Project No: 1607
28 October 2016
Buller District Council
6-8 Brougham Street
PO Box 21
Westport 7866
Attention Rachel Townrow - Team Leader Planning & Policy
C/ - Rebecca Inwood
Dear Rebecca,
Te Kuha mine application: terrestrial ecology review
This review is of the terrestrial ecology assessments provided in support of the application by
Stevensons Mining Ltd to develop the Te Kuha open cast coal mine at Westport1.
1. Introduction
Stevensons Mining Ltd (SML) has applied to Buller District Council (BDC) for resource consents under
the Resource Management Act (RMA) to develop and operate an open-cast coal mine at the southwestern part of the Mt William Range (near Te Kuha, Lower Buller Gorge) within Mining Permit area 41289.
The Te Kuha mine would cover 112 ha (although the AEE states that up to 116 ha may be stripped
within the mine footprint), while the associated water treatment infrastructure would cover another 3.3
ha, and a 9 km haul road would cover another 28.8 ha. A proposed coal transfer and handling facility
located next to the Stillwater-Ngakawau Railway is not included in this review.
The main activities associated with the proposal that relate to terrestrial ecology, as described in the
Applicant’s terrestrial ecology assessment reports, are summarised as follows:

Development and operation of an open cast coal mine, to mine approximately 4 million tonnes of
coal over a period of approximately 16 years.

Removal of around 144 ha2 of predominantly natural vegetation including herbfield, forest,
shrublands, and rockfield habitats from mine (112 ha), haul road (29 ha) and associated water
treatment infrastructure (3.3 ha).

Construction of a 9 km haul road to the proposed coal handling facility (the proposed coal
handling facility is not assessed here).

Construction of engineered landforms over the coal floor of the worked pit.
1
This assessment has been undertaken in accordance with our letter of engagement with Buller District Council
dated 16 September 2016.
2
The total area affected may be up to 148 ha if the area of 116 ha cited in the AEE is used for the mine footprint
E: [email protected]
P: 027 272 7930
M: PO Box 25057, St Heliers, Auckland
2
Progressive rehabilitation of completed areas.

As part of this review, we visited the site on 30 September 2016.
We have also reviewed the following documents that comprise the Applicant’s terrestrial ecology
assessments (the ‘Mitchell Partnerships reports’ or ‘the ecology reports’):


Appendix 10 to Stevensons Mining Ltd application entitled ‘Vegetation and fauna of the
proposed Te Kuha mine site’. Prepared by Mitchell Partnerships Ltd. June 2014.
Appendix 11 to Stevensons Mining Ltd application entitled ‘Additional ecological surveys to
inform a proposal to construct an open cast coal mine at Te Kuha, near Westport’. Prepared by
Mitchell Partnerships Ltd. May 2016.
2. Terrestrial Ecology Effects (Flora and Fauna)
2.1 Assessment of ecological characteristics
We consider that SML has adequately described the ecological characteristics and values of the Te Kuha
site. We agree with all aspects of the assessment unless stated otherwise in the following sections.
Vegetation / habitat types
Coal measure communities of the Te Kuha area are part of a vegetation type (coal measure vegetation;
CMV) that is virtually confined to the Ngakawau Ecological District. This vegetation type is typical of
rocks containing coal deposits and contains a particularly unique combination of species in a complex
mosaic of grassland, heathland, shrubland and low forest communities. One of the outstanding features
of CMV is the very high diversity of communities within a small area. This pattern is the result of the
complex interplay of landform, rock type, soil fertility and toxicity, drainage and natural fire history that
influence the present vegetation.
The vegetation of the proposed Te Kuha mine site is one of the least modified examples of coal measure
vegetation in the Ngakawau Ecological District and is particularly significant because of the absence of
recent fire. Although areas of similar vegetation occur on the Denniston and Stockton plateaux, these
areas have been much more substantially affected by human activities (e.g. fire and mining) and some
of the best examples of coal measure vegetation there are in areas that are currently being mined or
are held as state coal reserves.
Therefore, the context within which the Te Kuha mine is proposed, is one of an ecological landscape
characterised by special communities that are recognised as being some of the highest ecological value
of their type.
Mining permit 41-289 within which Te Kuha mine site sits covers approximately 884 ha, of which ca. 420
ha is coal measures vegetation. The Te Kuha site comprises approximately 119 ha of coal measures
vegetation out of the ca. 144 ha overall footprint of the mine and associated haul road and
infrastructure.
The ecology reports state that vegetation across most of the Te Kuha mining area is predominantly
natural; we concur with this assessment. The site exhibits a very high degree of ecological integrity with
few signs of recent anthropogenic disturbance; ecological weeds appear limited to localised occurrences
of the exotic rush Juncus bulbosus.
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The ecology reports identify 11 different vegetation associations:
Coal measures vegetation types (total 119 ha)

Herbfield

Manuka – Dracophyllum densum rockland.

Manuka shrubland

Mountain beech/yellow silver pine – pink pine forest.

Rimu - red beech – silver beech forest.

