Our eroding nation: Vanishing sand symbol of waste

SIMON COLLINS concludes his six-part series on the consequences for New Zealand of two centuries of environmental neglect.

Trees have been exposed under the disappearing sand at Pakiri Beach this year for the first time Greg McDonald can remember.

Mr McDonald, 39, is a member of the Ngati Wai people, who claim to have lived in the Pakiri area east of Wellsford for 600 years.

Although he grew up in Orakei and now lives mainly in Glen Innes, Auckland, he has been holidaying in a tree-shaded clump of family baches on the hapu's remaining 78ha of Pakiri land since he was a baby.

When the sand on the dunes is washed away - possibly a result of sandmining just offshore for Auckland's construction industry - Mr McDonald feels he has lost something he could have passed on to future generations.

"It's a finite resource, it's non-renewable."

That feeling is not unique to Maori. Many New Zealanders feel an emotional attachment to the land.

Yet we have not cared for it well. We have slashed our forests from 85 per cent of the land before humans arrived to 28 per cent today, compared with 67 per cent in Japan. We have thus allowed our soil to erode at 10 times the world average.

Through our cars and generally wasteful lifestyle, we have contributed to global warming, which is expected to intensify erosion on land and on the coasts via more storms and higher sea levels.

We have built seawalls which cut off our beaches from their natural supply of sand from dunes, and at places like Pakiri we have taken sand to use elsewhere.

We have done all this, of course, for good reasons - to earn a living from the land, to protect our homes, to provide raw materials for industry, and for our own convenience. If we aim to reduce erosion, that must be weighed up against all these objectives.

At Pakiri, about 2.3 million cubic metres of sand were extracted by dredges in the 33 years up to 1997 to make concrete, pipes, plaster and airport runways.

Kaipara Ltd (formerly Kaipara Excavators) has applied for a consent to take up to 2 million cubic metres more in the next 20 years, although this time it will come only from water that is at least 25m deep and at least 2km offshore.

A $1 million study found in 1999 that the miners were then taking sand from the beach at about five times the rate at which new sand was coming in from the ocean and from local rivers and cliffs.

It found that much of the sand in the region came originally from the Waikato River when it flowed into the Hauraki Gulf, from 220,000 to 65,000 years ago and again from 25,000 to 20,000 years ago.

"This is a finite resource because the Waikato River is not flowing this way any more," Mr McDonald says.

Even Waikato University's Professor Terry Healy, a consultant to Kaipara, says there is clear evidence of erosion all along the beach in the near-vertical edge of the dunes, fallen trees and exposed black sand. He says these effects will stop once the mining moves out beyond the 25m level.

In any case, the sand Kaipara wants is a mere 1.3 per cent of the sand available in the proposed 500sq km mining area between Pakiri and Little Barrier Island.

But Mr McDonald also has cultural concerns. He cites an attack by the Ngati Whatua on the Ngati Wai of Hauturu (Little Barrier) in the 1600s, when several Ngati Whatua waka were lost at sea.

"These people are on the sea floor, lying on the bottom."

The Ngati Wai Trust Board made a deal with Kaipara in 2001, dropping its objection to sand extraction in return for 50c for every cubic metre of sand extracted - a total of up to $1 million over the next 20 years.

Trust chairman Laly Haddon told the Environment Court that the trust opposed sand mining, but saw that it had no legal way to stop it.

But Mr McDonald says the trust was formed under "Pakeha" charitable trust law and does not represent all Ngati Wai people. He has appealed to the High Court against the Environment Court's decision to support a resource consent for offshore mining.

Balanced against his case is the value of using Pakiri sand elsewhere. Dr Healy inspected other offshore sand resources around Auckland and concluded that the area off Pakiri was the best available.

Jim Dahm of Coastline Consultants in Hamilton says there are better sites on land in the Waikato to get sand for concrete. He believes the offshore sand should be reserved for replenishing other beaches where sand is eroding, as was done at Mission Bay in 1997 and is proposed at a cost of $6 million for Kohimarama.

Dr Healy also sees a lot more beach replenishment in the future. He believes we should concentrate seaside development in a few towns where ratepayers could then afford to pay for sand infusions, rather than allowing people to build around the entire coastline.

"New Zealand has high stakes on its clean, green image. One reason tourists come here from the US, Asia and Europe is to see the wild, undeveloped coastline.

"If we allow houses to go everywhere, people will not want to come to New Zealand to see that. That is what has happened in Florida."

Like Pakiri sand, our land and coastline are non-renewable on any human timescale. We will need to handle pressures on them carefully, because future generations will have to live with the consequences of our actions.

Herald feature: Environment