4m/year) during the past half-century, despite sand extraction taking place.

Further information can be found in the report by Jacobs: Assessment of Effects on Coastal Processes – New Consent Area.

15. What resource consents is McCallum Bros Limited® applying for?

MBL is applying for three consents to extract sand from the Mangawhai-Pākiri embayment but intends to only operate under two consents.

The first consent is the application for a new consent to replace the current offshore consent that has, until recently, been owned by Kaipara Ltd. Kaipara Ltd started this application for a replacement offshore consent in 2018 and the application is currently being considered following a hearing before Commissioners. MBL purchased the offshore consent from Kaipara Ltd in October 2021 and is taken responsibility for completing the consenting process. MBL is not planning to materially change the application that has been made and has picked up the application in its entirety.

If granted, this new offshore  permit would allow 150,000 cubic metres of sand to be extracted from between the 25m and 40m depth contours per annum. More sand can be extracted from deeper water. Extraction would be limited to a total of 2 million cubic metres over the 20-year life of the permit.

The second consent application is for the renewal of the current inshore consent to allow for business continuity. This consent permits the extraction of up to 76,000 cubic metres of sand per annum from the inshore area, at depths of between 5 – 10m between the Auckland/Northland regional boundary and Poutawa Stream, south of Te Arai Point.

The third consent application proposes extraction activity be shifted  to a new area further offshore. This application, known as the mid shore application, was made following consultation with interest groups who preferred sand extraction to occur further offshore than the current inshore consented area.

If granted, this mid shore consent would allow MBL to extract an average of 125,000 cubic metres of sand from the15-25 metres water depth. The larger extraction volume would only increase in stages after monitoring showed no detrimental effects.

This consent would also operate between the Auckland/Northland regional boundary and Poutawa Stream.

If the new mid shore consent should be granted, MBL would surrender the current inshore consent it operates on and rescind the renewal application that is with Auckland Council at the moment.

For absolutely clarity, MBL is only seeking to operate under two consents – the offshore consent and either the mid shore or the inshore consent.

16. What period has McCallum Bros Limited® applied for resource consent?

MBL has applied for 35-year consent terms in both the renewal of the inshore consent and the new mid shore application. The application for the offshore consent is for 20-years.

MBL is only seeking to operate under two consents – the offshore consent and either the mid shore or the inshore consent.

It is important that the construction industry has a surety of supply. The granting of a long-term consent provides the Auckland construction industry with the necessary confidence that they will continue to have an ongoing and reliable supply of sand to produce the concrete needed to support continue infrastructure development required by a growing city.

17. Why are McCallum Bros Ltd® seeking to extract an increased volume of sand with the new mid shore consent?

As the upper North Island continues to grow and develop, the demand from the construction industry for sand is forecast to increase dramatically.

For example, Auckland is expected to see significant levels of population and household growth in the coming decades – with estimations of between 9,000 and 13,000 new dwellings being required every year. Increasing volumes of concrete will not only be required for these homes, but for roads, sewerage and water pipes, and public transport infrastructure.

The increased volume of sand able to be extracted from the new resource consent will help meet this demand and ensure the construction industry can continue to support the upper North Island’s growth.

Intensive surveying and research since the last century indicate that there is a substantial volume of sand accumulating in the Pākiri Mangawhai system, some of which can be extracted without causing detrimental effects on the system. Extraction volumes will only increased in conjunction with monitoring to ensure there are no negative effects on the environment.

18. Will the resource consent be publicly notified?

MBL understands that there is a high-level of community interest in its extraction operations and is committed to providing as much information as possible throughout this consenting process.

The application for a new offshore consent, which was started by Kaipara Ltd, was publicly notified. The hearing, at this point, has one final day to run while the commissioners wait for results regarding bathymetry work asked for. Once this has been completed the commissioners will be able to consider the application in its entirety on the evidence presented.

MBL has requested a public notification of the new mid shore consent application because this consent would see extraction activity occurring in a new location in the embayment. For that reason, MBL strongly believes it is important the community has the opportunity to hear the evidence and to make a submission.

In its application to renew the inshore consent, MBL sought limited notification for the renewal of the existing consent. This was because extraction activity has been occurring in that location for more than 75-years, there were no material changes proposed, and the issue has been closely examined in the past by the Courts and found to be sustainable.

However, Auckland Council has determined that this consent should be publicly notified and MBL will abide by the Council’s decision.

