Rules about discharges – what regional councils need to know

The Environment Court issued its second interim decision on the proposed Waikato Regional Plan Change 1 (PC1) at the end of February in the case of Oji Fibre Solutions (NZ) Limited v Waikato Regional Council [2026] NZEnvC 033.

The decision marks the first time the Environment Court has grappled with section 70 of the RMA since it was amended by the Resource Management (Consenting and Other System Changes) Amendment Act 2025.

What does section 70 require?

Despite being in the RMA since its inception, section 70 has only recently stepped into the judicial spotlight, particularly in the context of significant adverse effects on aquatic life (one of the listed effects in the section). Following those cases, section 70 was amended.

Using that effect as an example; section 70 requires regional councils to be satisfied, before they include permitted activity rules authorising discharges in their regional plans, that significant adverse effects on aquatic life shall not arise in the receiving waters after reasonable mixing as a result of any permitted activity rule allowing the discharge of a contaminant (or water) into water or onto land in circumstances where it may enter water, unless an exemption or alternative pathway applies.

The changes to section 70 now enable a regional council to include a rule in a regional plan that may result in:

• any conspicuous change in the colour or visual clarity;
• the rendering of fresh water unsuitable for consumption by farm animals; or
• any significant adverse effects on aquatic life:

Provided that:

• those effects are already in the receiving environment; and
• the rule includes standards for the permitted activity that will, either by itself or in combination with other provisions in the plan, contribute to a reduction in those effects over a period no greater than 10 years from the rule becoming operative.

Environment Court’s approach to section 70

Section 70 of the RMA was amended ‘mid-process’ for PC1, meaning that the Environment Court hearing the appeals on PC1 needed to engage with section 70(3) and satisfy itself of the requirements relating to the discharge rules.

Acknowledging that the section 70 bar was very high, the Environment Court described its response as being “to take a systematic and comprehensive bottom-up, step-by-step and multi-evidence approach that considered all relevant contributing factors, starting with a detailed review of the evidence already before us with fresh eyes focusing on the requirements of s 70(3).”

Being satisfied that the effects listed in section 70(3) were already occurring over large parts of the PC1 area, the Court then had to consider whether the various permitted activity rules in PC1, along with other provisions in the Plan, would contribute to a reduction in those effects over at least a 10-year period.

The Court grappled with the scientific uncertainty inherent in the monitoring and modelling of the listed effects in section 70(3) and concluded that it would not be possible to statistically demonstrate the extent, if any, of reductions of effects in 10 years’ time. The Court observed that it may take 20 years or longer for this to become apparent.

Because of this, the Court focused on whether the reductions in discharges of the four primary contaminants (nitrogen, phosphorus, sediment and E.coli) would contribute to a reduction in the effects within 10 years of PC1 becoming operative, and concluded that the permitted activity standards in combination with the other provisions of PC1 would ultimately contribute to a reduction in the section 70(3) effects within 10 years.