A High Court ruling has directed Environment Canterbury to revisit approvals for nitrogen and other pollutant discharges from dairy farms utilsing irrigation systems.

It was found that Environment Canterbury “misapplied” resource consents issued to Ashburton Lyndhurst Irrigation.

This facilitated a decade-long application of synthetic nitrogen fertilisers across an area spanning from the Southern Alps to the Canterbury coastline between the Ashburton and Rakaia rivers, covering roughly 177,000 hectares or 30% of the Ashburton district.

However, both the Council and the farmer-owned cooperative refuted the grounds for review, denying that the notification and discharge consent decisions were subject to legal errors.

This decision could have far-reaching implications for the replacement of discharge consents upon their expiry, especially in cases where the receiving environment remains significantly degraded.

Justice Cameron Mander said “It appears indisputable there will likely be continuing significant adverse effects on aquatic life for the time being.”

The Environmental Law Initiative propelled the legal challenge against ECan’s 2021 authorisation for the discharge, highlighting concerns regarding freshwater governance and the permitting procedures concerning aquatic pollution.

ELI claimed ECan neglected the broader ecological consequences of pollution, failing to account for the detrimental effects on rivers, coastal lagoons, and oceans.

It criticised the council for not adhering to its legal obligations, including considerations under the Canterbury Land and Water Regional Plan and the New Zealand Coastal Policy Statement.

The Ashburton River, culminating in the Hakatere hāpua and serving as a vital habitat for endangered native species, was a focal point in the court’s findings, acknowledging the inevitable negative impacts on aquatic life.

Justice Mander noted ECan’s lapse in integrating coastal policies, marking this as a legal misstep.

Although ELI’s contention regarding the lack of public notification for the consent did not succeed, the organisation was now scrutinizing additional consents nationwide for similar infringements.

Environment Canterbury said it was not aware of any other consents that may have breached the Resource Management Act.

“However, in light of the High Court decision, we will be reviewing how we apply both Section 107 of the RMA and the New Zealand Coastal Policy Statement regarding cumulative effects, in cases where discharge permits are lodged for catchments where existing water quality is having significant adverse effects on aquatic life.”