A lagoon, an irrigation scheme . . . and a giant can of worms
A court decision involving an irrigation scheme has posed serious questions about Canterbury’s approach to improving water quality, and may have national implications. Ahead of an appeal, Charlie Mitchell examines the case, and the unusual lagoon at its centre.
At the end of its sojourn from the mountains to the sea, the Hakatere/Ashburton River makes a strange detour. Most rivers flow directly into the ocean. This one stops short. Its mouth is dragged around a kilometre up the coast – as though the river regrets coming to an end, and wants to turn back – before quietly dribbling into the sea.
This is called a hāpua - an unusual geological feature rarely found outside Canterbury. It is a freshwater lagoon that forms when a braided river collides with a sandy beach subject to longshore drift (where waves hit the shore at an angle).
Hāpua are a passageway for migrating fish and an important habitat for nesting birds. They have enormous ecological value - so much so that the Hakatere hāpua is proposed to become a wildlife sanctuary.
They are also sensitive to pollution, which is where this story starts.
The declining health of the Hakatere hāpua is central to an ongoing court battle, which has put the status of hundreds of farms in doubt.
Last month, the High Court ruled that a resource consent given to Ashburton Lyndhurst Irrigation (ALI) – a large co-operative irrigation scheme – must be set aside.
Environment Canterbury (ECan) said it would appeal the ruling,which it said could have “broad repercussions” regionally and nationally.
The context
The hāpua, like many rivers and streams on the Canterbury Plains, is degraded.
Because it pools at a river mouth, it absorbs much of the upstream pollution. Although some of its water quality measures have improved with better farming practices, one pollutant in particular – nitrogen – is an ongoing problem.
High nitrogen levels are terrible for aquatic life. Like fertiliser in a garden, nitrogen in water fuels algal growth that can smother the river, particularly during low flows. It can also suck oxygen out of the water.
This is bad news for fish. Surveys show the hāpua contains numerous fish species, including longfin eels, bullies, and galaxiidae. They are likely affected by their degraded habitat.
Although farming is not the only cause of the pollution, it is the primary one. Near the river’s headwaters, nitrogen concentrations are less than 0.1mg/L; near the river mouth, they are more than 10 times higher. Between those two points, the river is fed with groundwater affected by nitrogen discharges from surrounding dairy farms.
Dairy farming, meanwhile, has been an economic lifeline for the district and brought prosperity to the community.
It is enabled by irrigation, using water provided through schemes such as Ashburton Lyndhurst Irrigation (ALI). The farmer-owned co-operative supplies around 230 farms (mostly dairy, but some arable), together covering an area around 30,000ha, using water from the Rangitata River.
The scheme needs resource consents to operate. One of those is a discharge consent, allowing its farmer shareholders to release a contaminant where it could enter water (in this case, mostly nitrogen from cow urine).
The scheme was given a discharge consent in 2014, but had to reapply in 2019.
What the council did
This falls under ECan’s jurisdiction, so it appointed an independent hearings commissioner to consider the application.
The main issue at hand was the environment. Under the Resource Management Act (specifically, section 107) a discharge consent cannot be given if it would have “significant adverse effects on aquatic life”.
This was a problem. The area’s water quality has undeniably deteriorated, which is most obvious at the hāpua. Even ALI’s application acknowledged the impact of farming on nitrogen levels in the groundwater.
For the hearing, an ECan scientist produced an environmental report. It concluded the hāpua was in a “vulnerable state”, with nitrogen concentrations worse than national bottom lines.
“The hāpua is highly vulnerable to eutrophication and the ecological health of the Hakatere/Ashburton River is showing signs of decline,” it concluded.
The commissioner hearing the case acknowledged the environmental issues.
The 2014 consent had been granted on the basis it would “avoid significant adverse effects” and “mitigate adverse environmental effects”, she said.
“This has proven to be untrue and land use activities have resulted in significant adverse cumulative effects on water quality and ecological values,” she said.
So, game over?
Not quite.
After its initial application – which was met with scepticism by ECan’s scientists – ALI made a revision. What if it committed to substantially reduce its nitrogen discharges?
The co-op proposed reducing nitrogen discharges 10% by 2025, and 20% by 2030 (both from a 2020 base). This would go beyond regional requirements.
It wouldn’t be easy, ALI said. It would require every farm to earn A grades on their environmental audits by 2025, and A+s by 2030. There could certainly be no expansion of irrigation. But it would be a meaningful reduction in the source of nitrogen pollution, and demonstrate the willingness – and capability – of farmers to improve the environment.
This was a good compromise for ECan. Its job is to both regulate and restore the environment, while also supporting the regional economy – positions occasionally at odds.
Walking this tightrope has meant focusing on pragmatism. Rather than strict rules shutting down farms en masse, it wants measurable improvement over time. Farms making such improvements via enforceable resource consent conditions would tick that box.
