Waitaha Hydro Scheme Terrestrial Flora Description and Assessment … 15 - WHS... · Waitaha Hydro...
Transcript of Waitaha Hydro Scheme Terrestrial Flora Description and Assessment … 15 - WHS... · Waitaha Hydro...
Waitaha Hydro Scheme
Terrestrial Flora Description
and
Assessment of Effects
Prepared By: TACCRA Ltd.
Date: 31 December 2013
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Disclaimer
This paper has been prepared at the request of and for the purposes of the client (Westpower
Ltd.) only. Neither TACCRA Ltd. nor any of its shareholders/employees accept any
responsibility on any grounds whatsoever, including liability in negligence or for the manner
in which information contained herein is subsequently used, to any other person or party.
D. J. Derks
For:
TACCRA Ltd.
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Table of Contents
Executive Summary ........................................................................................................................ 5
1.0 Introduction ............................................................................................................................. 13 2.0 Location of Works ................................................................................................................... 15
2.1 Headworks and Associated Works/Structures = Area 1 ..................................................... 15 2.2 Access Road, Powerhouse and Associated Works/Structures = Area 2 ............................. 15
3.0 Vegetation Description and Assessment Method – Area 1 ..................................................... 16
3.1 Vegetation Type Descriptions for Area 1 ........................................................................... 16 4.0 Vegetation Effects In Area 1 ................................................................................................... 26
4.1 Weir ..................................................................................................................................... 28 4.2 Intake Channel ..................................................................................................................... 28 4.3 Intake Structure and Intake Portal ....................................................................................... 29
4.4 Tunnel Portal Entrance ........................................................................................................ 30 4.5 Intake Access Road from Tunnel Portal Entrance to Intake Structures .............................. 30
4.6 Road to Contractors’ Facilities Area ................................................................................... 31
4.7 Contractors’ Facilities Area ................................................................................................ 32 4.8 Flushing Tunnel Outlet ........................................................................................................ 33
5.0 Other Observations Relating to Vegetation – Area 1 .............................................................. 33 6.0 Vegetation Description and Assessment Method - Area 2 ..................................................... 34
6.1 Vegetation Type Descriptions for Area 2 ........................................................................... 34 7.0 Vegetation Effects in Area 2 ................................................................................................... 48
7.1 Tunnel Portal Exit and Construction Apron ........................................................................ 49 7.2 Access Road and Transmission Line .................................................................................. 50 7.3 Waterway Training and Flood Protection – Alpha Creek ................................................... 52
7.4 Powerhouse and Switchyard ............................................................................................... 53 7.5 Powerhouse to Tunnel Portal Exit Access Road and Penstock ........................................... 54
7.6 Tailrace ................................................................................................................................ 54
7.7 Stopbank Protection for Powerhouse, Switchyard, Tailrace, Penstock and Access Road .. 55
8.0 Other Observations Relating to Vegetation – Area 2 .............................................................. 56 9.0 Significance and Natural Values Assessment ......................................................................... 57
9.1 Area 1 and Area 2 Vegetation Type(s) – Significance and Natural Heritage Value
Assessment ................................................................................................................................ 63
9.2 Summary of Vegetation Significance and Natural Heritage Value .................................... 72 10.0 Recommended Monitoring, Mitigation and Remediation ..................................................... 75
10.1 Area 1 - Monitoring/Mitigation/Remediation: .................................................................. 75
10.2 Area 2 - Monitoring/Mitigation/Remediation: .................................................................. 76 11.0 Summary/Conclusions .......................................................................................................... 77
11.1 Area 1 - Headworks and Associated Structures ................................................................ 77 11.2 Area 2 - Tunnel Portal Exit, Access Road/Transmission Line, Stream Training,
Powerhouse, Switchyard, Penstock, Tailrace and Stopbank Facilities ..................................... 80 Acknowledgements ....................................................................................................................... 83
References ..................................................................................................................................... 83 List of Appendices ........................................................................................................................ 84
Appendix A Map 1: Project Area General Location. ................................................................ 85
Appendix A Diagram 1: Headworks Infrastructure Concept. ................................................... 87 Appendix A Map 2: Infrastructure Locations and Vegetation Type Delineations – Area 1. .... 89 Appendix A Map 3: Infrastructure Locations and Vegetation Type Delineations – Area 2. .... 91 Appendix A Map 4: Wilberg Ecological District and Waitaha Catchment With LCDB Land
Cover Types. ............................................................................................................................. 93
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Appendix A Map 5: Base Area Delineation on Topographic Mapping. ................................... 95
Appendix A Map 6: Base Area LCDB Land Cover Types. ...................................................... 97 Appendix B: Species List with Maori and Common Names .................................................... 99
List of Figures
Figure 1 - Example of Vegetation Types 1/1 & 1/3: ..................................................................... 17
Figure 2 - Example of Vegetation Types 1/1 & 1/2: ..................................................................... 18 Figure 3 - Example of Vegetation Types 1/1 & 1/3: ..................................................................... 20 Figure 4 - Example of Vegetation Types 1/1 & 1/3: ..................................................................... 21 Figure 5 - Example of Vegetation Type 1/3: ................................................................................. 21 Figure 6 - Example of Vegetation Type 1/3: ................................................................................. 22
Figure 7 - Example of Vegetation Types 1/1 & 1/3: ..................................................................... 22
Figure 8 - Example of Vegetation Type 1/3 Shrub Component Cover in Morgan Gorge: ........... 23 Figure 9 - Example of Vegetation Type 1/3: ................................................................................. 23
Figure 10 - Example of Vegetation Type 1/4: ............................................................................... 25 Figure 11 - Example of Vegetation Type 1/4: ............................................................................... 25 Figure 12 - Example of Vegetation Type 2/1: ............................................................................... 36
Figure 13 - Example of Vegetation Type 2/2: ............................................................................... 37 Figure 14 - Example of Vegetation Type 2/2: ............................................................................... 38 Figure 15 - Example of Vegetation Types 2/3 & 2/3A: ................................................................ 39
Figure 16 - Example of Vegetation Type 2/3B: ............................................................................ 40 Figure 17 - Example of Vegetation Type 2/4: ............................................................................... 41
Figure 18 - Example of Vegetation Types 2/5 & 2/6: ................................................................... 43 Figure 19 - Example of Vegetation Types 2/5 & 2/6: ................................................................... 44 Figure 20 - Example of Vegetation Type 2/6: ............................................................................... 45
Figure 21 - Example of Vegetation Type 2/7: ............................................................................... 46
Figure 22 - Example of Vegetation Type 2/8: ............................................................................... 47 Figure 23 - Example of Vegetation Type 2/9: ............................................................................... 48
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List of Tables
Table 1: Weir Construction Distances and Potentially Affected Areas Within Vegetation Type.28 Table 2: Intake Channel Potentially Affected Areas Within Vegetation Type. ............................ 29 Table 3: Intake Structure and Intake Portal Potentially Affected Areas Within Vegetation Types.
....................................................................................................................................................... 30
Table 4: Tunnel Portal Entrance Potentially Affected Areas Within Vegetation Types. ............. 30 Table 5: Tunnel Portal Entrance Apron, Intake Access Road and River Protection Potentially
Affected Areas Within Vegetation Types. .................................................................................... 31 Table 6: Road to Contractors’ Facilities Distances and Potentially Affected Areas Within
Vegetation Types. .......................................................................................................................... 32
Table 7: Contractors’ Facilities Potentially Affected Area Within Vegetation Type. .................. 32 Table 8: Flushing Tunnel Outlet Potentially Affected Areas Within Vegetation Types. ............. 33 Table 9: Tunnel Portal Exit and Construction Apron Potentially Affected Area Within
Vegetation Types. .......................................................................................................................... 49
Table 10: Access Road Distances and Potentially Affected Areas Within Vegetation Types. .... 51 Table 11: Waterway Training and Flood Protection Works (Alpha Creek) Distance and
Potentially Affected Area Within Vegetation Type. ..................................................................... 53
Table 12: Powerhouse, Switchyard and Hard-fill Zone Potentially Affected Area Within
Vegetation Type. ........................................................................................................................... 53
Table 13: Powerhouse to Tunnel Portal Exit Road and Penstock Distance and Potentially
Affected Areas Within Vegetation Type. ...................................................................................... 54
Table 14: Tailrace Distance and Potentially Affected Area Within Vegetation Type. ................. 55 Table 15: Stopbank Distance and Potentially Affected Area Within Vegetation Type. ............... 56 Table 16: Criteria Framework for Determining Significance and Natural Heritage Values for
Purposes of Section 6(c) of the Resource Management Act 1991 (RPS & WDP) and Natural
Heritage Values (CMS). ................................................................................................................ 58
Table 17: LCDB Land Cover Class and Analogous Vegetation Type Area Summaries and
Comparisons for Wilberg Ecological District, Waitaha Catchment and Base Area and the
Scheme’s Project Footprint. .......................................................................................................... 62 Table 18: Summary of Significant Indigenous Vegetation and High Natural Heritage Value
Assessment Criteria Applicable To Area 1 and Area 2 Vegetation. ............................................. 73
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Executive Summary
1. Potential Environmental Effects:
Westpower is proposing a run-of-river hydroelectric power scheme development in the Waitaha
River valley, the Waitaha Hydro Scheme (the Scheme). The land on which the predominant
amount of indigenous vegetation potentially affected by the Scheme occurs is part of the
Waitaha Forest conservation unit being Stewardship Land administered by the Department of
Conservation (DOC). Various types of indigenous vegetation cover are present across the entire
area. No significant historical anthropogenic modification has occurred at any site potentially
affected by the Scheme within the Waitaha Forest conservation unit.
The Scheme consists of two sets of components in two distinct areas (see Appendix A, Map 1)
that will affect vegetation in various ways. (N.B: the order of description here is not necessarily
the order of any construction activity):
Area 1: Headworks including construction and maintenance of:
a) Weir.
b) Water intake structures.
c) A tunnel portal entrance and short section of access road at the true-right upstream end of
Morgan Gorge, just below Kiwi Flat.
d) A short access road to a contractors’ facilities area and the area itself on a small alluvial
terrace on the true-right c. 250 metres upstream of Morgan Gorge entrance.
e) A flushing tunnel outlet in the Morgan Gorge.
A main tunnel will provide access from the lower Waitaha Valley to the various
headworks facilities. It will contain flushing basin structures and a penstock. Construction
and operation of these underground components will not affect vegetation.
Area 2: Powerhouse and access road works including construction and maintenance of:
a) A heavy transport access road with power transmission line parallel, from the true left
side of Macgregor Creek in the lower valley to the site of powerhouse construction, with
roading extending on from the powerhouse to the tunnel portal exit site. N.B: Vegetation
description and effects assessment given in this report only pertain to that part of the
access road and transmission line shown on Appendix A, Map 3. The rest of the access
road and transmission line are expected to pass over private farmland and possibly other
Crown land and legal road. Vegetation effects, if any, on these areas will depend on
location of infrastructure. This is not finalised by Westpower at the time of preparation of
this report.
b) A section of access road from the powerhouse to the tunnel portal exit.
c) A tunnel portal exit on the true-right of the Waitaha River, c. 1.5 km in straight line
distance below the nearest part of the area of headworks infrastructure (and tunneling
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excavation itself, while not affecting vegetation, will require some area e.g. for access,
equipment and spoil handling/transfer).
d) Powerhouse and switchyard.
e) Penstock to convey water from the tunnel portal exit to the powerhouse.
f) Tailrace to carry water from the powerhouse back to the river.
g) Stopbank river protection for powerhouse, switchyard, a portion of access road and
penstock facilities.
h) Waterway training and flood protection at Alpha Creek (to protect the access road and
tailrace).
Two streams that are shown on the NZTopo50 1:50,000 map of the area but are unnamed have
been assigned in-house names by Westpower for descriptive purposes. These are:
1. Granite Creek = the first unnamed stream shown on map sheet NZTopo50-BW17 south
of Macgregor Creek.
2. Alpha Creek = the second stream shown on map sheet NZTopo50-BW17 south of
Macgregor Creek.
Vegetation clearance or disturbance during construction activities within the Scheme’s project
footprint (the area affected by construction), and the permanent removal of vegetation in the
lesser area of the Scheme’s operational footprint (areas permanently occupied by Scheme
components), are the principal environmental effect on indigenous vegetation.
The following table provides a summary of the areas of vegetation potentially affected by the
Scheme. It is important to note that areas given as construction, permanent and riparian
(construction) are not additive. The construction area is the expected maximum area potentially
affected by each Scheme component and the construction total is an indication of the Scheme’s
project footprint as it pertains to vegetation effect. Areas given as permanent and riparian areas
are sub-areas for purposes of describing amount of vegetation clearance associated with a given
Scheme component. In the case of permanent areas these indicate the operational footprint of
each Scheme component and for the Scheme in total. Riparian areas are given because activities
affecting indigenous vegetation in riparian margins will require consideration for regional and
district planning provision purposes.
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Areas of Vegetation Potentially Affected by Scheme Components and in Total:
Scheme Component(s) Construction
(ha)
Permanent
(ha)
Riparian
(Construction,
ha)
Area 1: Headworks and Associated
Infrastructure Item(s)
Weir. 0.0050 0.0010 0.0
Intake Channel. 0.0325 0.0163 0.0
Intake Structure and Intake Portal. 0.0478 0.0278 0.0294
Tunnel Portal Entrance. 0.0187 0.0187 0.0
Tunnel Portal Entrance Apron, Intake Access
Road and River Protection at Road Toe.
0.1370 0.0790 0.0410
Road to Contractors’ Facilities Area. 0.1040 0.0 0.0300
Contractors’ Facilities Area. 0.2200 0.0 0.0
Flushing Tunnel Outlet. 0.0100 0.0100 0.0100
Area 1 Sub-totals 0.5750 0.1528 0.1104
Area 1 Sub-totals Rounded Up 0.58 0.16 0.12
Area 2: Infrastructure Item(s)
Tunnel Portal Exit and Construction Apron. 0.2480 0.1800 0.0
Access Road and Transmission Line Parallel. 2.5470 2.4198 0.0450
Waterway Training and Flood Protection at
Alpha Creek.
0.3375 0.1688 0.1750
Powerhouse, Switchyard and Hard-fill Area. 0.3150 0.3150 0.0
Powerhouse to Tunnel Portal Exit Access Road
and Penstock.
0.1275 0.1275 0.0
Tailrace. 0.2000 0.2000 0.0250*
Stopbank as River Protection for Powerhouse,
Switchyard, Tailrace, Penstock and Access
Road.
0.1755 0.1169 0.1755
Area 2 Sub-totals 3.9505 3.5280 0.4205
Area 2 Sub-totals Rounded Up 3.96 3.53 0.43
Scheme Totals 4.5255 3.6808 0.5309
Scheme Totals Rounded Up 4.53 3.69 0.54 Note: Areas given as rounded sub-totals and totals in the above table are rounded up to two decimal places in every
case so as to avoid dropping any area as could occur if using conventional rounding of figures less than five.
Note: Areas do not include non-vegetated zones affected by work components or parts thereof, e.g. where these are
on exposed bedrock or in active river bed and are unvegetated pre-project. All are indicative based on
November 2013 Scheme plans supplied by Westpower and may vary from those given above depending on final
design, survey and siting.
Note: Riparian areas are for streams >3metres wide where provisions of the Proposed Regional Land and Water
Plan (WCRC, 2013) and the Westland District Plan (WDC, 2002) prescribe 10 metre riparian margin widths.
Streams 1 – 3 meters wide occur in or near various areas of activity and provisions of the Proposed Regional Land
and Water Plan (WCRC, 2013) prescribe 10 metre wide riparian margins for these if slope is >12o and 5 metre
wide riparian margins otherwise. This requirement will add some (expected to be relatively minor) area to the
estimates given above, however the detailed field survey and mapping of small stream location was not a component
of work undertaken as the basis of this report. The number and exact location of streams 1 - 3 metres wide that are
potentially affected will need to be determined for regional planning provision purposes, although it is not
considered that potential effects on vegetation will be any greater than already assessed and considered.
Note: Tailrace riparian area potentially affected as marked * is an estimate based on an oblique angle crossing of
the Waitaha River true-right 10 metre riparian zone by the 20 metre wide tailrace – actual affected area may vary
depending on final angle of traverse of the tailrace through the riparian margin, however any variation in affected
area carrying vegetation is expected to be minimal.
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2. Assessments Undertaken:
Fieldwork was undertaken in the periods 22/8/12 – 23/8/12 and 12/9/12 – 13/9/12 with a
subsequent visit on 30/9/13. It covered land administered by DOC within and surrounding the
Scheme project footprint. Areas covered are shown in Appendix A, Maps 1, 2 and 3. It involved
walkthrough as terrain permitted, but where possible by transect across the run of land. Use of
any predefined sampling system (random or systematic) on all areas was deemed impractical due
primarily to difficulty of terrain particularly about the headworks sites. Representative areas
were covered based on interpretation of cover type from aerial photography and field
observation.
This report:
Describes the main vegetation types present, and those potentially affected by the
Scheme.
Assesses uniqueness of the potentially affected vegetation types and whether any areas
have high natural heritage value in terms of the West Coast Conservation Management
Strategy 2010 – 2020 (DOC 2010).
Provides an assessment of significance of indigenous vegetation against criteria and
guidelines in the West Coast Regional Policy Statement (WCRC, 2000) and the Westland
District Plan (WDC, 2002).
Describes the potential effects, including residual effects, of the Scheme on indigenous
terrestrial vegetation.
Recommends monitoring and mitigation/site rehabilitation.
3. Results of Assessments:
Vegetation within Area 1, Area 2 and their surrounds would be considered as having high natural
heritage values under the West Coast Conservation Management Strategy 2010 – 2020 (DOC,
2010) criteria of intactness and viability. It is considered significant indigenous vegetation under
provisions of the Westland District Plan (WDC, 2002) on the basis of two criteria - intactness
and size of area, and protected status.
The predominant vegetation types present in Area 1 are typical of streamside and side-slope
areas across a relatively wide altitudinal range (e.g. 100 – 500 m.a.s.l.) within forested Westland
catchments. The vegetation types present on the recent alluvial flat and terrace sequence in
Area 2 are also typical of forested Westland catchments. GIS analysis undertaken using the Land
Cover Database (LCDB) land cover classes matched to the indigenous forest type assemblages
(all Vegetation Types except Vegetation Type 1/4, a shrubland type in Area 1) potentially
affected by the Scheme shows these are present across 27,903 hectares of the Wilberg Ecological
District. This is 44% of its total indigenous vegetation cover. They are present across
4,334 hectares of the Waitaha Catchment. This is 36% of its total indigenous vegetation cover.
The vegetation type assemblages present are common and widely represented in both the
Wilberg Ecological District and the Waitaha catchment. The indigenous forest assemblages also
occur extensively in catchments of similar valleys throughout central Westland. Vegetation
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Type 1/4, a small area of which is within the Scheme project footprint is analogous to the LCDB
Sub Alpine Shrubland land cover class. GIS analysis shows it occurs over 17,269 hectares in the
Wilberg Ecological District and therefore comprises 27% of its total indigenous vegetation
cover. It is present across 4,249 hectares of the Waitaha catchment and therefore comprises 35%
of its total indigenous vegetation cover. Like the indigenous forest vegetation of Area 1 and
Area 2, this shrubland vegetation is also common and widely represented, not only in the areas
noted above but in other valleys throughout central Westland.
No threatened plant species and no vegetation community uniqueness, attributes or species
associations/presence were identified within or surrounding the Scheme’s project footprint.
For streams >3 metres wide, provisions of the Proposed Regional Land and Water Plan (WCRC,
2013) and the Westland District Plan (WDC, 2002) prescribe 10 metre riparian margin widths.
Vegetation types present in riparian margins in Area 1 and Area 2 are not unique or
distinguished floristically from their counterparts not occupying a riparian strip. It is the arbitrary
riparian designation of fixed-width distance from stream bank, not vegetation, that distinguishes
these zones and that may have environmental planning restrictions that would not otherwise
apply.
For streams 1 – 3 metres wide, provisions of the Proposed Regional Land and Water Plan
(WCRC, 2013) prescribe 10 metre wide riparian margins if dominant slope angle is >12o and
5 metre riparian margins otherwise. This requirement will add some (expected to be relatively
minor) area to available estimates of affected riparian area, however the detailed field survey and
mapping of small stream location was not a component of work undertaken as the basis of this
report. The number and exact location of streams 1 - 3 metres wide that are potentially affected
will need to be determined for regional planning provision purposes, although it is not
considered that potential effects on vegetation will be any greater than already assessed and
considered.
The scale of proposed works within Area 1 is well within the spatial scale of natural disturbances
typical of this environment i.e., does not represent clearance of large areas in conjunction with a
change in land use and cover type. The nature of vegetation disturbance (removal) caused by the
proposed work would not be deemed inconsistent with natural disturbance events e.g. slips, at
this or similar sites. Construction involves clearance or at least some disturbance to
approximately 0.58 hectares of indigenous vegetation. This area, based on LCDB land cover
classes, is an extremely low proportion of the types present being:
0.15% of the c. 396 hectares of the similar indigenous forest vegetation
(385 hectares)/sub alpine shrubland (11 hectares) assemblages contained in the Base
Area, a zone below the 400 metre contour and on the true-right of the Waitaha River/true
left of Macgregor Creek carrying vegetation typical of that in the Scheme’s project
footprint, containing and surrounding the project footprint and considered its general
locale.
0.007% of the 8,583 hectares of their counterparts in the Waitaha catchment.
0.001% of the 45,172 hectares of their counterparts in the Wilberg Ecological District.
The headworks operational footprint is significantly less again, being 27% of the project
footprint for headworks. Following the construction phase, the activity becomes relatively
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benign, and appears to have low likelihood of requiring disturbance of vegetation at any of the
areas. Therefore, the proposed activity is not considered to have any long-term detrimental effect
on vegetation surrounding the various sites. Natural regeneration should occur across any areas
affected by construction (except those areas occupied by structural components).
Scheme effects on indigenous vegetation in Area 1 are considered negligible.
For the Scheme components in Area 2, scale of proposed works is well within the spatial scale of
natural features contributing to discontinuity in vegetation cover e.g:
a. The narrow linear footprint of the access road/transmission corridor, at 20 metres
maximum, is less than half the width of the Waitaha River bed at its narrowest in the
portion that the road parallels. (Note: for purposes of estimating vegetation clearance for
the road/transmission line an average of 15 metres has been used).
b. The alluvial flat area on which the proposed powerhouse, switchyard, access road to the
tunnel portal exit, tailrace and stopbank are located is of similar width to the Waitaha
River bed adjacent to it (and it is already predominantly open i.e. not carrying closed-
canopy vegetation cover).
Construction involves clearance or at least some disturbance to 3.96 hectares of indigenous
vegetation that, based on LCDB land cover classes, is an extremely low proportion of the types
present being:
1.0% of the c. 385 hectares of the similar indigenous forest vegetation assemblages
contained in the Base Area, a zone below the 400 metre contour and on the true-right of
the Waitaha River/true left of Macgregor Creek carrying vegetation typical of that in the
Scheme project footprint, containing and extending beyond the project footprint and
considered its general locale.
0.09% of the 4,334 hectares of their counterparts in the Waitaha catchment.
0.01% of the 27,903 hectares of their counterparts in the Wilberg Ecological District.
