Ecological Values at 2 Waikowhai Road Hillsborough

Ecological values at 2 Waikowhai Road Hillsborough

August 2015

Mitchell Partnerships Ltd Phone: +64 9 486-5773 PO Box 33 1642 Fax: +64 9 486-6711 Takapuna Mobile: 021 403 386 Auckland Email: [email protected]

TABLE OF CONTENTS

Page

1. INTRODUCTION 1

1.1 Background 1 1.2 Ecological Setting 3

2. VEGETATION AND FAUNA 5

2.1 Vegetation 5 2.2 Fauna 10

2.2.1 Birds 10 2.2.2 Lizards 10

3. SIGNIFICANCE ASSESSMENT 10

3.1 Introduction 10 3.2 Auckland District Plan – Auckland City Isthmus Section 11 3.3 Proposed Auckland Unitary Plan 12

4. ASSESSMENT OF EFFECTS AND PROPOSED MITIGATION 13

4.1 Assessment of Effects 13 4.2 Proposed Mitigation 13

5. CONCLUSION AND RECOMMENDATIONS 14

6. REFERENCES 15

LIST OF FIGURES

1: Service Plan for the proposed development at 2 Waikowhai Road, Hillsborough. 2

2: The indicative location of the SEA overlay (hatched green) in relation to the property at 2 Waikowhai Road (indicative boundary shown in red). Also shown are the indicative locations of the tall rimu tree (large blue dot) and the two rewarewa trees (small blue dot) that would remain as part of the development. (Sourced from Auckland Council GIS Plan Viewer). 3

LIST OF PLATES

1: Vegetation in part of what would become Lot 2. 5

2: Woolly nightshade within proposed Lot 3. (Note the two tall rewarewa trees shown in this would remain) 6

3: Vegetation within the proposed Lot 3. 7

4: Vegetation within the proposed Lot 4. 8

5: Vegetation along the eastern boundary of 2 Waikowhai Road, taken from within proposed Lot 4 looking north. 8

6: Rimu tree at 2 Waikowhai Road. 9

LIST OF TABLES

1: Plants proposed for planting at 2 Waikowhai Road. 14

1. INTRODUCTION 1.1 Background

Terry Sunny owns the property at 2 Waikowhai Road, Hillsborough described as Lot 54 DP 20213. The property is approximately 2,500 m2 in size1 with one dwelling. Mr Sunny proposes developing the site by subdividing to create four new lots ranging in size from 596 m2 to 679 m2. The existing building would be retained within the proposed Lot 1 and the remaining new lots would include a building platform as shown in the draft drainage plan included as Figure 1.

Vegetation at the property includes a large rimu (Dacrydium cupressinum) tree and two smaller rewarewa (Knightia excelsa) trees which would be retained as part of the development. Other vegetation includes shrubland with a high proportion of exotic weeds. Part of the site has been cleared of vegetation in the past and still contains a high proportion of bare soil.

Approximately 1,020 m2 of the proposed development is located within the Significant Ecological Area (“SEA”) overlay of the Proposed Auckland Unitary Plan as shown in Figure 2. As such an ecological report is required assess the nature and scale of effects of the proposed works within the SEA to support the application. The purpose of this report is to provide information about the ecological values of the site to inform the Auckland Council decision makers with respect to the proposal.

This report is set out as follows:

• Section 1, this introduction, describes the proposal and the ecological setting in which the property is located.

• Section 2, describes the walk through survey undertaken at the site and describes the vegetation, habitats and fauna present or likely to be present.

• Section 3 contains an assessment of the significance of the vegetation present at the site.

• Section 4 provides an assessment of the ecological effects of the proposal and recommends a planting programme intended to result in a positive ecological outcome.

• Section 5 provides our conclusions and recommendations with respect to the effects of the proposal.

• Section 6 lists the references used in compiling this report.

