17 June 2025
A surfer on the Pakiri coast is dwarfed by McCallum Bros' sand mining vessel. Photo/ Doug Moores
Mangawhai sandspit has recently been confirmed to have lost more than 420,000 tonnes of its locally-unique non-replenishing sand. Local Democracy Reporting Northland reporter Susan Botting explores in a two-part series how those connected with the rare landform view its health and what is on the line. Today she explores tensions around sand mining.
A seabed sand mining company working off the Mangawhai-Pakiri coastline for more than 80 years is challenging critics who say the sandspit is being hit hard by its actions.
Scientists and local leaders have raised fears for the health of the Mangawhai sandspit as they say large amounts of sand have been lost over time.
McCallum Bros chief operating officer Shayne Elstob said as far as he was aware there was no presented evidence that showed sand extraction affected the sandspit.
Recent Mangawhai Harbour Restoration Society (MRHS) research showed 420,000 tonnes of sand have been lost from the sandspit in the past six years.
Mangawhai Harbour Restoration Society chair Peter Wethey. Photo / Susan Botting - LDR Northland
MHRS chair Peter Wethey said seabed sand mining had impacted the spit.
Dr Terry Hume, research lead coastal geomorphologist and former University of Auckland professor, said mining influenced the sandspit due to coastal processes such as wave action and seabed sand movement.
He said the quantity of sand lost from the spit was the equivalent of skimming 8cm of sand off the roughly 3 sq km land feature.
The Environment Court turned down a McCallum Bros sand mining consent application renewal last May.
In an agreement, McCallum Bros is allowed to continue sand mining in the Mangawhai-Pakiri embayment until May next year at the latest.
Elstob said the company had appealed that decision and would challenge it before the High Court later this year.
He said the High Court outcome would influence whether the company stopped sand mining in the embayment altogether.
The outcome of the Fast Tracking Act panel’s decision on the company’s sand mining consent application further north in Bream Bay would also influence its future embayment extraction.
Elstob challenged the March 2025 Mangawhai sandspit research, saying there were two different survey methods used in showing the sand loss.
Looking east across Mangawhai sandspit where sand from adjacent Mangawahi Harbour is piped onto prescribed locations under a formal Department of Conservation concession. Photo / Susan Botting - LDR Northland
“Until a repeat survey is undertaken using the same technology the volume stated should be treated with some caution.”
He said there had been agreement from all coastal process experts at the Environment Court hearing that extraction from the offshore zone - which was at least 2km from shore - “posed little to no risk” to the Mangawhai-Pakiri embayment.
Elstob said the company was currently mining in the embayment’s southern end, some distance from the sandspit. This was in Auckland Council’s jurisdiction. It had not mined in the northern Northland Regional Council (NRC) jurisdiction where Mangawhai sandspit was. “Our ongoing topographic monitoring of the coastline does cover half of the shoreline of the Mangawhai spit and we have not seen any changes to the shoreline that could be attributed to sand extraction. “Instead they have been related to some of the extreme storm events we have been having in recent times,” Elstob said.
NRC in 2021 warned the nationally important sandspit was at risk of erosion from seabed sand mining.
Kaipara District Council opposed Auckland Council extension of the activity’s consent at the same time.
Professor Mark Dickson, University of Auckland coastal geomorphologist, said seabed sand mining was among factors influencing the health of the Mangawhai sandspit in what was a “hotbed of coastal management considerations”.
Northland coastal engineer Andre LaBonte says Mangawhai sandspit’s health was regressing after almost three generations of adjacent seabed sand mining. LaBonte said the situation was serious. He said McCallum Bros seabed sand mining, which started in 1953, had seen the equivalent of roughly the sandspit itself above the high tide mark mined out of the Mangawhai-Pakiri embayment. “Mangawhai sandspit is not holding its own. It’s only thanks to the local community’s efforts that the situation is not worse,” LaBonte said.
Elstob said it was not balanced to solely blame McCallum Bros for any perceived failing sandspit health. There had been up to four operators extracting sand since 1953, a number of whom had had coastal permits to extract sand from the Mangawhai spit and entrance.
Researcher and former University of Auckland professor Terry Hume talks about Mangawhai sandspit to a recent community meeting in the coastal settlement. Photo / Susan Botting
Hume said the sand in the sandspit was linked to the beach and sea bed through coastal processes. He said the quantity of sand lost amounted to 1.8% of the spit’s total volume. Hume said he was most concerned about the loss further lowering existing surface depressions, making them more vulnerable to inundation from the sea.
Mangawhai resident and former Kaipara Deputy Mayor Richard Bull said ongoing seabed sandmining had undoubtedly impacted the landmark feature. “We used to look out over the spit and out to the Hen and Chicks from our home and only be able to see a tiny bit of the Pacific Ocean. Now we can see heaps, four times as much sea,” Bull said. Bull’s family sold the sandspit to the Government in the 1980s.
16 June 2025
Community groups, leaders and experts fear for the future of the Mangawhai sandspit. Photo / NZME
Mangawhai sandspit has recently been confirmed to have lost more than 420,000 tonnes of its locally-unique non-replenishing sand. Many in the community worry about its future as a result. Local Democracy Reporting Northland reporter Susan Botting explores in a two-part series the rare landform’s health and what is on the line. Today she dives into how those closely connected to the sandspit feel about its current state.
