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Quay Street Seawall Upgrade Princes Wharf SectionAlternative Design and Construction Methodology

Date October 2018

Addendum to Resource Consent Application and AEE

Document Control

Title: Quay Street Seawall Upgrade Princes Wharf Section

Date Version Description Prepared by: Reviewed by: Authorised by:

15/10/18 1 Draft for client review Alexandra Scouller, Sarah McCarter

Jennifer Carvill R. Reinen-Hamill

26/10/18 2 Final for issue Alexandra Scouller, Sarah McCarter

Jennifer Carvill Richard Reinen-Hamill

Distribution:

Auckland Transport 1 copy

Auckland Council 1 copy

Tonkin & Taylor Ltd (FILE) 1 copy

Tonkin & Taylor Ltd Quay Street Seawall Upgrade Princes Wharf Section - Addendum to Resource Consent Application and AEE - Alternative Design and Construction Methodology Auckland Transport

October 2018 Job No: 1004393

Table of contents

1 Introduction 1 1.1 Context 1 1.2 Background and overview 1 1.3 Downtown Infrastructure Development Programme 2 1.4 Consenting approach 2 1.5 Proposed upgrade to the Princes Wharf section – jet grout column option 2 1.6 Overview of resource consent requirements 3

2 Environmental setting 5 2.1 Introduction 5 2.2 Archaeology 5 2.3 Existing services 5 2.4 Coastal environment 5

3 Description of proposed works 7 3.1 Introduction to proposed works 7 3.2 Overview of jet grout column option 7 3.3 Jet grout column construction 8

3.3.1 Gravity grouting 8 3.3.2 Jet grouting 9

3.4 Proposed hazardous substances 9 3.5 Timing, staging and duration of works 10 3.6 Plant and equipment 10 3.7 Site setup and enabling works 11

3.7.1 Pedestrian, cyclist and traffic management 11 3.7.2 Trees 13 3.7.3 Built heritage features 13 3.7.4 Site preparation and construction access 14 3.7.5 Relocation of services and utilities 14

3.8 Environmental Management Controls 15 3.8.1 Erosion and sediment control 15 3.8.2 Water management 15 3.8.3 Management of hazardous substances 16 3.8.4 Other controls 16

3.9 Reinstatement 16 3.9.1 Trees 16 3.9.2 Built heritage features 16

3.10 Consideration of alternative options 17 3.10.1 RMA context 17 3.10.2 Jet grout column option 17 3.10.3 Refinement of preferred options 17 3.10.4 Conclusion 18

4 Resource consent requirements 19 4.5.1 General archaeological authority 27 4.5.2 Signage Bylaw 2015 27

5 Assessment of effects on the environment 28 5.1 Introduction 28 5.2 Positive effects 28 5.3 Transportation effects 29

5.3.1 Approach to transportation effects assessment and mitigation 29



5.3.2 Effects on pedestrians 29 5.3.3 Effects on cyclists 29 5.3.4 Effects on public transport 29 5.3.5 Effects on property access 30 5.3.6 Vehicle traffic effects 30 5.3.7 Cumulative traffic effects 30 5.3.8 Summary of transport effects 31

5.4 Construction noise and vibration effects 32 5.4.1 Noise 32 5.4.2 Vibration 34

5.5 Historic heritage effects 34 5.5.1 Physical effects on built heritage 34 5.5.2 Effects on the setting of built heritage 34 5.5.3 Long-term effects of built heritage 35 5.5.4 Cumulative effects 35

5.6 Archaeological effects 35 5.7 Cultural effects 36 5.8 Effects on trees 36 5.9 Landscape and visual amenity effects 37

5.9.1 Temporary landscape effects 37 5.9.2 Temporary visual effects 38 5.9.3 Permanent landscape and visual amenity effects 39 5.9.4 Cumulative landscape and visual amenity effects 40

5.10 Geotechnical and groundwater diversion effects 41 5.10.1 Construction effects 41 5.10.2 Operational effects 42

5.11 Contaminated land effects 42 5.11.1 Effects of contaminated soil disturbance on human health 43 5.11.2 Effects of contaminated soil disturbance on the environment 43

5.12 Marine and groundwater quality effects 44 5.12.1 Runoff of exposed soil to stormwater 44 5.12.2 Spoil management 44 5.12.3 Potential effects on groundwater quality 44 5.12.4 Potential effects on the marine environment 45

5.13 Land disturbance and water quality effects 45 5.14 Hazardous substances, industrial and trade activities and air quality 46

5.14.1 Hazardous substance effects 46 5.14.2 Industrial and trade activity effects 46 5.14.3 Discharges to air 46

5.15 Scale of effects 47 5.15.1 Importance of the area 47 5.15.2 Sensitivity of the area and surrounding users 47 5.15.3 Cumulative effects 47 5.15.4 Combined effects 48