1 Length and area estimates in this report were calculated using the “Draw and Measure” tool available on the online version of the Proposed Auckland Unitary Plan maps, available at http://acmaps.aucklandcouncil.govt.nz/unitaryplan/FlexViewer.html. As such they are approximate only.

Figure 1: Service Plan for the proposed development at 2 Waikowhai Road, Hillsborough.

Figure 2: The indicative location of the SEA overlay (hatched green) in relation to the property at 2 Waikowhai Road (indicative boundary shown in red). Also shown are the indicative locations of the tall rimu tree (large blue dot) and the two rewarewa trees (small blue dot) that would remain as part of the development. (Sourced from Auckland Council GIS Plan Viewer).

1.2 Ecological Setting

Number 2 Waikowhai Road is located within the Tamaki Ecological District of the Auckland Ecological Region (McEwen 1987). The Tamaki Ecological District extends from Okura and Riverhead in the north to Ranui and Titirangi in the west and south to Papatoetoe and Howick covering approximately 59,904 ha. The district is surrounded by the Waitakere Ecological District (further west), the Rodney Ecological District (to

the north), the Inner Gulf Islands Ecological District (to the east) and the Manukau and Hunua Ecological Districts (to the south). The Tamaki Ecological District was characterised on the basis of geology and topography and encompasses the volcanic cones and lava flows of Auckland Isthmus as well as the drowned valley of the Waitemata Harbour and the ridge and gully system of the North Shore (McEwen 1987). The district experiences warm humid summers and mild winters with an annual rainfall of approximately 1200 – 1400 mm (McEwen 1987). Soils are mainly fertile, friable and free draining derived from volcanic ash, or volcanic flows with smaller areas of clay textured soils from sedimentary rocks (McEwen 1987). The district has been significantly modified, initially by Maori settlement and then by urbanisation.

Historically the vegetation is assumed to have comprised typical North Island lowland forest with kauri (Agathis australis) and abundant puriri (Vitex lucens) and taraire (Beilschmiedia tarairi) and dominated by pohutukawa (Metrosideros excelsa) near the coast with extensive areas of tidal flats and mangroves (Avicennia marina subsp. australasica) (Lindsay et al. 2009). Only 6.9% of the Tamaki district remains in indigenous cover and only a small amount of that vegetation (around 20%) is legally protected (Lindsay et al. 2009). All natural ecosystems within the Tamaki district except kauri forest are severely depleted with less than 5% of the original extent remaining. The district also includes originally rare ecosystems2. The priorities for protection within the district include volcanic boulderfields, originally rare ecosystems, coastal ecosystems (estuarine, wetland, shrubland and forest), sites with particular threatened plants (Centipeda minima, Epilobium hirtigerum and Fissidens berteroi) and breeding sites and habitat for grey duck (Anas superciliosa superciliosa) (Lindsay et al. 2009).

Along the northern edge of the Manukau Harbour between White Bluff and Titirangi, there is a string of semi-contiguous coastal forest reserves administered by Auckland Council as part of their network of parks throughout the city. Some of these reserves are linked for recreational use via the Manukau Coastal Walkway. Beyond Titirangi these forests extend to the Waitakere Ranges. Together these reserves act as a habitat corridor for wildlife, including kereru or New Zealand pigeon (Hemiphaga novaeseelandiae) which are important seed dispersers in native forest.

In 2004 a volunteer project administered by Auckland Council was set up to carry out intensive rat and possum control within nine reserves between Wairaki Stream Reserve in the west and Hillsborough Reserve in the east. This project, called the Waikowhai Wildlife Sanctuary, covers 100 ha currently including Waikowhai Reserve, which adjoins 2 Waikowhai Road. Management within the Waikowhai Wildlife Sanctuary includes 12 trap lines for rodents and possums, seven rodent poison lines and two possum poison lines operated by 28 volunteers (S. Peters, Auckland Council, pers. comm.). The Waikowhai Wildlife Sanctuary aims to reduce possum and rat numbers to low levels within the management area to protect native wildlife, monitor pest numbers and encourage the study of flora and fauna within the sanctuary zone.