19. How do the McCallum Bros Ltd® resource consents link to the Kaipara Ltd consent application that is currently being considered?

Kaipara Ltd is a separate company that held a separate consent to extract sand in the Mangawhai-Pākiri embayment. A new offshore consent is currently being considered.

The offshore consent, which was originally granted in 2003, allows for the extraction of 2 million cubic metres of sand over a 20-year period, in depths of greater than 25 metre water depth.

In 2006, MBL and Kaipara Ltd signed an agreement where MBL operated the consent and distributed the sand. Kaipara were responsible for administration of the consent and liaison with Auckland Council.

In October 2021, Kaipara Ltd sold this consent to MBL. As part of this agreement, MBL has assumed responsibility for finalising the new offshore consent.

20. Why did MBL purchase the offshore consent and application owned by Kaipara Ltd?

MBL has had an agreement in place with Kaipara Ltd since 2006 as the sole operator and extractor of sand from the offshore permit. That agreement allowed MBL to extract sand under licence from Kaipara and then distribute and sell it to its client base. The extraction, distribution and sale of sand, as well as associated products, is a core part of MBLs business so the purchase of the existing consent and application was a simple decision for the business.

21. Why didn't MBL purchase the Kaipara consent earlier?

Kaipara had never offered to sell the existing consent to MBL, so the opportunity had not arisen.

22. Why wait until now to undertake the purchase, and what does it involve?

Kaipara Ltd made the application for the new consent in 2018. As the application went to Hearing, there has been a pandemic and a significant market boom that has had a major impact on suppliers to the construction industry.

Due to significant growth in their quarrying and associated businesses, Kaipara made a decision to concentrate their efforts and investment in those areas, rather than spending time and effort on a part of their business that wasn’t critical to their strategies into the future. They did not see sand extraction as a key part of their business and subsequently made a decision to offer that to MBL, who they knew had significant interests in the consents.

The sale and purchase is made up of two parts. The existing Coastal Permit, which expires in November 2023, or when 2 million cubic metres is extracted, as well as the current application being processed by Auckland Council and being heard at the moment.

23. Does anything change in the current consent?

No, the purchase of the existing consent is a simple transferral of all the rights and obligations of the current consent. There is no change to the volume limit on the consent of a maximum of 2,000,000 cubic metres or its expiry date in November 2023.

The current consent will expire when either the volume or time trigger is reached, whichever is soonest.

24. Does anything change in the application?

MBL will continue with the application in its entirety, which is still waiting on a final day to be heard.

25. Does the sale of the offshore permit and application by Kaipara Ltd indicate that they do not have confidence that it will be granted?

The simple decision Kaipara made was that the owning of a sand extraction permit was not in line with their company direction or interests in the short or long term.

We believe the evidence presented shows that sand can continue to be extracted from the Mangawhai-Pākiri embayment sustainably and with minimal environmental and ecological impact, and we remain positive that a Coastal Permit can be granted with corresponding conditions that would allow ongoing extraction to take place in the embayment.

26. Will MBL continue to pursue their nearshore consent and mid shore applications now that they own this consent?

MBL is currently going through the public notification process for both its nearshore permit renewal plus the new application for a mid shore coastal permit. Unfortunately, the offshore sand alone as a resource is not a complete solution for the market requirements.

The sand from these two areas is different to the offshore sand, and is provided to different customers. These customers cannot take the offshore sand either due to its coarseness, shell content or colouration.

Inshore Sand                                                                    Offshore Sand 

27. What is the environmental impact of the extraction activity?

MBL has worked hard, and invested heavily, to minimise the impact of its activities on the environment.

This includes commissioning extensive research from a range of specialists and leading experts to understand the ecological, noise and coastal impact of sand extraction in the embayment. These studies have all concluded that sand extraction in the Mangawhai-Pākiri embayment is sustainable and has a less than minor impact on the environment.

MBL has also invested heavily in new technology, including a purpose-built and state-of-the-art vessel, the William Fraser.

Built in 2019 to MBL design specifications, the William Fraser has a number of features which reduces the impact of extraction on the environment and other users in the embayment. Technology on board has permitted the safe use of the vessel at night, allowing extraction to now take place predominantly at night between the hours of 8pm and 3am. This significantly reduces the visual impact of the vessel as well as reducing the impact on recreational users of the embayment.