5.16 Summary of effects 48

6 Statutory assessment 50 6.2.4 Matters relevant to discharge permits (section 107) 51

7 Relevant planning documents 53

8 Consultation and feedback 57 8.1 Introduction 57 8.2 Auckland Council 57



8.3 Māori engagement 57 8.4 Heritage 58 8.5 Service Providers 58

9 Proposed conditions of consent 59

10 Conclusion 60

11 Applicability 61

Appendix A : Drawings – jet grout column option

Appendix B: Construction Methodology for Jet Grout Column Option

Appendix C : Archaeological Assessment Addendum

Appendix D : Hazardous Substances and Industrial and Trade Activities and Air Discharge Assessment

Appendix E : Construction Noise and Vibration Assessment Addendum

Appendix F : Integrated Transport Assessment Addendum

Appendix G : Arboricultural Assessment Addendum

Appendix H : Built Heritage Impact Assessment Addendum

Appendix I : Environmental Management Response Plan

Appendix J : Landscape and Visual Amenity Assessment Addendum

Appendix K : Geotechnical and Groundwater Effects Addendum

Appendix L : Ground Contamination Assessment Addendum

Appendix M : Project Context and Options Assessment Addendum

Appendix N : Consultation Documentation

Appendix O : Assessment of Planning Standards

Appendix P : Assessment Criteria

Appendix Q : Assessment of Objectives and Policies

Appendix R : Proposed draft conditions of consent



Glossary of abbreviations

Term Definition

AC Auckland Council

AC36 36th America’s Cup

ACCAB Auckland City Centre Advisory Board

AEE Assessment of Effects on the Environment

AEMMRP Adaptive Environmental Monitoring and Management Response Plan

AEP Annual Exceedance Probability

AHB Auckland Harbour Board

APEC Asia-Pacific Economic Cooperation

AT Auckland Transport

ATOC Auckland Transport Operations Centre

AUP Auckland Unitary Plan – Operative in Part

BHCMP Built Heritage Construction Management Plan

CBD Central Business District

CCMP City Centre Master Plan

CCP Communication and Consultation Plan

CD Chart Datum

CEHA Coastal Erosion Hazard Area

CEMP Construction Environmental Management Plan

Coastal Plan Auckland Regional Plan: Coastal

CMA Coastal Marine Area

CMP Conservation Management Plan

CNVMP Construction Noise and Vibration Management Plan

CRL City Rail Link

CRLL City Rail Link Limited

CTMP Construction Traffic Management Plan

DSI Detailed Site Investigation

ECBF East Coast Bays Formation

ECI Early Contractor Involvement

EMP Environmental Management Plan (Chapter E33 of the AUP)

EMRP Environmental Management Response Plan

ESCP Erosion and Sediment Control Plan

GSMCP Ground Settlement Monitoring and Contingency Plan

HAIL Hazardous Activities Industries List

HGMPA Hauraki Gulf Marine Park Act

HH-EOP Historic Heritage Overlay Extent of Place

HIA Built Heritage Impact Assessment

HNZ Heritage New Zealand

HNZPTA Heritage New Zealand Pouhere Taonga Act 2014



Term Definition

HOTC Heart of the City

HSW-HS Health and Safety at Work (Hazardous Substances) Regulations 2017

IL4 Importance Level 4

ITA Integrated Transport Assessment

LOS Level of Service

MCA Multi Criteria Assessment

MCI Macroinvertebrate Community Index

MfE Ministry for the Environment

MHWS Mean High Water Springs

NES Soil National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011

NPS-FM National Policy Statement – Freshwater Management

NZCPS New Zealand Coastal Policy Statement

POAL Ports of Auckland

PSI Preliminary Site Investigation

RAP Remedial Action Plan

RMA Resource Management Act 1991

SCPA Sediment Control Protection Area

SDF Sustainable Development Framework

SMP Site Management Plan

SRP Spill Response Plan

T+T Tonkin + Taylor

WP Waterfront Plan



Executive summary

This report (referred to as the AEE Addendum) is an addendum to the resource consent application and Assessment of Effects on the Environment (AEE) for the Quay Street Seawall Upgrade – Princes Wharf section lodged in May 2018 (Council ref: BUN60320273). This is for the resource consents necessary to authorise the proposed construction of the Princes Wharf section of the upgrade of the Quay Street seawall. In particular, this AEE Addendum addresses an alternative design and construction methodology, jet grout columns (referred to as the jet grout column option), which is now proposed for the upgrade of the Quay Street seawall in this location and the Ferry Basin section (subject to a separate AEE addendum).

This AEE Addendum should be read in conjunction with the resource consent application and AEE lodged with Auckland Council in May 2018 (Council ref: BUN60320273) and the section 92 further information response for the Princes Wharf section, dated 11 July 2018. Where information in the AEE is applicable to the AEE addendum, it is referred to in the relevant report sections for conciseness.