Vegetation within Waikowhai Reserve nearest 2 Waikowhai Road could be described as secondary forest locally dominated by mahoe (Melicytus ramiflorus) but with common tree ferns (especially silver fern (Cyathea dealbata) and wheki (Dicksonia squarrosa)) and cabbage trees (Cordyline australis), particularly near the margins. Other species occasionally present in the canopy include kowhai (Sophora tetraptera), pigeonwood (Hedycarea arborea), karaka (Corynocarpus laevigatus) and mapou (Myrsine australis). The canopy is 8 – 12 m tall, but with common emergent

2 Originally rare ecosystems are those that have only ever been present in limited amounts and were rare prior to human colonisation (Williams et al. 2007).

pohutukawa (Metrosideros excelsa), kanuka (Kunzea robusta), rewarewa, kohekohe (Dysoxylum spectabile) and puriri (Vitex lucens) and occasional emergent kahikatea (Dacrycarpus dacrydioides) and rimu. The forest structure is multi-layered and includes epiphytes such as supplejack (Ripogonum scandens) and ferns and a healthy ground and shrub layer.

2. VEGETATION AND FAUNA 2.1 Vegetation

We carried out a walk through survey of the property at 2 Waikowhai Road on 10 July 2015 and spent slightly more than one hour on site. During that time we explored the site and the adjacent reserve, recorded the plant species encountered, described the habitat, photographed representative examples of the vegetation and compiled a list of birds seen or heard. The results of this survey are described below.

In part of what would become Lot 2, north of the two rewarewa trees to be retained, the vegetation included a high proportion of weeds such as woolly nightshade (Solanum mauritianum), smilax (Asparagus asparagoides), ginger (Hedychium gardnerianum), inkweed (Phytolacca octandra), lilly pilly (Syzygium smithii), loquat (Eriobotrya japonica) and gorse (Ulex europaeus). Native species present in that area included silver fern (Cyathea dealbata), mamaku (Cyathea medullaris), karamu (Coprosma robusta), kohekohe, New Zealand jasmine (Parsonsia heterophylla), kawakawa (Macropiper excelsum), mapou, mahoe, hangehange (Geniostoma ligustrifolium) and Gahnia xanthocarpa. This vegetation is typically less than 2 m tall, but emergent trees (mostly tree ferns) are up to 4 m tall. An example of this vegetation is shown in Plate 1.

Plate 1: Vegetation in part of what would become Lot 2.

To the north of proposed Lot 2 (within the neighbouring property at 6 Waikowhai Road) vegetation that was also within the SEA overlay has been removed and the site has undergone earthworks and construction. At the time of the site visit there was no longer any connectivity of natural habitats in that area.

Within what would become Lot 3, side casting of soil from the previous vegetation clearance has created a large amount of bare soil down slope and this is surrounded by weed species as described above as well as pampas (Cortaderia selloana), German ivy (Delairea odorata) and agapanthus (Agapanthus praecox subsp. orientalis). Several taller lilly pilly (Syzygium smithii) trees in that area are undoubtedly providing a source of seeds for birds to disperse this weed nearby. Native species within the proposed Lot 3 were also similar to those described within the proposed Lot 2 but included houpara (Pseudopanax lessonii) and rangiora (Brachyglottis repanda). Examples of that vegetation are shown in Plates 2 and 3. Note that the taller trees in the centre of Plate 3 are the weed species lilly pilly and the greyer tree behind is a pohutukawa which is outside the site boundary.

Plate 2: Woolly nightshade within proposed Lot 3. (Note the two tall rewarewa trees shown in this plate would remain)

Plate 3: Vegetation within the proposed Lot 3.

Within the proposed Lot 4, the edge vegetation was similarly weedy and the native vegetation was short in stature and early seral in composition. An example of that vegetation is shown in Plates 4 and 5.