Other features of the vessel that reduce environmental impact are an electric driven pump to reduce underwater noise and eliminate the risk of oil spills, moon pools to direct all discharges at keel level below the vessel, a wide drag head to reduce the depth of extraction, and engines within a soundproofed superstructure to reduce terrestrial noise as much as possible.

All of these features reduce sediment plumes, increase survivability of biota passing through the pump, reduce the distance that underwater and terrestrial noise can be heard and reduce the chance of contaminants being able to enter the coastal marine area.

28. How close does McCallum Bros Ltd® operate to the beach?

MBL’s current consent requires sand to be extracted in depths of between 5 – 10m water depth.

Due to the wording of the consent conditions, the exact distance from the beach while extraction occurs can vary significantly and is dependent on the location of the nearshore bar and the depth where extraction is occurring. This can vary significantly based on the tide and recent storm activity in the embayment. However, extraction normally occurs at least 500m from shore.

MBL takes its consent obligations extremely seriously and takes a great deal of care to ensure it only ever extracts sand from the areas where it is permitted to do so.

The extraction vessel, the William Fraser, is fitted with the latest European technology to record the exact location of all extraction activity. This includes the highly sophisticated Marine Navigation System (MAXSea), which accurately records the location of the ship when the extraction activity is being undertaken.

These records are provided to Auckland Council regularly.

29. Why does McCallum Bros Ltd® extract sand during the night?

MBL is absolutely committed to minimising the impact of its activities on the local community, and this includes reducing the visual impact as well as the impact on recreational users.

The Mangawhai-Pākiri embayment is an area of high natural beauty and MBL wants the community to enjoy the visual and recreational aspects of the area. For that reason, it limits extraction activities to night-time hours wherever possible.

This provides some added benefits, including reducing the number of birds who are attracted to the vessel while it is operating. Nights also tend to provide calmer ocean conditions, meaning personnel are less affected by weather patterns.

30. Does the extraction activity damage the seafloor?

The Mangawhai-Pākiri embayment is an open coastal environment that is exposed to heavy storm and sea activity at times. Due to this, the seafloor is highly mobile. Animals living in this environment are used to significant changes and are generally very robust and accustomed to disturbance.

Independent research commissioned by MBL found that sand extraction is having a less than minor impact on benthic burrowing and surface species, as well as fish and other species living or passing through the embayment.

The most significant possible impact is caused by the drag head, which extracts a furrow approximately 1.5m wide and between 80 and 100mm deep. Many burrowing species were, however, were found to not be picked up at that dredge depth. Those species that were picked up were typically very robust and survived passing through the dredge equipment before being returned to the seafloor with minimal harm.

Species such as fish were found to likely move out of the way and were not found to be picked up by the drag head.

Given the highly mobile nature of the embayment, where new sand enters the system and large volumes of sand circulate, the seafloor can recover in as little as 12 hours. In an average swell, the furrow is difficult to locate after one day in depths of less than 15m.

For further information, please refer to the Bioresearches reports: Assessment of Ecological Effects: For Sand Extraction from the Pakiri Extraction Areas February 2019 and Assessment of Ecological Effects: For Sand Extraction from Midshore Pakiri Embayment.

31. Does sand extraction contribute to coastal erosion?

Independent research commissioned by MBL, as well as the required monitoring, has analysed this closely and found that the effects of sand extraction on coastal processes and erosion is less than minor.

While it is acknowledged that erosion does occur during storm events, just like at any beach in the country, the evidence also shows the sand is quickly replaced indicating that there is no long-term erosion.

Aerial photography survey results, and related studies, over the last 50 years have also found that the shoreline has been growing at an average of 0.4m per year as new sand enters the system, further indicating that sand extraction is occurring at sustainable levels and is not contributing to coastal erosion.

32. What impact is the extraction activity having on recreational fishing?

As part of the resource consent process, MBL commissioned independent research from some of New Zealand’s leading research and science companies to understand the impact of its extraction activities on the local environment.

The research found that sand extraction was having no discernible impact on any fish species in the embayment. Fish are not entrained during the process of extraction and were expected to move away from the drag head as it moved across the seafloor.

It is possible some fish species actually benefit from extraction due to the occasional exposure of worms or shellfish, which they can opportunistically eat. The food source of recreational fish species was also found not to be significantly different between extraction and non-extraction areas.

Another possible impact on recreational fishing in the area is the presence of the vessel operating while fishers are using the bay. This is reduced significantly by the vessel operating during the hours of darkness, when use of the embayment is at its lowest.