The same pertains for all Scheme components in Area 2 as for Area 1, where, following the
construction phase, the activity becomes relatively benign, and appears to have low likelihood of
requiring disturbance of vegetation. Therefore, the proposed activity is not considered to have
any long-term detrimental effect on vegetation surrounding the various sites. Natural
regeneration should occur across any areas affected by construction (except those areas occupied
by structural components).
Forming and maintaining an access road to the powerhouse and tunnel portal exit affects the
greatest area and range of vegetation. While no uniqueness in terms of overall vegetation type(s)
is attributable to the general area in which the proposed access routes to these facilities would be
located, defining a route that results in least damage to all vegetation, and especially large
hardwood trees taken as being 60+ cm diameter at breast height (dbh) and large podocarp trees
taken as being 30+ cm dbh is a priority. This should be achievable because large hardwood and
podocarp tree densities across the recent terrace landforms the access road would mainly traverse
are very low. Appropriate final route delineation and ground survey will be key activities in
achieving this.
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Scheme effects on indigenous vegetation in Area 2 are considered minor.
Overall, effects of the Scheme on vegetation (classified as significant indigenous vegetation
under the Westland District Plan (WDC, 2002) and on any contribution to high natural heritage
values under the West Coast Conservation Management Strategy 2010 – 2020 (DOC, 2010) are
likely to be minor. This is based on the small amount of clearance (approximately 4.53 hectares)
that will occur within the surrounding contiguous area and within the combined indigenous
forest and shrubland cover of the Base Area of c. 396 hectares, combined with measures to be
implemented wherever practicable that avoid affecting important habitat components e.g. large
forest trees.
4. Suggested Approach to Effects Identified:
Risk Reduction and Monitoring
Weed incursion is a risk wherever earthmoving machinery is transported from areas where
weeds have been present, and in particular where gravel, and to a lesser extent rock, is carted in
to an area. While broadleaved herbaceous weeds that have wind dispersed seed are present in
low densities in areas without closed-canopy forest cover e.g., in grassed clearings and on
streamside zones, brushweed species are not established in Area 1 or Area 2 apart from a very
small zone of Ulex europaeus in an area of grassed alluvial flat adjacent to Macgregor Creek on
its true-left side that is grazed by cattle.
Earthmoving machinery should be thoroughly washed down prior to entering any part of Area 1
or Area 2 so as to reduce the risk of weed seed transport.
Recommended monitoring for weed establishment, in particular for Ulex europaeus but also for
other woody species e.g. Leycesteria formosa, should be undertaken at least annually and be
ongoing for all areas where gravel/rock has been carted in for Scheme components that comprise
the operational footprint.
For the headworks contractors’ facilities area, the access road to this and for any portion of the
tunnel portal exit apron decommissioned after construction is finished, annual monitoring for
weed establishment for a minimum of five seasons is recommended.
Remediation
Monitoring results will identify if there is any requirement for weed control in respect of any
Scheme component and the most appropriate control method to employ if required. If weed
control is found necessary anywhere in the Scheme project footprint it needs to be done as soon
as practicable in the most effective season for best control results for the species concerned, and
in any case prior to plants attaining seeding maturity.
Mitigation
Scheme design and location ensures that only a very small total area of indigenous vegetation is
affected. Infrastructure location largely avoids areas that carry mature podocarp/hardwood forest
or higher densities of large hardwood trees in those types where podocarp presence is reduced.
The access road/transmission line, intake access road and access road to the contractors’
facilities area traverse a variety of vegetation types and together incorporate most of the Scheme
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project footprint as it affects vegetation. While potential effects are minor, they can be further
reduced by defining access road/transmission line, intake access road and access road to the
contractors’ facilities area routes that, subject to engineering considerations, result in least
damage to all vegetation, and especially large (60+ cm dbh) hardwood trees and podocarp trees
(30+ cm dbh). A component of this work would be to enumerate and mark all large trees within a
fixed width of the road formation centerlines and use these data to make any practicable road
alignment adjustments to avoid as many of these large trees as possible.
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1.0 Introduction
Westpower is proposing a run-of-river hydroelectric power scheme development in the Waitaha
River valley, the Waitaha Hydro Scheme (the Scheme) and have commissioned this report
describing terrestrial flora as a component of project planning.
The land on which the predominant amount of indigenous vegetation potentially affected by the
Scheme occurs is within Reserve 1672 and Section 1, Survey Office Plan 12094. These
landholdings are part of the Waitaha Forest conservation unit being Stewardship Land
administered by the Department of Conservation (DOC). The proposed activity sites are within
the Wilberg Ecological District, the general area of proposed activities being predominantly on
the true-right side of the Waitaha River upstream from Macgregor Creek to the upper end of the
Morgan Gorge (Appendix A, Map 1).
The Scheme consists of two sets of components in two distinct areas that will affect vegetation in
various ways. (N.B: the order of description here is not necessarily the order of any construction
activity):
Area 1: Headworks including construction and maintenance of:
a) Weir.
b) Water intake structures.
c) A tunnel portal entrance and short section of access road at the true-right upstream
end of Morgan Gorge, just below Kiwi Flat.
d) A short access road to a contractors’ facilities area and the area itself on a small
alluvial terrace on the true-right c. 250 metres upstream of Morgan Gorge entrance.
e) A flushing tunnel outlet in the Morgan Gorge.
A main tunnel will provide access from the lower Waitaha Valley to the various
headworks facilities. It will contain flushing basin structures and a penstock.
Construction and operation of these underground components will not affect
vegetation.
Area 2: Powerhouse and access road works including construction and maintenance of:
a) A heavy transport access road with power transmission line parallel, from the true left
side of Macgregor Creek in the lower valley to the site of powerhouse construction,
with roading extending on from the powerhouse to the tunnel portal exit site. N.B:
Vegetation description and effects assessment given in this report only pertain to that
part of the access road and transmission line shown on Appendix A, Map 3. The rest
of the access road and transmission line are expected to pass over private farmland
and possibly other Crown land and legal road. Vegetation effects, if any, on these
areas will depend on location of infrastructure. This is not finalised by Westpower at
time of preparation of this report.
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b) A section of access road from the powerhouse to the tunnel portal exit.
c) A tunnel portal exit on the true-right of the Waitaha River, c. 1.5 km in straight line
distance below the nearest part of the area of headworks infrastructure (and tunneling
excavation itself, while not affecting vegetation, will require some area e.g. for
access, equipment and spoil handling/transfer).
d) Powerhouse and switchyard.
e) Penstock to convey water from the tunnel portal exit to the powerhouse.
f) Tailrace to carry water from the powerhouse back to the river.
g) Stopbank river protection for powerhouse, switchyard, a portion of access road and
penstock facilities.
h) Waterway training and flood protection at Alpha Creek (to protect the access road
and tailrace).
Indigenous vegetation of various types and cover densities occurs across the entire project area,
except the active riverbed and tributary streambed zones. Exotic plant species occur, in particular
on open riverbed/floodplain surfaces however incidence is relatively low and no other significant
historical anthropogenic modification has occurred at any site. Cattle grazing of a river flat area
upstream of Macgregor Creek appears to be sporadic. Possums and deer appear to be present in
low numbers and their impact on vegetation is likewise low.
The purpose of this report is to assess the effects of the Scheme on indigenous terrestrial
vegetation. In doing so this report:
Describes the main vegetation types present in the area and those potentially affected by
the Scheme.
Assesses the significance or uniqueness of the potentially affected vegetation types.
Describes and assesses the potential effects of the Scheme on indigenous terrestrial
vegetation.
Proposes mitigation and rehabilitation.
Describes predicted residual effect of the Scheme, overall, on vegetation.
This report presents the findings of a field assessment of vegetation undertaken in the periods
22/8/12 – 23/8/12 and 12/9/12 – 13/9/12 with a subsequent visit on 30/9/13. Fieldwork covered
land administered by DOC surrounding the proposed project footprint (construction and
operational areas combined) and the operational footprint i.e., permanent site occupancy once
construction is completed. It did not extend outside the Waitaha Forest conservation unit.
Vegetation type descriptions and species noted are based on visual assessment.
15
2.0 Location of Works
Construction activities are differentiated in two main areas in different parts of the lower
Waitaha Valley. For purposes of vegetation description and assessment these areas are hereafter
designated Area 1 (headworks) and Area 2 (including powerhouse and associated infrastructure,
access road and transmission line, and tunnel portal exit) as shown on Appendix A, Map 1, being
approximately 1.5 kilometres apart in straight line distance between closest proposed works
points.
Two streams that are shown on the NZTopo50 1:50,000 topographic mapping of the area but are
unnamed have been assigned in-house names by Westpower Ltd. to facilitate description of
Scheme components and their location. These are:
1. Granite Creek = the first unnamed stream shown on map sheet NZTopo50-BW17 south
of Macgregor Creek.
2. Alpha Creek = the second stream shown on map sheet NZTopo50-BW17 south of
Macgregor Creek.
N.B: The locations and distances given in Sections 2.1 and 2.2 are based on information
provided by Westpower as of November 2013 for capturing relevant data and forming vegetation
type descriptions for the various areas, however exact sites of construction of any of the
proposed works may vary slightly in terms of grid references and infrastructure distances given
in this report.
2.1 Headworks and Associated Works/Structures = Area 1
This is the area of proposed weir, water intake and associated structures, tunnel portal entrance,
access roading, contractors’ facilities area and flushing tunnel outlet (Appendix A, Map 1, Map 2
& Diagram 1) at the upstream end section of Morgan Gorge with the majority of construction
activity concentrated at c. NZTM E1415825; N5222160 at altitude of c. 240 m.a.s.l. Associated
with headworks construction is the proposed contractor’s facilities area on the nearest flat zone
of sufficient size on the same side of the river at c. NZTM E1416125; N5222050.
Tunneling will not impact on vegetation except in relation to tunnel entry portals and any
associated apron placement as noted above.
2.2 Access Road, Powerhouse and Associated Works/Structures = Area 2
This is the area for a tunnel portal exit and tunneling excavation, and for heavy transport access
road, power transmission line, powerhouse, switchyard, penstock, tailrace and stopbank
infrastructure (Appendix A, Map 1 & Map 3).
It extends from Macgregor Creek along the true-right side of the Waitaha River to c. 0.75 km
below Morgan Gorge.
16
3.0 Vegetation Description and Assessment Method – Area 1
Different vegetation types were identified to describe the principal variations present within
Area 1, and their extent. The types identified and described are sometimes quite clearly
demarcated by topographical change e.g. by a terrace dropover where a clear type change occurs
between higher and lower terraces, or between a recent alluvial flat and a forested margin.
However, this is not always the case and it is common to have varying degrees of intergradation
where topographical change is gradual and types merge. Also, the vegetation types were
determined by the main species within cover tiers (e.g. emergent, canopy, understory/shrub,
groundcover). It was not intended that the survey provide a complete catalogue of every species
present within a given type.
Vegetation assessment and description within the area and within vegetation types was on the
basis of observation by walkthrough, as terrain permitted, but where possible by transect across
the run of land. Use of any predefined sampling system (random or systematic) on all areas was
deemed impractical due primarily to difficulty of terrain particularly about the headworks sites.
Representative areas were covered based on interpretation of cover type from aerial photography
and field observation, with final delineation on the basis of checks and/or changes observed
during traverse. The result is a segregation of Area 1 into four vegetation types for descriptive
purposes. These are coded 1/1, 1/2, 1/3 and 1/4 (see Appendix A, Map 2).
3.1 Vegetation Type Descriptions for Area 1
Key landforms in Area 1 include hill foot slopes, terraces and terrace faces associated with these
and an area of relatively recent alluvial terrace. The principal forest types present here can be
broadly grouped as kamahi forest and seral forest using the classification described by James et
al., (1973), and as lowland forest and seral low forest under the classifications described by
Wardle, (1977, 1979 and 1991).
Note: Seral vegetation communities occur on sites prone to disturbance e.g. unstable gullies,
steep faces and on recent alluvial surfaces or waterway banks. Seral forest vegetation is typically
a mix of broadleaved indigenous hardwood tree species in a regeneration phase, along with
broadleaved indigenous shrub species and tree ferns.
Type 1/1 – Forest Margin/Riparian Mixed Ground Cover and Shrub Hardwood:
This type is a mixed moss/herb/fern/monocot and shrub hardwood low cover occurring in a
narrow strip (typically 3 – 6 metres wide) from the exposed gravel/sand/rock of the active river
bed to intergrade with the shrub margin of Vegetation Type 1/3 on the true left of the Waitaha
River and in a similar situation between active riverbed and margin of Vegetation Type 1/2 on
the true-right side. The majority is inundated at time of highest river flows.
Components of this cover type also occupy the bedrock surfaces of the Morgan Gorge between
the upper level of permanently scoured-clean rock and the lower margin of the Vegetation Type
1/3 shrub component that covers the Morgan Gorge sides. Seedlings of forest tree species e.g.
Metrosideros umbellata, Weinmannia racemosa, Podocarpus hallii, Dacrydium cupressinum and
Prumnopitys ferruginea occur occasionally in this type on the lower levels of Morgan Gorge
17
sides however the latter three podocarps do not appear on the river bank margins upstream of the
gorge.
Cover height range within Vegetation Type 1/1 is from ground surface to c. 1.5 metres at the
margins of this type where it intergrades with the other forest type shrub tiers. Species
comprising the higher cover include the shrubs Coriaria arborea, Coprosma rugosa, Hebe
salicifolia, Carpodetus serratus, Carmichaelia arborea, Olearia arborescens, Olearia ilicifolia
and Olearia avicenniifolia and monocots Phormium cookianum, Astelia fragrans and Cortaderia
richardii.
Ground cover species include mosses and thallose liverworts (Marchantia berteroana and
Monoclea forsteri), and Nertera depressa, Hydrocotyle moschata, Gingidia montana,
Hypochoeris radicata, Pratia angulata, Anisotome hastii, Acaena anserinifolia, Rubus parvus,
Raoulia tenuicaulis, Parahebe lyallii, Cirsium palustre, Cirsium arvense, Uncinia sp., Schoenus
pauciflorus, Poa spp., Agrostis dyeri, Festuca sp., Carex goyenii, Hierochloe novae-zelandiae,
Rytidosperma setifolium, and Blechnum sp. “black spot”. In damp zones under other cover or on
banks, Blechnum chambersii and Blechnum colensoi occur.
Figure 1 - Example of Vegetation Types 1/1 & 1/3:
Vegetation Type 1/1 occupies a narrow strip of c. 3 – 6 metres between the active Waitaha River
bed and the shrub hardwood margin of Vegetation Type 1/3 at the foot of the slope beyond the
river bank.
Type 1/2 - Regenerating Hardwood Shrub/Tree Mix With Low Podocarp Element:
This is an area of closed-canopy regenerating hardwood shrub and tree cover occupying a foot
slope face on the true-right of the Waitaha River extending upstream from the upper end of
Morgan Gorge for c. 150 metres. It extends c. 20 - 40 metres upslope to gradually intergrade
with Vegetation Type 1/3.
18
Canopy height is c. 6 - 8 metres with prevalent species being Griselinia littoralis (particularly
frequent), Weinmannia racemosa, Carpodetus serratus, Olearia ilicifolia, Olearia arborescens,
and Pseudowintera colorata. Occasional small (c. 30 cm diameter at breast height (dbh))
Podocarpus hallii stems are present in upper zones where an intergrade with Vegetation
Type 1/3 occurs.
Understory and shrub species include canopy species regeneration, Schefflera digitata,
Aristotelia serrata, Coprosma ciliata, Coprosma rhamnoides, Coprosma foetidisima, Coprosma
rotundifolia (in drier zones), Coprosma tayloriae, Coprosma colensoi, Myrsine divaricata,
Pseudopanax anomalus, occasional Quintinia acutifolia and scattered Prumnopitys ferruginea
and Podocarpus hallii seedlings. Cyathea smithii tree ferns occur throughout, while Dicksonia
squarrosa tree ferns are less prevalent. Carmichaelia arborea, Coriaria arborea and Hebe
salicifolia are present about margins.
Ground cover species are mosses including Hypopterygium novae-seelandiae, Mniodendron
dendroides, and Cyathophorum bulbosum, liverworts (Monoclea forsteri, Marchantia
berteroana and Schistochila sp.), Nertera vilosum, Nertera depressa, Viola filicaulis, Microlaena
avenacea, Uncinia uncinata, Astelia fragrans, Pneumatopteris pennigera, Asplenium bulbiferum,
Leptopteris superba, Blechnum sp. “black spot”, Blechnum fluviatile, Blechnum colensoi,
Metrosideros diffusa and scattered seedlings of canopy and shrub species.
Epiphytes include Asplenium flaccidum, Hymenophyllum spp., Trichomanes reniforme, and
Astelia fragrans.
Figure 2 - Example of Vegetation Types 1/1 & 1/2:
Vegetation Type 1/2 occupies the foot slope face and upper terrace margins at the entry to
Morgan Gorge. Moss and herbaceous components of Vegetation Type 1/1 occur in a very narrow
strip on the large rocks between the active Waitaha River bed and the margin of Vegetation
Type 1/2.
19
Type 1/3 – Mature Podocarp/Hardwood Hill Forest:
This occurs on terraces, terrace faces and hill foot slope/side slope areas. The type is mature
podocarp/hardwood hill forest with the podocarp element more prevalent on terrace zones and in
particular along better-drained terrace edges, ridges and on higher-level slopes. In gully sides and
on faces, including the upper sides of Morgan Gorge, the podocarp element is reduced,
hardwoods forming the canopy.
Canopy emergents are principally Dacrydium cupressinum (dbh range typically 50 – 100+ cm),
and to lesser extent, Podocarpus hallii, Prumnopitys ferruginea and Metrosideros umbellata.
Libocedrus bidwillii trees typically 40 – 80 cm dbh, occur either as scattered individuals or in
small patches, in particular on the upper terrace surface on the true right of the Morgan Gorge,
and Podocarpus hallii trees appear more frequent here.
Canopy height is c. 16 – 22 metres in upper zones, reducing on lower faces and into Morgan
Gorge sides, where a hardwood canopy prevails and podocarps are absent or if present occur
rarely and are small. Weinmannia racemosa and Quintinia acutifolia are main canopy species
along with Metrosideros umbellata and occasional smaller stems of the emergent podocarp
species.
The understory/shrub tier includes canopy species regeneration and Pseudopanax crassifolius,
Pseudopanax colensoi, Pseudopanax anomalus, Pseudopanax simplex, Griselinia littoralis,
Carpodetus serratus, Pseudowintera colorata, Neomyrtus pedunculata, Phyllocladus alpinus,
Archeria traversii, Schefflera digitata, Coprosma lucida, Coprosma grandifolia, Coprosma
foetidissima, Coprosma rhamnoides, Coprosma tayloriae, Coprosma colensoi, Coprosma
linariifolia, and Coprosma ciliata. Ascarina lucida, Hedycarya arborea, Myrsine divaricata,
Coprosma rotundifolia and Neomyrtus pedunculata become more common in the shrub tier on
terraces and upper level slopes. Cyathea smithii and Dicksonia squarrosa tree ferns occur in
varying densities throughout.
Ground cover includes regeneration of canopy and understory species. Various mosses occur
(including Dendroligotrichum dendroides, Cyathophorum bulbosum, Hypopterygium novae-
seelandiae and Mniodendron dendroides) and liverworts are present (particularly Schistochila
spp.). Cover includes Lycopodium volubile, Nertera vilosum, Nertera depressa, Microlaena
avenacea, Uncinia spp., Astelia fragrans, Leptolepia novae-zelandiae, Lastreopsis hispida,
Pneumatopteris pennigera, Leptopteris superba, Blechnum chambersii, Blechnum sp. “black
spot”, Blechnum discolor, Phymatosorus diversifolius, Tmesipteris tannensis, Hymenophyllum
demissum, Hymenophyllum revolutum, Metrosideros diffusa, Luzuriaga parviflora, Poa colensoi,
Arthropodium candidum, Phormium cookianum and Gahnia sp. Patches of Histiopteris incisa
are present in open areas of gullies.
Climbers include Metrosideros diffusa, Metrosideros fulgens, and Rubus schmidelioides.
Epiphytes include Hymenophyllum revolutum, Hymenophyllum multifidum, Hymenophyllum
demissum, Phymatosorus diversifolius, Ctenopteris heterophylla, Asplenium flaccidum, Astelia
fragrans, Weinmannia racemosa and Quintinia acutifolia.
In zones above the scoured-clean bedrock in gorge areas, but prior to establishment of forest
shrub species as main cover, there is a zone of moss/liverwort and herbaceous and monocot
cover. This can vary in width from a few metres to ten metres or more. At least some parts of the
20
zone are affected by flooding at times of high river flow. Various moss species are common
along with liverworts (including Monoclea forsteri, Marchantia berteroana and Schistochila
sp.). Scattered seedlings of tree and shrub species occur e.g. Metrosideros umbellata, Hebe
salicifolia, Weinmannia racemosa, Coprosma rugosa, Carmichaelia arborea, Olearia
arborescens, Olearaia ilicifolia, and Olearia avicenniifolia. Otherwise, principal cover species
include Cortaderia richardii, Blechnum sp. “black spot”, Uncinia sp., Forstera tenella,
Parahebe lyallii, Agrostis dyeri, Hydrocotyle moschata, Geum leiospermum, Gunnera monoica,
Pratia angulata and Schoenus pauciflorus.
Figure 3 - Example of Vegetation Types 1/1 & 1/3:
Vegetation Type 1/3 occupies terrace faces and upper terrace margins at the entry to Morgan
Gorge. Vegetation Type 1/1 extends in a strip between the active river bed and the margin of
Vegetation Type 1/3 on the hill face at left of the photograph.
21
Figure 4 - Example of Vegetation Types 1/1 & 1/3:
Vegetation Type 1/3 on the terrace face at the true-left entry to Morgan Gorge. Vegetation Type
1/1 extends in a strip between the active river bed and the margin of Vegetation Type 1/3 at left
of the photograph and the moss/herb/monocot component rises around the bedrock of the gorge
entrance to occupy a margin c. 6 metres wide at the actual gorge entry.
Figure 5 - Example of Vegetation Type 1/3:
Vegetation Type 1/3 on the terrace edge and mid to upper face at the true-right entry to Morgan
Gorge – possible site of the tunnel portal entrance is approximately middle of photograph.
22
Figure 6 - Example of Vegetation Type 1/3:
Vegetation Type 1/3 on the terrace edge and mid to upper face on the true-right of the Waitaha
River upstream of Morgan Gorge in the zone to be traversed by access roading to the
contractors’ facilities area and from the tunnel portal entrance to headworks weir/intake
infrastructure.
Figure 7 - Example of Vegetation Types 1/1 & 1/3:
Example of Vegetation Type 1/1 grading to Vegetation Type 1/3 hardwood shrub component
cover on the true-left wall at the entrance to Morgan Gorge.
23
Figure 8 - Example of Vegetation Type 1/3 Shrub Component Cover in Morgan Gorge:
Vegetation Type 1/3 hardwood shrub cover on faces of Morgan Gorge. This grades uphill to
higher-stature hardwood canopy forest cover, with a minor podocarp element.
Figure 9 - Example of Vegetation Type 1/3:
Vegetation Type 1/3 on lower hill foot slopes above the northern margin of Kiwi Flat (note that
this is not part of the proposed headworks area – it is included as an illustration of the stature and
composition of this type of hardwood footslope forest cover with very low to no incidence of
large podocarp emergents).