There would still be some hitches to the plan.
Firstly, it wasn’t clear that reducing nitrogen discharges by that amount would definitely reduce nitrogen concentrations in the river and hāpua.
The way nitrogen gets into water is hideously complicated; it involves soil types, groundwater flows, climate, and a jumble of other factors. Basically, because some nitrogen is locked to the soil – “legacy
nitrogen” – it can take many years to enter water. It means the problem could get worse before it gets better, regardless of what the farms are doing.
Nevertheless, ECan’s scientists – who agreed it was “difficult to determine” if the proposed reductions would make a difference – said the situation could be monitored for 5 years, and if there was no improvement, stronger cuts could be required.
At the end of the hearings, the commissioner made her decision. ALI had acknowledged “the magnitude of the changes required”, and with the reduction provisions in place, the impact on aquatic life would be “monitored, reduced and with time remedied”.
The appeal
In Wellington, a charitable trust called the Environmental Lawyers Initiative (ELI) was looking for cases to take up.
The group challenges what it believes are legally flawed decisions involving the environment, and has taken legal action against central and local governments on issues such as marine bycatch and wetland protection.
This case stood out. The Resource Management Act (RMA) was clear: a discharge cannot have “significant adverse effects on aquatic life.”
The commissioner who granted the consent accepted this had already happened. How, then, could it be allowed to continue?
It filed a judicial review of the commissioner’s decision, which was heard by the High Court.
The group made three separate arguments:
❚ Councils cannot grant discharge
consents that would significantly
impact aquatic life.
❚ The commissioner did not consider coastal rules which include policies to “avoid” damage to indigenous biodiversity. Given the scheme’s impact on the hāpua, which is on the coast, this was an error.
❚ The application was significant enough to have been opened for wider public consultation.
The first argument was the most important, and also the simplest.
The law says you can’t grant consent if it has “significant adverse effects on aquatic life”.
The judge, in his ruling, noted how simple this seemed on its face. But he pointed out the commissioner had considered this problem – she had simply decided the provisions requiring nitrogen reductions would, over time, address the pollution.
The legal question was whether this was enough to get around the RMA’s seemingly clear requirement.
The second argument was less cut and dry.
Because there are national rules around coastal areas, the ELI said these needed to be considered by the commissioner, and they were not.
The reason was that none of the farms in the ALI scheme border the ocean - the closest is 17km inland. While the ELI argued coastal farms could theoretically join the scheme, the co-op said this was unlikely due to the make-up of its pipe network.
In the co-op’s view, it was not applying to discharge on or near the coast, so the coastal policies were irrelevant. ECan had also given regard to coastal policies when creating its plans, which this consent would fall under.
The legal question was whether the nitrogen coming from the farms upstream – which seeps into groundwater, feeds the river, and ends up in the hāpua – is, legally, impacting the coast.
The final argument concerned the consultation process. There were no public submissions; ECan was only required to consult one affected party, Te Rūnanga o Ngāi Tahu (which opposed the application).
The ELI said the case was of regional significance, and thus should have been open to wider comment.
The court
There was little doubt, in the end. The judge ruled conclusively in favour of the ELI on the first two arguments, but not the third.
He accepted the argument that, even if nitrogen reductions were required over time, the consent allowed current levels to continue.
“On the commissioner’s own findings, it appears indisputable there will likely be continuing significant adverse effects on aquatic life for the time being,” the ruling said.
On the second argument, he found the pollution upstream could not be separated from the impact downstream.
Given the commissioner knew about the “known existing deleterious effects on that area of the coastal environment” the farms had contributed to, not considering coastal policies was an error of law.
And so the consents were set aside.
What happens now?
The ruling is a dilemma for ECan.
“The Court’s interpretation of the RMA calls into question the framework we have developed with our mana whenua partner and communities over a long period to drive freshwater improvements,” said ECan chief executive Dr Stefanie Rixecker. “The High Court decision tells us that significant adverse effects must be immediately avoided at the time the consent is granted, which is very difficult to achieve.”
For that reason, the agency would be appealing the ruling, she said. “We have decided to appeal the decision because of its potentially wide impact – both in Canterbury and nationally – and it is important for us, consent applicants, and communities across New Zealand, that we have clarity and certainty.”
It has left the ALI’s farmers in limbo. The scheme will have to re-apply for resource consent, which – until an appeal is decided – would be heard in accordance to the court ruling.
So, too, would any other discharge consent applications coming before councils.
Following its success, the ELI has planned to review other discharge consents, including those granted by ECan.
“ELI’s win in this case raises serious questions about how ECan makes consent decisions relating to freshwater pollution,” said director of research and legal Matt Hall.
“ELI will be looking at other consents, both in Canterbury and around the country to check whether they have also breached the clear prohibition in section 107 of the RMA.”
“The ecological health of the Hakatere/Ashburton River is showing signs of decline.” ECan scientist’s environmental report