Plate 4: Vegetation within the proposed Lot 4.

Plate 5: Vegetation along the eastern boundary of 2 Waikowhai Road, taken from within proposed Lot 4 looking north.

Generally speaking the vegetation along the existing eastern boundary of the property (within proposed Lot 4 and along the edge of the proposed driveway) is less weedy than that along the western boundary (within proposed Lots 2, 3 and 4), although weeds still form a significant component of the vegetation. These tend to be grasses and herbaceous weeds such as scotch thistle (Cirsium vulgare) and ox tongue (Helminthotheca echioides) rather than the woody weeds found along the western boundary. The cut edge of this vegetation is shown in Plate 5, whilst the tall rimu tree located near the eastern boundary, and which would remain, is shown in Plate 6.

Plate 6: Rimu tree at 2 Waikowhai Road.

2.2 Fauna

2.2.1 Birds Birds seen or heard near 2 Waikowhai Road included kereru, Californian quail (Callipepla californica), grey warbler (Gerygone igata) and rock pigeon (Columba livia). Other common forest birds and urban garden birds such as tui (Prostemadera novaeseelandiae) and fantail (Rhipidura fuliginosa) are also likely to occur there.

2.2.2 Lizards We have not undertaken a lizard survey at the site, but note that the site is likely to provide suitable habitat for native copper skink (Oligosoma aenea) and perhaps exotic rainbow skink (Lampropholis delicata). Neither of these species are of conservation concern.

Ornate skinks (O. ornatum), Auckland green gecko (Naultinus elegans) and forest gecko (Mokopirirakau granulatus) may also use parts of the reserve surrounding the site, but are unlikely to use the habitats affected by the proposal.

3. SIGNIFICANCE ASSESSMENT 3.1 Introduction

Criteria for assessing the significance of the ecological values at the proposed site are contained in the following:

• Auckland District Plan – Operative Auckland City Isthmus Section (1999) (“the District Plan”);

• Auckland Regional Council Regional Policy Statement (1999) (“the ACRPS”); and,

• The Proposed Auckland Unitary Plan (“the Unitary Plan”).

In general, the ACRPS identifies significant natural heritage resources at the regional level and District Plan identifies significant sites at the district level. Joint work between the Department of Conservation and the Auckland Regional Council resulted in the identification of “Sites of Natural Significance” where the values of those sites were considered to meet the requirements of section 6 (a), (b) and (c) of the Resource Management Act (1991). These sites were published in the Conservation Management Strategy for Auckland 1995 – 2005 (Volume II). The ecological values of the proposed site are assessed against the significance criteria of the above documents below.

By way of summary, it is concluded that the ecological values of the proposed site are not significant in the context of the above documents.

3.2 Auckland District Plan – Auckland City Isthmus Section

Section 5A4.4 of the District Plan recognises that in an urban context the remaining natural habitats must be regarded as significant in terms of their relative scarcity rather than their pristine quality and scale. Ecological Areas are recognised in the Plan in a number of ways:

• Those Ecological Areas that are considered the most significant are marked on the District Plan maps and listed in a Schedule of Significant Ecological Areas in Appendix 3C of the Plan. The rules in the Plan control activities that may occur on or near these areas in order to ensure their physical conservation and maintenance of their function.

• In the coastal margin, all indigenous plants are protected from damage and clearance including effects associated with earthworks and the building of structures. Additional protection is given to trees on most of the naturally vegetated clifflines of the Isthmus (Part 5B.7)

• Coastal ecological areas will be subject to a requirement for an esplanade reserve or strip, where it is proposed to subdivide or develop the land. (Part 5B.8).

• In Open Space 1, and 2 zonings the protection of indigenous vegetation is a priority. (Part 9).

• Many significant ecological areas are on council reserves.

• Financial contributions are taken for environmental purposes, particularly when adverse effects on significant ecological areas cannot be avoided or remedied. (Part 4B).