Based on this, no impact on recreational fishers using the embayment is anticipated.

For further information, please refer to the Bioresearches reports: Assessment of Ecological Effects: For Sand Extraction from the Pakiri Extraction Areas February 2019 and Assessment of Ecological Effects: For Sand Extraction from Midshore Pakiri Embayment.

33. What is the impact on marine life?

As part of the resource consent process, MBL commissioned independent research from some of New Zealand’s leading research and science companies to understand the impact of extraction activities on the local environment.

This research found current sand extraction activities in the embayment are having no discernible ecological effects on the seabed environment, or on fish, birds or marine mammals.

Marine mammals are not permanent residents of the embayment and any transiting the area were likely to avoid the immediate area where extraction has occurred. There are many cases, however, were both dolphins and seals have approached the vessel to investigate what is happening and have been seen hunting fish that may be following the vessel. The effects of underwater noise were considered to be less than minor, and this is largely attributed to the use of a modern electric driven pump.

Fish were also found to be largely unaffected. Any fish in the area were found to avoid the drag head but were sometimes found to come close to the vessel and feed on the oversized material being returned to the water.

Birds were found to be attracted to the vessel when it was extracting during the day looking for food. Extraction at night greatly reduces the number of birds present around the vessel, but it does increase the risk of some species (such as Petrels) interacting with the vessel lighting. For that reason, minimal lighting is used and reduced to only what is required for navigational purposes and safe operation of the vessel while extraction is occurring. Extra lighting required is yellow in colour and downward facing to minimise risk to sea birds and light pollution in general.

Crabs, cockles and snails were found to have survivability rates greater than 80% if they were entrained through the extraction process.

Worms are more vulnerable due to not having a shell for protection, but it was found many retracted into their burrows and were not entrained by the draghead. Research in the embayment found that worm populations in extracted areas were similar to those in control areas, indicating that the extraction activity was having no significant impact on them.

For further information, please refer to the Bioresearches reports: Assessment of Ecological Effects: For Sand Extraction from the Pakiri Extraction Areas February 2019 and Assessment of Ecological Effects: For Sand Extraction from Midshore Pakiri Embayment.

34. Does McCallum Bros Ltd® pay for the sand that is extracted?

MBL currently pays a royalty to the government for the sand it extracts. The royalty rate, which is set by the Crown Minerals Act requires a payment of $1.70 per cubic metre of sand extracted.

35. Why can’t sand be extracted from other locations?

The Mangawhai-Pākiri embayment is the most environmentally sustainable source for sand due to the large volume of sand available, its quality and the proximity to Auckland.

Sand from the embayment can be easily barged to central Auckland where it can be distributed to local concrete manufacturers in the most emission friendly manner.

Sand of similar quality and volume can be found in the Kaipara Harbour, but this cannot be easily shipped to Auckland without going around Cape Reinga at enormous cost and time.

Instead, if the sand was extracted from the Kaipara, it would need to be trucked to Auckland from Helensville. Given Auckland’s sand demands and construction needs, this would see 21,000 return truck and trailer movements every year on the North-western motorway, resulting in increased congestion and an extra 1,340 tonnes of CO2 emissions in the atmosphere.

Because sand is a high-mass, low-value product, it is expensive to transport long distances via the road network. This means construction costs would need to increase as concrete prices rose to adjust for the increased transportation costs. Economic research has found that using the Kaipara to meet Auckland’s sand requirements would cost an extra $132 million in transport costs over 20 years.

Most sands south of Auckland are unsuitable for major civil engineering projects because they contain large volumes of volcanic material from the central plateau. This can impact the quality of the concrete produced.

Sourcing the sand south of Auckland would also add substantial truck and trailer movements to the already congested Auckland motorway network, resulting in a substantial increase in carbon dioxide emissions.

For further information, refer to the report by M.E Consulting The Economic Contribution and Impact of Pakiri Sand Extraction.

36. Why hasn't MBL started extraction on the Kaipara Ebb Tide Delta, which it applied for in 2006?

MBL did apply for consent to extract sand in 2006 from the outside of the Kaipara Harbour on the Ebb Tide Delta. Due to a number of commercial and operational issues involved in working on the west coast of New Zealand it abandoned these plans and withdrew the application.

These factors included, but weren’t limited to, the lesser available extraction days meaning getting sufficient volume for the market was difficult, having to work across at least one bar crossing to get to an unloading port, having no vessel capable of consistently working that coast and losing a significant customer as a partner in the project.