24
Type 1/4 - Shrub Hardwood, Successional:
This occurs on a relatively recent alluvial terrace extending from the active stream bed of the
Waitaha River true-right, north to the hill footslope margin, the terrace surface being c. 6 –
8 metres above the bed of the river and not showing signs of flood inundation. The type is dense,
closed-canopy hardwood shrub cover, typical canopy height being c. 3 – 5 metres.
Predominant canopy species include Olearia ilicifolia, Pseudopanax anomalus, Coprosma
ciliata, Coprosma tayloriae, Coprosma sp., Coprosma colensoi, Carmichaelia arborea and
Myrsine divaricata. Other canopy hardwoods of less frequent occurrence are Griselinia littoralis
(and very occasionally as an emergent), Pennantia corymbosa, Pseudowintera colorata and
Hebe salicifolia.
A dense understory tier includes all of the canopy species, with increased presence of
Pseudowintera colorata. Carpodetus serratus and Coprosma rotundifolia are understory
components.
Common ground cover species are the moss Hypopterygium novae-seelandiae, the thallose
liverworts Monoclea forsteri and Marchantia berteroana, ferns (Blechnum fluviatile,
Polystichum vestitum, Leptopteris superba, Blechnum colensoi and occasional young Cyathea
smithii tree ferns), the monocots Microlaena avenacea and Uncinia uncinata and the
broadleaved herbs Cardamine debilis and Epilobium pedunculare.
A frequent climber is Rubus schmidelioides.
Epiphytes are the ferns Ctenopteris heterophylla, Asplenium flaccidum, Grammitis magellanica,
Hymenophyllum demissum and Hymenophyllum revolutum. Mosses, in particular Weymouthia
mollis, are common.
25
Figure 10 - Example of Vegetation Type 1/4:
Typical stature and composition of Vegetation Type 1/4 as seen along the edge of the alluvial
terrace above the active bed of the Waitaha River, northern margin of Kiwi Flat.
Figure 11 - Example of Vegetation Type 1/4:
Typical stature and species composition of Vegetation Type 1/4.
26
4.0 Vegetation Effects In Area 1
The potential effects of each infrastructure component of the Scheme within Area 1 are
described below as to the size of affected area within each Vegetation Type, within riparian
margins if applicable, and in total.
All distance and area figures given in Tables 1 - 8 are indicative. The November 2013 Scheme
plans supplied by Westpower were used for the purpose of this assessment of effects. They may
be subject to variation depending on final location, access and construction requirements.
Areas given as construction, permanent and riparian (construction) in Tables 1 – 8 are not
additive. The construction area is the expected maximum area potentially affected by each
Scheme component and the construction total is an indication of the Scheme’s project footprint
as it pertains to vegetation effect. Areas given as permanent and riparian areas are sub-areas for
purposes of describing amount of vegetation clearance associated with a given Scheme
component. In the case of permanent areas these indicate the operational footprint of each
Scheme component and for the Scheme in total.
Where riparian areas are given in Tables 1 – 8 these are for streams >3metres wide where
provisions of the Proposed Regional Land and Water Plan (WCRC, 2013) and the Westland
District Plan (WDC, 2002) prescribe 10 metre riparian margin widths. Riparian areas are given
because activities affecting indigenous vegetation in riparian margins will require consideration
for regional and district planning provision purposes.
N.B. Streams 1 – 3 metres wide occur near the various areas of possible activity in Area 1 and
provisions of the Proposed Regional Land and Water Plan (WCRC, 2013) prescribe 10 metre
wide riparian margins for streams of this size if dominant slope angle is >12o and 5 metre wide
riparian margins otherwise. This requirement may add some area to the riparian area estimates
given, however the detailed field survey and mapping of small stream location was not a
component of work undertaken. The number and exact location of streams 1 – 3 metres wide that
are potentially affected will need to be determined for regional planning provision purposes,
although it is not considered that potential effects on vegetation will be any greater than already
assessed and considered.
An arbitrarily defined Base Area, being a zone encompassing Area 1 and Area 2, plus an
additional area representative of the vegetation types they exhibit is considered the Scheme’s
general locale. This Base Area is delineated by the 400 metre contour from the true-left margin
of Macgregor Creek at NZTM E1417875 N5225100 through to the Waitaha River true-right
margin in the Waitaha Gorge at NZTM E1419938 N5222050, thence by the true-right margin of
the Waitaha River and the true-left forest/bed margin of Macgregor Creek, as mapped on
NZTopo50-BW17. Where necessary the delineation around the Kiwi Flat area has been adjusted
with reference to 2010 - 2012 aerial photography to account for minor river channel changes and
vegetation colonisation since topographic map compilation. The Base Area is shown on
Appendix A, Map 5 and Appendix A, Map 6. It encompasses a total area of c. 436.2 hectares
comprising primarily indigenous vegetation (396 hectares) broadly classified as lowland
forest/seral low forest (James et al., 1973; Wardle, 1979). These 396 hectares of lowland
forest/seral low forest are the basis for percentage calculations in computing scale of vegetation
effects of the Scheme components and in total.
27
In assessing the level of potential effects of clearance of indigenous vegetation associated with
the Scheme a range of potential effects was considered based on a commonly available
continuum/guideline1. The scale of effects adopted for these purposes was:
Nil Effect.
Less than Minor - Negligible Effect.
Minor Effect.
More than Minor Effect.
Significant Effect.
For classifying potential effect of activities on vegetation in Area 1 a conservative approach was
adopted based, at the lowest end of the scale, on observed disruption to vegetation (i.e. landslip,
erosion etc.) that occurs naturally within the Scheme locale. Accordingly, the following scale is
applied:
Negligible Effect:
The total area of any temporary effect(s) associated with Scheme components in Area 12
is no more than 0.5 ha or 1.0% (whichever is greater) of the total area of similar
vegetation type assemblages in the locale;
AND
The total area permanently affected by Scheme components in Area 12 is no more than
0.5% of the total area of similar vegetation type assemblages in the locale.
Minor Effect:
The total area of any temporary effect(s) associated with Scheme components in Area 12
is no more than 1.0 ha or 2.0% (whichever is greater) of the total area of similar
vegetation type assemblages in the locale;
AND
The total area permanently affected by Scheme components in Area 12 is no more than
1.0% of the total area of similar vegetation type assemblages in the locale.
No Scheme effects were identified as being greater than negligible or minor relating to
vegetation clearance in terms of this assessment.
1 Source: Quality Planning website (www.qualityplanning.org.nz).
2 For the purposes of assessment of effects under Section 7.0 of this report, Area 2 replaces Area 1 in this
description.
28
4.1 Weir
The effect of weir works on vegetation is negligible, given that construction activities and the
weir structure are principally located in the active bed of the river on already exposed bedrock
with minimal vegetative cover. The area of activity is not deemed to be in riparian margin as it is
in the bed of the river. Vegetation that is present is Type 1/1 (see Appendix A, Diagram 1 and
Map 2).
Assuming permanent site occupancy area of the weir is 20 m2 as shown in Diagram 1, and a
construction-affected area of four times that, total potentially affected areas (combined
construction and permanent site occupancy by structure) by vegetation type are shown in
Table 1. As a maximum, 50% is deemed to carry some vegetation, the remainder being un-
vegetated bedrock and active river channel and therefore not included in the Table 1 areas.
Natural regeneration of current vegetation cover could be expected to occur relatively soon after
cessation of construction activities on all but the permanently occupied area, as scale and type of
disturbance is similar to that occurring at or about the site by natural causes e.g. minor slips and
major flood events and existing vegetation has established following these disturbances.
A further possible effect on vegetation could be that caused by any re-grading of the riverbed
after weir construction, however investigations into possible sedimentation buildup/change
indicate effects of the weir in its proposed location are unlikely to be substantial (Hicks, 2013). If
any small areas of existing vegetation were to be covered over by sediment aggradation or cut
away as new river channel(s) form as a result of weir effect, this process appears likely to be
confined to a minor portion of lower Kiwi Flat. It would be expected to be short term and would
not be inconsistent with the fluvial processes by which the flat has formed and is maintained
(Hicks, 2013). Natural regeneration would be expected in a matter of years, and this should
exhibit the range of species currently present, as it would if it were a site of natural disturbance.
Table 1: Weir Construction Distances and Potentially Affected Areas Within Vegetation Type.
Vegetation
Type
Distance
(m)
Construction
(ha)
Permanent
(ha)
Placement Within
Riparian Margins:
Distance (m)
Placement Within
Riparian Margins:
Construction (ha)
1/1 True-right side of
Waitaha River = 5
0.0025 0.0005 0.0 0.0
1/1 True-left side of
Waitaha River = 5
0.0025 0.0005 0.0 0.0
Totals 10 m x 5 m wide 0.0050 0.0010 0.0 0.0
4.2 Intake Channel
Effect of the intake channel on vegetation is negligible, given that construction activities and the
intake channel are principally on already exposed bedrock or boulder covered areas with
minimal vegetative cover. The area of activity is not deemed to be in riparian margin as it is in
the bed of the river. Vegetation that is present is Type 1/1 (Appendix A, Diagram 1 and Map 2).
29
Assuming permanent site occupancy area of the channel is c. 9.5 metres wide
average x 34 metres (accommodating cut of bedrock) and a construction-affected area of that
again, total potentially affected area is c. 650 m2. Area (combined construction and permanent
site occupancy by structure) by vegetation type is shown in Table 2. As a maximum, 50% of the
affected area is deemed to carry some vegetation, the remainder being un-vegetated bedrock and
boulder area and therefore not included in the Table 2 area.
Table 2: Intake Channel Potentially Affected Areas Within Vegetation Type.
Vegetation
Type
Construction
(ha)
Permanent
(ha)
Placement Within Riparian Margins:
Construction (ha)
1/1 0.0325 0.0163 0.0
Totals 0.0325 0.0163 0.0
4.3 Intake Structure and Intake Portal
The bedrock walls at the entrance to, and within Morgan Gorge, are scoured clean of vegetation
by flood events up to c. 8 meters. Sparse vegetation cover that is present above the clear zone
contains liverwort/moss, herbaceous and monocot components of Vegetation Type 1/1 in a
narrow band of a few meters wide before merging to Vegetation Type 1/3 shrub cover in the
gorge and with Vegetation Type 1/2 about and upstream of the gorge entrance.
Assuming permanent site occupancy area of the intake structure is c. 13 metres long x 8 metres
wide and a construction-affected area of double that again, total potentially affected area is
c. 312 m2. This work is likely to be within Vegetation Type 1/1 and Vegetation Type 1/2 in an
affected area ratio of c. 1/3 and 2/3 respectively. It is assumed the intake portal excavation will
be 6 metres x 6 metres. To this is added an allowance for side margin vegetation clearance effect
of 4 metres (each side) and top margin effect of 6 metres, giving an estimated total of 168 m2 and
that this will be both construction area and remain permanently occupied, probably affecting
Vegetation Type 1/2 and Vegetation 1/3 in similar amounts. Potentially affected areas (combined
construction and permanent site occupancy by structure) by vegetation type are shown in
Table 3. Overall effect of proposed works is likely negligible.
Part of the affected area is contained within what could be considered true-right riparian margin
of the Waitaha River. Vegetation types present in this area are not unique or distinguished
floristically from their counterparts not occupying the riparian strip. It is the arbitrary riparian
designation in the Proposed Regional Land and Water Plan (WCRC, 2013) and Westland
District Plan (WDC, 2002) of fixed-width distance from stream bank, not vegetation, that
distinguishes this zone – vegetation present would not preclude the activity here. Vegetation
recovery on any disturbed area not occupied by structures is likely to occur naturally, and exhibit
the range of species currently present.
30
Table 3: Intake Structure and Intake Portal Potentially Affected Areas Within Vegetation Types.
Vegetation
Type
Construction
(ha)
Permanent
(ha)
Placement Within Riparian Margins:
Construction (ha)
1/1 Intake 0.0100 0.0040 0.0
1/2 Intake 0.0210 0.0070 True-right side of Waitaha River = 0.0210
1/2 Portal 0.0084 0.0084 True-right side of Waitaha River = 0.0084
1/3 Portal 0.0084 0.0084 0.0
Totals 0.0478 0.0278 0.0294
4.4 Tunnel Portal Entrance
The tunnel portal entrance and an apron area will likely be located in Vegetation Type 1/2 and
Vegetation Type 1/3 in approximately equal proportions. The indicative dimensions of the tunnel
are 5 metres x 5 metres giving 25 m2
cleared (although this may need to be adjusted to suit
construction plant requirements). To this is added an allowance for side margin vegetation
clearance effect of 6 metres each side and top margin effect of 6 metres, giving an estimated total
of 187 m2 or 0.0187 ha, and that this will be both construction area and remain permanently
occupied. Potentially affected area (combined construction and permanent site occupancy by
structure) by vegetation type are shown in Table 4. Tunnel portal entrance siting should be
possible to avoid works in any riparian margin. Overall effect of proposed works on vegetation is
considered negligible.
Table 4: Tunnel Portal Entrance Potentially Affected Areas Within Vegetation Types.
Vegetation
Type
Construction
(ha)
Permanent
(ha)
Placement Within Riparian Margins:
Construction (ha)
1/2 0.00935 0.00935 0.0
1/3 0.00935 0.00935 0.0
Totals 0.01870 0.01870 0.0
4.5 Intake Access Road from Tunnel Portal Entrance to Intake Structures
The tunnel portal entrance is likely to be located on a relatively steep terrace face section. There
will be a requirement for some area of apron to allow equipment entry/egress and as a lead-in to
the access road. Based on Westpower planning information as of November 2013, a c. 10 metre
diameter permanent apron area is necessary, giving c. 80 m2. This is likely to affect similar areas
of Vegetation Type 1/2 and Vegetation Type 1/3.
Initial concept information (Appendix A, Diagram 1) shows c. 100 metres of access road
extending from the tunnel portal entrance apron to the intake structure area is needed (this is
indicative, with final length and width subject to survey and depending on portal location and
attaining suitable grade). If a 4 metre carriageway and 1 metre water-tabling allowance is applied
the road will occupy 500 m2, predominantly affecting Vegetation Type 1/2 (est. 90%), the
remainder being Vegetation Type 1/3.
31
A further zone of river protection and road combined at the toe of the slope is estimated to
involve an area of c. 300 m2 (c. 20 metres long paralleling the river x 15 metres wide as indicated
by Appendix A, Diagram 1), of which 30% is likely un-vegetated gravel and rock/boulders in the
river bed, meaning c. 210 m2
of vegetated or partially vegetated area affected, being
predominantly Vegetation Type 1/2 (est. 75%), the remainder being Vegetation Type 1/1. The
estimated 210 m2
affected area is predominantly, if not all, within the true-right riparian margin
of the Waitaha River. Vegetation types present in this area are not unique or distinguished
floristically from their counterparts not occupying the riparian strip. It is the arbitrary riparian
designation in the Proposed Regional Land and Water Plan (WCRC, 2013) and Westland
District Plan (WDC, 2002) of fixed-width distance from stream bank, not vegetation, that
distinguishes this zone – vegetation present would not preclude the activity.
Allowing an additional affected area for construction (batter slopes, cuttings, fill zones) of a
similar amount again as the 0.058 ha permanently occupied area of road and tunnel portal
entrance apron added to the permanently occupied area of road, tunnel portal entrance apron and
river protection area of c. 0.079 ha gives a total construction-affected area of c. 0.137 ha.
Potentially affected areas by vegetation type are shown in Table 5. At this scale, effect of
proposed works on vegetation is considered negligible, vegetation recovery on any disturbed
area not occupied by structures is likely to occur naturally, and exhibit the range of species
currently present.
Table 5: Tunnel Portal Entrance Apron, Intake Access Road and River Protection Potentially
Affected Areas Within Vegetation Types.
Vegetation
Type
Construction
(ha)
Permanent
(ha)
Placement Within Riparian Margins:
Construction (ha)
1/3 Tunnel Portal Entrance Apron 0.0080 0.0040 0.0
1/2 Tunnel Portal Entrance Apron 0.0080 0.0040 0.0
1/3 Intake Access Road 0.0100 0.0050 0.0
1/2 Intake Access Road 0.0900 0.0450 True-right side of Waitaha River
20 m x 10 m strip = 0.0200
1/2 Protection/Road 0.0158 0.0158 True-right side of Waitaha River 0.0158
1/1 Protection/Road 0.0052 0.0052 True-right side of Waitaha River 0.0052
Totals 0.1370 0.0790 0.0410
4.6 Road to Contractors’ Facilities Area
Access to a proposed contractors’ facilities area on an alluvial terrace upstream of the tunnel
portal entrance requires formation of c. 130 metres of road sufficient to allow machinery
traverse. The final dimensions and location of this road are to be confirmed, but for purposes of
this assessment an approximate location is as per Appendix A, Map 2 and it is assumed that
carriageway and watertabling dimensions would be similar to those given above for the intake
access road, with an additional width allowance for cut/fill disturbance of 3 metres, therefore this
section will affect c. 1,040 m2, predominantly of Vegetation Type 1/4 (est. 75%) the remainder
being Vegetation Type 1/2. It may be possible to position this road outside (north) of the
Waitaha River riparian margin, however available area is narrow and may not allow complete
riparian margin avoidance. For vegetation effect assessment purposes and contingency, it is
assumed that c. 60 meters of the road distance will be partially in riparian margin, affecting
32
a 5 metre wide zone i.e., 300 m2 of riparian margin predominantly within Vegetation Type 1/4.
Vegetation present in the riparian area is not unique or distinguished floristically from its
counterpart not occupying the riparian strip. It is the arbitrary riparian designation in the
Proposed Regional Land and Water Plan (WCRC, 2013) and Westland District Plan
(WDC, 2002) of fixed-width distance from stream bank, not vegetation, that distinguishes this
zone – vegetation present would not preclude the activity here.
Potentially affected areas by vegetation type are shown in Table 6. This section of road will not
be required post-construction of the headworks infrastructure. The area can be rehabilitated or
left to regenerate naturally (see Section 10.0 re recommended mitigation). At this scale, and
considering the temporary nature of the site occupancy, effect of proposed works on vegetation
is within the scale of natural disturbance events in this environment and considered negligible.
Table 6: Road to Contractors’ Facilities Distances and Potentially Affected Areas Within
Vegetation Types.
Vegetation
Type
Distance
(m)
Construction
(ha)
Permanent
(ha)
Placement Within Riparian Margins:
Construction (ha)
1/2 40 0.0260 0.0 0.0
1/4 90 0.0780 0.0 True-right side of Waitaha River
60 m x 5 m strip = 0.030
Totals 130 0.1040 0.0 0.030
4.7 Contractors’ Facilities Area
A contractors’ facilities area of c. 2,000 – 2,200 m2 is proposed, to be located in the most
practicable siting on the first available flat zone of sufficient area upstream of Morgan Gorge
(Appendix A, Map 2). Final dimensions and location may be subject to change from those
shown, which have been used as preliminary input for effects assessment. The area is all within
Vegetation Type 1/4 and site configuration and placement should be able to be adjusted so as to
avoid works in the Waitaha River riparian zone. Vegetation types present in this riparian area are
not unique or distinguished floristically from their counterparts not occupying the riparian strip.
It is the arbitrary riparian designation of fixed-width distance from stream bank set by provisions
of the Proposed Regional Land and Water Plan (WCRC, 2013) and the Westland District Plan
(WDC, 2002), not the vegetation, which distinguishes this zone – vegetation present would not
preclude the activity.
This facilities area will not be required post-construction. The area can be rehabilitated or left to
regenerate naturally (see Section 10.0 re recommended mitigation). Considering the temporary
nature of the site occupancy, effect of proposed works on vegetation is considered negligible.
Table 7: Contractors’ Facilities Potentially Affected Area Within Vegetation Type.
Vegetation
Type
Construction
(ha)
Permanent
(ha)
Placement Within Riparian Margins:
Construction (ha)
1/4 0.220 0.0 0.0
Total 0.220 0.0 0.0
33
4.8 Flushing Tunnel Outlet
Settling basin and penstock intake structures are to be contained in excavations associated with
tunneling. The only effect on vegetation from this Scheme component will be requirement for an
outlet for a flushing tunnel discharge from the true-right wall of the Morgan Gorge back into the
river (see Appendix A, Diagram 1). The location for this is not fixed at time of preparation of
this report however a key requirement is that it is above any flood level. It would be on the stable
rock wall of the gorge. Assuming a 4 metre x 4 metre adit cross section and an allowance for
side margin vegetation clearance effect of 2 metres each side and top margin effect of 6 metres
(depending on vegetation cover/stature and substrate stabilisation requirements and area extent),
gives 80 m2, plus allowing a 10 metre x 4 metre ‘drop zone’ from tunnel base to river gives
40 m2, half of which is estimated to be un-vegetated bedrock of the lower gorge wall. All of the
above areas are assumed to be permanently occupied or affected by the Scheme, giving an
estimated total of 100 m2 with at least some vegetation and that this will comprise a minor
amount of Vegetation Type 1/1, c. 20%, and otherwise will be within Vegetation Type 1/3.
Overall effect of proposed works on vegetation is considered negligible.
Part of the affected area is contained within what could be considered true-right riparian margin
of the Waitaha River. Vegetation types present in this area are not unique or distinguished
floristically from their counterparts not occupying the riparian strip. It is the arbitrary riparian
designation of fixed-width distance from stream bank, set by provisions of the Proposed
Regional Land and Water Plan (WCRC, 2013) and the Westland District Plan (WDC, 2002), not
the vegetation, which distinguishes this zone – vegetation present would not preclude the activity
here.
Table 8: Flushing Tunnel Outlet Potentially Affected Areas Within Vegetation Types.
Vegetation
Type
Construction
(ha)
Permanent
(ha)
Placement Within Riparian Margins:
Construction (ha)
1/1 0.002 0.002 True-right side of Waitaha River 0.002
1/3 0.008 0.008 True-right side of Waitaha River 0.008
Total 0.010 0.010 0.010
5.0 Other Observations Relating to Vegetation – Area 1
Generally, the state of vegetation of all types described above, both within the areas of proposed
works and the wider area, appears healthy and stable with the exception of change due to
naturally caused events e.g. occasional slips, changes in river channel location and windfall
zones, these being random and relatively infrequent. While possums and deer are present,
browse effect on indigenous vegetation at all sites appears very low. Sign indicates low possum
numbers in particular on the northern footslopes bordering Kiwi Flat and in the terrace below
Morgan Gorge, with very limited effect on vegetation in the Scheme area. Likewise for deer,
sign is sporadic and concentrated on the grassed and sandy areas of flats. Grazing is evident on
grassed clearing/flat areas, but appears sporadic and at a low level – this will be seasonally
variable, highest in spring and summer – however even then would not be of significant
detriment to the majority of indigenous vegetation present given the low deer population density.
Once into areas of shrub/bush cover deer movements disperse, and vegetation appears little
affected. No goats or goat sign were observed in this part of the Scheme area.
34
Exotic herbaceous weed species adapted for wind dispersal of seed (e.g. Cirsium spp.) are
present in low concentrations outside of forest areas e.g. along river and stream margins. No
brushweed species were observed in this part of the Scheme area.
6.0 Vegetation Description and Assessment Method - Area 2
The same strategy for field work and vegetation type delineation and description was used in
Area 2 as for Area 1 and the same survey objectives, descriptive aims and provisos apply. Area 2
(see Appendix A, Map 3) as assessed is a strip c. 1,950 metres long, that varies between c. 180
and 320 metres wide, along the true-right of the Waitaha River upstream of the true-left side of
Macgregor Creek. This does not imply that all of this width will be affected by any works, the
width being chosen arbitrarily to coincide with landform change where possible, but mainly to
cover sufficient area to provide some flexibility in final location of any access road and other
infrastructure without the requirement to extend the surveyed area eastward later if it were found
too narrow in the first instance.