Slips/ bare ground

Ephemeral pond

Yellow silver pine – manuka shrubland

Rimu/hard beech forest
Not coal measures vegetation types (total ca. 25 ha – mostly on the lower reaches of the proposed haul
road route)

Pakihi

Exotic pasture

Regenerating shrubland
No historically rare ecosystems were recorded, however we consider that the presence of coal
measures vegetation is, in of itself, of national importance given the limited geographical distribution of
this ecosystem type and the rate at which it is declining, primarily due to the effects of mining
elsewhere on the Denniston and Stockton Plateaux. We agree with Mitchell Partnerships that the CMV
which covers much of the Te Kuha proposed footprint meets the definition of being historically rare.
Apart from CMV overall, ephemeral wetlands and herbfields represent habitat that is of conservation
significance and also (for the herbfield) represents one of only a few places that the threatened plant
Euphrasia wettsteiniana is found. Additional plant species of conservation interest or of local
importance include Dracophyllum densum (nationally At Risk), Celmisia dubia, Actinotus novaezelandiae and Parkinson’s rata (Metrosideros parkinsonii). All of these species are either found
elsewhere locally outside of the proposed mining area or in some cases regionally or elsewhere in New
Zealand.
Several bryophyte surveys of the site have confirmed that the site supports a very species-rich, intact
(no exotic bryophytes or lichens) and complex array of habitats and associated bryophyte and lichen
communities. Te Kuha appears to support assemblages not seen elsewhere by bryophyte experts and
ranks highly in terms of overall species diversity, including the presence of 13 threatened or rare
bryophyte or lichen species. The ecology report notes that these species and assemblages found within
the mining footprint are likely to be present in adjoining areas outside of the footprint given the
presence of nearby apparently similar habitat – however no information is presented to substantiate
this.
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Fauna/ Wildlife
Specialist teams of fauna experts for the Applicant surveyed the site during 2013 with some returning
for additional survey in 2015. Results from previous surveys (1986 and 2001) are also used by the
Applicant to add relevance and context to more recent results.
No bats were detected in surveys undertaken by SML despite thorough survey inside and surrounding
the footprint.
Two lizard species were detected in surveys. These included a single specimen of the native speckled
skink and three records of forest gecko, both of which are classified as Nationally At Risk. West Coast
green gecko (Threatened, Nationally Vulnerable) were not detected but are regarded by Mitchell
Partnerships as likely to be present. The ecology reports consider that densities of these species are
likely to be low and that rehabilitated sites will be recolonised by lizards.
We consider that the assumption around low density of geckos (in particular) in the low coal measures
herbfield and shrubland may be misplaced as high densities of forest gecko, as well as the presence of
West Coast green gecko and Nelson green gecko, have recently been found during lizard salvage
undertaken in similar low coal measures vegetation at similar altitudes at the Escarpment Mine site on
the nearby Denniston Plateau.
Thirty-three (33) bird species, including 23 indigenous and 10 introduced species were recorded from
the mining permit area. Two threatened species were identified: great spotted kiwi (low density but
widespread within the permit area) and New Zealand falcon (one sighting). Five At Risk bird species
(western weka, South Island fernbird, New Zealand pipit, long-tailed cuckoo, and South Island rifleman)
were recorded within the mining permit area.
All birds recorded are present within the wider areas of the Ngakawau Ecological District.
Eighty invertebrate taxa were identified in the 2013 survey with additional taxa recorded in the 2015
surveys. Most species were native and overall community composition is regarded by the Applicant’s
expert as typical of wider locations. The high proportion of native species is indicative of a high level of
natural integrity. Of note, an undescribed Rhytida-like snail species belonging to a new, undescribed
genus was recorded during the 2013 survey. In the 2015 survey ‘several others’ were seen inside and
outside the mine footprint (although no indication is given of how close those individuals were to the
mine footprint). This suggests that the snail population is likely to extend beyond mine footprint
boundary, however we consider that there is still a paucity of information on which to base a robust
effects assessment.
An apparently new species of leaf-veined slug was recorded from one site within the mine footprint
during the 2013 survey; no additional sightings were made during the 2015 survey.
Powelliphanta snails were not found despite appropriate search methods and effort.
Sign of pig, goat, deer and possum were found variously throughout the site. Rat and stoats are also
assumed to be present.
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2.1 Assessment of ecological significance
The ecology report provides a comprehensive assessment of ecological significance against the Buller
District Plan Section 4 criteria for determining significant indigenous vegetation and significant habitats
of indigenous fauna in the district. We consider this assessment to be relevant and applied
appropriately.
The 2016 ecology addendum also assesses the site ecological values against proposed Plan Change 141
which seeks to adopt a reduced set of the nine ecological significance criteria in the Operative District
Plan. We understand that Plan Change 141 is not yet operative; therefore, we consider only the
Operative criteria in our assessment.
The Operative ecological significance criteria include nine descriptors of ecological value. Table 1
provides a summary of the assessment undertaken against the criteria (sourced from the Applicant’s
ecology report, with additions).
Table 1. Assessment of Te Kuha site ecological values against the District Plan criteria for determining
ecological significance.
Criterion
Qualification
Representativeness 
Ecosystem relatively undisturbed recently by fire