37. How much concrete is made from the sand extracted from the Mangawhai-Pākiri embayment?

Currently Auckland produces about 1.8 million cubic metres of pre-cast and ready-mix concrete. This requires approximately 790,000 tonnes of sand on an annual basis.

MBL supplies at least 45% of that volume, which equates to 780,000 cubic metres of concrete. Much of this concrete is used in high strength infrastructural projects.

On top of that, there is demand for at least another 200,000 tonnes of sand for the industrial, landscape, turf and equestrian markets in the Auckland Region.

Current projections for Auckland growth are conservative, with demand outstripping supply in the housing and commercial property sectors. Governmental stimulus and funding of large infrastructure projects is continuing to drive demand for sand, which has seen double digit growth for the last several years – well beyond the 2.5% high growth models originally put forward by Auckland Council in their Unitary Plan.

In fact, given Auckland’s current housing shortage, infrastructure needs, and growth forecasts provided in the Auckland Unitary Plan, it is estimated that demand for sand is likely to increase by at least 40% when conservative growth figures are used. Based on growth in the last two years at 6%, it is expected to almost triple to as much as 2.8 million cubic metres by 2043.

38. What would the impact be if sand extraction was stopped at Mangawhai-Pākiri embayment?

Failure to obtain resource consent for sand extraction in the Mangawhai-Pākiri embayment would lead to a significant supply shock to the Auckland construction market, driving up the cost of concrete materials and likely result in the delay of new infrastructure and housing developments while an alternative source of sand were secured.

It is likely that extraction activities would need to shift to the Kaipara Harbour, which also contains large volumes of high-quality marine sand. This sand, however, cannot be moved as efficiently to Auckland. It would have to be trucked to the city, resulting in tens of thousands of additional truck movements along the already congested North-Western motorway, as well as increased carbon emissions.

The higher cost of transporting sand from Kaipara would likely see concrete prices increase as concrete manufacturers had no choice but to pass on the costs they incur for the sand, further increasing the cost of building and infrastructure development. In fact, it is estimated supplying all of Auckland’s sand requirements from the Kaipara Harbour would add an additional $132 million in direct transport costs alone over 20 years.

39. What companies does McCallum Bros supply?

Sand extracted from the Mangawhai-Pākiri embayment is shipped down to the Ports of Auckland where it is distributed to a number of concrete manufacturers in the region, including Allied Concrete, Bridgeman Concrete, Counties Concrete, Hynds Pipes and Wilson Tunnelling.

The concrete produced from Pākiri sand has been used in some of Auckland’s largest and most iconic infrastructure projects, including the Sky Tower, Waterview Tunnel, Newmarket Viaduct, Auckland War Memorial Museum, the Central Wastewater Interceptor and the Auckland Harbour Bridge.

40. Is the sand extracted directly off the beach?

No. MBL has never extracted off the beach.

The current nearshore extraction permit does not allow sand to be extracted at less than 5 m water depth or 100m seaward from the crest of the nearshore bar.

As the nearshore bar moves, it can make it difficult to ascertain distance from the shore and as vessels have got bigger over time, they can look closer than they really are.

That is one of the reasons why MBL has proposed to move further offshore in its new consent application, and to have precise co-ordinates to define the extraction limits. That way, it can provide increased transparency in its operating limits to the Council and the public.

41. How does sand extraction at Pākiri compare to iron sand mining?

The extraction of mineral or iron sand off the Taranaki Coast has been compared to extraction at Pākiri, but in reality the two are very different.

Trans-Tasman Resources (TTR) applied to extract 27,000,000 cubic metres of iron sand annually from an area of 5 sq km for a period of 35 years off the Taranaki Coast offshore at Patea. This is a mining practice with much larger volumes extracted, processed and returned to the seabed over a smaller area than Pākiri.

42. How do the extraction volumes compare between the TTR application and the Pākiri application?

Total extraction applied for the preferred option of the mid-shore and offshore applications at Pākiri is 275,000 cubic metres per annum. Extraction volume on the TTR application is 27,000,000 cubic metres per annum. Of that 2,700,000 cubic metres of processed iron ore would be kept and 24,300,000 cubic metres would be returned to the seafloor.

On an annual or total extracted volume basis, Pākiri is approximately 1% of the volume won on the Taranaki coastline. Importantly, sand extraction at Pākiri also receives inputs from coastal processes, so the sand is replenished.