Table of Contents
Judy Gill
Natural disasters do not begin with storms alone. They begin with decisions made years earlier – decisions about land use, vegetation, risk tolerance and which knowledge systems are permitted to guide public policy.
Recent events in Hawke’s Bay and at Mount Maunganui provide two geographically distinct but structurally similar case studies. In both, the removal of mature trees under policy-driven restoration frameworks preceded severe physical damage when extreme weather occurred. In both, councils acted within documented governance structures that prioritised mātauranga Māori-based policy frameworks over established environmental science.
The outcomes were physical, measurable, and destructive.
Hawke’s Bay: Tukituki River and Cyclone Gabrielle
In mid-February 2023, Cyclone Gabrielle caused widespread flooding across Hawke’s Bay. Rivers overtopped stopbanks, floodplains were inundated and large volumes of debris were mobilised downstream. [1][2][3]
Along the Tukituki River, behind the stopbank, approximately 20 large, mature poplar trees had stood for decades. These trees were healthy and well established. They provided shade for neighbouring paddocks and river users, and – critically – their deep root systems contributed to bank stability and resistance to flood forces.
Around four years prior to Cyclone Gabrielle, the local council removed these poplars and they were replaced with newly planted native trees. While ecologically well-intentioned, these replacements were young, shallow-rooted and incapable of performing the same stabilising function in the short to medium term.
When the river flooded during Gabrielle, the remaining poplar stumps and large woody debris lying between the riverbank and the stopbank were mobilised by fast-moving floodwaters. This mass of debris was swept downstream and crashed directly into Lindsey Bush, a significant area of established native vegetation.
The consequences: very old native trees were destroyed, the parking area was wiped out and the toilet block was destroyed. The damage occurred after the removal of the poplars – when destabilised debris was free to move under flood conditions.
Mount Maunganui: Landslides and Governance Context
In January 2026, significant landslides occurred Mount Maunganui, prompting renewed public concern about land stability and vegetation management on the maunga.
The governance context is not disputed and is well documented.
Ownership of the Mount was returned to iwi in 2007. The reserve is jointly managed by Tauranga City Council and the Mauao Trust, representing Ngāi Te Rangi, Ngāti Ranginui, Ngāti Pūkenga and Waitaha.
The Mauao Historic Reserve Management Plan (2018) mandates the progressive removal of exotic (non-native) trees, including large, well-established specimens. The plan explicitly prioritises:
· iwi-led ecological restoration
· removal of exotic trees from archaeological and culturally significant sites
· replacement with native vegetation (“restoring the Cloak of Mauao”)
· incorporation of mātauranga Māori into land-management decisions [5].
Council records confirm that since 2018:
· numerous large exotic trees (including pine, oak, poplar, and macrocarpa) have been removed
· removals have involved ground crews and helicopter operations
· removals have occurred near steep slopes and archaeological terraces.
Whether the recent slips are primarily geotechnical, climatic or management-related requires formal investigation. However, the policy framework under which large-scale tree removal occurred is clear, documented and publicly available.
This governance context has been summarised and referenced publicly by Anthony Smart (23 January 2026).
The Common Issue
These two cases are not identical in terrain or mechanism, but they share a critical feature:
Mātauranga Māori is being used by councils and iwi as a decision-making authority in place of internationally established environmental science, displacing standard methods of environmental risk assessment.
In both Hawke’s Bay and at the Mount, land-management decisions prioritised symbolic or ideological restoration goals over:
· the stabilising role of mature trees
· the decades required for replacement vegetation to perform equivalent functions
· the physical realities of floodplains, slope stability, debris mass and water velocity.
The outcomes were governed by fast-moving water, heavy debris, gravity and soil failure.
Environmental science exists precisely to model these forces – through hydrology, geomorphology, geotechnical engineering and risk assessment. When those disciplines are subordinated to policy frameworks that do not operate on the same evidentiary basis, predictable consequences follow.
This is not a debate about culture, identity or symbolism. It is a question of standards.
Environmental decisions that affect public safety, infrastructure and ecosystems require environmental science. Cultural or ideological frameworks – whatever their value in other contexts – are not substitutes for scientific risk modelling.
References
[1] RNZ – Cyclone Gabrielle coverage (Hawke’s Bay flooding):
https://www.rnz.co.nz/tags/cyclone%20gabrielle
[2] Hawke’s Bay Regional Council – Cyclone Gabrielle response and river flooding:
https://www.hbrc.govt.nz/our-council/cyclone-gabrielle-response/
[3] NIWA – Cyclone Gabrielle weather and flooding analysis:
https://niwa.co.nz/weather/cyclone-gabrielle
[4] Hawke’s Bay Forestry Group – Post-Event Woody Debris Assessment (2023):
https://www.hbforestrygroup.co.nz/wp-content/uploads/2023/04/Cyclone-Gabrielle-Post-Event-Woody-Debris-Assessment-Hawkes-Bay-2023-2.pdf
[5] Tauranga City Council – Mauao Historic Reserve Management Plan (2018):
https://www.tauranga.govt.nz/Portals/0/data/council/plans/files/mauao-reserve-management.pdf