Terrain allowed transect walk-through and representative areas were covered based on
interpretation of cover type from aerial photography, with splitting of types into sub-types in
some cases on the basis of changes observed during traverse.
The Area 2 survey zone is larger and encompasses a greater range of landforms than does
Area 1, in particular a sequence of alluvial terraces increasing in surface age with increased
height in an eastward progression, from the relatively recent alluvial flats adjacent to the current
active Waitaha River bed that have no closed forest species cover, to the higher terrace and hill
footslopes that carry mature podocarp/hardwood hill forest. Steeper terrace faces and footslopes
within this area have likely been subject to effects of shifts on the Alpine Fault resulting in
periodic disturbance via slips and colluvium deposition and exhibit a hardwood predominant
forest cover with very low incidence or absence of large podocarp trees. The result is a
segregation of Area 2 into twelve vegetation types for descriptive purposes. These are coded 2/1,
2/2, 2/3 etc. (Appendix A, Map 3).
There is no evidence of major modification to Area 2 vegetation by human activity e.g. clearance
or logging.
6.1 Vegetation Type Descriptions for Area 2
Predominant landforms in Area 2 are a set of relatively recent, low alluvial outwash terraces,
terrace faces and tributary stream fans at altitude of c. 140 – 160 m.a.s.l.
The principal forest types present here can be broadly grouped as kamahi forest (mature and
establishing or regenerating) and seral forest using the classification described by James et al.,
(1973), and as lowland forest (mature and establishing or regenerating) under the classifications
described by Wardle, (1977, 1979 and 1991).
35
Type 2/1 – Regenerating Podocarp/Hardwood Forest (Stage 1):
This occurs on a narrow, low, recent terrace that runs east to a vertical or near vertical terrace
face at the foot of which varying amounts of debris accumulation from face slipping form a
slope. The vegetation type is podocarp/hardwood in an early regenerational phase with tree ferns
a significant canopy element. Canopy height is c. 5 – 7 metres average and no large podocarp or
hardwood trees are present. It is typical of that observed on relatively young, well drained
surfaces.
Canopy cover is principally Weinmannia racemosa, Carpodetus serratus, Quintinia acutifolia,
Melicytis ramiflorus and with the tree ferns Cyathea smithii and Dicksonia squarrosa.
Occasional Prumnopitys ferruginea stems are present and scattered Dacrydium cupressinum
pole-sized (<20 cm dbh) stems are emergent above the hardwood component. Ripogonum
scandens occurs in the canopy in places (and in lower tiers).
The shrub tier includes canopy species regeneration and Podocarpus hallii, Ascarina lucida,
Hedycarya arborea, Myrsine australis, and Coprosma grandifolia. Cyathea smithii and
Dicksonia squarrosa tree ferns are abundant. Along margins, Carmichaelia arborea, Coprosma
rugosa, Olearia avicenniifolia, Olearia ilicifolia and Olearia arborescens are present.
Ground cover under the closed canopy is primarily litter with various mosses (including
Cyathophorum bulbosum and Hypopterygium novae-seelandiae) and liverworts (particularly
Monoclea forsteri, Hymenophyton flabellatum, and Schistochila spp.). Other cover includes
Asplenium bulbiferum, Asplenium flaccidum, Lastreopsis hispida, Blechnum sp. “black spot”,
Blechnum discolor, Hymenophyllum demissum, Grammitis billardieri, Nertera vilosum,
Microlaena avenacea, Uncinia uncinata, Astelia fragrans, Metrosideros diffusa, and scattered
seedlings/young plants of canopy and shrub tiers. Histiopteris incisa is present about margins.
Climbers include Metrosideros diffusa and occasional Ripogonum scandens patches occur,
principally in the sub canopy.
Epiphytes include Asplenium flaccidum, Grammitis spp., Hymenophyllum spp., Trichomanes
venosum, Tmesipteris tannensis, Phymatosorus diversifolius, Astelia fragrans, Weinmannia
racemosa and Quintinia acutifolia.
Within Type 2/1 there are occasional semi-clearings on slopes at the foot of the terrace, a result
of slips from above. Canopy, shrub and ground cover species present in the closed-canopy areas
are represented, however additional species observed in these areas and not noted in closed-
canopy areas include the shrubs Pennantia corymbosa and Coprosma tayloriae and as ground
cover components, Polystichum vestitum, Pteridium esculentum, Acaena anserinifolia, Lotus
pedunculatus, Cortaderia richardii and other mixed grass and thistle species.
The terrace face is included in Type 2/1. Cover consists of a similar hardwood species
assemblage to that which comprises the terrace canopy and shrub tiers along with Hebe
salicifolia and Griselinia littoralis, and prevalent ground cover species include Blechnum spp.
ferns observed on the terrace and Astelia fragrans, along with mosses and liverworts.
36
Figure 12 - Example of Vegetation Type 2/1:
Vegetation Type 2/1 stature and composition on the low terrace in the foreground and on the
terrace face and regenerating slip in the background.
37
Type 2/2 – Grass, Sparse Shrub and Tree Fern Combination (Early Successional):
This occurs on a relatively recent alluvial flat that has a flood channel around its eastern margin
that has carried water in recent flood events. This channel is predominantly vegetated and not an
active portion of the river. Cover is typically between 0.5 and 0.8 metres high. Very occasional
regeneration of forest trees in seedling stage is present e.g. Metrosideros umbellata and
Weinmannia racemosa. Shrub cover consists of scattered individual stems or as small clumps.
Common species are Coprosma rugosa, Coprosma propinqua, Coprosma elatirioides,
Coprosma rubra, Pennantia corymbosa, Carmichaelia arborea, Pseudopanax crassifolius,
Carpodetus serratus, Hedycarya arborea, Myrsine divaricata, Ascarina lucida, Dracophyllum
longifolium, Pseudopanax simplex and the tree ferns Cyathea smithii and Dicksonia squarrosa.
Monocots and other ground cover species on the main flat and flood channel include abundant
Cortaderia richardii and scattered Astelia fragrans, Phormium cookianum, Blechnum discolor,
Blechnum sp. “black spot”, Blechnum fluviatile, Blechnum penna-marina, Hypolepis
rufobarbata, Histiopteris incisa, Metrosideros diffusa and Acaena anserinifolia. Grasses
(Agrostis tenuis, Poa spp., Festuca sp., Trisetum tenellum, Anthoxanthum odoratum, Holcus
lanatus) and mosses are intermingled along with other broadleaved herbaceous plants including
Cirsium arvense, Cirsium palustre, Ranunculus repens, Lotus pedunculata, Hydrocotyle novae-
zelandiae, Celmisia coriacea, Stellaria media, Plantago lanceolata, Hypochoeris radicata, and
Gunnera monoica.
Species present as ground cover along the flat margin with the active riverbed in what is a flood-
inundation zone include Marchantia berteroana, Acaena anserinifolia, Nertera ciliata, Gunnera
monoica, Raoulia tenuicaulis, Parahebe lyallii and Rytidosperma setifolium.
Figure 13 - Example of Vegetation Type 2/2:
Vegetation Type 2/2 composition and cover of the river flat flood channel.
38
Figure 14 - Example of Vegetation Type 2/2:
Vegetation Type 2/2 composition and cover on the river flat.
Type 2/3 – Mature Podocarp/Hardwood Hill Forest:
This occurs on elevated terrace and hill foot slope/side slope areas. The type is mature
podocarp/hardwood hill forest with the podocarp element more prevalent on terrace zones and in
particular along better-drained terrace edges and ridges. In gully sides and on faces the podocarp
element is reduced or absent, hardwoods forming the canopy.
Canopy emergents are principally Dacrydium cupressinum (dbh range typically 70 – 110+ cm),
and to lesser extent, Prumnopitys ferruginea and Metrosideros umbellata. Canopy height is c. 16
– 22 metres, with Weinmannia racemosa and Quintinia acutifolia the main canopy species along
with smaller stems of the emergent podocarps.
The understory/shrub tier includes canopy species regeneration and Podocarpus hallii, Ascarina
lucida, Hedycarya arborea, Myrsine divaricata, Neomyrtus pedunculata, Pseudopanax
crassifolius, Griselinia littoralis, Pseudowintera colorata, Coprosma foetidissima, Coprosma
rhamnoides, Coprosma tayloriae, and Coprosma ciliata. Cyathea smithii and Dicksonia
squarrosa tree ferns are common.
Ground cover is primarily litter with various mosses (including Dawsonia superba,
Cyathophorum bulbosum, Hypopterygium novae-seelandiae and Mniodendron dendroides),
liverworts (particularly Schistochila spp.) and occasional patches of Lycopodium volubile. Other
cover includes Nertera vilosum, Nertera depressa, Nertera ciliata, Microlaena avenacea,
Arthropodium candidum, Uncinia sp., Astelia fragrans, Trichomanes reniforme, Lastreopsis
hispida, Sticherus cunninghamii, Blechnum sp. “black spot”, Blechnum discolor,
Hymenophyllum demissum, Hymenophyllum revolutum, Grammitis billardieri, Metrosideros
diffusa, and scattered seedlings/young plants of canopy and shrub tiers.
39
Climbers include Ripogonum scandens, Freycinetia baueriana subsp. banksii, Metrosideros
diffusa, Metrosideros fulgens, Metrosideros perforata and Rubus cissoides.
Epiphytes include Asplenium flaccidum, Grammitis spp., Hymenophyllum revolutum,
Hymenophyllum spp., Trichomanes venosum, Tmesipteris tannensis, Phymatosorus diversifolius,
Astelia fragrans, Weinmannia racemosa and Quintinia acutifolia.
Type 2/3A – Mature Hardwood Forest, Podocarp Element Reduced/Absent:
This is a variation of Type 2/3 occurring particularly on foot slope faces in the northern portion
of Area 2. The main difference is that the emergent podocarp element typical of Type 2/3 is
significantly reduced and absent in places, the canopy height is lower (est. 8 – 12 metres on
densest-cover faces) and has a higher proportion of Cyathea smithii and Dicksonia squarrosa
tree ferns and Ripogonum scandens and Freycinetia baueriana subsp. banksii thickets.
Figure 15 - Example of Vegetation Types 2/3 & 2/3A:
Typical composition and stature of Vegetation Type 2/3A on face terrain, grading into
Vegetation Type 2/3 in higher ridge areas.
Type 2/3B – Poorly Drained Lower Stature Hardwood Forest with Minor Presence of
Dacrycarpus dacrydioides:
This is a relatively small area on a slight terrace c. 3 metres high along its western margin. It is
adjacent to Macgregor Creek on its northern edge and at the same level, exhibiting poor drainage
and recent alluvial deposits from Macgregor Creek overflow. The vegetation here grades to
Vegetation Type 2/3A, however key differences are lower canopy height (c. 6 – 10 metres),
extremely dense thickets of Ripogonum scandens and Freycinetia baueriana subsp. banksii as
canopy cover in conjunction with hardwoods as per Vegetation Type 2/3A and a low incidence
of Dacrycarpus dacrydioides as saplings and pole sized stems and a single stem of tree size
40
estimated at c. 60 cm dbh. The few emergent Dacrydium cupressinum trees present show
advanced dieback, likely a result of sedimentation and impeded drainage due to the gravel and
silt deposition by Macgregor Creek.
Figure 16 - Example of Vegetation Type 2/3B:
Vegetation Type 2/3B occurs at middle-left of the picture adjacent to Macgregor Creek. The
relatively small area of this type is evident as naturally occurring dieback of hardwoods and
emergent Dacrydium cupressinum trees along the true-left creek margin.
Type 2/4 – Regenerating Podocarp/Hardwood Forest (Stage 2; Average Canopy Height >
Stage 1):
This occurs on two sets of recent terrace surfaces (slightly higher and older than that supporting
Vegetation Type 2/1 cover). One smaller area is between Macgregor Creek and Granite Creek –
this intergrades eastward with Type 2/3 and 2/3A. A larger area extends in a band from Granite
Creek south to about NZTM E5224240; N1415340 and east to the foot of a terrace face beyond
which it intergrades upslope with its Vegetation Type 2/4A sub-type in places and otherwise
Vegetation Type 2/3. Vegetation Type 2/4 is podocarp/hardwood forest in a regenerational phase
slightly more advanced than that of Vegetation Type 2/1. Canopy height is typically c. 6 – 10
metres with tree ferns a significant component in places. No large podocarp or hardwood trees
are present.
Canopy cover is principally Weinmannia racemosa and the tree ferns Cyathea smithii and
Dicksonia squarrosa. Other canopy hardwoods of less frequent occurrence are Quintinia
acutifolia, Carpodetus seratus, Griselinia littoralis, and Pennantia corymbosa. Occasional
Prumnopitys ferruginea and Dacrydium cupressinum pole-sized (< 20 cm dbh) stems are
emergent above the hardwood component, mainly along the western margin of this type.
Ripogonum scandens occurs in the canopy in places (and in lower tiers).
41
The shrub tier includes canopy species regeneration and tree ferns along with Pseudopanax
crassifolius, Pseudopanax colensoi, Ascarina lucida, Hedycarya arborea, Melicytus ramiflorus,
Coprosma rotundifolia, Coprosma ciliata, Coprosma tayloriae, and Pseudowintera colorata.
Along margins Coprosma species are prevalent, including those internal to the forest plus
Coprosma propinqua and Coprosma elatirioides.
Ground cover species include the mosses Cyathophorum bulbosum, Hypopterygium novae-
seelandiae and Mniodendron dendroides, liverworts (particularly Schistochila spp. and
occasional Monoclea forsteri), Blechnum sp. “black spot”, Blechnum discolor, Blechnum
fluviatile, Blechnum colensoi, Lastreopsis hispida, Asplenium bulbiferum, Asplenium polyodon,
Uncinia spp., Nertera vilosum, Nertera depressa, Microlaena avenacea and Metrosideros
diffusa.
Climbers include Ripogonum scandens, Rubus cissoides and Metrosideros diffusa.
Epiphytes include Dendrobium cunninghamii, Asplenium flaccidum, Grammitis spp.,
Hymenophyllum spp., Trichomanes venosum, Rumohra adiantiformis, Astelia fragrans,
Melicytus ramiflorus, Weinmannia racemosa and Quintinia acutifolia.
Figure 17 - Example of Vegetation Type 2/4:
Typical Vegetation Type 2/4 composition and cover – i.e. the hardwood/tree fern regeneration
extending from the grassed flat margin back to the foot of the ridge in middle distance where it
grades into Vegetation Type 2/3.
42
Type 2/4A - Regenerating Podocarp/Hardwood Forest (Stage 3; Average Canopy Height >
Stage 2):
This is a variation of Vegetation Type 2/4 occurring on a slightly more elevated (3 – 4 metre
higher) terrace. The main difference is that canopy height is greater (est. 14 metres average) and
with Weinmannia racemosa trees of 60 – 100+ cm dbh scattered through as emergents between
18 and 24 metres tall.
Type 2/5 – Regenerating Podocarp/Hardwood Tree and Shrub Admixture With Occasional
Emergent Trees:
Occupying the northern c. 2/3 of a low outwash terrace/ex alluvial flat, this area of
podocarp/hardwood forest is in early stages of regeneration. While there are occasional small
clearings, the canopy is closed over the majority of the area and is c. 8 – 12 metres high,
however drops in height and thins with progression southward to become c. 6 – 7 metres as it
intergrades with Vegetation Type 2/6 and tree ferns become an increasing proportion of cover
here.
Scattered larger Weinmannia racemosa trees of 40 - 80 cm dbh, occasional small Dacrydium
cupressinum trees of c. 30 cm dbh, and very occasional Metrosideros umbellata trees (largest
observed was est. 90 cm dbh) occur as canopy emergents.
Predominant canopy species is Weinmannia racemosa, along with the tree ferns Cyathea smithii
and Dicksonia squarrosa. Carpodetus serratus, Griselinia littoralis, Pseudopanax crassifolius,
Dacrydium cupressinum and Prumnopitys ferruginea are less frequently occurring components.
Understory and shrub tier species include those of the canopy, and Pseudowintera colorata,
Hedycarya arborea, Melicytus ramiflorus, Ascarina lucida, Pennantia corymbosa, Quintinia
acutifolia, Pseudopanax colensoi, Coprosma rhamnoides, Coprosma rotundifolia, Coprosma
tayloriae and Coprosma sp. Very occasional Dacrycarpus dacrydioides saplings were observed.
Along margins, scattered Carmichaelia arborea and Coprosma propinqua are present.
Ground cover species include the mosses Cyathophorum bulbosum, Hypopterygium novae-
seelandiae and Mniodendron dendroides, liverworts (Schistochila spp. and occasional Monoclea
forsteri), occasional clusters of Polystichum vestitum, and Blechnum fluviatile, Lastreopsis
hispida, Nertera vilosum, Nertera depressa, Cardamine debilis, Stellaria media, Uncinia spp.,
Microlaena avenacea, Acaena anserinifolia and Metrosideros diffusa.
Climbers include sparse Ripogonum scandens, Rubus cissoides, Rubus schmidelioides and
Metrosideros diffusa.
Epiphytes observed were Asplenium flaccidum, Tmesipteris tannensis, Grammitis spp.,
Hymenophyllum spp., Trichomanes venosum, Rumohra adiantiformis, Asplenium flaccidum,
Melicytus ramiflorus, Weinmannia racemosa and Quintinia acutifolia.
43
Figure 18 - Example of Vegetation Types 2/5 & 2/6:
Vegetation Type 2/5 composition and cover at the southern end of its area, grading into
Vegetation Type 2/6.
Type 2/6 – Regenerating Hardwood Tree/Shrub/Tree Fern Admixture with Grassed Clearings:
This type grades from Type 2/5 and occupies the southern c. 1/3 of the same low outwash
terrace/ex alluvial flat. Regeneration of hardwood forest tree and shrub species, tree ferns and
colonising shrub species occur as scattered individual stems or as small closed-cover stands
interspersed with variable-sized grassed clearings. A moderate amount of recent and old deer
sign (grazing and droppings) was evident in these clearings however there was very little sign of
browse on other vegetation (shrubs, trees etc.).
Predominant tree and shrub species are Griselinia littoralis, Weinmannia racemosa, Melicytis
ramiflorus, Pseudowintera colorata, Pseudopanax crassifolius, Pseudopanax simplex,
Carpodetus serratus, Hedycarya arborea, Myrsine divaricata, Ascarina lucida, Pennantia
corymbosa, Coprosma rugosa, Coprosma rubra, Coprosma elatirioides, Coprosma propinqua,
Coprosma tayloriae, and the tree ferns Cyathea smithii and Dicksonia squarrosa. Occasional
Podocarpus hallii saplings were observed.
Monocots and other ground cover species include regeneration of the tree and shrub species
along with Cortaderia richardii and scattered Astelia fragrans, Blechnum sp. “black spot”,
Blechnum fluviatile, Histiopteris incisa, Pteridium esculentum, Paesia scaberula, Polystichum
vestitum, Ctenopteris heterophylla, Metrosideros diffusa, Cardamine debilis, Acaena
anserinifolia and Stellaria media.
Climbers include Rubus cissoides, Rubus schmidelioides, Metrosideros diffusa and Metrosideros
perforata.
44
Epiphytes, mainly occurring on tree ferns, include Asplenium flaccidum, Tmesipteris tannensis,
Grammitis spp., Hymenophyllum spp., Trichomanes venosum, Rumohra adiantiformis, Astelia
fragrans, Melicytus ramiflorus, Weinmannia racemosa and Quintinia acutifolia.
Grasses and broadleaved herbaceous plants in clearings include Agrostis tenuis, Poa sp.,
Anthoxanthum odoratum, Holcus lanatus, Ranunculus repens, Lotus pedunculata, Taraxacum
officinale, Cirsium arvense, Cirsium palustre, Hypochoeris radicata, and Plantago lanceolata.
Species present as ground cover along the margin with the active riverbed in what is a flood-
inundation zone are as for Vegetation Type 2/2 but with increased presence of Cortaderia
richardii.
Figure 19 - Example of Vegetation Types 2/5 & 2/6:
Emergent trees and the higher canopy of Vegetation Type 2/5 are shown in the background, with
typical Vegetation Type 2/6 composition and cover in the foreground.
45
Figure 20 - Example of Vegetation Type 2/6:
Typical Vegetation Type 2/6 composition and cover – grassed clearings interspersed with shrub
hardwood and tree fern clusters.
Type 2/7 – Grassed Alluvial Flat with Sparse Colonising Hardwood Shrub Presence:
This type occurs on a relatively recent alluvial flat. Colonising shrub species occur as individuals
or small clusters interspersed throughout a predominantly grassed area. It differs from
Vegetation Types 2/2 and 2/6 in that it has a higher proportion of open grass sward cover.
Shrub and young tree species include Coprosma rugosa, Coprosma propinqua, Coprosma
areolata, Coprosma sp., Pennantia corymbosa, Carpodetus serratus, Aristotelia serrata, and
Myrsine divaricata.
Grasses and broadleaved herbaceous plants in main clear zones include Agrostis tenuis, Poa
spp., Anthoxanthum odoratum, Festuca sp., Holcus lanatus, Trisetum tenellum, Ranunculus
repens, Lotus pedunculata, Taraxacum officinale, Hypochoeris radicata, Trifolium repens,
Cirsium arvense, Cirsium palustre, Plantago lanceolata, Hydrocotyle novae-zelandiae and
Acaena anserinifolia.
Other ground cover species occurring singly or as patches are Paesia scaberula, Polystichum
vestitum, Blechnum sp. “black spot”, Blechnum discolor, Histiopteris incisa and Cortaderia
richardii.
Scattered Ulex europaeus plants have established about the northern margin near the outwash fan
of Macgregor Creek.
46
Figure 21 - Example of Vegetation Type 2/7:
Typical Vegetation Type 2/7 composition and cover.
Type 2/8 – Tree Fern/Hardwood Shrub/Monocot with Low Incidence of Dacrycarpus
dacrydioides:
A restricted area on the immediate true-left of Macgregor Creek, this has been affected by
shingle and rock deposits at times of flooding. Cover varies from c. 3 – 4 metres high where it
grades to Vegetation Type 2/3B to the north and to Vegetation Type 2/4 to the south. Species
composition is similar to Vegetation Type 2/4 re hardwood shrubs and tree ferns. There is a more
open area closer to Macgregor Creek, where Dicksonia squarrosa and Cyathea smithii tree ferns
are prevalent, along with scattered Coprosma spp. and Rubus spp. and Metrosideros diffusa
clusters are common on supporting vegetation. Occasional Dacrycarpus dacrydioides seedlings
and saplings are present. Cortaderia richardii is frequent in the open and Acaena anserinifolia is
present on gravel areas.
47
Figure 22 - Example of Vegetation Type 2/8:
Typical Vegetation Type 2/8 composition and cover is shown in the mid foreground.
Type 2/9 – Mixed Ground Cover/Shrub Hardwood Riparian:
This occupies narrow (10 – 20 metres wide) strips on either side of Alpha Creek, and is typical
of vegetation colonising relatively recent and/or disturbed rock and alluvial deposit surfaces in
forested valley catchments.
