Request for Information Regarding the Management of Darwin’s Barberry in Te Kopahou Reserve and Surrounding Areas

To the Wellington City Council,

This is a formal request for information under the Local Government Official Information and Meetings Act (LGOIMA) concerning the Council’s decision-making and operational response to the presence and spread of Darwin’s barberry (Berberis darwinii) within Te Kopahou Reserve and the adjacent reserves at Wrights Hill and Polhill Gully.

Darwin’s barberry is listed as an Unwanted Organism under the National Pest Plant Accord. It is widely recognised for its aggressive ecological behaviour: it outcompetes native vegetation in regenerating forests, alters the understorey, and serves as a host for plant pathogens of economic concern. Despite this, the species has been allowed to establish and proliferate across substantial areas of Wellington’s western reserves. The infestation, which began with a small area on Wrights Hill, now appears to dominate more than half of Te Kopahou Reserve.

In sharp contrast, other regional councils have taken decisive and enforceable action:

Waikato Regional Council requires progressive containment and reporting.

Bay of Plenty classifies the plant for exclusion or containment, depending on the sub-region.

Environment Canterbury applies sustained control measures to prevent spread.

Otago targets it in site-led biodiversity protection zones.

Auckland mandates its destruction even when privately planted.

These approaches represent clear recognition of the risk. Wellington, by contrast, has done little beyond a passive Site-Led classification under the Greater Wellington Regional Pest Management Plan. The result has been unchecked spread and a visible ecological shift in multiple reserves.

This failure is not merely neglectful—it is operationally contradictory. The Council has invested heavily in mammalian predator control, particularly in collaboration with Forest & Bird and other conservation groups. Yet this has come at the expense of managing invasive flora. The dominance of barberry is the direct consequence of that imbalance.

Moreover, the Council is now actively propagating the spread of barberry. The success of Zealandia has boosted populations of native frugivorous birds, such as kererū and tūī, which now serve as efficient seed dispersers. These birds are carrying barberry seed into the very areas where the Council has facilitated reforestation. The consequence is that Council-led efforts to restore biodiversity are simultaneously enabling the dominance of a high-risk invasive.

Accordingly, I request:

Any documentation, reports, meeting minutes, correspondence or internal briefings that informed or justified the decision to not pursue containment or eradication of Darwin’s barberry in Te Kopahou, Wrights Hill, or Polhill Gully.

Any ecological assessments or vegetation surveys since 2010 that record or discuss the extent and impact of Darwin’s barberry in these locations.

Copies of work orders, operational plans, or contractor instructions addressing barberry—whether for monitoring, removal, or intentional omission from weed control efforts.

Any evaluation by the Council of the role native birds play in propagating barberry into reserves, and what mitigation responses, if any, have been considered.

An outline of the current prioritisation methodology used by Council in pest plant management, particularly how decisions are made to resource mammal eradication over invasive flora.

Any correspondence or memoranda of understanding with Forest & Bird or similar partners that relate to pest management prioritisation.

Clear confirmation of whether any funded control or eradication efforts are planned for Darwin’s barberry in the above reserves—and if so, when they will commence.

The scale and visibility of the infestation demand explanation. Other councils have acted. Wellington has not. The cost of delay is now evident on the ground. I look forward to receiving all relevant information that explains why Council permitted this outcome and what it intends to do in response.