• The land subdivision provisions of the plan present opportunities to protect significant ecological areas by a contribution of land or by a conservation covenant, or by the imposition of conditions of consent.

The overall objective of the District Plan is to “conserve, protect and enhance the natural environment and resources of the district.” The District Plan provides criteria against which areas of ecological significance should be assessed as follows: a) The naturalness of the area when compared to similar ecosystems within the relevant ecological district or environmental domain; b) The extent to which an area is of sufficient size to maintain its intrinsic values; c) The natural diversity of species, natural communities and ecosystems, including diversity along environmental gradients; d) The importance of the area to indigenous fauna; e) The degree to which there has been cumulative loss of the extent and species diversity of this type of ecosystem from the prehuman state within the ecological district or environmental domain;

f) the rarity of the ecosystem or community; g) the presence of threatened species; h) the presence of species at their distributional limits; i) the importance of the area for assisting the movement of indigenous species; j) the importance of the area for maintaining water quality in freshwater and saline environments; k) the importance of the area for maintaining the biodiversity values of adjacent freshwater or saline environments.

Rules apply to scheduled ecological areas.

The parcel of land affected by this proposal (including any natural vegetation thereon) is zoned Residential Activity in the District Plan and is not scheduled as an Ecological Area.

Using the criteria outlined above the vegetation present at 2 Waikowhai Road is neither sufficiently natural, large, important to fauna, diverse or rare to trigger significance.

3.3 Proposed Auckland Unitary Plan

The Proposed Auckland Unitary Plan (“Unitary Plan”) classifies areas of significant indigenous vegetation and the significant habitats of indigenous fauna in the Region as “Significant Ecological Areas” (“SEAs”). The Unitary Plan uses the following five criteria to identify SEAs in the Region:

• Representativeness: The area is important for the indigenous habitats and/or ecosystems it supports because they are ecologically representative of the mature and successional stages of the vegetation of each ecological district in Auckland and provide cumulatively for at least 10 per cent of the natural extent of each ecosystem type.

• Stepping stones, buffers and migration pathways: The area is significant because of its context with other habitats or ecosystems. This includes groups of smaller sites that together form an important vegetation component in the landscape, cumulatively provide critical habitat for a native species, provide buffers to other significant ecological areas or act as stepping stones or ecological corridors providing for movement of species across the landscape.

• Threat status and rarity: The area supports genes, species, habitats and/or ecosystems that have been classified as threatened with extinction or are naturally rare in Auckland or New Zealand.

• Uniqueness or distinctiveness: The area supports genes, species, communities, habitats and/or ecosystems that are endemic, or near endemic, and only naturally occur in Auckland.

• Diversity: The area supports indigenous vegetation that is ecologically diverse, close to the typical species or ecosystem diversity for that habitat or supports indigenous vegetation that extends across at least one environmental gradient.

The parcel of land affected by this proposal is zoned Mixed Housing Suburban in the Proposed Auckland Unitary Plan. The Unitary Plan identifies over 3,000 sites which it considers meet the above criteria as SEAs in its planning maps. Shrubland vegetation at the proposed site is included within that list as part of SEA T- 5334 which meets the significance criteria 1, 2, 3 and 4, which are representativeness, threat status and rarity, diversity and stepping stones, migration pathways and buffers respectively. The site specific assessment undertaken as part of this effects assessment indicates that although the Waikowhai Reserve clearly meets the criteria for ecological significance, the site itself does not contain values sufficient to warrant SEA classification and in actuality contains a number of weed species that if allowed to persist would compromise the ecological values of the adjacent reserve. These weed species, include woolly nightshade, lilly pilly, ginger, smilax, wandering jew (Tradescantia fluminensis), Japanese honeysuckle (Lonicera japonica) and agapanthus.