Hardwood tree regeneration is Weinmannia racemosa and Metrosideros umbellata. Shrub
species include Coriaria arborea, Hebe salicifolia, Carpodetus serratus, Aristotelia serratus,
Ascarina lucida, Fuchsia excorticata, Carmichaelia arborea, Coprosma spp., Olearia ilicifolia
and Olearia avicenniifolia.
Common ground cover species are mosses, lichens, Lycopodium volubile, Blechnum sp. “black
spot”, Blechnum penna-marina, Paesia scaberula, Lastreopsis hispida, Cortaderia richardii, and
scattered Lotus pedunculata, grasses, broadleaved herbs e.g. Hypochoeris radicata, Acaena
anserinifolia and Nertera depressa.
48
Figure 23 - Example of Vegetation Type 2/9:
Typical Vegetation Type 2/9 composition and cover is shown in the foreground.
7.0 Vegetation Effects in Area 2
The potential effects of each infrastructure component of the Scheme within Area 2 are
described below as to the size of affected area within each Vegetation Type, within riparian
margins if applicable, and in total.
All distance and area figures given in Tables 9 - 15 are indicative. The November 2013 Scheme
plans supplied by Westpower were used for the purpose of this assessment of effects. They may
be subject to variation depending on final location, access and construction requirements.
Areas given as construction, permanent and riparian (construction) in Tables 9 – 15 are not
additive. The construction area is the expected maximum area potentially affected by each
Scheme component and the construction total is an indication of the Scheme’s project footprint
as it pertains to vegetation effect. Areas given as permanent and riparian areas are sub-areas for
purposes of describing amount of vegetation clearance associated with a given Scheme
component. In the case of permanent areas these indicate the operational footprint of each
Scheme component and for the Scheme in total.
Where riparian areas are given in Tables 9 – 15 these are for streams >3metres wide where
provisions of the Proposed Regional Land and Water Plan (WCRC, 2013) and the Westland
District Plan (WDC, 2002) prescribe 10 metre riparian margin widths. Riparian areas are given
because activities affecting indigenous vegetation in riparian margins will require consideration
for regional and district planning provision purposes. N.B. Streams 1 – 3 metres wide occur near
the various areas of possible activity in Area 2 and provisions of the Proposed Regional Land
and Water Plan (WCRC, 2013) prescribe 10 metre wide riparian margins for streams of this size
if dominant slope angle is >12o and 5 metre wide riparian margins otherwise. This requirement
49
may add some area to the riparian area estimates given, however the detailed field survey and
mapping of small stream location was not a component of work undertaken. The number and
exact location of streams 1 – 3 metres wide that are potentially affected will need to be
determined for regional planning provision purposes, although it is not considered that potential
effects on vegetation will be any greater than already assessed and considered.
The same criteria apply to Area 2 as for Area 1 (refer Section 4.0) in assessing scale of Scheme
effects on vegetation.
7.1 Tunnel Portal Exit and Construction Apron
The final site of the tunnel portal exit may be subject to change but for purposes of this
assessment it is taken to be at or about c. NZTM E1415324; N5223550, consistent with the
November 2013 Scheme plans. Removal of vegetation will be required across the east-west
width of the footslope at this site to access the foot of the main terrace riser, and for some
distance north and south of the tunnel portal area, to give machinery access and allow room for
construction, equipment, and spoil handling. Final area requirements are not defined on the
ground at time of this assessment. For purposes of vegetation assessment, an indicative affected
area is assumed to be c. 40 metres east-west and 50 metres north-south so as to give sufficient
room for construction activities and to accommodate the penstock and access way in this area
after tunnel construction is complete. In addition, vegetation on the vertical terrace face will be
removed for the actual tunnel portal and excavation. An estimate of area affected is based on an
8 metre wide x 7 metre high tunnel, with side margins of 8 metres each side for the height of the
terrace face (estimated as 20 metres) and top margin of 8 metres width, also to the top of the
terrace face. This gives a potentially affected area of c. 480 m2.
The larger tunnel portal exit dimensions of 8 metres x 7 metres are required as this is a single
portal as opposed to the separate portals (intake portal and tunnel portal entrance) in the
headworks area. Table 9 gives potentially affected areas by vegetation type.
It is unlikely that the full width of area required for construction purposes will need to remain
permanently cleared of vegetation and it is assumed that 33% of the area could regenerate or be
re-vegetated after cessation of construction (see Section 10.0 below, re recommended
mitigation). Vegetation effect is considered negligible.
Table 9: Tunnel Portal Exit and Construction Apron Potentially Affected Area Within
Vegetation Types.
Vegetation
Type
Construction
(ha)
Permanent
(ha)
Placement Within Riparian
Margins:
Construction (ha)
2/1 Tunnel Portal Exit 0.048 0.048 0.0
2/1 Tunnel Portal Exit Apron 0.100 0.066 0.0
2/2 Tunnel Portal Exit Apron 0.100 0.066 0.0
Totals 0.248 0.180 0.0
50
7.2 Access Road and Transmission Line
The proposed access road location is approximately as shown on Appendix A, Map 3. This
route was not defined on the ground at time of preparation of this report, so actual affected areas
within vegetation types cannot be confirmed however variation from figures given herein is
expected to be negligible (if any). A maximum expected width for the access road and
transmission line where these are adjacent is 20 metres. In the case of transmission line pole
location, this is intended to follow the road alignment wherever practicable and where straight-
line distances are reasonable but may depart from the road alignment (subject to topographical
suitability and large tree avoidance considerations) to reduce angles in the line. Where this
occurs, some small area of vegetation clearance would be required at individual pole sites that
are additional to the road width, however this will likely be concomitant with a reduction in
cleared zone width that accommodates only the road in such departure zones.
Therefore, for potentially affected area calculations it is assumed an average width of affected
area is 15 metres for road and transmission line combined, for the c. 1,698 metre route distance
as indicatively mapped (Appendix A, Map 3). The actual location of the road may be adjusted
subject to engineering considerations, to avoid large trees where possible, or to facilitate
alignment. N.B: a ‘corridor’ zone is shown (Appendix A, Map 3) in which that possible
adjustment of the maximum 20 metre wide access road/transmission line location may occur –
this ‘corridor’ zone does not delineate the final potentially affected area of formed road.
Given the above, the most likely vegetation types affected and areas of each are shown in
Table 10. Vegetation types present in riparian margins in this area are not necessarily unique or
distinguished floristically from their counterparts not occupying a riparian strip. It is the arbitrary
riparian designation of fixed-width distance (10 metres) from stream bank contained in the
Proposed Regional Land and Water Plan (WCRC, 2013) and Westland District Plan
(WDC, 2002), not vegetation, that distinguishes these zones – vegetation present would not
preclude the activity.
It is likely that the majority of area required for access road/transmission line construction
purposes will need to remain permanently cleared of vegetation (possibly 95% of the total
construction-affected area) to enable continued access and facility inspection and maintenance,
however total construction-affected area, at c. 2.547 hectares, is 0.6% of the Base Area
vegetation and considered negligible.
51
Table 10: Access Road Distances and Potentially Affected Areas Within Vegetation Types.
(Note: Table lists individual segments within vegetation type starting at Macgregor Creek and proceeding south (see Appendix A, Map 3)).
Vegetation
Type
Distance
(m)
Construction
(ha)
Permanent
(ha)
Crossings of Riparian Margins:
Distance (m)
Crossings of Riparian Margins:
Construction (ha)
2/8 132
0.1980 0.1881 0.0 0.0
2/3B 120 0.1800 0.1710 True-left side of Macgregor Creek
10.0
True-left side of Macgregor Creek
0.015
2/3A 144
0.2160 0.2052 0.0 0.0
2/3 54
0.0810 0.0770 0.0 0.0
2/9 48 0.0720 0.0684 Both sides of Granite Creek
20.0
Both sides of Granite Creek
0.030
2/3 108
0.1620 0.1539 0.0 0.0
2/4A 306
0.4590 0.4361 0.0 0.0
2/4 714 1.0710 1.0175 Both sides of Alpha Creek
(Distance accounted for under separate waterway
training/flood protection works at this site, see
Section 7.3, below, so not included again here)
Both sides of Alpha Creek
(Area accounted for under separate waterway
training/flood protection works at this site, see
Section 7.3, below, so not included again here)
2/3 36 0.0540
0.0513 0.0
0.0
2/1
36 0.0540 0.0513 0.0 0.0
Totals 1698 2.5470 2.4198 30.0 0.045
52
7.3 Waterway Training and Flood Protection – Alpha Creek
November 2013 Scheme plans provided by Westpower show the indicative area within which
flood protection works are proposed on a portion of Alpha Creek where the creek exits the
terrace/terrace face to the east where, until that point, it is in an incised/defined channel, but
after exiting the terrace can flow in a number of directions. It is proposed to control and train
any flow to a defined channel within the creek. Proposed works may include the development
of a single, defined channel (including stopbanks on one or two sides) of the lower portion of
Alpha Creek to train and divert flows, in particular flood flows, to a single flow path. The aim
of the works is to prevent large flood flows and associated alluvium affecting the tailrace
and/or access road and to contain the stream at the access road crossing point. The potentially
affected zone is shown on Appendix A, Map 3. It involves a c. 150 metre strip commencing c.
30 metres north of the current stream confluence with the Waitaha River and extending east in
a direct line up the stream outwash fan, with c. 135 metres of the total distance being
vegetated. Width of this potentially affected area is c. 25 metres giving a maximum area of
3,375 m2, all of which is within Vegetation Type 2/4.
This work will involve crossing a 25 metre x 10 m portion of riparian vegetation on the true-
right of the Waitaha River. Provisions of the Proposed Regional Land and Water Plan
(WCRC, 2013) and the Westland District Plan (WDC, 2002) prescribe 10 metre riparian
margin widths for streams >3 metres wide whether permanently flowing or not. These
provisions apply to Alpha Creek. The eastern-most c. 75 metres of the proposed flood
protection work zone is likely to involve the entire 10 meter wide riparian margin on each
side of Alpha Creek, and may involve slightly more depending on final route location relative
to the current stream channel(s). Vegetation types present in riparian margins in this area are
not necessarily unique or distinguished floristically from their counterparts not occupying a
riparian strip. It is the arbitrary riparian designation of fixed-width distance (10 metres) from
stream bank contained in the Proposed Regional Land and Water Plan (WCRC, 2013) and
Westland District Plan (WDC, 2002), not vegetation, that distinguishes these zones –
vegetation present would not preclude the activity.
The current stream course(s) run beneath closed canopy forest cover and it is expected that
regeneration of the range of indigenous species currently present would occur naturally and it
is possible that at least 50% of the construction-affected area could become revegetated. This
is likely to also apply to a similar portion of any riparian margin area affected by construction.
The scale of vegetation clearance involved in this Scheme component is within that of
naturally occurring disturbance events e.g. slips and stream channel changes in this locality
and environment. Evidence of these occurrences is the set of two different-aged but relatively
recent slips, one regenerating, the other fresh, in this same stream c. 400 metres upstream of
its confluence with the Waitaha River (see Appendix A, Map 3). Areas potentially affected by
this Scheme component are shown in Table 11. Vegetation effects are considered negligible.
53
Table 11: Waterway Training and Flood Protection Works (Alpha Creek) Distance and
Potentially Affected Area Within Vegetation Type.
Vegetation
Type
Distance
(m)
Construction
(ha)
Permanent
(ha)
Placement Within
Riparian Margins:
Distance (m)
Placement Within
Riparian Margins:
Construction (ha)
2/4 135 0.3375 0.1688 True-right side of Waitaha
River
10
Both sides of Alpha Creek
2 x 75 m long parallel
strips =
75
True-right side of Waitaha
River
25 m x 10 m strip = 0.025
Both sides of Alpha Creek
75 m x 2 x 10 m
strips =
0.150
Totals 135 0.3375 0.1688 85 0.175
7.4 Powerhouse and Switchyard
The final site of a powerhouse and associated switchyard may be subject to change but for
purposes of this assessment it is taken from the November 2013 Scheme plans supplied by
Westpower as at or about NZTM E1415320; N5223700. This infrastructure involves a
proposed building area of 30 metres x 15 metres that will be permanently occupied, giving a
total potentially affected area of 450 m2, and an associated switchyard area of 20 metres x 30
metres, that will also require permanent clearance of the 600 m2
site it occupies. There is also
a requirement for an area surrounding the powerhouse and switchyard for vehicle and other
access that will be hard-fill (graveled and possibly surfaced e.g. sealed) and remain
permanently cleared after construction. This will be about twice the area occupied by the
powerhouse and switchyard nominal dimensions combined i.e., will involve an additional c.
2,100 m2 of vegetation clearance (see Appendix A, Map 3). While construction is likely to
involve temporary clearance of additional vegetation about the building sites for e.g.
foundation excavation and equipment/materials storage, area potentially affected by this is
included in and assumed to become part of the permanent hard-fill area. Area potentially
affected by these Scheme components is given in Table 12. Vegetation effects are considered
negligible.
Table 12: Powerhouse, Switchyard and Hard-fill Zone Potentially Affected Area Within
Vegetation Type.
Vegetation
Type
Construction
(ha)
Permanent
(ha)
Placement Within Riparian Margins:
Construction (ha)
2/2 Powerhouse 0.045 0.045 0.0
2/2 Switchyard 0.060 0.060 0.0
2/2 Hard-fill Zone 0.210 0.210 0.0
Totals 0.315 0.315 0.0
54
7.5 Powerhouse to Tunnel Portal Exit Access Road and Penstock
In addition to the access road to the powerhouse location there is also a requirement for a
short section of access road from the powerhouse to the tunnel portal exit. For purposes of
this assessment this road section is assumed to extend from the southern margin of the hard-
fill area surrounding the powerhouse, along the alignment of the penstock and immediately
adjacent to it. Based on November 2013 Scheme plans supplied by Westpower, distance
traversed is c. 85 metres and an assumed width is c. 15 metres to allow the short section of
penstock required from the tunnel portal exit to the powerhouse to be run adjacent to this road
and within the 15 metre strip (see Appendix A, Map 3). Vegetation effects are considered
negligible.
Table 13: Powerhouse to Tunnel Portal Exit Road and Penstock Distance and Potentially
Affected Areas Within Vegetation Type.
Vegetation
Type
Distance
(m)
Construction
(ha)
Permanent
(ha)
Placement Within Riparian Margins:
Construction (ha)
2/2 85 0.1275 0.1275 0.0
Totals 85 0.1275 0.1275 0.0
7.6 Tailrace
Indicative tailrace location is shown on Appendix A, Map 3. An estimated width affected by
the tailrace and its construction is 20 metres3 and total distance measured from Appendix A,
Map 3 is c. 120 metres, of which c. 100 metres is through ground that is vegetated or partially
so, the remainder being in the gravel/rock zone of the Waitaha River bed. Potentially affected
area carrying vegetation is therefore c. 2,000 m2, all of which is expected to be permanently
cleared/occupied. A settling pond for interception of sediment during tunnel excavation and
powerhouse construction is proposed. Its planned dimensions are 20 metres wide x 30 metres
long, to be constructed in the tailrace zone and later subsumed by the tailrace, so that it does
not add to the affected area. The tailrace crosses the true-right riparian margin of the Waitaha
River at an oblique angle, affecting an estimated 250 m2 of this riparian zone, approximately
half of which is vegetated or partially vegetated, the remainder being bare rock and gravel at
the point where the main channel of Alpha Creek exits the forest as of November 2013.
Potentially affected areas by vegetation type are shown in Table 14. The tailrace will involve
crossing the riparian margin of the Waitaha River true-right however the scale and type of
disturbance to vegetation for this alone is well within the scale of disturbance that could occur
naturally by e.g. bank-cutting, slips or tributary course changes, all common occurrences in
this environment and climate. Vegetation types present in riparian margins in this area are not
necessarily unique or distinguished floristically from their counterparts not occupying a
riparian strip. It is the arbitrary riparian width designation in the Proposed Regional Land and
Water Plan (WCRC, 2013) and Westland District Plan (WDC, 2002) of 10 metre distance
3 Pers. Comm: S. Matheson, Westpower/Electronet, telephone conversation with J. Derks, 7/9/2012.
55
from a waterway bank, not vegetation, that distinguishes these zones – vegetation present
would not preclude the activity. Vegetation effects are considered negligible.
Table 14: Tailrace Distance and Potentially Affected Area Within Vegetation Type.
Vegetation
Type
Distance
(m)
Construction
(ha)
Permanent
(ha)
Placement Within Riparian Margins:
Construction (ha)
2/2 100 0.200 0.200 Waitaha River true-right 0.025*
Totals 100 0.200 0.200 0.025*
Note: Tailrace riparian area potentially affected as marked * is an estimate based on an oblique angle crossing
of the Waitaha River true-right 10 metre riparian zone by the 20 metre wide tailrace – actual affected area may
vary depending on final angle of traverse of the tailrace through the riparian margin, however any variation in
affected area carrying vegetation is expected to be minimal.
7.7 Stopbank Protection for Powerhouse, Switchyard, Tailrace, Penstock and Access Road
There is potential flood risk to the site of powerhouse, switchyard, tailrace, penstock and
portion of access road located on the alluvial flat. The predominant component of risk is via a
channel that is vegetated, but that shows signs of occasional water flow from the main river at
times of heavy flooding, that runs along the eastern margin of the flat. There may also be a
risk if the course of the river were to deviate from its current position and cut on the true-right
side.
Stopbank rock protection is specified in construction planning, with indicative stopbank
location shown on Appendix A, Map 3. The affected area estimate is based on an armour-
rocked stopbank with 12 metre basal width, commencing at the toe of the terrace near the
southern extremity of the alluvial flat, extending across the upstream end of the flood channel
and along the western flat margin to link with the hard fill zone surrounding the powerhouse
and switchyard, and finish at its northern end, a distance of c. 195 metres. Some portion (estimated to be 25% of total width) of the foot of this structure is likely to
occupy the bed of the Waitaha River, this zone being deemed un-vegetated for affected area
calculation. The remainder is deemed to be located in the Waitaha River true-right riparian
margin. Under these assumptions, total area potentially affected is 2,340 m2, of which
1,755 m2 is at least partially vegetated riparian margin. Potentially affected areas by
vegetation type are shown in Table 15.
Vegetation types present in riparian margins in this area are not necessarily unique or
distinguished floristically from their counterparts not occupying a riparian strip. It is the
arbitrary riparian width designation in the Proposed Regional Land and Water Plan
(WCRC, 2013) and Westland District Plan (WDC, 2002) of 10 metre distance from a
waterway bank, not vegetation, that distinguishes these zones – vegetation present would not
preclude the activity.
Magnitude of effect of this activity on vegetation is within the scale of disturbance that could
occur naturally by e.g. bank-cutting, slips or river course changes, all common occurrences in
this environment and climate. It is likely that a portion of the stopbank will support a
vegetation cover, in particular the river side, if flood events deposit silt between the stopbank
56
rocks. A conservative estimate of area that could be revegetated by either natural regeneration
or supplementary planting (see Section 10.2) is 33% of the total affected in construction.
Effect on vegetation is likely negligible.
Table 15: Stopbank Distance and Potentially Affected Area Within Vegetation Type.
Vegetation
Type
Distance
(m)
Construction
(ha)
Permanent
(ha)
Placement Within
Riparian Margins:
Distance (m)
Placement Within Riparian
Margins:
Construction (ha)
2/2 195 0.1755 0.1169 True-right side of
Waitaha River
195
True-right side of Waitaha
River
195 m x 9 m strip = 0.1755
Totals 195 0.1755 0.1169 195 0.1755
8.0 Other Observations Relating to Vegetation – Area 2
Generally, the state of vegetation of all types described above, both within the areas of
proposed works and the wider area, appears healthy and stable with the exception of change
due to naturally caused events e.g. occasional slips, changes in river channel location, and
windfall zones, these being random and relatively infrequent. While possums and deer are
present, browse effect on indigenous vegetation at all sites appears very low. Sign indicates
low possum numbers. The sign that is present tends to be concentrated about forest margins
bordering river flats and on the recent terraces and stream side faces with predominant
broadleaved hardwood shrub cover, however the possum numbers present are having a very
limited effect on vegetation in the Scheme project footprint and surrounding area.
Likewise for deer, sign is sporadic and concentrated on the grassed and sandy areas of flats.
Grazing is evident on grassed clearing/flat areas, but appears occasional and at a low level –
this will be seasonally variable, highest in spring and summer – however even then would not
be of significant detriment to the majority of indigenous vegetation present given the low deer
population density. Once into areas of shrub/bush cover, deer movements disperse and
vegetation appears little affected.
No goats or goat sign were observed in this part of the Scheme area on the true-right of the
Waitaha River above Macgregor Creek, however goats are present in moderate numbers on
the true-left, from below Douglas Creek up to Labyrinth Creek.
Cattle grazing appears to have been regular on the alluvial flat zone bordering the true-right of
the Waitaha River and true left of Macgregor Creek that carries Vegetation Type 2/7, with
sign of heavy grazing having occurred a few weeks prior to 2012 field work in this area. It has
not affected vegetation other than the grasses and broadleaved species present in this zone and
cattle do not appear to traverse further upriver on the true-right side.
Exotic herbaceous weed species adapted for wind dispersal of seed (e.g. Cirsium spp.) are
present in low concentrations outside of forest areas e.g. along river and stream margins and
in admixture with grasses on more open alluvial flat areas. Scattered Ulex europaeus plants
have established in low density in a restricted area of the alluvial flat zone bordering the true-
57
right of the Waitaha River and true-left of Macgregor Creek that carries Vegetation Type 2/7.
No other brushweed species were noted in any areas.
9.0 Significance and Natural Values Assessment
The West Coast Conservation Management Strategy 2010 – 2020 (DOC, 2010), developed
under provisions of the Conservation Act, 1987: “establishes objectives for the integrated
management of natural and historic resources … and is the key conservation management
tool which the Department uses to implement legal, policy and strategic direction”
(DOC, 2010, p. 3). The West Coast Conservation Management Strategy 2010 – 2020 Part 3,
Section 3.3.2.3 Prioritising Natural Heritage Work, Policy 1 specifies seven criteria to apply
in identifying what might constitute natural heritage and assessing its relative value.
The West Coast Regional Policy Statement (2000) - Policy 9.2 prescribes sixteen
criteria/guidelines to be considered in recognising and providing protection for areas of
indigenous vegetation, any one of which may determine whether an area is significant for
purposes of Section 6(c) of the Resource Management Act 1991 (RMA, 1991). The Westland
District Plan, Section 4.9 Natural Habitats and Ecosystems - Policy D (WDC, 2002)
prescribes eight criteria for use in defining areas of significant indigenous vegetation and
significant habitats of indigenous fauna for purposes of Section 6(c) of the Resource
Management Act 1991 (RMA, 1991) and states that all areas of significant indigenous
vegetation and habitats shall meet one or more of these.
Table 16 contains the criteria from the three different sources discussed above and aligns
these criteria where they vary in terminology but are deemed to have the same or similar
intent, and where a criterion from one source can apply more than once to a criterion or
criteria from other sources.
In Table 16 and or purposes of discussion of significance and natural values assessment the
following abbreviations are assigned:
RPS = West Coast Regional Policy Statement (2000).
WDP = Westland District Plan (2002).
CMS = West Coast Conservation Management Strategy 2010 – 2020.
The structure of some criteria encompasses wider habitat considerations, applicable to flora as
a component of habitat and to any fauna reliant on that habitat. Habitat significance and
natural heritage values as they apply to fauna are covered in detail by other surveys and
reporting re the Scheme (refer Buckingham, 2014 and Whittaker, 2013).