New Zealand’s fastest-growing coastal settlement risks a more than $100 million economic disaster if Mangawhai Sandspit fails, a community leader warns.The caution comes from community group Mangawhai Matters member Dr Phil McDermott, a former Massey professor of resource and environmental planning. He said a second breach of the sandspit where sea washed in from the Pacific Ocean would hit the economy on many fronts. McDermott was among a range of community leaders, councils, coastal experts and government organisations to raise their fears for the spit’s future. They have overwhelmingly given the spit’s health a bare pass of C report card, pointing to a range of reasons. Rising sea levels and intensifying storms are among the issues sounding warning bells. McDermott said the economic hit would be from plummeting property values and disappearing tourism. “There are so many pressures including significant development,” McDermott said. Mangawhai Matters successfully legally challenged unfettered Mangawhai development.
Mangawhai Matters’ Dr Phil McDermott. Photo / Susan Botting - LDR Northland
The sandspit breached in 1978 after a huge storm. The resulting 600m channel split the 3km long, 3sq km spit in half for more than a decade. The breach led to today’s main northern harbour entrance filling up with sand as Mangawhai Harbour discharged via a new exit point to the sea. Renegade action by the local community known as “the Big Dig” opened the channel. The blockage led to stagnating harbour water. House prices fell and properties weren’t selling. Banks in some cases did not want to provide mortgage lending. Work to close this gap finally started in 1991. Mangawhai sandspit is at the epicentre of competing tensions between seabed sand mining, local and central government bureaucracy, community groups, conservation, harbour health, mana whenua, population growth, tourism, recreation and development. Mangawhai Matters community group chair Doug Lloyd said surveying showed the harbour and sandspit were rated the most important feature of their local area. When Lloyd arrived in Mangawhai in 1989 there were about 600 people there. Now there are up to 20,000 over the summer peak. There are more than 2000 new houses on the cards in several big developments.
Mangawhai Harbour Restoration Society chair Peter Wethey. Photo / Susan Botting - LDR Northland
Mangawhai Harbour Restoration Society (MHRS)’s Peter Wethey chairs the community group credited by many as having had a key role in the spit surviving to the degree it has. The society runs New Zealand’s only dredging operation of its type, sucking up sand blown into the sea from Mangawhai Sandspit and putting it back on to the rare coastal landform.
Wethey said the dredging was about keeping the harbour’s ever-filling navigation channels open and protecting the spit with an about 800m long harbourside bund – effectively a man-made sand dune strip edging to protect it from future breaching. MHRS dredge operator Mark Vercoe said the process of sustainably delivering sand from the harbour floor to the prescribed location, that continued to strengthen spit protection, was an exacting one. Just over 5000 Kaipara District Council (KDC) Mangawhai Harbour catchment ratepayers contribute $80 annually towards the society for its work. Kaipara Mayor Craig Jepson said the money was well spent to protect the spit, echoing many in the community by saying the group had to navigate significant bureaucracy to do its work.
Kaipara District Council mayor Craig Jepson in Mangawhai. Photo / NZME
Northland Regional Council (NRC) governs consenting for the dredge’s sand extraction with up to 50,000 cubic metres of sand dredgings allowed annually. More recently that quantity was not fixed but instead dependent on location and dredging depth. Dredging must take place between April and December each year, depending on where it happens and the values of those locations – outside the fairy tern breeding season. DoC rules on where the dredgings can go on the spit. DoC acting operations manager – Whangārei Sarah Newman-Watt said the Mangawhai government wildlife refuge reserve was protected for its ecological significance, particularly for its critical nesting habitat for New Zealand’s fairy tern/tara-iti and northern dotterel.
DoC acting operations manager - Whangārei Sarah Newman-Watt. Photo / Supplied - Local Democracy Reporting Northland
She said the sandspit was the country’s largest tara-iti breeding site with fewer than 45 individuals left. Fairy Tern Trust convenor and Mangawhai property owner of three decades Heather Rogan said the spit was critical for the bird’s future. It was currently home to all but one of New Zealand’s tara-iti nesting sites.
University of Auckland coastal geomorphologist professor Mark Dickson at a recent Mangawhai meeting. Photo / Susan Botting - LDR Northland
University of Auckland coastal geomorphologist professor Dr Mark Dickson said it was about how well the spit would do its job of protecting the Mangawhai community. The work of the community was essential. Thousands of sand dune plants, kilometres of sand fencing to trap sand, pest control work and dredgings from the harbour going on to the sandspit towards maintaining its resilience are among this work. Dickson said the spit would undoubtedly breach again if left to its natural cycles without this community input. “The spit’s not quite holding its own. It requires quite a level of intervention,” Dickson said.
Save Our Sands spokesperson Ken Rawyard gave the spit a D health report card. He said DoC was prohibiting the re-establishment of critical vegetation cover on the spit because of concerns about the fairy tern. Newman-Watt said this was not the case. It was actively encouraging the re-establishment of appropriate dune vegetation where it supported the sandspit’s health and resilience and did not conflict with conservation goals. Fairy terns needed open shell patches with very little to no vegetation for nesting. “At known nesting sites, DoC removes or limits vegetation to preserve these rare habitat conditions,” Newman-Watts said. Mangawhai sandspit was a dynamic system that required careful, site-specific management.
NRC local coastal south councillor Rick Stolwerk acknowledged there were processes that needed to be navigated before dredging began. He said the spit was not faring as well as it could, but community members were doing great work.
Te Uri o Hau Environs representative Cindy Hempsall did not want to comment on Mangawhai sandspit.
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