Representative bird, lizard, invertebrate communities

High quality examples of southern rata – mountain
Overall value
High
beech forest and yellow-silver pine – pink pine forests
Distinctiveness

Highly distinctive coal measures vegetation

Highly distinctive invertebrate communities and
High
communities of bryophytes and lichens
Intactness

Native species dominate at the site; few weeds are
Very High
present

Human-induced modification of vegetation is noticeably
absent
Size

The site is large and surrounded by extensive natural
High
areas which are vulnerable to the direct and associated
effects of the activity
Protected status

Parts of the site (mine and haul road) are within the
Moderate
Westport Water Conservation Reserve and trigger this
criterion
Connectivity

The Te Kuha area is well connected to surrounding
High
habitats, including the forests of the Lower Buller River
to the south, the Mt Rochfort Conservation Area to the
north and east, and pakihi on German and Caledonian
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Terraces within the Ballarat Stewardship area to the
west.
Threat

The site ranks highly as it supports several species of
High
threatened or at risk plants, lizards, bryophytes and
lichen. It may support the only known populations of
two invertebrate species.
Migratory Habitat

It is unlikely that this site is important to migratory birds
Low
Scientific or

Currently, the site represents the only known locality for
High
Cultural value
the new species of leaf-veined slug and the Rhytida-like
snail. If this is confirmed, Te Kuha would become the
type locality which would afford a high level of
significance.
Based on this assessment, the Te Kuha site meets almost all of the ecological criteria. We regard the Te
Kuha site to exhibit high ecological value and for the purposes of Section 6(c) of the Resource
Management Act, to clearly constitute a site of national ecological significance.
2.1 Assessment of adverse ecological effects
In making our assessment of potential adverse effects of the Application, we have taken a precautionary
approach where information is lacking or clear direction as to the level of effect cannot be clearly
inferred from the available site information. We regard this approach as appropriate because of the
high overall ecology values of the site and the potential loss of nationally and locally significant species,
communities and ecosystems that may arise should this development proceed.
The ecology report considers the key adverse effect on terrestrial ecology to be the removal of native
vegetation within an area characterised by high overall ecology values, high intactness and high
ecological integrity, including the removal of threatened, rare or characteristic species, communities
and assemblages of native species associated with a rare ecosystem type (coal measures vegetation).
The complete removal of vegetation and soils by mining (followed by its gradual return over a period of
several decades) is expected to have prolonged adverse effects on the flora and fauna at the site.
Specifically, potential adverse effects include:

the removal of approximately 144 ha of predominately natural vegetation / habitat through
stripping of vegetation and soils including:
o 123 ha (but elsewhere in the Application documents cited as 119 ha) of coal measures
vegetation that is of very high quality;
o Approx. 20 ha of other native vegetation of high quality (but not CMV);
o 0.9 ha of exotic pasture

varying degrees of direct loss or reduction in habitat availability for:
o a number of common indigenous species, including keystone species such as tui and
kereru and distinctive communities such as invertebrates associated with specialised
coal measure plant communities;
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o
o
o
o
ecologically distinct species such as (Celmisia dubia and Metrosideros parkinsonii), the
undescribed species of Rhytida-like snail and the undescribed leaf-veined slug;
the nationally threatened Euphrasia wettsteiniana and the rare plant Dracophyllum
densum;
Nationally threatened or at risk species including:
 Four nationally threatened and 10 nationally at risk bryophytes and lichens;
 Nationally Threatened and at risk birds, including:
 Great spotted kiwi (nationally vulnerable; resident);
 New Zealand falcon (nationally critical) (occasional visitor);
 Western weka (At Risk, Declining);
 South Island rifleman (At Risk, Declining);
 New Zealand pipit (At Risk, Declining);
 South Island fernbird (At Risk, Declining);
 Long-tailed cuckoo (At Risk, Naturally Uncommon) (occasional visitor);
The Nationally At Risk forest gecko and speckled skink (numbers unknown) and
probably the Nationally Threatened; Nationally Vulnerable West Coast Green gecko;

Approximately 22 km of new edge habitat, which is likely to result in changed ecological
conditions over an additional ca. 60 ha of coal measures and other native habitat, including places
where invertebrate, bryophyte and lichen communities or species of conservation significance
may reside and be adversely affected;

Construction and operation related disturbance, including the increased presence of noise,
lighting and an increased presence of people and machinery during construction and operational
activities;

Introduction of weed plants and non-native bryophytes in roading aggregate or on soil adhering
to vehicles and machinery that will reduce overall ecological intactness of ecological systems and
may fundamentally change native communities; and

