New Zealanders will have until July 27 to have their say on sweeping changes to the Resource Management Act (RMA), which will govern the management of forestry and slash. Under proposed changes to the National Environmental Standards for Commercial Forestry (NES-CF), councils would be more restricted in their ability to set harsher controls.

Other proposals would require all forest harvests to have ‘slash mobilisation risk assessments’ as part of their harvest management plans, and/or change requirements around slash removal.

Feedback on the proposed changes…

Dr Steve Urlich, Senior Lecturer in Environmental Management, Lincoln University, comments:

“Stabilising hill country is a national emergency as intense rainfall occurs more frequently. Recent cyclones and atmospheric rivers have led to loss of life, profound economic and infrastructure damage, and ecosystem degradation.

“Extensive erosion can occur on pastoral hill farms and clearcut forests. Cyclone Gabrielle highlighted public concern on the damage and dangers of forest slash.

“The Government tightened the national rules around slash removal in 2023, but is proposing to relax these due to cost and compliance issues.

“However, the proposals will not effectively reduce the risk to downstream communities and environments from slash and sediment.

“Extensive harvesting on gully heads often results in large volumes of slash and broken trees being left to the elements. This is because of self-assessed health and safety risks.

“The Government needs to amend the national rules to:

• Limit the size of clearcuts to <20% of catchment size.
• Retire gully heads, overly steep faces, and deep incised gullies.
• Prevent new plantings in these extremely high-risk areas.
• Require forest roads and skids to be engineered to withstand 1-in-100 year rainfall events

“The last point will be expensive, but the human, financial and ecological costs are currently intolerable.”

No conflicts of interest.

Dr Nathanael Melia, Senior research fellow, New Zealand Climate Change Research Institute, Victoria University of Wellington; and Founding Director of Climate Prescience, comments:

“It is a positive move that the proposed amendments to the Resource Management (National Environmental Standards for Commercial Forestry) Regulations (NES-CF) is open to consultation and seems to finally offer movement in the right direction. I have been aware of slash mobalisation following extreme rainfall since the 2018 Tolaga Bay Queen’s Birthday Storm. It’s 2025, and we are still discussing possible legislation to address these issues.

“The too-long, didn’t read version is: MfE are suggesting that they may like to consider asking forest harvest operations if they wouldn’t mind taking a second look in some cases before clearing the slope, please.

“It’s good to see the action required being based on a site’s Erosion Susceptibility Classification rather than a set of blanket rules that would restrict the industry’s good actors. However, there is nuance here, some types of erosion that harvest can exacerbate are classed as ‘low risk-no further action’. Others deemed more serious suggest ‘further assessment required’, but with seemingly no mandate for these assessments to be independent and free from conflicts of interest, I fail to see how this is helpful.

“Other recommendations suggest that harvest planners ‘should’ use past rainfall observations to assess slash management needs. This reflects that these recommendations are to be self refereed, based on estimates from recorded events rather than this new extreme climate we are in, and require zero material action. Other predictive measures of slash mobilisation are mentioned and put in the too hard basket. Worse, slope features physically present and observable that are consistent with active erosion that ‘channel landslide to waterway’ are considered not measurable, not a predictor of risk, and only of some consequence.

“The bibliography suggests that all the relevant material is known, but only the non-confrontational evidence is used in this draft. The good news is that this is open to consultation; however, there is a risk that these weak suggestions will be seen as red tape by some operators, who will want to lobby for a less restrictive environment. Meanwhile, there are very few independent experts to argue for higher standards required to keep slash away from the public and our sensitive environment.”

No conflicts of interest.

Mark Bloomberg, Adjunct Senior Fellow, Te Kura Ngahere New Zealand School of Forestry, University of Canterbury, comments:

“Firstly, I do not wish to comment in any way on the current situation in the Tasman region. The immediate focus there is protecting life and property, urgently mitigating dangerous situations and repairing flood damage. Commentary at this stage would be inappropriate.

“My comments relate solely to the proposed changes to regulations 69(5)-(7) in Part 2.2 of the Primary Sector discussion document.

“In the discussion document, the NES-CF regulations introduced in 2023 (regulations 69(5)–(7)) to manage slash on the forestry harvest cutover are considered ‘costly to implement and not fit for purpose’. Proposed redress is to amend regulation 69 to require a slash mobilisation risk assessment (SMRA) for forest harvests as part of the existing harvest management plan, and/or amend regulation 69(5) to require all slash above an identified size to be removed from the forest cutover.

“These changes will not help. The problem is not “slash” per se. The problem is the significant adverse effects of illegal discharges (slash, sediment, logging waste) from clear-felled forest lands. The proposals do not address the root causes of these illegal and catastrophic discharges from clear-felling sites on erosion-susceptible land. These root causes and their effects can be most directly avoided or mitigated by:

• Setting the activity status of clear-fell harvesting and matters for control or discretion in a way that allows regulators to properly regulate the risk from discharges, with no requirement for extra stringency in regional plans, i.e. the NES-CF should provide adequate stringency.
• Limiting the size and location of clear-felling coupes on erosion-susceptible land
• Developing a robust nationally-based standard for identifying and mapping landslide-susceptible areas, as well as landslide hazards and discharge flow paths downslope and downstream of clear-felling areas. There would need to be a major commitment by the government and the forestry industry to train, certify, and support a cadre of professionals capable of making these assessments.”

Conflict of interest statement: “Mark Bloomberg receives research and consultancy funding from the government’s Envirolink fund and from local authorities and forestry companies. He is a member of the NZ Institute of Forestry and the NZ Society of Soil Science. He co-authored a recent article in The Conversation with Dr Steve Urlich of Lincoln University, which covers a lot of the same ground as the comments above.”

Please note: This article was originally published as a media release by the Science Media Centre NZ. Wood Central has shared this article in full, and without edit, under a Creative Commons License.