Mega-irrigation schemes back to court, as Canterbury water wars heat up

Sunday, 19 January 2025

The contentious issue of mega-irrigation schemes on the Canterbury Plains is heading back to court, as environmental lawyers challenge a second council decision.

The fresh case will centre on the threat of nitrogen polluting drinking water supplies.

Environment Canterbury (ECan) lost a landmark legal challenge last year, when the High Court found it unlawfully granted a resource consent to allow the discharge of nitrogen and other contaminants from irrigated dairy land between the Hakatere/Ashburton and Rakaia rivers.

It was a watershed case that recognised and reinforced environmental bottom lines that were written into the 1991 Resource Management Act but not consistently enforced.

But, bowing to pressure from big farm lobby groups and local government, who argued it would stymie the industry with too many regulatory roadblocks, ministers swiftly amended the legislation as part of the Government’s rewrite of the Resource Management Act (RMA).

Undeterred, advocacy group Environmental Law Initiative (ELI) are now challenging a second pollution discharge consent granted by ECan in 2018.

That permits MHV Water to discharge nitrogen and other contaminants over 138,000ha of land between the Hakatere/Ashburton and Rangitata Rivers, within the Upper and Lower Hinds/Hekeao Plains Areas.

The Mayfield-Hinds-Valetta irrigation scheme delivers water to just over 200 shareholders. Water from the the Rangitata Diversion Race is delivered to farms via around 320km of open race and 100km of pipes.

As with the earlier case, fought over the Ashburton Lyndhurst Irrigation Ltd (ALIL) irrigation scheme, ELI argues ECan erred in granting the consent by contravening Section 107 of the RMA.

That prohibits consents that are likely to result in significant adverse effects on aquatic life.

Both ALIL and MHV’s discharge was previously managed under a joint consent, but they applied for separate consents in 2018.

They were both granted by commissioner Sharon McGarry, in separate decisions, in 2021.

In both cases she noted that nitrogen discharges from farming practices, including cattle manure, fertilisers, and dairy shed effluent, had caused serious adverse effects on aquatic life.

However, the consent was granted because ALIL and MHV both gave commitments to staged nitrogen reductions.

In MHV’s case, farmers were bound to a strict set of requirements, including a 15% reduction in nitrogen losses by 2025, and 25% by 2030. At the time, its nitrogen losses were estimated to be around 16 tonnes a day.

The High Court quashed the consent granted to ALIL, which had allowed, over a decade, the use of synthetic nitrogen fertiliser in a 177,000ha area that stretches between the Hakatere/Ashburton and Rakaia rivers.

The Ashburton flows into the Hakatere hāpua (a lake which forms behind a bank along the beach), a breeding area for vulnerable native fish and birds.

ECan is now appealing.

ELI believes ECan should have revoked the MHV Water consent once it lost the ALIL case.

It asserts that the regional council also failed to take into account the impact of nitrogen discharge on drinking water supplies. Much of the local community relies on groundwater.

Elevated nitrate levels in drinking water sources can pose serious health risks, particularly to infants.

Neither community drinking water operators nor owners of private drinking water wells were notified about the application.

And that meant the regional council didn’t receive key information that it needed to understand the effects of increased pollution nor the costs for drinking water suppliers to mitigate those effects, its statement of claim to the court argues.

As well as that, ELI claims the co-operative withheld information requested by the council on the potential impact on drinking water supplies, rendering the non-notification and the consent decision unlawful.

The ALIL court ruling was met with a chorus of concern from major dairy interests.

They said it did not reflect the original intent of the RMA.

Until the legal challenge, the conventional approach had accepted the legislation’s provisions applied only to discharges from “an identifiable source”, like a pipe, rather than pollutants from widespread or dispersed sources, such as pasture run-off of animal wastes, fertiliser and sediments, lobbyists and irrigators argued in submissions to the government.

The ALIL decision and a 2020 case between Southland Regional Council and Aratiatia Livestock, a dairy company that farms 600 hectares in Western Southland, overturned this approach and would have made it too difficult to grant discharge permits and many farmers would require a resource consent to farm, the sector claimed.

Cabinet agreed, and in August announced the legislation would be amended under urgency.

ELI alleges ECan’s decision-making process “was deficient in multiple respects” and there are “firm grounds” for the consent to be overturned.

“Environment Canterbury should be guaranteeing communities have access to clean drinking water and protecting freshwater ecosystems,” senior legal researcher Lottie Boardman said.

“Yet the Council has permitted industrial-scale pollution to drinking water and freshwater habitat in the area between Hakatere/Ashburton River and the Rangitata River. Unchallenged, this will continue for years to come.”

ELI’s challenge to the consent will be decided based on the law as it was in 2021.

The court could decide to overturn the consent and send MHV’s application back to ECan to be reheard.

ECan would need to apply the newly amended provisions. Section 107 still prevents councils from issuing a discharge consent that would contribute to “any significant adverse effect on aquatic life”.

But a new clause gives councils discretion to allow otherwise prohibited adverse effects in certain circumstances, where water is already significantly polluted.

ECan’s general counsel, Robyn Fitchett, confirmed in a statement to the Sunday Star-Times: “Environmental Law Initiative has lodged a judicial review of Canterbury Regional Council’s granting of the Mayfield-Hinds-Valetta Water Limited irrigation scheme discharge consent.

“The application challenges the decision to grant the consent on points of law. Because the matter is before the court we won’t be commenting further.”

Jason Hurst, MHV Water’s interim general manager, said the cooperative was disappointed the judicial review was raised while the ALIL case was under appeal.

“We will work with ECan, who are the first respondent, as we work through the legal process,” he said. “We do not undertake to change our approach in seeking continuous improvement across our farming systems for environmental gains.”

He added: “Our farmers continue to actively work towards improved environmental outcomes with 94% of farmers an ‘A’ Farm Environmental Audit grade or better during the last year.”

Auditors rate farms from A to D depending on how closely farmers conform with good management practice guidelines, nitrogen loss limits and record-keeping.

“We continue to undertake an extensive water monitoring programme to help drive sustainable decision making,” Hurst said.

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