APPENDIX SEVEN Ecological Assessment Assessment of Ecological Values and Ecological Effects of the proposed Porirua Adventure Park development Paul Blaschke, Blaschke and Rutherford Environmental Consultants Alison Davis, Aristos Consultants For Porirua Adventure Park Limited May 2018 Acknowledgements Information: David Moss, Dave Allen, Lyn Adams, Angus Hulme-Moir, Philippa Crisp, Sharyn Westlake (GWRC), Ruth Barrett (Porirua Library), Graeme Ussher (RMA Consultants), Frances Forsyth (Wildlands Consultants). Astrid van Meeuwen-Dijkgraaf (Wildlands Consultants) for permission to use information from her earlier assessment. Caption (front cover): Recovering forest surrounding the old northern water reservoir in Rangituhi/Colonial Knob Scenic Reserve. In background is regenerating forest below dead pine and macrocarpa trees and in the distance, regenerating shrubland near the top station of the proposed gondola and trail network. Table of Contents 1.0 INTRODUCTION 1 1.1 BACKGROUND 1 1.2 PROPOSED WORKS 2 2.0 METHODS 4 2.1 VEGETATION, HABITATS AND FACILITIES SURVEY 4 2.2 FAUNA SURVEY 4 3.0 EXISTING ENVIRONMENT 6 3.1 CLIMATE 6 3.2 GEOLOGY AND SOILS 6 3.3 MITCHELL STREAM 7 3.4 CONTAMINATED LAND 7 3.5 LAND USE AND COVER 8 3.6 ECOLOGICAL DISTRICT AND LAND ENVIRONMENT 14 3.7 VEGETATION 14 3.8 SIGNIFICANT VEGETATION/NATURAL AREAS 21 3.9 FAUNA HABITATS 21 3.10 BIRDS 21 3.11 LIZARDS 29 3.12 BATS 30 3.13 FRESHWATER FAUNA 30 3.14 SUMMARY OF THREATENED SPECIES AND ECOSYSTEMS 33 3.15 PEST PLANTS 34 3.16 PEST ANIMALS 35 3.17 SUMMARY OF ECOLOGICAL VALUES 36 4.0 ASSESSMENT OF ECOLOGICAL EFFECTS 37 4.1 CONSTRUCTION EFFECTS 37 4.2 OPERATIONAL EFFECTS 45 4.3 OVERALL ASSESSMENT OF ECOLOGICAL EFFECTS 47 5.0 METHODS TO AVOID, REMEDY OR MITIGATE OR OFFSET POTENTIAL ADVERSE EFFECTS 50 5.1 AVOIDANCE MEASURES 50 5.2 REMEDIATION MEASURES 52 5.3 MITIGATION ‘PACKAGE’ 54 REFERENCES 58 APPENDIX 1: VEGETATION AND HABITAT DESCRIPTIONS 61 APPENDIX 2: CALCULATIONS FOR VEGETATION CLEARANCE FOR PROPOSED TRAILS 65 APPENDIX 3: SCIENTIFIC NAMES OF PLANT SPECIES IN TEXT 69 Figure 1: Location of the proposed Porirua Adventure Park, Porirua City. 2 Figure 2: Location of the bird count stations and line transects for the proposed Porirua Adventure Park 5 Figure 3: A time sequence of photos showing the landscape of what is now the Rangituhi/western reserves in Porirua City. 9 Figure 4: 1904 map of the southern Porirua basin 11 Figure 5: Location and extent of vegetation types in the application site. 16 Figure 6: Photos illustrating the various vegetation types within the Porirua Adventure Park application site. 17 Figure 7: Birds detected along line transects within the proposed Porirua Adventure Park application site, February 2018. 25 Figure 8: Birds recorded along the proposed Gondola corridor within the application site, February 2018. 28 Figure 9: Photo of the Wellington green gecko (Naultinus punctatus). 29 Figure 10: Mitchell Stream crossing within the Spicer Botanical Park. 32 Figure 11: Proposed trials to be constructed for the Porirua Adventure Park. 40 Figure 12: Mitigation proposed for Porirua Adventure Park – indicative sites for revegetation and pest animal control 57 Table 1: Vegetation types, and their stature within the application site. 15 Table 2: Bird species observed at the Rangituhi/Colonial Knob Scenic Reserve and Te Rahui o Rangituhi/Colonial Knob Parklands, January-February 2018. 23 Table 3: Mean number of individuals of common indigenous bird species per five-minute bird count from a survey undertaken in February 2018within the proposed Porirua Adventure Park site. 24 Table 4: Freshwater fish records from the upper Mitchell Stream and its tributaries, within Colonial Knob Scenic Reserve and Colonial Knob Park, Porirua City 31 Table 5: Recommended methodology to assess level of adverse effects on ecology. 37 Table 6: Vegetation clearance for proposed trail construction by Reserve 38 Table 7: Trail lengths (m) by vegetation type for all reserves 39 Table 8:Summary of the level of ecological effects and proposed responses 48 1.0 Introduction 1.1 Background Porirua Adventure Park Limited are seeking the necessary resource consents and Department of Conservation (DOC) and Porirua City Council (PCC) approvals to establish an operative an adventure park being ‘The Porirua Adventure Park’ (Fig. 1). As part of the development, a number of related construction activities are proposed. Under this proposal an integrated group of recreation and tourism activities would be centred on a network of mountain bike and walking trails within DOC and PCC reserve land in the western hills of Porirua City; a short distance southwest of the Porirua CBD. The proposal detail, including all physical works proposed on the site, is covered in detail in Section 5 of the Resource Consent Application. The land parcels that form the ‘application site’ are listed in Section 4 of the Resource Consent Application and illustrated on the accompanying master plan drawings. The various parcels of land are known as Te Rahui o Rangituhi / Colonial Knob Parklands (TRoR) and the Porirua Scenic Reserve (PSR) that are administered by PCC, the Rangituhi/Colonial Knob Scenic Reserve (RCKSR) that is administered by the Department of Conservation (‘DOC’), the Spicer Botanical Park that is administered via a joint venture arrangement between Wellington City Council (WCC) and PCC, and the Spicer Landfill that is administered by PCC and Wellington City Council. This assessment of ecological effects has been undertaken under subcontract to Blaschke and Rutherford Environmental Consultants. In this report, the natural features of the application site are described, a detailed description and assessment of the ecological values at the application site undertaken, and potential ecological effects identified. Options are then proposed to avoid, remediate and mitigate adverse effects from the development. In 2014 an earlier unrelated proposal for a network of MTB trails was made to PCC. An assessment of effects including ecological effects was made at that time by Wildland Consultants Ltd (Wildlands 2014). This report draws on the previous assessments in some respects for the purposes of assessing and determining the existing ecological values of the application site only. The two authors of the report are familiar with the site and wider environs, and Paul Blaschke has previously provided ecological advice for mountain bike tracks within the PCC land parcels subject to this application for Porirua City Council. pg. 1 Figure 1: Location of the proposed Porirua Adventure Park, Porirua City. 1.2 Proposed Works As further described in section 5 of the Resource Consent Application, the proposal includes the following elements: a. The establishment and operation of recreational activity; b. A Base Station compound containing an operations building, café / restaurant, a surf simulator, a demonstration and bike repair centre, toilets, changing rooms, administration and the gondola station and gondola maintenance station; c. A Top Station compound containing a cafe, bathroom facilities, a covered walkway, a helicopter landing area (location TBC) and a service shed; d. A gondola allowing access from the Base Station to the Top Station; e. Downhill mountain bike trails; f. Learning skills areas; g. A collection hub; h. A zipline; i. A carpark located within the Spicer Landfill ‘borrow area’ j. Vehicle access; k. Helicopter access; l. Infrastructure servicing; m. Vegetation clearance; and n. Earthworks and construction works; pg. 2 Of the most relevance to this report, the proposal includes earthworks and construction associated with the construction of the Base Station and the Top Station, the construction of trails through the three reserve areas (that includes stream crossings), native vegetation removal and works within the bed of the Mitchell Stream. pg. 3 2.0 Methods The methodology for this review and assessment included both desktop and site work. A wide range of relevant documentation was read, assessed and referenced where appropriate. Unpublished information was obtained from team members, PCC, GWRC and DOC staff, and other colleagues and incorporated into this report as relevant. The bibliography gives a guide to the sources drawn on. A number of pre-application meetings were held with the councils and DOC as further described in Section 6 of the Resource Consent Application. More than six-person days between the two report authors were spent in on-site assessment, over eight visits between December 2017 and April 2018. Some visits were made with other team members and one with PCC staff and peer consultants. 2.1 Vegetation, habitats and facilities survey All vegetation types identified in a previous assessment (Wildlands 2014; see section 3.7 for details) were inspected. Streams, the reservoir areas and the route of all trails were walked including the 20m wide gondola line corridor. The site of all gondola towers and top and bottom station facilities were also inspected. 2.2 Fauna survey Information on fauna habitat and fauna at the application site was gathered from a desktop literature review including of the wider locality, information from people with knowledge on various fauna groups at the site, and from three site visits undertaken on 19 January 2018, 17 February 2018 and 24 February 2018. The site visits focused on assessing the characteristics and quality of habitat for indigenous fauna, and recording birds present within the application site. From the first visit a list was compiled from observations made of bird species present. During the second and third visits a combination of line transects and five-minute bird counts were undertaken to record all birds heard and seen along the gondola corridor and in the area where new or upgraded mountain bike trails are proposed (Fig. 2). Survey methods followed standard protocols established in New Zealand for bird surveys (DOC 2012). These methods provide a structured way of recording all birds present at a site and an estimate of conspicuous or relative density.