Increased access by pest animals to vegetation communities and native fauna populations (with
increased potential for herbivory or predation) by way of the haul road and worked areas as part
of normal mining operations.
We generally concur with Mitchell Partnerships’ assessment of potential adverse effects (before
considering any on-site remediation and mitigation) on the ecological values within the Te Kuha site.
While all of the activities or implications of mining have the potential to result in adverse effects, a
subset of these can be regarded as resulting in significant adverse effects.
We have assessed the significance of effects using the approach advocated by EIANZ3 which determines
the level of an effect by a combination of the magnitude of the effect and the value of the affected
ecological feature. The resulting matrix approach has been developed specifically as a guide for
ecologists undertaking effects assessments under the RMA, and is a valuable sounding board for
projects such as Te Kuha mine.
The effects that we consider qualify as significant adverse effects include:
1. The removal of 123 ha of coal measure ecosystem which represents a relatively high proportion
of this ecosystem type (in the context of existing loss and future management of this ecosystem
type nationally) which is also one of the least affected and most intact areas of coal measure
vegetation;
3
Environment Institute of Australia and New Zealand. March 2015. Ecological Impact Assessment (EcIA): EIANZ
guidelines for use in New Zealand terrestrial and freshwater ecosystems. Produced by EIANZ. 104 pp.
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2. The loss of the high level of intactness and ecological integrity within the south-western part of
the Mt William Range (i.e. within the surrounds of the Te Kuha site);
3. The potential loss of a significant portion or the whole known distribution and population of the
undescribed species of Rhytida-like snail and the undescribed species of leaf-veined slug;
4. The loss of the only known local population of the nationally threatened plant Euphrasia
wettsteiniana;
5. Loss of ecologically distinct bryophyte and lichen communities and their habitat over the mine
footprint, haul route and associated changes to edge-affected habitat;
6. The loss of a significant portion of the known distribution of several nationally threatened and
rare bryophytes and lichens; and
7. Loss of populations of lizards that may be distinctive and which are likely to include several
nationally rare or threatened species.
In making the above assessment, we have taken a precautionary approach where information is lacking.
Ecological information that could help us to clarify the importance of several of the aspects of
ecologically significant effects listed above includes:
1. A more comprehensive evaluation of the state of the lizard fauna at the site to provide
assurance that Te Kuha does not include a high abundance of forest gecko, West Coast green
gecko or the presence of other species (e.g. Nelson green gecko). Alternatively, in the absence
of further surveys we assume that the potential effects on lizards will be more than minor.
2. For the Rhytida-like snail and the undescribed species of leaf-veined slug, the provenance and
status of populations found within and around Te Kuha need to be resolved as a matter of
importance. Is Te Kuha, and the mine site and vicinity specifically, the only place where these
species exist? In the absence of wider contextual information, we have assumed that the
removal of habitat and creation of changed environmental conditions through edge effects
could result in the local or total extinction of these species.
3. The bryophyte communities identified at the site are recognised by the Applicant’s experts as
significant assemblages of species that have formed communities unlike any encountered
elsewhere. There is no evidence presented as to the distribution of similar communities of this
nature outside of the project footprint; such survey would greatly assist in assessments of the
local importance of these communities.
4. How confident is SML that the overall footprint proposed in its Application will not increase
significantly following detailed design? The footprint has increased from 105 ha in the 2013
ecological assessment of effects to 144 ha in the 2015 updated ecology report and up to 148 ha
in the AEE. Further increases (for example for reasons relating to DT storage, overburden dump
areas or mine scheduling) could have considerable additional adverse effects on sensitive or
special communities or populations of localised species.
5. We have not had access to the technical reports of the field visit assessments undertaken by Dr
Glenny on which the assessments of effects dated 2014 and 2016 for bryophytes and lichens are
based. Those reports may hold additional information, particularly regarding contextual
importance of species occurrence and rehabilitation potential (for example through direct
transfer, re-colonisation, and community resilience to exotic species colonisation) that may
further assist in our assessment of effects.
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3. Rehabilitation (on-site remedy) and on-site mitigation
3.1 Overview
Rehabilitation of the mine site is proposed by SML to partially reduce the extent and severity of adverse
effects on ecologically significant aspects on the site’s terrestrial ecology.
The Application provides an extensive analysis of the functional aspects of rehabilitation, covering
timing and staging in relation to mine schedules, the use of Direct Transfer (DT) as a superior method of
conserving plant and animal communities, and practical aspects of revegetation, soil and erosion
control, and biological community restoration in relation to site environmental constraints and
opportunities. The Applicant’s experts draw on many years of experience with nearby mine sites (in
particular Strongman, Stockton Plateau and Denniston Plateau open cast coal mines).
We have visited or been involved with rehabilitation at many of the sites cited as case examples in the
ecology reports regarding rehabilitation. We agree with all of the information presented by the
Applicant’s ecology experts regarding the challenges and successes at other sites. We also agree with
the Applicant’s experts that the Te Kuha site offers similarities to other mine rehabilitation projects, and
also factors that create some uncertainty regarding the quality of outcomes that may be achievable at
this site.
Key aspects of the rehabilitation proposed in the ecology reports include:




Prioritisation of the use of DT where possible such that up to 20 % of the mine and a ‘high
proportion’ of the road batters can be restored using DT sourced from within the project footprint;
Avoiding locating spoil dumps and infrastructure within highest ecological value habitats;
Use of techniques, resources and approaches that either avoid localised effects on biodiversity or
minimise the risk of biodiversity loss and biosecurity incursions (i.e. prevention and minimisation of
exotic weed and plant, and pest animal incursions and establishment within the Te Kuha site);
Use of best industry practice to establish vegetation cover that is appropriate for the site (e.g. ecosourced plants) and is undertaken in a way that minimises time between loss of natural ecosystems
and restoration of functional replacements.
The practical outcomes on the ground anticipated by the Applicant’s experts are:





At least 18 ha of DT out of the 112 ha mine footprint, with a focus on low growing vegetation types
that harbour rare plants or which support diverse bryophyte and lichen communities;
At least 80 ha of planted finished landform (the treatment of the remaining ca. 14 ha of mine
footprint is not described in the Application – this needs clarification by the Applicant);
The substantial road batters will be largely rehabilitated during construction works using DT;
Direct transfer of 1.4 ha (AEE table 14) of yellow sliver pine – manuka scrub (out of 11.5 ha within
the mine footprint (the ecology report dated 2016 cites this DT as 2.4 ha). Proportions of other
habitat types that will be subject to DT are not provided, but should be to give a degree of certainty
of outcome for best rehabilitation approaches for rare ecosystem types.
A programme of ongoing weed control and pest animal control is envisaged by the Applicant’s
experts until rehabilitation closure criteria are achieved.
On-site mitigation such as wildlife and rare plant salvage is not proposed in the ecology reports
(although rare plant salvage by hand is as part of rehabilitation of rockfield habitats). We recommend
that the Applicant consider undertaking salvage of lizards, rare plants and some invertebrates (e.g. leaf
veined slug and Rhytida-like snail) where feasible, as doing so may contribute to mitigation of some
unavoidable adverse effects on these species.
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3.2 Objectives
Three rehabilitation objectives are set out in the ecology reports:
1. Rapidly ensure stable, erosion-resistant surfaces are created that prevent loss of soil;
2. Achieve a high degree of naturalness in the short term and long term; and
3. Support ecological objectives including:
a. Minimise the area affected by the mining and associated activities;
b. Establish self-sustaining vegetation cover that can develop into native vegetation
mosaics and is resistant to weeds, fire and pests; and
c. Conserve genetic resources, particularly those of threatened and at risk species.
Ultimately, achieving all of the objectives within the context of the mine development will require a
‘tool-box’ approach that is able to provide a hierarchy of responses that best meet the above objectives,
depending on the available time and resources as the mine proceeds.
The objectives are broad in terms of a focus on recreating processes and functional components instead
of seeking a diversity of communities or species richness directly comparable to the pre-mining state.
We regard this as appropriate, because (as the Applicant’s expert also recognises in the rehabilitation
report), the vegetation cover that is likely to be able to be achieved on the post-mining engineered
landform will be coarser than the present mosaic of fine-scale communities and habitats (and the
underlying pattern of fine-scale landform heterogeneity).
Rehabilitation closure criteria are referred to in 7.5 of the Appendix 10 report, however no criteria seem
to be proposed to support measurement or achievement of the objectives. Section 8.2 of Appendix 10
recommends that a Rehabilitation Management Pan be prepared to address DT, management of edge
effects, active planting and other aspects of the rehabilitation approaches. Also recommended by the
Applicant’s expert is the development of a weed and animal pest control programme.
We support the development of all three of the above guides and measures of rehabilitation success.
We regard these as critical components that are needed both to demonstrate the commitment of the
Applicant to prioritising ecological outcomes for rehabilitation, and for demonstrating the practical
aspects of undertaking the stated rehabilitation in the context of the engineering requirements for this
particular site.
3.3 Achievability
The ecology report presents a compelling argument for effective and successful rehabilitation with
closure criteria able to be met within 10 years post-mining. We do not doubt the value of the learnings
obtained from other nearby mine sites, nor do we disagree with the challenges that are set out in the
Applicant’s assessment of the technical feasibility of undertaking rehabilitation. However, in our
opinion, the Applicant’s case concentrates on a ‘best practicable’ outcome and does not fully
acknowledge how risk and uncertainty for undertaking rehabilitation at the Te Kuha site may be
expressed in achievable ecological outcomes.
Our comments on the achievability of the rehabilitation proposed are:
1. While DT will be prioritised, the area of DT able to be applied amounts to some 18 ha out of a
mine footprint of ca. 112ha (excluding haul road effects). At least 80 ha (or at least 94 ha if one
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2.
3.
4.
5.
assumes that any area not subject to DT will be cleared and planted) of the footprint will be
cleared of its current cover of intact, natural mosaic of ecosystems.
There is no guarantee that the DT that will be undertaken will conserve the target communities.
DT of low vegetation types in environments such as Te Kuha has been undertaken only in the
last 10 years, and while this shows promise for maintaining species composition and structure,
longer-term risk of hydrological change on these engineered surfaces and its effects on
vegetation composition has not yet been determined. If engineered surfaces do not replicate
the moist environments required by low-growing vegetation assemblages, risk of colonisation
by woody, tall-growing vegetation increases, with progressive change to tall shrubland and
forest.
The planted areas will, in reality, bear little resemblance to the complex mosaic of vegetation
communities that occur on the site pre-mining. This is simply a factual reality that the creation
of an engineered landform cannot replicate the complex environmental factors that currently
exist, and the current vegetation is dependent upon and utterly influenced by these factors. At
most, the planted area will support a much-reduced richness of common, fast-growing native
plants that in the short term will provide a vegetation cover, and in the long term may provide