An assessment of the vegetation in Area 1 and Area 2 is made against each of the criteria
groupings that apply via discussion under headings based on the criteria in Table 16 that are
relevant to terrestrial flora.
58
Table 16: Criteria Framework4 for Determining Significance and Natural Heritage Values for Purposes of Section 6(c) of the Resource Management Act 1991 (RPS & WDP)
and Natural Heritage Values (CMS).
RPS
(Policy 9.2)
WDP
(Policy 4.9D)
CMS
(Policy 3.3.2.3(1)) a) The desirability for their protection by statute or covenant.
b) Protection status, including reserves created under the West Coast
Accord.
(iv) Protected Status.
The area has been set aside by New Zealand Statue or Covenant for protection and
preservation or is a recognised wilderness area.
c) The degree to which the area is representative of an association of
species or an ecosystem that is typical of the region.
(ii) Representativeness.
The area is one of the best examples of an association of species which is typical
of its ecological district.
Representativeness,
Diversity.
d) The likelihood of the area retaining its viability, quality and integrity of
processes over a long time period.
(i) Intactness and Size.
The area is unmodified by human activity, comprises a predominantly intact
indigenous system and is not affected in a major way by weed or pest species;
AND,
The area of indigenous vegetation has a predominant cover of 5 hectares or more.
Viability,
Intactness.
e) The presence or absence of an indigenous species or community of
indigenous species that is rare or threatened regionally or nationally.
(vi) Threat.
The area supports an indigenous species or community of species which is
threatened within the ecological district or threatened nationally.
Threatened Species
and Habitat.
f) The degree to which the area is distinctive in terms of indigenous species
that are unusual, endemic, or that reach a distribution limit in the region.
(iii) Distinctiveness.
The area has indigenous species or an association of indigenous species which is
unusual or rare in the ecological district, or endemic or reaches a distribution limit
in the ecological district. The area may be distinctive because of the influences of
factors such as altitude, water table, soil type or geothermal activity.
Diversity.
g) The extent to which the area has been modified from a natural state or
affected by weeds or pest species.
(i) Intactness and Size.
The area is unmodified by human activity, comprises a predominantly intact
indigenous system and is not affected in a major way by weed or pest species;
AND,
The area of indigenous vegetation has a predominant cover of 5 hectares or more.
Viability,
Intactness.
4 Framework adapted from model provided by M. Kennedy, West Coast Planning Ltd., Paroa.
59
Table 16: Criteria Framework for Determining Significance and Natural Heritage Values for Purposes of Section 6(c) of the Resource Management Act 1991 (RPS & WDP)
and Natural Heritage Values (CMS) Ctd.
RPS
(Policy 9.2)
WDP
(Policy 4.9D)
CMS
(Policy 3.3.2.3(1)) h) Its connection with other areas of significant indigenous vegetation or
significant habitats of indigenous fauna.
(v) Connectivity.
The area is connected to one or more other significant areas in a way (including
through ecological processes) which makes a major contribution to the overall
value or natural functioning of those areas.
Viability.
i) Its contribution to the avoidance or mitigation of natural hazards.
j) Its use or value on a local, regional or national scale for public access,
recreation, amenity and heritage purposes.
(viii) Scientific or Other Cultural Value.
The area is a type, locality or other scientific reference area, is listed as a
geopreservation site, or has a distinctive amenity value (e.g. it contributes to a
distinctive and outstanding landscape of the district, has other significant cultural
value or is of international importance).
Natural Landscape
Character.
k) The relationship of Poutini Ngai Tahu and their culture and traditions
with their ancestral lands, water, sites, waahi tapu, mahinga kai and other
taonga.
(viii) Scientific or Other Cultural Value.
The area is a type, locality or other scientific reference area, is listed as a
geopreservation site, or has a distinctive amenity value (e.g. it contributes to a
distinctive and outstanding landscape of the district, has other significant cultural
value or is of international importance).
Taonga Species and
Habitat.
l) The contribution of the area or habitat to maintenance and enhancement
of ecological and reproductive processes, water quality, water flow and
soil conservation.
(v) Connectivity.
The area is connected to one or more other significant areas in a way (including
through ecological processes) which makes a major contribution to the overall
value or natural functioning of those areas.
Diversity.
m) The relationship of the area or habitat to any water body included in a
water conservation order.
n) Whether they occur near wetlands and estuaries.
o) The importance to migratory species, including whitebait. (vii) Migratory Species.
An inter-tidal area or area of forest, wetland, lake, estuary or other natural habitat
that is important for migratory species or for breeding, feeding or other vulnerable
stages of indigenous species.
Diversity,
Taonga Species and
Habitat.
p) The relevance of ecological districts in relation to matters (c), (e) and (f).
60
For comparison of vegetation type occurrence/distribution in considering significance and
natural heritage values and to provide context between areas potentially affected by the
Scheme compared to the areas in the locale and further afield, a GIS analysis5 using Land
Cover Database (LCDB)6 land cover classes aligned as far as practicable to their counterpart
vegetation types as described above for the Scheme area, has been done at three levels:
1. For the Wilberg Ecological District (Appendix A, Map 4).
2. For the Waitaha catchment being all that area within the catchment south of the
NZTM North 5226000 line so as to exclude lowland cover types and areas not
relevant for purposes of this comparison (Appendix A, Map 4).
3. For the Base Area as previously defined in Section 4.0 and as shown on Appendix A,
Map 5 and Appendix A, Map 6, considered the Scheme’s locale.
While the different LCDB land cover classes are mapped for individual areas down to one
hectare, the land cover class descriptions are necessarily broad, with 33 land cover/land use
classes covering all land cover and land use (including urban/infrastucture and agricultural)
activities across New Zealand. The detailed field survey undertaken as a basis of this report
and the differentiation and mapping of vegetation cover gives a much finer stratification. To
enable comparison by area, Vegetation Types described for Area 1 and Area 2 are, where
necessary, amalgamated to fit with the most applicable LCDB land cover type, with results
given in Table 17.
Total land area within the Wilberg Ecological District is c. 84,113.8 hectares and within the
Waitaha catchment (as previously defined) is c. 15,998.8 hectares. Of these total areas,
62,937 hectares = 75% of the Wilberg Ecological District and 12,041 hectares = 75% of the
Waitaha catchment, carry indigenous vegetation of some type under the LCDB land cover
classes (i.e., the above areas exclude exotic forest, deciduous hardwoods, high producing
exotic grassland, lakes and ponds, permanent ice and snow and river land cover classes).
GIS analysis undertaken using the LCDB land cover classes matched to the indigenous forest
type assemblages (all Vegetation Types excluding Vegetation Type 1/4) potentially affected
by the Scheme shows these are present:
Across 27,903 hectares comprising 44% of the Wilberg Ecological District indigenous
vegetation cover.
Across 4,334 hectares comprising 36% of the Waitaha catchment indigenous
vegetation cover.
They are therefore common and widely represented in both Wilberg Ecological District and
the Waitaha catchment. The indigenous forest assemblages also occur extensively in
catchments of similar valleys throughout central Westland (James et al., 1973; Wardle, 1979).
5 GIS mapping and GIS area data procurement services supplied by Boffa Miskell Ltd., Christchurch. Data
analysis and summarisation by TACCRA Ltd. 6 Ref: www.lcdb.scinfo.org.nz - Land Cover Database v.3.0, 2012.
61
Vegetation Type 1/4, a small area of which is also potentially affected by the Scheme, is
analogous to the LCDB Sub Alpine Shrubland cover class. Under those criteria, GIS analysis
shows it is present:
Across 17,269 hectares comprising 27% of the Wilberg Ecological District indigenous
vegetation cover.
Across 4,249 hectares comprising 35% of the Waitaha catchment indigenous
vegetation cover.
As for the indigenous forest vegetation, this shrubland vegetation is also common and widely
represented, not only in the areas noted above but in other valleys throughout central
Westland (James et al., 1973; Wardle, 1979).
62
Table 17: LCDB Land Cover Class and Analogous Vegetation Type Area Summaries and Comparisons for Wilberg Ecological District, Waitaha
Catchment and Base Area and the Scheme’s Project Footprint.
LCDB Land Cover Class +
Corresponding Vegetation Type(s)*
Area in
Wilberg
Ecological
District
Area in
Waitaha
Catchment
Area
In
Base
Area
Area of Scheme
Project
Footprint in
LCDB Cover
Class/Vegetation
Type(s)
Area in Base
Area as % of
LCDB Cover
Class/Vegetation
Type(s) in
Wilberg
Ecological
District
Area of Scheme
Project
Footprint as %
of LCDB Cover
Class/Vegetation
Type(s) in
Wilberg
Ecological
District
Area of Scheme
Project
Footprint as %
of LCDB Cover
Class/Vegetation
Type(s) in
Waitaha
Catchment
Area of Scheme
Project
Footprint as %
of LCDB Cover
Class/Vegetation
Type(s) in Base
Area
Alpine Grass/Herbfield 2,994.50 509.06 0.00 0.00 0.00 0.00 0.00 0.00 Broadleaved Indigenous Hardwoods
*(2/4, 2/4A, 2/5 & 2/6)
379.13 126.82 29.97 1.8675 7.90 0.493 1.50 6.36
Deciduous Hardwoods 0.00 1.20 0.00 0.00 0.00 0.00 0.00 0.00
Exotic Forest 4.34 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Fernland 0.29 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Forest - Harvested 22.41 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Gorse and/or Broom
*(2/9)
137.19 63.69 12.14 0.0720 8.85 0.052 0.11 0.59
Gravel and Rock
*(2/7)
14,913.98 3,254.76 21.21 0.00 0.14 0.00 0.00 0.00
High Producing Exotic Grassland 310.32 62.53 0.00 0.00 0.00 0.00 0.00 0.00
Indigenous Forest
*(1/1, 1/2, 1/3, 2/1, 2/2, 2/3, 2/3A, 2/3B & 2/8)
27,386.56 4,143.05 343.24 2.2880 1.25 0.008 0.06 0.67
Lake and Pond 29.31 44.51 0.00 0.00 0.00 0.00 0.00 0.00
Landslide 75.29 16.56 3.00 0.00 3.99 0.00 0.00 0.00
Low Producing Grassland 127.83 1.79 0.00 0.00 0.00 0.00 0.00 0.00
Manuka and/or Kanuka 3.86 0.57 0.00 0.00 0.00 0.00 0.00 0.00
Permanent Snow and Ice 5,574.60 537.68 0.00 0.00 0.00 0.00 0.00 0.00
River 343.92 55.42 15.78 0.00 4.59 0.00 0.00 0.00
Sub Alpine Shrubland
*(1/4)
17,268.94 4,249.10 10.84 0.2980 0.06 0.002 0.007 2.75
Tall Tussock Grassland 14,541.30 2932.10 0.00 0.00 0.00 0.00 0.00 0.00 Totals 84,113.79 15,998.84 436.19 4.5255 0.52 n.a. n.a. n.a.
Note: All area figures in the above table are hectares.
Note: the Waitaha catchment is not entirely contained within the Wilberg Ecological District (see Appendix A, Map 4) therefore it can exhibit individual LCDB land cover class areas greater
than those for the Wilberg Ecological District, e.g., Lake and Pond.
Note: Project Footprint as used in the above table refers to the area that encompasses temporary (i.e. construction) and permanent installations, infrastructure and accessways.
Note: * Denotes the Vegetation Types identified in this report e.g. 2/1, 2/2, 2/3 etc. as assigned to their respective or most representative LCDB land cover class as mapped under the LCDB. In
this case Vegetation Type 2/7 is shown as Gravel and Rock and Vegetation Type 2/9 is shown as Gorse and/or Broom under LCDB mapping whereas they would more aptly be classified
Broadleaved Indigenous Hardwood.
63
9.1 Area 1 and Area 2 Vegetation Type(s) – Significance and Natural Heritage Value Assessment
The criteria or criteria groups contained in Table 16 are used as the basis for discussion and
analysis in determining which, if any, result in terrestrial flora being considered significant
indigenous vegetation or of high natural heritage value, and if so, what effects of the Scheme
would be on it.
RPS 9.2(a). The desirability for their protection by statute or covenant.
Area 1 & Area 2 Vegetation Characteristics Compared to Criterion RPS 9.2(a):
The majority of the Scheme project area carrying indigenous flora is within the Waitaha
Conservation Area - already public conservation land. The remainder of the Scheme project
area i.e. north of Macgregor Creek, is predominantly freehold farmland with lesser amounts
of other Crown land and legal road. Indigenous terrestrial flora that is present on these areas
of other tenure is not considered to be of conservation or other protection (e.g. soil and water)
value warranting inclusion under any statute or covenant.
Significance Outcome: Not identified as significant indigenous vegetation.
RPS 9.2(b). Protection status, including reserves created under the West Coast Accord.
WDP 4.9D(iv) Protected status - The area has been set aside by New Zealand Statue or
Covenant for protection and preservation or is a recognised wilderness area.
Area 1 & Area 2 Vegetation Characteristics Compared to Criteria RPS 9.2(b) &
WDP 4.9D(iv):
The majority of the Scheme project area carrying indigenous flora is within the Waitaha
Forest conservation unit. As conservation land (stewardship land), the area is administered
under New Zealand statute. It is not part of a recognised wilderness area.
Significance Outcome: Significant indigenous vegetation.
Note: These criteria prescribe an arbitrary designation. They do not infer or confer high
vegetation values. The land area of Westland is approximately 1,140,000 hectares.
Approximately 85% (969,850 hectares) is administered by the Department of Conservation
(WDC, 2002), therefore the protected status characteristic is very common. The Scheme
would not affect status of land administration for the Waitaha Forest conservation unit and the
activity would not be precluded on the basis of vegetation present in the Scheme project
footprint.
64
RPS 9.2(c). The degree to which the area is representative of an association of species or an
ecosystem that is typical of the region.
WDP 4.9D(ii). Representativeness - The area is one of the best examples of an association of
species which is typical of its ecological district.
CMS 3.3.2.3(1). Representativeness and Diversity.
Area 1 & Area 2 Vegetation Characteristics Compared to Criteria RPS 9.2(c), WDP 4.9D(ii)
& CMS 3.3.2.3(1) – Representativeness and Diversity:
The predominant vegetation encompassed by Area 1 and Area 2 is typical of that observed on
streamsides, alluvial flats, terrace sequences and hill footslope and side-slope areas across a
relatively wide altitudinal range (e.g. 100 – 600 m.a.s.l.) within forested catchments. For
example, the Wilberg Ecological District (including the Waitaha, Wanganui, Poerua and
majority of the Perth catchments) contains in excess of 45,100 hectares of similar vegetation
cover. The Waitaha catchment contains in excess of 8,500 hectares. While typical, none of the
Vegetation Types in Area 1 and Area 2 would alone or together be distinguished as one of the
best examples of a species association noted as characteristic of the Wilberg Ecological
District, these being: mixed podocarp-hardwood forest on lower slopes; rata-kamahi forest at
higher altitudes; subalpine scrub; snow tussockland; cushion bogs; herbfield and high-alpine
vegetation (McEwen, 1987). Species present and their assemblages do not display degrees of
representativeness or diversity that distinguish these areas from counterparts in their location
in the Waitaha catchment, in the Wilberg Ecological District or the region.
Significance/Natural Heritage Value Outcome: Not identified as significant indigenous
vegetation or of high natural heritage value.
RPS 9.2(d). The likelihood of the area retaining its viability, quality and integrity of processes
over a long time period.
WDP 4.9D(ii). Intactness and Size - The area is unmodified by human activity, comprises a
predominantly intact indigenous system and is not affected in a major way by weed or pest
species; AND, The area of indigenous vegetation has a predominant cover of 5 hectares or
more.
CMS 3.3.2.3(1). Viability and Intactness.
Area 1 & Area 2 Vegetation Characteristics Compared to Criteria RPS 9.2(d), WDP 4.9D(ii)
& CMS 3.3.2.3(1) – Viability and Intactness:
Vegetation present in Area 1 and Area 2 is part of a predominantly intact indigenous system
greater than 5 hectares in cover and is not affected in a major way by weed or pest species. It
has not been modified to any marked extent by human activity.
Environmental and physical influences on vegetation in the Waitaha catchment are unlikely to
change in the long term. Effects of natural events (including catastrophic disturbance by e.g.
65
major earthquake) may alter current vegetation characteristics (including species mix,
frequency of occurrence, size class distributions, change from mature to regenerational phases
of forest cover) over time, however the area should retain viability, intactness and integrity of
processes.
Significance/Natural Heritage Value Outcome: Significant indigenous vegetation, based on
area and lack of modification. Areas exhibit high natural heritage value due to intactness and
viability retention potential.
Note: Effects of the Scheme on the area’s vegetation viability, quality, integrity and intactness
are likely to be inconsequential considering its small project footprint within the surrounding
contiguous area (total footprint of 4.5255 hectares within the indigenous vegetation cover of
the Base Area of c. 396 hectares, representing an affected area of 1.1%), combined with
measures to be implemented wherever practicable, that avoid affecting important habitat
components e.g. large forest trees.
RPS 9.2(e). The presence or absence of an indigenous species or community of species that is
rare or threatened regionally or nationally.
WDP 4.9D(vi). Threat - The area supports an indigenous species or community of species
which is threatened within the ecological district or threatened nationally.
CMS 3.3.2.3(1). Threatened Species and Habitat.
Area 1 & Area 2 Vegetation Characteristics Compared to Criteria RPS 9.2(e), WDP 4.9D(vi)
& CMS 3.3.2.3(1) – Threatened Species and Habitat:
No indigenous flora species have been identified (see Species List, Appendix B) that are
listed as threatened by de Lange, et al., (2012) or Hitchmough et al., (2007). This applies
nationally and to the Wilberg Ecological District.
Significance/Natural Heritage Value Outcome: Not identified as significant indigenous
vegetation or of high natural heritage value.
66
RPS 9.2(f). The degree to which the area is distinctive in terms of indigenous species that are
unusual, endemic, or that reach a distribution limit in the region.
WDP 4.9D(iii). Distinctiveness - The area has indigenous species or an association of
indigenous species which is unusual or rare in the ecological district, or endemic or reaches
a distribution limit in the ecological district. The area may be distinctive because of the
influences of factors such as altitude, water table, soil type or geothermal activity.
CMS 3.3.2.3(1). Diversity.
Area 1 & Area 2 Vegetation Characteristics Compared to Criteria RPS 9.2(f), WDP 4.9D(iii)
& CMS 3.3.2.3(1) - Diversity:
Vegetation types and assemblages are widely represented in the Wilberg Ecological District
and in neighbouring ecological districts (refer discussion under RPS 9.2(c) and WDP 4.9D(ii)
above). No species observed reaches a distribution limit or is endemic here and physical
factors do not promote distinctiveness. Species diversity is no more or less varied for
vegetation types in these areas than in their counterparts in the general area (Base Area), other
parts of the Wilberg Ecological District or at similar sites in other valleys of central Westland
and would not differentiate Area 1 or Area 2 as having high natural heritage value.
Significance/Natural Heritage Value Outcome: Not identified as significant indigenous
vegetation or of high natural heritage value.
RPS 9.2(g). The extent to which the area has been modified from a natural state or affected by
weeds or pest species.
WDP 4.9D(i). Intactness and Size - The area is unmodified by human activity, comprises a
predominantly intact indigenous system and is not affected in a major way by weed or pest
species; AND, The area of indigenous vegetation has a predominant cover of 5 hectares or
more.
CMS 3.3.2.3(1). Viability and Intactness.
Area 1 & Area 2 Vegetation Characteristics Compared to Criteria RPS 9.2(g), WDP 4.9D(i)
& CMS 3.3.2.3(1) Viability and Intactness:
Vegetation present in Area 1 and Area 2 is part of a predominantly intact indigenous system
greater than 5 hectares in cover and is not affected in a major way by weed or pest species. It
has not been modified to any marked extent by human activity.
While deer and possums are present in the areas, their observed effect on vegetation is low at
current population levels. Brushweed establishment (Ulex europaeus) appears restricted to a
minor pocket at the northern extremity of Area 2 and other weed establishment is limited to
non-forested areas, involving herbaceous species adapted to wind dispersal of seed. The
majority of vegetation cover is closed-canopy indigenous forest or shrubland that will
generally limit the establishment of Ulex europaeus and herbaceous weeds (e.g. Cirsium spp.)
The area should retain viability and intactness.
67
Significance/Natural Heritage Value Outcome: Significant indigenous vegetation, based on
area and lack of modification. Areas exhibit high natural heritage value due to intactness and
viability retention potential.
RPS 9.2(h). Its connection with other areas of significant indigenous vegetation or significant
habitats of indigenous fauna.
WDP 4.9D(v). Connectivity - The area is connected to one or more other significant areas in
a way (including through ecological processes) which makes a major contribution to the
overall value or functioning of those areas.
CMS 3.3.2.3(1). Viability.
Area 1 & Area 2 Vegetation Characteristics Compared to Criteria RPS 9.2(h), WDP 4.9D(v)
& CMS 3.3.2.3(1) - Viability:
Vegetation cover of Area 1 and Area 2 is contiguous with the extensive area of similar types
that form a continuous unbroken sequence both north-west from the Waitaha River to higher
altitude forest of the eastern side of the Hitchen Range, and from north to south on the true-
right side of the Waitaha River from the lower to upper valley. It is therefore connected to,
and is a component of, habitat of other significant areas however the amount contained in the
Scheme’s project footprint is extremely small (1.1% of Base Area vegetation) and would not
make a major contribution to the overall value or functioning of those other areas or detract
from their viability if modified.
Significance/Natural Heritage Value Outcome: Not identified as significant indigenous
vegetation or of high natural heritage value.
RPS 9.2(i). Its contribution to the avoidance or mitigation of natural hazards.
Area 1 & Area 2 Vegetation Characteristics Compared to Criterion RPS 9.2(i):
Retention of vegetation cover on steep terrain, in particular where high rainfall occurs, can
reduce risk of erosion and slips. Relative to the area of the Waitaha catchment, the areas of
vegetative cover within Area 1 and Area 2 contained in the Scheme’s project footprint would
be inconsequential as a contributor to the avoidance of natural hazards given the extremely
small area (4.5255 ha in total) involved and being primarily located on low altitude alluvial
flats and terrace landforms.
Significance Outcome: Not identified as significant indigenous vegetation.
68
RPS 9.2(j). Its use or value on a local, regional or national scale for public access,
recreation, amenity and heritage purposes.
WDP 4.9D(viii). Scientific or Other Cultural Value - The area is a type, locality or other
scientific reference area, is listed as a geopreservation site, or has a distinctive amenity value
(e.g. it contributes to a distinctive and outstanding landscape of the district, has other
significant cultural value or is of international importance).
CMS 3.3.2.3(1). Natural Landscape Character.
Area 1 & Area 2 Vegetation Characteristics Compared to Criteria RPS 9.2(j), WDP 4.9(viii)
& CMS 3.3.2.3(1) - Natural Landscape Character:
None of the attributes of vegetation in Area 1 or Area 2 potentially affected by Scheme
components, within the project footprint, contribute to a type, locality or amenity which is
distinctive within the district in terms of vegetation composition or uniqueness.