4. ASSESSMENT OF EFFECTS AND PROPOSED MITIGATION 4.1 Assessment of Effects

The proposal would remove around 1,020 m2 of weedy early seral vegetation located on the edge of Waikowhai Reserve as described above. The large rimu tree and two smaller rewarewa trees would remain. The native species to be removed mostly comprise silver fern, mamaku, kohekohe and hangehange. The amount of newly created edge would increase slightly from approximately 125 m to approximately 152 m because of the configuration of the vegetation in relation to the site.

4.2 Proposed Mitigation

The proposal to remove vegetation provides an opportunity to clear weeds from the site. This would significantly reduce the risk of their establishing or spreading in Waikowhai Reserve. It also presents an opportunity improve the ecotone habitat between the adjacent reserve and the residential area in order to better buffer the reserve from edge effects and particularly weeds in the future.

On that basis we recommend that all weeds, particularly woody weeds such as gorse, bird dispersed weeds such as lilly pilly and those which survive under canopy such as ginger and wandering jew, be eradicated from the site as part of the development.

We further recommend that a dense hedge of native species be established which will grow quickly and serve to replace the existing edge shrubland with species which would not compromise the future ecological integrity of the reserve. The hedge could be located either at the boundary or immediately inside it, but if located inside we would recommend planting a mix of native species, including manuka, between the hedge and the reserve to avoid weeds becoming established there. Ground covers such as creeping fuchsia (Fuchsia procumbens), Creeping pohuehue (Muehlenbeckia axillaris)

and Coprosma acerosa could also be used to assist in providing dense edge habitat for native species.

A list of hedging plants suitable for planting along the perimeter of the proposed lots is provided in Table 1. We recommend planting one or more rows of plants 30- 50 cm tall at a spacing of 50 – 80 cm apart and including fertiliser to aid in growth. We also recommend that all plants sourced be a “wild” variety sourced from an appropriate nursery, not garden cultivars for garden situations.

Table 1: Plants proposed for planting at 2 Waikowhai Road.

Common Name Latin Name Akeake Dodonaea viscosa Broadleaf Griselinia littoralis Totara Podocarpus totara Kohuhu Pittosporum tenuifolium Karo Pittosporum crassifolium Akiraho Olearia paniculata Manuka Leptospermum scoparium Korokio Corokia virgata Karamu Coprosma robusta Shining karamu Coprosma lucida Flax Phormium tenax

5. CONCLUSION AND RECOMMENDATIONS

Vegetation within the site is early seral and contains a high proportion of introduced weeds that have the potential to spread to the adjacent reserve area. In the longer term these weeds could compromise the ecological values of the area because they are shade tolerant and/or bird-dispersed. Apart from kereru the species present are typical of semi-rural and urban areas and include exotic weeds, introduced birds and common native species capable of persisting in a highly modified environment.

There are no particular ecological values present at the site which would be adversely affected or removed by the proposal to develop the site more intensively. The proposed development provides the opportunity to remove weeds from the site and purposefully create dense edge vegetation to better buffer the reserve from the adjacent residential activities and minimise future weed invasion. On that basis, provided that the planting proposed in Section 4.2 is completed and maintained, the proposal would result in a positive ecological outcome.

The soils at the site will contain weed seeds, tubers and other propagules. For that reason we also recommend that any earthworks undertaken at the site prevent soils from leaving the site and entering the reserve and that any excavated soils taken offsite be disposed of at a suitable site where the establishment of weeds would not adversely affect local ecological values.

6. REFERENCES

Lindsay, H., Wild, C., Byers, S. 2009. Auckland Protection Strategy. A report to the Nature Heritage Fund Committee. Published by the Nature Heritage Fund. Wellington. 71 pp + appendices.

McEwen, W.M. 1987. (Editor). Ecological Regions and Districts of New Zealand (third revised edition in four 1:500,000 maps). New Zealand Biological Resources Centre publication no. 5. Department of Conservation, Wellington.

Signed:

Dr Gary Bramley Mitchell Partnerships Ltd

Phone: +64 9 486-5773 Mobile: 021 403 386 Email: [email protected]