some structurally analogous community that can be used by a subset of the plant and animal
species currently present.
The Applicant’s expert anticipates closure criteria will be achieved by 10 years after planting. If
the criteria (which we have not seen for review) only seek vegetative cover of mainly native
species, then we agree that this is achievable. However, the objectives of the rehabilitation
programme promise far more than this (see Section 3.2 of this report) – with objectives of
‘naturalness’ and ‘self-sustaining vegetation cover’. Given that 12-year old planted areas at
Stockton Mine (as the most similar site to Te Kuha) have yet to achieve full cover, and that Te
Kuha’s far wetter environment will likely result in slower growth rates, we suggest that a
timeframe of at least 20-30 years should be envisaged for a ‘self-sustaining’ cover to be
established and far longer (100 + years) before such plantings may provide habitat for
invertebrates, bryophytes, lichens and birds of conservation importance (there is no guarantee
of this).
Given that the mine development and rehabilitation programme is proposed by the Applicant to
take around 20 years (Table 11 of Appendix 11), with some areas taking an additional 10 years
to achieve final void filling (Section 3.7 of the AEE) this means that it could take at least 60 years
before the Te Kuha mine site is returned to a reasonable standard of native vegetation cover
(not including the haul road which is not proposed to be fully rehabilitated).
The ecology report identifies risks to the rehabilitation programme; however, these risks are not
reflected in the range of possible outcomes of the rehabilitation. The risks that we have
identified include:
a. The ability of the engineered landform to support vegetation is not assessed in the
rehabilitation plan; rather it alludes to an assumption that acid-forming substrates will
not be present, and that vegetation will be able to survive and establish. Does the
Applicant guarantee that the engineered landform will support substrates suitable for
the establishment of vegetation of the types proposed in the rehabilitation
programme?
b. Will the finished landform blend with the surrounding unmodified landform? The
ecology report states that there will be no high walls and that the landforms will blend
seamlessly. There is no reference to engineering calculations or plans that demonstrate
rehabilitation to this quality is feasible. If benches and high walls are anticipated as part
of the final landform, this may change the achievability of parts of the rehabilitation
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programme, especially in respect to the prevention of invasive weeds, re-establishment
of an intact vegetation cover over parts of the site and achievability of a ‘natural’ longterm vegetation pattern.
c. The planting programme assumes an availability of appropriate planting substrate,
presumably sourced from stockpiled soils and ‘jumble-dump’ materials. There is no
evidence presented as to material volumes needed or available to support the planting
programme. Unless suitable types and depths of planting media are available, planting
outcomes may be of considerably poorer quality than the Applicant’s expert anticipates.
d. Several of the plant species that comprise important components of mine rehabilitation
planting elsewhere are not appropriate for use at Te Kuha (e.g. they do not occur
locally). Can a planting palate adequate to meet the plant diversity, survival and growth
goals of the programme be developed in the absence of these species used elsewhere?
e. The Applicant states that the haul road will partially rehabilitated, yet there seems to be
no solid commitment to retiring the entire road and rehabilitating it to native
vegetation. We have assumed, based on the description in the Application, that the
road will be maintained as a long-term feature of the site.
While the technical details of rehabilitation appear to be well considered (albeit without necessarily
considering the risks associated with some key components), we would have also hoped to see direction
from the Applicant as to the quality of outcomes able to be committed to, and the way in which
ecological rehabilitation forms an integral part of the mine operating programme.
Specifically, we would expect to see –at this AEE stage – the following:
1. An outline rehabilitation management plan laying out the commitment to minimum standards
of operation in regard to DT, planting, and practical treatment of material handling, road
construction and mine scheduling that enable best practicable use and conservation of
ecological resources at the site. At present, there are inconsistencies between the proposed
concepts of rehabilitation in the ecology report and what appears to be committed to in the
AEE. An outline plan would provide greater assurance as to what is being committed to. As part
of this, restoration goals and measurable closure and success criteria would be proposed that
enable an objective assessment of the minimum contribution that rehabilitation will make to
preventing, minimising and remedying adverse effects within the project footprint.
2. Commitment to the development of a rehabilitation tool-box which provides technical
information sheets/ training regarding best practice methods and standards for each of the
techniques described in the Rehabilitation Plan. The primary purpose of the tool-box would be
to ensure that construction managers and operators are aware of the overall ecological
objectives and are conversant with how good quality outcomes can be achieved on the ground
when entering, handling and restoring ecological communities.
3. An outline weed and pest animal management plan that provides indicative objectives, methods
and techniques that will be employed to prevent the incursion and establishment of exotic
weeds, and the potential for increased impacts by introduced animal pests.
3.1 Anticipated outcomes
The real crux of the restoration problem at Te Kuha is that the current vegetation is the product of a
complex mosaic of factors that will not be reproduced after mining. The reality is that high quality DT is