No characteristic(s) distinguish vegetation in Area 1 or Area 2 from similar assemblages
present over a similar range of altitude and landforms in other parts of the Waitaha Valley and
neighbouring valleys. For example, the Wilberg Ecological District (including the Waitaha,
Wanganui, Poerua and majority of the Perth catchments) contains in excess of
45,100 hectares of similar vegetation cover. The Waitaha catchment contains in excess of
8,500 hectares. The range of types are also represented in valleys further north
(Hokitika/Whitcombe) and south (Whataroa, Franz Josef, Fox, Cook, Copeland/Karangarua)
in central and south Westland. Therefore, and as discussed above in terms of criterion
WDP 4.9D(viii), vegetation present in Area 1 and Area 2 would not be considered an
outstanding area of indigenous vegetation in terms of the criterion of distinctiveness. As a
result, and when viewed from the perspective of vegetation composition, the characteristics of
vegetation within Area 1 and Area 2 would not be a determining factor in identifying any
distinctive amenity and/or outstanding landscape character within the District. Assessment of
other components of natural landscape character are beyond the scope of this report and are
covered by other Scheme reporting (refer Boffa Miskell Ltd., 2014).
No parts of Area 1 or Area 2 containing the Scheme project footprint as it affects terrestrial
vegetation are listed geopreservation sites or scientific reference areas, have other significant
cultural value (as far as is known)7 or are of international importance.
Significance/Natural Heritage Value Outcome: Not identified as significant indigenous
vegetation or of high natural heritage value.
7 Pers. Comm: S. Cotton, Consultation Officer, Westpower Ltd., 17/12/2013 - That cultural impact assessment
will be undertaken once a draft Assessment of Environmental Effects has been provided to iwi. Westpower has
met with Te Rūnanga o Ngati Waewae and Te Rūnanga o Makaawhio to discuss the proposal. While there have
been no significant concerns or issues raised to date re indigenous vegetation, there is a strong affiliation and
interest in preservation of natural values within the area such as the Whio/Blue Duck population.
69
RPS 9.2(k). The relationship of Poutini Ngai Tahu and their culture and traditions with their
ancestral lands, water sites, waahi tapu, mahinga kai and other taonga.
WDP 4.9D(viii). Scientific or Other Cultural Value - The area is a type, locality or other
scientific reference area, is listed as a geopreservation site, or has a distinctive amenity value
(e.g. it contributes to a distinctive and outstanding landscape of the district, has other
significant cultural value or is of international importance).
CMS 3.3.2.3(1). Taonga Species and Habitat.
Area 1 & Area 2 Vegetation Characteristics Compared to Criteria RPS 9.2(k), WDP
4.9D(viii) & CMS 3.3.2.3(1) – Taonga Species and Habitat:
Species of flora observed in Area 1 and Area 2 are common and widely represented in the
locale, in the wider Waitaha catchment and at similar sites in other valleys of central
Westland. As far as is known, vegetation within the Scheme’s project footprint area is not
recognised as having significant cultural value and the areas are not distinguished as
significant sites in respect of taonga species or their habitat in terms of vegetation8.
Significance/Natural Heritage Value Outcome: Not identified as significant indigenous
vegetation or of high natural heritage value.
8 Pers. Comm: Op cit
5
70
RPS 9.2(l). The contribution of the area or habitat to maintenance and enhancement of
ecological and reproductive processes, water quality, water flow and soil conservation.
WDP 4.9D(viii). Connectivity - The area is connected to one or more other significant areas
in a way (including through ecological processes) which makes a major contribution to the
overall value or functioning of those areas.
CMS 3.3.2.3(1). Diversity.
Area 1 & Area 2 Vegetation Characteristics Compared to Criteria RPS 9.2(l), WDP 4.9D(viii)
& CMS 3.3.2.3(1) - Diversity:
Vegetation cover of Area 1 and Area 2 is contiguous with the extensive area of similar types
that form a continuous unbroken sequence both north-west from the Waitaha River to higher
altitude forest of the eastern side of the Hitchen Range, and from north to south on the true-
right side of the Waitaha River from the lower to upper valley. It is therefore connected to,
and is a component of, habitat of other significant areas however the amount contained in the
Scheme project footprint is extremely small (1.1% of the Base Area indigenous vegetation
cover) and would not make a major contribution to the overall ecological value or functioning
of those other areas. Natural breaks in vegetation connectivity via natural features e.g. the
Waitaha River bed, are of greater width and length than the narrow linear area footprint of the
access road/transmission line which constitutes the largest individual infrastructure item of
the Scheme. Any effect of the Scheme on water quality, water flow and soil conservation and
diversity via vegetation change would be inconsequential considering the area involved.
Significance/Natural Heritage Value Outcome: Not identified as significant indigenous
vegetation or of high natural heritage value.
RPS 9.2(m). The relationship of the area or habitat to any water body included in a water
conservation order.
Area 1 & Area 2 Vegetation Characteristics Compared to Criterion RPS 9.2(m):
The Waitaha River is not subject to a water conservation order. The nearest area subject to a
water conservation order is in excess of 100 km from the Scheme project area, being the
Ahaura River (National Water Conservation (Grey River) Order 1991 (WCRC, 2013)).
Significance Outcome: Not identified as significant indigenous vegetation.
71
RPS 9.2(n). Whether they occur near wetlands or estuaries.
Area 1 & Area 2 Vegetation Characteristics Compared to Criterion RPS 9.2(n):
There are no areas of wetland vegetation in the Scheme project area, or recognised wetland
areas near it. The closest wetland listed (identifier HARP021 Lake Ianthe) in the Proposed
Regional Land and Water Plan (WCRC, 2013) is located at the southern end of Lake Ianthe.
The closest point of this wetland and Area 2 (Area 1 being further removed) is c. 9.1 km. It is
separated from the Scheme project area by the Bonar Range. No significance would apply to
vegetation in Area 1 or Area 2 under this criterion.
Significance Outcome: Not identified as significant indigenous vegetation.
RPS 9.2(o). The importance to migratory species, including whitebait.
WDP 4.9D(vii). Migratory Species – An inter-tidal area or area of forest, wetland, lake,
estuary or other natural habitat that is important for migratory species for breeding, feeding
or other vulnerable stages of indigenous species.
CMS 3.3.2.3(1). Diversity, Taonga Species and Habitat.
Area 1 & Area 2 Vegetation Characteristics Compared to Criteria RPS 9.2(o), WDP 4.9D(vii)
& CMS 3.3.2.1(1) – Diversity, Taonga Species and Habitat:
While migratory fauna species may be present e.g. Long-tailed cuckoo in summer as an
international migrant and wood pigeon throughout the year as a locally-seasonal migrant
(Buckingham, 2014) in habitat afforded by the flora present, neither Area 1 nor Area 2
vegetation would constitute important habitat for migratory species, given the small areas
they contain and the widespread occurrence of the assemblages in other areas in the Waitaha
catchment and other central Westland valleys. The same assessment applies re natural values
and as noted by Buckingham (2014), the Scheme is expected to have little influence on
migratory species.
Significance/Natural Heritage Value Outcome: Not identified as significant indigenous
vegetation or of high natural heritage value.
72
RPS 9.2(p). The relevance of ecological districts in relation to matters (c), (e) and (f).
Area 1 & Area 2 Vegetation Characteristics Compared to Criterion RPS 9.2(p):
Relevance of ecological districts is encapsulated in the criteria prescribed in the Westland
District Plan, Policy 4.9D (WDC, 2002) that specifically refer to ecological district
consideration and align with RPS 9.2(c) = WDP 4.9D - Representativeness, RPS 9.2(e) =
WDP 4.9D - Threat and RPS 9.2(f) = WDP 4.9D - Distinctiveness.
The discussion and assessment outcomes given above for those criteria also apply for this
criterion. For all three the result is:
Significance/Natural Heritage Value Outcome: Not identified as significant indigenous
vegetation or of high natural heritage value.
9.2 Summary of Vegetation Significance and Natural Heritage Value
None of the seven criteria/guidelines set out in the West Coast Conservation Management
Strategy 2010 – 2020 Part 3, Section 3.3.2.3 Prioritising Natural Heritage Work, Policy 1,
(DOC, 2010) applied to assessment of vegetation in Area 1 or Area 2 result in high natural
heritage value status determination where there is no correspondence/alignment of a criterion
from Policy 4.9D of the Westland District Plan (WDC, 2002).
The same applies to significant indigenous vegetation status determination using the sixteen
criteria in the West Coast Regional Policy Statement (2000) - Policy 9.2 (WCRC, 2000)
where a significant indigenous vegetation outcome is not also concomitant with
correspondence/alignment of a criterion in Policy 4.9D of the Westland District Plan
(WDC, 2002).
Therefore, a summary as to whether any high natural heritage values pertain and of
significance of indigenous vegetation is provided by an outcome of significance under one or
more of the Westland District Plan (WDC, 2002) Policy 4.9D criteria (i.e., the WDP 4.9D
criteria discussed in Section 9.1). This alignment and summary is shown in Table 18.
73
Table 18: Summary of Significant Indigenous Vegetation and High Natural Heritage Value
Assessment Criteria Applicable To Area 1 and Area 2 Vegetation.
RPS
(Policy 9.2)
WDP
(Policy 4.9D)
CMS
(Policy 3.3.2.3(1)) b) Protection status, including reserves
created under the West Coast
Accord;
(iv) Protected Status.
The area has been set aside by New Zealand
Statue or Covenant for protection and
preservation or is a recognised wilderness area.
d) The likelihood of the area retaining its
viability, quality and integrity of
processes over a long time period;
(i) Intactness and Size.
The area is unmodified by human activity,
comprises a predominantly intact indigenous
system and is not affected in a major way by
weed or pest species; AND, The area of
indigenous vegetation has a predominant cover
of 5 hectares or more.
Viability,
Intactness.
f) The extent to which the area has been
modified from a natural state or
affected by weeds or pest species;
(i) Intactness and Size.
The area is unmodified by human activity,
comprises a predominantly intact indigenous
system and is not affected in a major way by
weed or pest species; AND, The area of
indigenous vegetation has a predominant cover
of 5 hectares or more.
Viability,
Intactness.
Vegetation of Area 1 and Area 2 (being contiguous with a greater area within the Waitaha
catchment) is significant indigenous vegetation under the Westland District Plan
(WDC, 2002) on the basis of two WDP (Policy 4.9D) criteria - intactness and size of area and
protected status. As shown in Table 16 and Table 18, the WDP (Policy 4.9D) criterion of
intactness and size also encompasses West Coast Regional Policy Statement (2000) - Policy
9.2 criteria d) and f) parameters re area retaining viability, quality and integrity of processes,
and extent of modification. The arbitrary designation as per the WDP (Policy 4.9D) protected
status criterion also encompasses West Coast Regional Policy Statement (2000) - Policy 9.2
criterion b). Both pertain to land administration and do not infer or confer high vegetation
values.
High natural heritage values of viability and intactness also pertain as per the West Coast
Conservation Management Strategy 2010 – 2020 (DOC, 2010) and are concomitant with the
WDP (Policy 4.9D) criterion of intactness and size.
Work undertaken by Westpower:
1. Contributes to a record of vegetation in this area at a more detailed level of
stratification and accuracy of description than available via the LCDB land cover type
stratification. Examples are Vegetation Type 2/7 being mixed scattered indigenous
hardwood shrub cover and grassed alluvial flat mapped as Gravel and Rock in the
LCDB system, and Vegetation Type 2/9, being indigenous streamside vegetation,
mapped under the LCDB system as Gorse and/or Broom.
74
2. Adds detail to vegetation records for the Wilberg Ecological District, where the
summary in McEwen (1987, p. 3) states:
“Vegetation: a sequence of vegetation belts characteristic of high rainfall areas where
beech is lacking: mixed podocarp-hardwood forest on lower slopes; rata-kamahi
forest at higher altitudes; subalpine scrub; snow tussockland, cushion bogs, herbfield
and high-alpine vegetation. Little botanical knowledge.”
These advances are consistent with management objectives and policies of the West Coast
Conservation Management Strategy 2010 – 2020, Section 3.3.2.1: Knowledge and
Information Needs, Objective 1, Policies 3 and 4 and under Section 3.3.2.1: Knowledge and
Information Needs rationale where it is acknowledged that extra information: “…may assist
with the management of conservation values.” (DOC, 2010, p. 73).
The criteria under which significance and high heritage values accrue to Area 1 and Area 2
vegetation are predominantly arbitrary (land status, size of area). Nothing was identified in
the field survey that suggests any vegetation community uniqueness, attributes or species
presence that would distinguish Area 1 and Area 2 vegetation from any other similar sites
throughout the central Westland area and that would preclude these areas in total or in part
from the proposed Scheme activities on the basis of vegetation. Reasons are:
No threatened flora species were identified and none are endemic to the areas.
All species recorded have a wide distribution range in the Waitaha catchment, the
Wilberg Ecological District and other neighbouring Ecological Districts e.g.
Whitcombe Ecological District to the north and Glaciers Ecological District to the
south.
The Scheme’s design that aims to minimise affected area by utilising tunnel access to
headworks infrastructure, aligning transmission line route and access road to reduce
clearance area and locating these wherever practicable on landforms that require least
earthworks and where mature podocarp/hardwood forest is least prevalent.
The project footprint of the Scheme is a very small component of its locale (1.1% of
the Base Area), and the operational footprint (area permanently cleared of vegetation)
is still less at 0.93% of the Base Area. Clearance of these amounts of vegetation of the
types involved would have inconsequential effect on vegetation connectivity,
intactness, or viability as high natural heritage values.
The Scheme would not affect status of land administration for the Waitaha Forest
Conservation Unit and the activity would not be precluded on the basis of vegetation
present in the Scheme’s project footprint area because its protected status designation
is arbitrary, not a consequence of vegetation.
75
10.0 Recommended Monitoring, Mitigation and Remediation
The Scheme’s overall effect on indigenous vegetation is considered minor. Design minimises
effects of infrastructure placement and permanently occupied area and effects associated with
construction, on vegetation. There are two potential effects on flora other than the areas
involved. These are the number of large trees that may be affected, and weed incursion risk.
Recommended measures aimed at reducing these effects or risk at sites of Scheme
activities/infrastructure follow.
10.1 Area 1 - Monitoring/Mitigation/Remediation:
All Places in Area 1 Where Earthmoving Machinery Enters:
Machinery should be thoroughly washed down (track-gear, undercarriage) prior to entering
any part of Area 1 so as to reduce risk of weed seed transport.
Tunnel Portal Entrance and Intake Access Road:
While no uniqueness in terms of overall vegetation type(s) is attributable to the general area
in which the possible road to the contractors’ facilities area is proposed, defining a route that
results in least damage to all vegetation, and especially large (60+ cm dbh) hardwood trees
and podocarp trees (30+ cm dbh) will be a priority. The tunnel portal entrance and intake
access road route and area descriptions contained in this report are indicative for purpose of
this assessment of effects and are based on the November 2013 Scheme plans provided by
Westpower. They may be subject to variation depending on final route location and
construction requirements that can only be determined after final line marking and survey is
complete. A component of this work would be to enumerate and mark any large trees in a
zone around the possible tunnel portal entrance site and within a fixed width of the road
formation centerline and use these data to make portal placement and road alignment
adjustments, subject to engineering considerations, to avoid such trees if possible.
Post-construction weed monitoring and control will be important, particularly where gravel is
carted in as this is a likely source of Ulex europaeus seed, and possibly other weeds e.g.
Leycesteria formosa. At least annual monitoring is recommended, and this should be on an
ongoing basis, with any necessary weed control undertaken as soon as practicable in the most
effective season for best control results for the species concerned, but in any case prior to
plants attaining seeding maturity.
Access Road To Contractors’ Facilities Area:
The same consideration to large tree avoidance applies here as to the intake access road.
This section of road will not be required after completion of headworks construction. Post-
construction and site decommissioning, weed monitoring and control will be important,
particularly where gravel is carted in as this is a likely source of Ulex europaeus seed, and
possibly other weeds e.g. Leycesteria formosa. At least annual monitoring during road use
and for a minimum of five seasons after decommissioning is recommended, with any
76
necessary weed control undertaken as soon as practicable in the most effective season for best
control results for the species concerned, but in any case prior to plants attaining seeding
maturity.
It is expected that natural regeneration of indigenous cover would occur relatively quickly if
scarification/ripping of compacted surfaces was undertaken and that it would comprise a
range of species present prior to works.
Contractors’ Facilities Area:
This facilities area will not be required post-construction of the headworks infrastructure and
the area can be rehabilitated via supplementary planting or left to regenerate naturally. It is
expected that natural regeneration would comprise a range of indigenous species present prior
to works, and occur relatively quickly if scarification/ripping of compacted surfaces to
provide fresh, loose gravel substrate was undertaken.
Post-construction and site decommissioning, weed monitoring and control will be important,
particularly where gravel is carted in as this is a likely source of Ulex europaeus seed, and
possibly other weeds e.g. Leycesteria formosa. The same monitoring and any necessary
control measures should be undertaken here as recommended above for the contractors’
facilities access road.
10.2 Area 2 - Monitoring/Mitigation/Remediation:
All Places in Area 2 Where Earthmoving Machinery Enters:
Machinery should be thoroughly washed down (track-gear, undercarriage) prior to entering
any part of Area 2 so as to reduce risk of weed seed transport.
Access Road/Transmission Line:
While no uniqueness in terms of overall vegetation type(s) is attributable to the general area
in which the possible access road and transmission line is proposed, defining a route that
results in least damage to all vegetation, and especially large (60+ cm dbh) hardwood trees
and podocarp trees (30+ cm dbh) will be a priority. Field observations indicate trees of these
sizes are in very low densities in all vegetation types likely to be affected by access road and
transmission line construction.
The access road/transmission line route and area descriptions contained in this report are
indicative for purpose of this assessment of effects and are based on the November 2013
Scheme plans provided by Westpower. They may be subject to variation depending on final
route location and construction requirements that can only be determined after final line
marking and survey is complete. A component of this work would be to enumerate and mark
all large trees within a fixed width of the road formation centerline and use these data to make
any practicable road alignment adjustments to avoid as many of these large trees as possible.
Relatively easy terrain of the landforms where this infrastructure construction is likely should
allow some route variation if required. Tree avoidance should be achievable, so that effect on
77
large forest trees is not considered a factor that would preclude any parts of the general area
from the activity.
Gravel carted in is a likely source of Ulex europaeus seed, and possibly other weeds e.g.
Leycesteria formosa. Continuing vehicle use to access the various facilities during the
operation of the Scheme poses a lesser risk of weed conveyance. Ongoing post-construction
weed monitoring and control will be important and should be a scheduled component of
Scheme maintenance.
Tunnel Portal Exit, Powerhouse, Switchyard, Hard-fill Area, Powerhouse to Tunnel Portal
Exit Access Road, Tailrace and Stopbank:
Natural regeneration of the range of species present prior to any clearance would be expected
to occur relatively quickly on any of the above areas not permanently occupied, e.g. the site of
the former Amethyst Power Scheme pipeline and access, exhibiting similar landform and
vegetation types, had become overgrown by indigenous vegetation within c. 10 years of
cessation of use. Supplementary planting could enhance speed of re-vegetation if required and
where suitable substrate exists. To increase speed and success of plant establishment in
rocked areas such as the stopbank, or the naturally rocky bed of the flood channel, deposition
of soil material (obtained from other Scheme component construction) over the armour-
rocked bank face(s) or flood channel bed, would be highly beneficial in any case and in
particular prior to any supplementary planting.
Gravel and rock carted in, and vehicle use present the same risks at these infrastructure sites
as for the access road/transmission line and the same provisions are applicable for all areas of
these facilities not covered by buildings or hard surface (e.g. concrete/seal) re weed
monitoring and any control.
11.0 Summary/Conclusions
11.1 Area 1 - Headworks and Associated Structures
Vegetation within Area 1 is significant indigenous vegetation under provisions of the
Westland District Plan (WDC, 2002) on the basis of two criteria - intactness and size
of area, and protected status. It would also be considered as having high natural
heritage values under West Coast Conservation Management Strategy 2010 – 2020
(DOC, 2010) criteria of intactness and viability.
The predominant vegetation types present at the site of proposed headworks and their
associated facilities are typical of streamside and side-slope areas across a relatively
wide altitudinal range (e.g. 100 – 500 m.a.s.l.) within forested Westland catchments.
They form a common assemblage widely represented in the rest of the Waitaha Valley
and in similar valleys throughout central Westland. Nothing was identified in the field
survey that suggests any vegetation community uniqueness, attributes or species
presence that would distinguish this site from any other similar sites throughout the
central Westland area and that would preclude any parts of it from the proposed
activity on the basis of its vegetation.
78
Areas given as construction, permanent and riparian (construction) in the following
summary table are not additive. The construction area is the expected maximum area
potentially affected by each Scheme component and the construction total is an
indication of the Scheme’s project footprint as it pertains to vegetation effect. Areas
given as permanent and riparian areas are sub-areas for purposes of describing amount
of vegetation clearance associated with a given Scheme component. In the case of
permanent areas these indicate the operational footprint of each Scheme component
and for the Scheme in total. Riparian areas are given because activities affecting
indigenous vegetation in riparian margins will require consideration for regional and
district planning provision purposes. The different areas of vegetation potentially
affected by each infrastructure component and in total are:
Area 1: Headworks and Associated Infrastructure
Item(s)
Construction
(ha)
Permanent
(ha)
Riparian
(Construction, ha)
Weir. 0.0050 0.0010 0.0
Intake Channel. 0.0325 0.0163 0.0
Intake Structure and Intake Portal. 0.0478 0.0278 0.0294
Tunnel Portal Entrance. 0.0187 0.0187 0.0
Tunnel Portal Entrance Apron, Intake Access Road
and River Protection at Road Toe.
0.1370 0.0790 0.0410
Road to Contractors’ Facilities Area. 0.1040 0.0 0.0300
Contractor’s Facilities Area. 0.2200 0.0 0.0
Flushing Tunnel Outlet. 0.0100 0.0100 0.0100
Totals 0.5750 0.1528 0.1104
Totals Rounded Up 0.58 0.16 0.12
Note: Areas given as rounded sub-totals and totals in the above table are rounded up to two decimal
places in every case so as to avoid dropping any area as could occur if using conventional rounding of
figures less than five. All areas are indicative based on November 2013 Scheme plans supplied by
Westpower and may vary from those given above depending on final design, survey and siting.
Note: Riparian areas are for streams >3metres wide where provisions of the Proposed Regional Land
and Water Plan (WCRC, 2013) and the Westland District Plan (WDC, 2002) prescribe 10 metre
riparian margin widths.
For headworks components and associated infrastructure, the scale of proposed works
is well within the spatial scale of natural disturbances typical of this environment i.e.
does not represent clearance of large areas in conjunction with a change in land use
and cover type. The nature of vegetation disturbance (removal) caused by the
proposed work would not be deemed inconsistent with natural disturbance events e.g.
slips, at this or similar sites. Construction involves clearance or at least some
disturbance to 0.58 hectares or 0.15% of the c. 396 hectares of the similar indigenous
forest vegetation/shrubland assemblages contained in the Base Area (being the zone
contiguous with Scheme activities, containing and surrounding this part of the Scheme
project footprint in terms of vegetation effects and considered its locale), 0.007% of
the 8,583 hectares of their counterparts in the Waitaha catchment and 0.001% of the
45,172 hectares of their counterparts in the Wilberg Ecological District, based on
LCDB land cover class data. The area permanently affected (operational footprint) is
significantly less, being 27% of the project footprint for headworks. Therefore, the
proposed activity is not considered to have any significant, long-term detrimental
effect on vegetation surrounding the proposed site and other than in the construction
phase, is a benign activity that would not affect the wider area in any way. Natural
regeneration should occur across any areas affected by construction (except those
areas occupied by structural components).
