Water, water - everywhere? Concerns for the Aupōuri aquifer

Will avocados be the death of the Aupōuri aquifer? Picture / File

They might not all be familiar with Samuel Taylor Coleridge's Rime of the Ancient Mariner, and specifically the lines Water, water everywhere/Nor any drop to drink.

But plenty of people are worried by applications to take up to six million cubic metres and more of water from the Aupōuri aquifer on top of what is already being taken, and the more than two million cubic metres granted to the Motutangi-Waiharara Water Users' Group last year.

Those figures, of course, are maximums. Those granted consents might not take any water at all in a wet year, and however dry it gets may take no more than they are permitted to, but dry years, when they do need to pump water out of the ground, will presumably be years in which recharging of the aquifer is at its lowest.

Therein lies the rub for many. No one really seems to know how the aquifer is recharged, where water enters the aquifer and at what rate, or how much can be taken before it dries up, or worse, pressure within the aquifer reduces to where sea water is drawn into it. If, or when, that happens, one imagines that the aquifer will be tainted for all time, whether it is needed to grow avocados or simply to make a cup of tea.

If the climate change science is settled, and that's still a moot point for some, then the science applying to the Aupōuri aquifer certainly is not, at least as far as the Environment Court is concerned. Earlier this year the court found in favour of the MWWUG's 17 applications, but with a strong note of caution. It ruled that consents should be granted on a staged basis over nine years, starting with 25 per cent of the quantities requested. If at any stage the aquifer was to show signs of distress, it said, the take should reduce to the previous staged quantity, and if distress persisted, the consents could be withdrawn.

The question, surely, is whether any signs of distress, presumably drying up or salt water intrusion, would be discovered before they became irreversible. That would demand much greater faith in the 'experts' than many people on the Aupōuri Peninsula are able to muster. The consensus seems to be that once damage is noticed, the aquifer will have passed the point of no return.

And don't forget that the Far North District Council has a consent to take around 1.7 million cubic metres a year at Sweetwater, at the southern end of the aquifer, to secure Kaitaia's reticulated water supply. That consent doesn't seem likely to be taken up any time soon, but who knows? One day the council might get its act together sufficiently to actually start drawing the water it has been told it is allowed to take.

The writer doesn't know whether extraction at Sweetwater would affect the aquifer further north, but neither does anyone else. When the council's single test bore was turned on some years ago it was reported that a number of private bores to the north dried up, and that was simply a test, involving a relatively minuscule amount of water.

The writer has absolutely no knowledge whatsoever regarding how aquifers behave, or the specific dynamics of the Aupōuri aquifer, but those who claim to know what they are talking about don't seem to have all the answers either. No one seems to know how much water is in there or the extent to which the water has simply been stored, possibly over tens of thousands of years, and is therefore a finite resource.

It should be deeply concerning that the Environment Court has allowed for the possibility that it is a finite resource, and has been moved to warn that taking water from it could one day have a calamitous impact.

The worst that could happen, perhaps, is that private bore owners will have to depend on rainfall for their water supplies, and the burgeoning avocado industry will prove to be a flash in the pan. Those who have invested huge sums of money in an industry that demands more water than can be provided by rainfall alone are presumably prepared to take that risk, but it's a bit rich to expect everyone else who lives on the peninsula to accept the possibility of it turning into a desert with equanimity. Not to mention those whose concern for the environment generally trumps the potential of the avocado industry to generate jobs and income.

Meanwhile Far North District Council has been called upon by the Pukenui-Houhora Residents' Association to stand by the community, somewhat ironically given that it too plans to draw from the aquifer at some point, to safeguard the aquifer, as required under the Pukenui-Houhora Community Development Plan, submitted at the council's request in 2011.

The council, obviously, has a keen interest in creating an environment that encourages people to invest in the district, and contribute to its financial prosperity, so on the one hand it should be keen to see ever more avocado trees planted on the peninsula. It also has a duty, however, to protect the environment, and given what the association fairly describes as "soft" data in terms of the health of the aquifer, it must be wary of allowing continued extraction, especially in light of the Environment Court's concerns.

The council has a tough decision to make; sitting on the fence shouldn't be an option, but the writer has a dollar to say that is what it will do. What's the bet that it will leave it up to the NRC's independent commissioners, and eventually the Environment Court?

The association has also, quite fairly, expressed concerns about the manner in which the Northland Regional Council has chosen a limited notification process, open only to a specific geographical area, and then only to those who currently take water from bores or surface water bodies, some seven months after the applications were made, and giving the ordinary folk from Waihopo to Ahipara less than one calendar month to submit. The NRC might not be actively attempting to stifle objections, as it stands accused of doing by the association, but, wittingly or otherwise, it does seem to be making the process easier for the applicants than it might otherwise be.

The NRC and the Environment Court are certainly at odds in terms of the potential impact of further extraction, the former taking the view that impacts would be no more than minor, albeit allowing for further research and monitoring, while the latter said earlier this year that it really didn't know what the impacts of the MWWUG consents might be. We will all know one day, if the latest applications are granted. And if they turn out to be more than minor, will it be be too late to do anything about them?

And if these consents are granted, will they be the last? Will those who need water for whatever purpose be allowed to keep taking it until it runs out or turns brackish? And if either of those outcomes eventuate, will withdrawing the consents enable the aquifer to recover? Who knows?

There seems to be a great deal that we don't know, which, to the layman, doesn't seem to be a great starting point for making decisions. Surely, at the very least we should understand how the aquifer works before we allow its intensified exploitation. Guessing isn't good enough, but that seems to be what we have done in the past, and might well continue to do in the future.