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proposed over only a small portion of the project footprint. The rest of the site will be restored to a
vegetation cover that may not resemble the pre-mining cover for at least 50 years and is certain not to
provide replacement habitat for diverse plant, bryophyte and animal communities for many more years
after that. These effects cannot be considered to be temporary – they are more appropriately regarded
as permanent.
The replacement of the existing complex mosaic of communities with a far less complex array of mostly
planted communities will not be a like-for-like replacement; rather it will be functionally similar, but less
diverse in terms of species, habitats, and fine-scale mosaics. The end result, even if undertaken to the
rehabilitation quality described in the AEE, will most likely result in a different complex of species to
what is there now, including the likely addition of exotic species (e.g. bryophytes) and changes to
community composition. To compound the likely landform and ecological changes to the site, it appears
that the haul road will not be rehabilitated in full, leaving a significant fragmentation effect throughout
natural ecosystems covering an adjoining ca. 200 ha and presenting a fire, weed and pest animal risk to
the broader area surrounding the site.
At Section 7.9.2 of Appendix 10, the Applicant recommends that decisions around rehabilitation
priorities and preferred outcomes be deferred to a peer review panel that is formed should consents be
granted. We disagree. Rehabilitation priorities and anticipated outcomes require a level of certainty so
that an assessment of rehabilitation effectiveness can be taken into account when considering
mitigation effectiveness. We strongly advocate for the set of proposed consent conditions to contain
declared priorities, objectives, outcomes and measures of success to ensure that a minimum reasonable
standard of rehabilitation is sought and achieved. The formation of a peer review panel to guide
decision making post-consents is valuable, however it should not replace declarations of intent by the
Applicant as part of the consenting process.
The proposed rehabilitation programme provides a compelling argument for best practice delivering
best ecological results. However, the lack of certainty or provision of evidence around some critical
design aspects (fate of haul road post-mining, acid-forming material within engineered landform root
zones, availability of plant species for revegetation programme, long-term outcomes of DT and lowstature vegetation, planted area growth rates) forces consideration of less-than optimal outcomes for
biodiversity within the mine and haul road footprint.
Given the high ecological value of the Te Kuha site and the risks associated with providing quality
rehabilitation outcomes (including guaranteeing biosecurity management), we see this project as
presenting a very real risk of permanently diminishing the ecologically significant communities present
at Te Kuha and reducing the ecological value of the surrounding natural landscape, including RAP 7 and
the values associated with the Westport Water Conservation Reserve.
In our opinion, even with the best realistic outcome that may arise from the proposed rehabilitation
programme, there will still be substantial significant, residual, adverse effects on ecological values that
are not avoided, remedied or mitigated (on-site). We disagree completely with the statement made by
the Applicant in the AEE (Section 5.7.6) that ‘Overall, the long-term effect of the proposed Te Kuha Mine
Project on local biodiversity is acceptable given the proposed attention to effective rehabilitation’.
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4. Off-site Mitigation (Offsetting/Compensation)
4.1 Overview
Ecosystem management of areas outside of the immediate mine project footprint is proposed in the
ecology reports to mitigate4 the adverse effects of habitat removal at the mine site. The off-site
mitigation as proposed in the ecology report includes:
1. Multi-species pest control over a large area of native habitat around the Te Kuha site. Mitchell
Partnerships proposes that an ecosystem management area, whereby all introduced mammals
are controlled for the purposes of improving native plant and animal communities, be created
to link Te Kuha to an ecosystem recovery area encompassing parts of the Denniston and
Stockton Plateau. An area of 9,500 ha is proposed by Mitchell Partnerships as appropriate.
Although not mapped in the ecology report, presumably this area would include coal measures
ecosystems of a similar type as within the Te Kuha mine area, as well as native habitats not
within coal measure ecosystems.
2. An area of coal measure ecosystem in the vicinity of the proposed Te Kuha mine that is
permanently protected from mining. Although not stated in the ecology report, could be a
valuable contribution to safeguarding local coal measures ecosystems from potential future
development. This area could comprise the balance of mining permit MP-41-289 (approximately
720 ha of which ca. 380 ha would comprise CMV) and would involve a legal mechanism being
established to protect this area from future open cast mining (and associated access,
infrastructure and overburden removal or placement activities).
The AEE does not appear to support this level of off-site mitigation. The AEE refers to a ‘Te Kuha
Biodiversity Enhancement Area (TBEA), however this area is not spatially defined, nor is there clear
alignment with the proposals described in the ecology report. It is difficult to assess the worth of the
TBEA concept without reference to its location, the environments that it encompasses and details of the
anticipated management benefits. There is no mention in the AEE of a permanent protection area to
safeguard coal measures ecosystems from future mining (as is proposed in the ecology report).
4.2 Adequacy of proposed off-site mitigation measures
If we assume that the proposed TBEA aligns somewhat with the first of the off-site initiatives listed in
4.1 above, the benefits could be:


Some degree of recovery and protection of plant communities, including rare species (e.g.
red mistletoe) from pest animal browse if such pests are not currently being managed by
DOC. Greatest benefits to vegetation are likely to be for taller-stature podocarp forest
included in the ecosystem management area, rather than lower stature coal measure
communities because pest animal levels are generally lower.
Most probably a benefit to birds, bats and snails (depending on occurrence within the
agreed management area), including birds of the same species as found within the
proposed Te Kuha footprint.
4
Off-site management proposed by the Applicant can also be considered to offset or compensate for residual
adverse effects depending on the type, scale and management proposed.
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Overall, the TBEA initiative could provide a substantial ecosystem-level benefit for the recovery of
(mostly dissimilar) native plant and animal communities – depending on the size of the area and the
management proposed. If governed by appropriate management plans, and if set up to provide lasting
benefits to indigenous biodiversity, the off-site programme could contribute towards addressing
residual effects of species and habitat loss within the mine footprint.
The off-site mitigation proposed in the AEE at it stands, however, is unlikely to provide replacement
benefits that outweigh the potential permanent loss of Rhytida-like snail and leaf-veined slug species,
nor does it address the risk and uncertainty associated with the potential for significantly reduced
intactness and integrity that will result within the broader Te Kuha coal measure ecosystem or its
increased vulnerability to biosecurity threats.
4.3 Management Plans and governance
Management plans for on-site management of biodiversity, rehabilitation and off-site ecosystem
recovery are proposed by the Applicant to be provided should consents be granted for the project.
Detail that could populate several of these management plans is within the AEE and outline objectives
are variously described in the AEE or ecology report text for others. Some of the mattes raised in the
ecology report are not brought into the AEE, making it difficult to assess which matters relating to
ecological mitigation are supported by the Applicant and which are not.
It would be helpful if the Applicant could provide even outline management plans relating to the
biodiversity aspects, so that it provides some confidence regarding the scope, scale and management
standards that will be undertaken for management of biodiversity on-site and off-site mitigation.
5. Other matters
Should consents be granted for this project, other matters that affect the implementation of ecological
programmes at mine sites, and which are relevant to this project, include:
1. At a site such as Te Kuha where ecological outcomes must be prioritised, a site Environmental
Manager who reports directly to the General Manager of the Consent Holder (with no less
seniority than anyone involved in mine planning) should be appointed. This will ensure that
decisions regarding environmental matters and objectives assume at least the same priority as
decisions regarding mine operations.
2. Prioritise ecological outcomes such that they are at least the same or higher importance as mine
design and scheduling so that fundamental requirements for quality rehabilitation are
prioritised e.g. merged natural and engineered landforms, appropriate growth substrate is
present for planted areas, tie pit development to DT targets.
3. Bonding of the project needs to include the costs of off-site mitigation that is triggered as a
proportion of the mine site development. This acknowledges that on-site rehabilitation (and the
bonding associated only with on-site rehabilitation) is not sufficient to fully mitigate adverse
effects from mine development, and that off-site mitigation agreed by the Applicant must be
fully funded for the life of the mine’s impacts.
We strongly advocate that such provisions are included within the set of resource consent conditions.
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6. Conclusions
The proposed Te Kuha mine site and associated infrastructure will remove significant vegetation and
habitats of significant fauna over approximately 144 ha of largely unmodified indigenous ecosystems.
Individually, the values of the site include threatened or rare ecosystem, communities and species. The
site may also be the only location for two new invertebrate species and the best location known of
particular bryophyte and lichen assemblages. Overall, the values of the site trigger eight of the nine
District Plan criteria that qualify a site as ecologically significant. The site is undeniably of high ecological
significance.
Development of the site will have adverse effects that are unavoidable and which are ecologically
significant at a national, regional and local scale, and which are effectively permanent.
Rehabilitation proposed by the Applicant promises best practice to minimise effects and if successful
will do so for some habitats and species. However, for the most part, there will be a substantial
permanent loss of ecological values (including significant ecological values) and an increased risk to the
ecological integrity of surrounding areas.
The certainty of loss of ecological values is partly balanced by the uncertain outcomes of on-site
rehabilitation and the, yet to be defined, off-site ecosystem recovery programme (the scope of which is
not clearly defined in the AEE or the accompanying ecology reports).
However, in our opinion that is a poor exchange for removing the largely unmodified ecosystems
present at Te Kuha given the substantial uncertainties surrounding the proposed rehabilitation and offsite mitigation.
In our opinion, even with the best realistic outcome that may arise from the proposed rehabilitation
programme, there will still be significant residual adverse effects on terrestrial ecology values (in
particular significant indigenous vegetation and significant habitat of indigenous fauna) that are not
avoided, remedied or mitigated.
Yours Sincerely,
Graham Ussher
Principal Ecologist
Principal Ecologist5
C:\Users\Graham\Google Drive\RMA Ecology Ltd\Active Projects\1607 Te Kuha\working\TeKuhaMine.ecologyrpt.REV1.27Oct2016.docx
5 This report has been prepared for the benefit of our Client with respect to the particular brief given to us and it may not be relied upon in
other contexts or for any other purpose without our prior review and agreement. Any use or reliance by a third party is at that party’s own risk.
Where information has been supplied by the Client or obtained from other external sources, it has been assumed that it is accurate, without
independent verification, unless otherwise indicated. No liability or responsibility is accepted by RMA Ecology Limited for any errors or
omissions to the extent that they arise from inaccurate information provided by the Client or any external source.
Te Kuha Mine terrestrial ecology review
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Te Kuha Mine terrestrial ecology review
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