79
Access road construction from the tunnel portal entrance to the intake and to the
contractors’ facilities area accounts for the majority of area in taller forest cover
potentially affected by the Scheme in Area 1. While no uniqueness in terms of overall
vegetation type(s) is attributable to the general area in which the proposed access
roading is located, defining routes, subject to engineering considerations, that result in
least damage to all vegetation, and especially large (60+ cm dbh) hardwood trees will
be a priority.
The tunnel portal entrance site location will be primarily determined by engineering
considerations. While the potentially affected area is small, there may be large trees at
the site or in close proximity. If there is flexibility in shifting location, priority should
be given where possible to avoiding clearance of or damage to large podocarp
(30+ cm dbh) and large hardwood (60+ cm dbh) trees.
Vegetation types present in riparian margins in this area are not unique or
distinguished floristically from their counterparts not occupying a riparian strip. It is
the arbitrary riparian designation of fixed-width distance from stream bank, not
vegetation, that distinguishes these zones and that may have environmental planning
restrictions that would not otherwise apply. For streams 1 – 3 metres wide provisions
of the Proposed Regional Land and Water Plan (WCRC, 2013) prescribe 10 metre
wide riparian margins if dominant slope angle is >12o and 5 metre wide riparian
margins otherwise. This requirement will add some (expected to be relatively minor)
area to available estimates of affected riparian area, however the detailed field survey
and mapping of small stream location was not a component of work undertaken as the
basis of this report. The number and exact location of streams 1 - 3 metres wide that
are potentially affected will need to be determined for regional planning provision
purposes, although it is not considered that potential effects on vegetation will be any
greater than already assessed and considered.
Effects of the Scheme on the Area 1 vegetation (being classed as significant
indigenous vegetation under the Westland District Plan (WDC, 2002) criteria of
intactness and size of area, and protected status) and any contribution to high natural
heritage values under the West Coast Conservation Management Strategy 2010 – 2020
(DOC, 2010) criteria of intactness and viability are likely to be negligible. This
conclusion is based on:
o the very small amount of clearance that will occur within the surrounding
contiguous area (total headworks project footprint of 0.58 hectares within the
similar indigenous forest vegetation (385 hectares)/sub alpine shrubland
(11 hectares) assemblages of the Base Area); and,
o the temporary nature of the majority of clearance, with 0.16 hectares being the
Scheme’s operational footprint, combined with measures to be implemented
wherever practicable that avoid affecting important habitat components e.g.
large forest trees.
80
11.2 Area 2 - Tunnel Portal Exit, Access Road/Transmission Line, Stream Training, Powerhouse, Switchyard, Penstock, Tailrace and Stopbank Facilities
Vegetation within Area 2 is significant indigenous vegetation under provisions of the
Westland District Plan (WDC, 2002) on the basis of two criteria - intactness and size
of area, and protected status. It would also be considered as having high natural
heritage values under West Coast Conservation Management Strategy 2010 – 2020
(DOC, 2010) criteria of intactness and viability.
The vegetation types present on the recent alluvial flat and terrace sequence on which
the activities are proposed are typical of forested Westland catchments, being common
and widely represented in the Waitaha Valley, and in similar valleys throughout
central Westland. Nothing was identified in the field survey that suggests any
vegetation community uniqueness, attributes or species presence that would
distinguish this from any other similar areas or that would preclude any part of it from
the proposed activities on the basis of its vegetation.
Areas given as construction, permanent and riparian (construction) in the following
summary table are not additive. The construction area is the expected maximum area
potentially affected by each Scheme component and the construction total is an
indication of the Scheme’s project footprint as it pertains to vegetation effect. Areas
given as permanent and riparian areas are sub-areas for purposes of describing amount
of vegetation clearance associated with a given Scheme component. In the case of
permanent areas these indicate the operational footprint of each Scheme component
and for the Scheme in total. Riparian areas are given because activities affecting
indigenous vegetation in riparian margins will require consideration for regional and
district planning provision purposes. The different areas of vegetation potentially
affected by each infrastructure component and in total are:
Area 2: Infrastructure Item(s) Construction
(ha)
Permanent
(ha)
Riparian
(Construction, ha)
Tunnel Portal Exit and Construction Apron. 0.2480 0.1800 0.0
Access Road and Transmission Line 2.5470 2.4198 0.0450
Waterway Training and Flood Protection at Alpha
Creek.
0.3375 0.1688 0.1750
Powerhouse, Switchyard and Hard-fill Area. 0.3150 0.3150 0.0
Powerhouse to Tunnel Portal Exit Access Road and
Penstock.
0.1275 0.1275 0.0
Tailrace. 0.2000 0.2000 0.0250*
Stopbank as River Protection for Powerhouse,
Switchyard, Tailrace, Penstock and Access Road.
0.1755 0.1169 0.1755
Totals 3.9505 3.5280 0.4205
Totals Rounded Up 3.96 3.53 0.43
Note: Areas given as rounded totals in the above table are rounded up to two decimal places in every
case so as to avoid dropping any area as could occur if using conventional rounding of figures less
than five. All areas are indicative based on November 2013 Scheme plans supplied by Westpower and
may vary from those given above depending on final design, survey and siting.
Note: Riparian areas are for streams >3metres wide where provisions of the Proposed Regional Land
and Water Plan (WCRC, 2013) and the Westland District Plan (WDC, 2002) prescribe 10 metre
riparian margin widths. Tailrace riparian area potentially affected as marked * is an estimate based on
an oblique angle crossing of the Waitaha River true-right 10 metre riparian zone by the 20 metre wide
tailrace – actual affected area may vary depending on final angle of traverse of the tailrace through the
riparian margin, however any variation in affected area carrying vegetation is expected to be minimal.
81
For components of Scheme infrastructure in Area 2, the scale of proposed works does
not represent clearance of large areas in conjunction with a change in land use and
cover type. Construction (the project footprint) involves clearance or at least some
disturbance to 3.96 hectares or 1.0% of the c. 385 hectares of the similar indigenous
forest vegetation assemblages contained in the Base Area, (being the zone contiguous
with Scheme activities, containing and surrounding this part of the Scheme project
footprint in terms of vegetation effects and considered its locale), 0.09% of the 4,344
hectares of their counterparts in the Waitaha catchment and 0.01% of the 27,903
hectares of their counterparts in the Wilberg Ecological District, based on LCDB land
cover class data. The area permanently affected (operational footprint of 3.53 ha) is
less, being 89% of the project footprint of these Scheme components in Area 2.
Therefore, the proposed activity is not considered to have any long-term detrimental
effect on vegetation surrounding the proposed site and other than in the construction
phase, is a benign activity that would not affect the wider area in any way. Natural
regeneration should occur across any areas affected by construction (except those
areas occupied by structural components).
Access road construction to the powerhouse accounts for the majority of vegetated
area potentially affected by the Scheme in Area 2 and traverses the largest diversity of
vegetation types. While no uniqueness in terms of overall vegetation type(s) is
attributable to the general area in which the proposed access road is located, defining a
route that results in least damage to all vegetation, and especially large (60+ cm dbh)
hardwood trees and podocarp trees (30+ cm dbh) will be a priority. Field observations
indicate trees of these sizes are in very low densities in all vegetation types likely to be
affected by access road construction. Relatively easy terrain of the landforms where
any of this infrastructure construction is likely should allow some route variation if
required. Tree avoidance should be achievable.
Vegetation types present in riparian margins in this area are not unique or
distinguished floristically from their counterparts not occupying a riparian strip. It is
the arbitrary riparian designation of fixed-width distance from stream bank, not
vegetation, that distinguishes these zones and that may have environmental planning
restrictions that would not otherwise apply. For streams 1 – 3 metres wide provisions
of the Proposed Regional Land and Water Plan (WCRC, 2013) prescribe 10 metre
wide riparian margins if dominant slope angle is >12o and 5 metre wide riparian
margins otherwise. This requirement will add some (expected to be relatively minor)
area to available estimates of affected riparian area, however the detailed field survey
and mapping of small stream location was not a component of work undertaken as the
basis of this report. The number and exact location of streams 1 - 3 metres wide that
are potentially affected will need to be determined for regional planning provision
purposes, although it is not considered that potential effects on vegetation will be any
greater than already assessed and considered.
82
Effects of the Scheme on the Area 2 vegetation (being classed as significant
indigenous vegetation under the Westland District Plan (WDC, 2002) criteria of
intactness and size of area, and protected status) and any contribution to high natural
heritage values under the West Coast Conservation Management Strategy 2010 – 2020
(DOC, 2010) criteria of intactness and viability are likely to be minor, considering:
o the small amount of clearance that will occur (Scheme project footprint of 3.96
hectares in Area 2) within the surrounding contiguous indigenous forest
vegetation assemblage cover of the Base Area of c. 385 hectares;
o the narrow, linear footprint of the access road/transmission line combined with
measures to be implemented wherever practicable that avoid affecting
important habitat components e.g. large forest trees; and,
o a low likelihood of any vegetation disturbance post-construction.
83
Acknowledgements
The services of James Bentley and Corey Murray, Boffa Miskell Ltd., Christchurch, for
mapping and GIS analysis, and Martin Kennedy, West Coast Planning Ltd., Paroa, for review
and advice on components of this report, are acknowledged, with thanks.
References
Boffa Miskell Ltd. (2014). Waitaha Hydro Scheme: Natural Character, Landscape and Visual
Amenity Effects. (Report prepared by Boffa Miskell for Westpower Ltd.). Boffa Miskell Ltd.,
Christchurch, New Zealand. Unpbl.
Buckingham, R. (2014). Proposed Waitaha Hydro Scheme: Assessment of the Potential
Environmental Effects of the Proposed Waitaha Hydro Scheme on Terrestrial Vertebrate
Fauna (Bats and Birds) (internal report prepared for Westpower Ltd.). Wildlife Surveys Ltd.,
Mapua, New Zealand. Unpbl.
de Lange, P. J., Rolfe, J. R., Champion, P. D., Courtney, S. P., Heenan, P. B., Barkla, J. W.,
Cameron, E. K., Norton, D. A., & Hitchmough, R. A. (2012). New Zealand Threat
Classification Series 3 – Conservation Status of New Zealand Indigenous Vascular Plants.
Department of Conservation, Wellington, New Zealand.
DOC (2010). West Coast Conservation Management Strategy 2010 – 2020 (Volume 1), West
Coast Tai Poutini Conservancy Management Planning Series No. 10. Department of
Conservation, Hokitika, New Zealand.
Hicks, D. M. (2013). Sediment Investigations Relating to a Proposed HEP Scheme on the
Waitaha River (internal report prepared for Westpower Ltd.). National Institute of Water and
Atmospheric Research Ltd., Christchurch, New Zealand. Unpbl.
Hitchmough, R., Bull, L. & Cromarty, P. (Compilers). (2007). New Zealand Threat
Classification System Lists 2005. Department of Conservation, Wellington, New Zealand.
James, I., Jane, G. & Barr, C. (1973). The Forests and Sub-alpine Scrublands of the Hokitika
Catchment. Protection Forestry Division, Report No. 116, New Zealand Forest Service,
Rangiora, New Zealand.
McEwen, M. (Ed.). (1987). Ecological Regions and Districts of New Zealand, Part 4. New
Zealand Biological Resources Centre, Publication No. 5 (in four parts). Department of
Conservation, Wellington, New Zealand.
Wardle, P. (1977). Plant Communities of Westland National Park (New Zealand) and
Neighbouring Lowland and Coastal Areas. New Zealand Journal of Botany, 15: 323-98.
Wardle, P. (1979). Plants and Landscape in Westland National Park. National Parks Scientific
Series Number 3, National Parks Authority, Department Of Lands And Survey, Wellington,
New Zealand.
84
Wardle, P. (1991). Vegetation of New Zealand. Cambridge University Press, New York,
U.S.A.
WCRC. (2000). West Coast Regional Policy Statement (2000). West Coast Regional Council,
Greymouth, New Zealand.
WCRC. (2013). Proposed Regional Land and Water Plan (March 2013). West Coast Regional
Council, Greymouth, New Zealand.
WDC. (2002). Westland District Plan. Westland District Council, Hokitika, New Zealand.
Whitaker, A. H., (2013). An Assessment of the Potential Effect of the Proposed Waitaha
Hydro Scheme on the Lizard Fauna of the Lower Waitaha River, Westland (internal report
prepared for Westpower Ltd.). Whitaker Consultants Ltd., Motueka, New Zealand. Unpbl.
List of Appendices
Appendix A Map 1: Project Area General Location.
Appendix A Diagram 1: Headworks Infrastructure Concept.
(Diagram supplied by Geotech Consulting Ltd. via Westpower
Limited. N.B: Not intended as a scale drawing. Scale on A3
copy herewith is c. 1:1260 and is indicative for concept
purposes only).
Appendix A Map 2: Infrastructure Locations and Vegetation Type Delineations –
Area 1.
Appendix A Map 3: Infrastructure Locations and Vegetation Type Delineations –
Area 2.
Appendix A Map 4: Wilberg Ecological District and Waitaha Catchment With
LCDB Land Cover Types.
Appendix A Map 5: Base Area Delineation on Topographic Mapping.
Appendix A Map 6: Base Area LCDB Land Cover Types.
Appendix B: Species List with Maori and Common Names
85
Appendix A Map 1: Project Area General Location.
86
87
Appendix A Diagram 1: Headworks Infrastructure Concept.
88
89
Appendix A Map 2: Infrastructure Locations and Vegetation Type Delineations – Area 1.
90
91
Appendix A Map 3: Infrastructure Locations and Vegetation Type Delineations – Area 2.
92
93
Appendix A Map 4: Wilberg Ecological District and Waitaha Catchment With LCDB Land Cover Types.
94
95
Appendix A Map 5: Base Area Delineation on Topographic Mapping.
96
97
Appendix A Map 6: Base Area LCDB Land Cover Types.
98
99
Appendix B: Species List with Maori and Common Names
Note: nt = not threatened. For higher plants status is ex de Lange et al. (2012), for
mosses/liverworts from Hitchmough et al. (2007).
Note: * denotes exotic species.
Large Trees
Botanical Name Maori Name (& other Common Name) Status
Dacrydium cupressinum Rimu (Red pine) nt
Dacrycarpus dacrydioides Kahikatea (White pine) nt
Griselinia littoralis Kapuka (Broadleaf) nt
Libocedrus bidwillii Kaikawaka (New Zealand cedar) nt
Metrosideros umbellata Rata (Southern rata) nt
Podocarpus hallii Totara-kiri-kotukutuku (Hall’s totara) nt
Prumnopitys ferruginea Miro (Brown pine) nt
Quintinia acutifolia Tawheowheo (Westland Quintinia) nt
Weinmannia racemosa Kamahi nt
Smaller Trees/Shrubs
Botanical Name Maori Name (& other Common Name) Status
Archeria traversii (Shrubby mountain heath) nt
Aristotelia serrata Makomako (Wineberry) nt
Ascarina lucida Hutu nt
Carmichaelia arborea (Tree broom) nt
Carpodetus serratus Putaputaweta (Marble leaf) nt
Coprosma areolata (Thin leaved coprosma) nt
Coprosma elatirioides - nt
Coprosma ciliata - nt
Coprosma colensoi - nt
Coprosma foetidisima Hupiro (Stinkwood) nt
Coprosma grandifolia Raurekau (Large-leaved coprosma) nt
Coprosma linariifolia Mikimiki (Yellow-wood) nt
Coprosma lucida Karamu nt
Coprosma propinqua Mingimingi nt
Coprosma rhamnoides - nt
Coprosma rotundifolia - nt
Coprosma rubra - nt
Coprosma rugosa - nt
Coprosma tayloriae - nt
Coriaria arborea Tutu nt
Dracophyllum longifolium Inaka (Turpentine scrub) nt
Fuchsia excorticata Kotukutuku (Tree fuchsia) nt
Hebe salicifolia Koromiko nt
Hedycarya arborea Porokaiwhiri (Pigeonwood) nt
Leycesteria formosa*9 Himalayan honeysuckle *
9 Note: Leycesteria formosa was not observed in any area during fieldwork. It is included here because it is
discussed in Section 10.0 as a possible weed risk.
100
Appendix B: Species List Ctd.
Smaller Trees/Shrubs Ctd.
Botanical Name Maori Name (& other Common Name) Status
Melicytis ramiflorus Mahoe (Whitey wood) nt
Myrsine divaricata Mapou (Weeping mapou) nt
Myrsine australis Matipou (Red mapou) nt
Neomyrtus pedunculata Rohutu nt
Olearia arborescens (Tree daisy) nt
Olearia avicenniifolia (Mountain akeake) nt
Olearia ilicifolia Hakeke (Mountain holly) nt
Pennantia corymbosa Kaikomako nt
Phyllocladus alpinus (Mountain toatoa) nt
Pseudopanax anomalus - nt
Pseudopanax colensoi Orihou (Three finger) nt
Pseudopanax crassifolius Horoeka (Lancewood) nt
Pseudopanax simplex Haumakoroa nt
Pseudowintera colorata Horopito (Pepperwood) nt
Schefflera digitata Pate (Seven finger) nt
Ulex europaeus* (Gorse) *
Tree Ferns/Ferns/Fern Allies
Botanical Name Maori Name (& other Common Name) Status
Asplenium bulbiferum Pikopiko (Hen and chickens fern) nt
Asplenium flaccidum Raukatauri (Hanging spleenwort) nt
Asplenium polyodon (Sickle spleenwort) nt
Blechnum chambersii Nini (Lance fern) nt
Blechnum colensoi Peretao (Colenso’s hard fern) nt
Blechnum discolor Piupiu (Crown fern) nt
Blechnum fluviatile Kiwakiwa (Creek fern) nt
Blechnum sp. “black spot” Kiokio (Palm-leaf fern) nt
Blechnum penna-marina (Little hard fern) nt
Ctenopteris heterophylla (Comb fern) nt
Cyathea smithii Katote (Soft tree fern) nt
Dicksonia squarrosa Wheki (Rough tree fern) nt
Grammitis billardieri (Common strap fern) nt
Grammitis magellanica (Strap fern) nt
Histiopteris incisa Mata (Water fern) nt
Hymenophyllum demissum Irirangi (Filmy fern) nt
Hymenophyllum multifidum (Much divided filmy fern) nt
Hymenophyllum revolutum (Filmy fern) nt
Hymenophyllum spp. (Filmy ferns) nt
Hypolepis rufobarbata - nt
Lastreopsis hispida (Hairy fern) nt
Leptolepia novae-zelandiae (Lace fern) nt
Leptopteris superba Heruheru (Prince of Wales fern) nt
Lycopodium volubile Waewaekoukou (Climbing clubmoss) nt
101
Appendix B: Species List Ctd.
Tree Ferns/Ferns/Fern Allies Ctd.
Botanical Name Maori Name (& other Common Name) Status
Paesia scaberula (Ring fern, Scented fern) nt
Phymatosorus diversifolius Kowaowao (Hound’s tongue) nt
Pneumatopteris pennigera Piupiu (Gully fern) nt
Polystichum vestitum Punui (Prickly shield fern) nt
Pteridium esculentum Rarauhe (Bracken fern) nt
Rumohra adiantiformis (Leathery shield fern) nt
Sticherus cunninghamii Waekura (Unbrella fern) nt
Tmesipteris tannensis (Chain-fern) nt
Trichomanes reniforme Raurenga (Kidney fern) nt
Trichomanes venosum (Veined filmy fern) nt
Climbers/Spreading/Perching
Botanical Name Maori Name (& other Common Name) Status
Dendrobium cunninghamii Pekapeka, Winika (Christmas orchid) nt
Freycinetia baueriana subsp. banksii Keikei nt
Metrosideros diffusa Akatea (White climbing rata) nt
Metrosideros fulgens (Rata vine) nt
Metrosideros perforata Akatea (White rata) nt
Ripogonum scandens Kareao (Supplejack) nt
Rubus cissoides Tataramoa (Bush lawyer) nt
Rubus parvus (Creeping lawyer) nt
Rubus schmidelioides Tataramoa (Bush lawyer) nt
Sedges/Tussocks/Grasses
Botanical Name Maori Name (& other Common Name) Status
Agrostis dyeri - nt
Agrostis tenuis* (Browntop) *
Anthoxanthum odoratum* (Sweet vernal) *
Arthropodium candidum Repehina-papa (Forest floor lily) nt
Astelia fragrans Kahaha (Bush flax) nt
Carex goyenii (Goyen’s sedge) nt
Cortaderia richardii Toetoe nt
Festuca sp. (Fescue tussock) nt
Gahnia sp. (Giant sedge) nt
Hierochloe novae-zelandiae (Holy grass) nt
Holcus lanatus* (Yorkshire fog) *
Microlaena avenacea (Bush rice grass) nt
Phormium cookianum Wharariki (Mountain flax) nt
Poa colensoi - nt
Poa sp. (Annual poa) nt
Rytidosperma setifolium (Bristle tussock) nt
Schoenus pauciflorus (Sedge grass) nt
Trisetum tenellum - nt
102
Appendix B: Species List Ctd.
Sedges/Tussocks/Grasses Ctd.
Botanical Name Maori Name (& other Common Name) Status
Uncinia sp. (Hookgrass) nt
Uncinia uncinata (Hookgrass) nt
Herbaceous/Ground Cover
Botanical Name Maori Name (& other Common Name) Status
Acaena anserinifolia Piripiri (Bidibid) nt
Anisotome hastii (Haast’s carrot) nt
Cardamine debilis (N.Z. Bitter cress) nt
Celmisia coriacea Tikumu (Mountain daisy) nt
Cirsium palustre* (Marsh thistle) *
Cirsium arvense* (Californian thistle) *
Epilobium pedunculare (Creeping willowherb) nt
Forstera tenella - nt
Geum leiospermum (Mountain avens) nt
Gingidia montana (Mountain anise) nt
Gunnera monoica - nt
Hypochoeris radicata* (Catsear or flatweed) *
Hyrocotyle moschata (Hairy pennywort) nt
Hydrocotyle novae-zelandiae (Pennywort) nt
Lotus pedunculatus* (Lotus) *
Luzuriaga parviflora Nohi (Lanternberry) nt
Nertera ciliata - nt
Nertera depressa (Bead plant) nt
Nertera vilosum - nt
Parahebe lyallii (Lyall’s speedwell) nt
Plantago lanceolata* (Narrow leaved plantain) *
Pratia angulata Panakenake nt
Ranunculus repens* Buttercup *
Raoulia tenuicaulis Tatahuna (Mat daisy) nt
Stellaria media* (Chickweed) *
Traxacum officinale* (Dandelion) *
Trifolium repens* (White clover) *
Viola filicaulis (Forest violet) nt
Mosses/Liverworts
Botanical Name Maori Name (& other Common Name) Status
Cyathophorum bulbosum Moss nt
Dawsonia superba Giant moss nt
Dendroligotrichum dendroides Giant moss nt
Hymenophyton flabellatum Liverwort nt
Hypopterygium novae-seelandiae (Umbrella moss) nt
Marchantia berteroana (Thallose liverwort) nt
Monoclea forsteri (Thallose liverwort) nt
103
Appendix B: Species List Ctd.
Mosses/Liverworts Ctd.
Botanical Name Maori Name (& other Common Name) Status
Mniodendron dendroides (Umbrella moss) nt
Schistochila appendiculata (Liverwort) nt
Schistochila nobilis (Liverwort) nt
Weymouthia mollis (Hanging moss) nt