This AEE Addendum considers possible scenarios of the Princes Wharf section being constructed as a standalone project, overlap in the construction programme with more than one section being constructed at one time, as well as various possible combinations of seawall options being implemented (e.g., palisade wall for the Princes Wharf section and jet grout columns for the Ferry Basin section).

Auckland Transport requests public notification of the AEE Addendum in conjunction with the AEE.

Jet grout columns are proposed to be installed landward of the existing seawall on the northern side of Quay Street, within the road reserve, for a length of approximately 105 m. The concept design proposes up to five rows of 1.4 m diameter columns spaced at 1.2 m centres north-south, so that there is 200 mm overlap between the columns in that direction. In the east-west direction the columns are proposed to be spaced at 3.0 m centres.

The jet grout columns will be installed by jet grouting, which is a construction process that employs a high kinetic energy jet in a circular motion, to break down the soil formation, erode the soil particles into suspension and mix the in-situ soils with cement grout. Gravity grouting (also known as pre-drilling) may also be required in areas where basalt rock is encountered.

The construction duration for the Princes Wharf section is expected to be approximately 27 weeks.

Mitigation measures for the jet grout column option are recommended throughout the specialist addendum reports and in the assessment of effects contained within this AEE Addendum to ensure adverse effects are appropriately avoided, remedied or mitigated. In some instances these involve the preparation of management plans at a stage when further details of the construction method have been determined. Auckland Transport has proposed a suite of draft conditions to address the potential effects. These proposed draft conditions provide for either the original proposal of a palisade wall, or the alternative proposal of jet grout columns to be constructed.

The requirements for resource consent are determined by the rules in both the Auckland Unitary Plan operative in part (AUP) and the regulations in the NES for Assessing and Managing Contaminants in Soil (NES Soil). The proposal requires various consents under the Auckland-wide and Historic Heritage Overlay provisions of the AUP. Overall, the proposal is a discretionary activity.

The AEE Addendum and supporting technical addendums include a comprehensive analysis of the relevant environmental effects. The proposal to upgrade the seawall to Importance Level 4 (IL4) with a robust design life of 100 years will provide significant resilience for the city’s transport and utility infrastructure. This resilience is in terms of seismic events, future climate change, and changing



marine use patterns. The Seawall Project is a key enabler for a suite of projects that will bring significant social and economic benefits to both Auckland and New Zealand. Further, once all heritage features have been reinstated and trees have been successfully re-established there will be no long term adverse effects, resulting in the only long term effects being positive.

The combined potential temporary adverse effects of the jet grout column construction works may be more than minor when considered as a whole. Notwithstanding this, given the substantial positive effects and the suite of proposed conditions, it is considered that any adverse effects can be appropriately managed. The works are consistent with Part 2 of the Resource Management Act 1991 and with the relevant objectives and policies of the applicable statutory documents.

Auckland Transport has consulted with Mana Whenua and a range of stakeholders and interest groups regarding the jet grout column option. Engagement and consultation will continue during the detailed design, consenting and construction phases of the project.

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1 Introduction

1.1 Context

This report (referred to as the AEE Addendum) is an addendum to the resource consent application and Assessment of Effects on the Environment (AEE) for the Quay Street Seawall Upgrade – Princes Wharf section lodged in May 2018 for the resource consents necessary to authorise the proposed construction of the Princes Wharf section of the upgrade of the Quay Street seawall. In particular, this AEE Addendum addresses an alternative design and construction methodology, jet grout columns, which is now proposed for the upgrade of the Quay Street seawall in this location.

This AEE Addendum should be read in conjunction with the resource consent application lodged with Auckland Council in May 2018 (Council ref: BUN60320273) and the section 92 further information response for the Princes Wharf section, dated 11 July 2018.

1.2 Background and overview

In May 2018, Auckland Transport (AT) lodged three separate applications for resource consent for the upgrade of the Quay Street seawall (the Seawall Project). The Seawall Project has been divided up into four sections for the purpose of resource consent applications and construction, and to date applications have been lodged for three of these four sections. The Ferry Building section is still in the design phase and the resource consent application for this section will be lodged at a later date.

For two of the lodged applications, relating to the Princes Wharf section and the Ferry Basin section, AT would like to include in the application for resource consent an alternative design and construction methodology. This is in addition to the methodology described in the application documentation already submitted to Auckland Council. This is a result of the Early Contractor Involvement (ECI) phase of the Seawall Project, where alternative seawall upgrade options have been considered.

The alternative seawall methodology (referred to as the jet grout column option) proposed is for the installation of jet grout columns in the Quay Street road reserve, landward of the existing seawall. The Ferry Basin section (which is the subject of a separate application and AEE addendum) also includes works in the coastal marine area, including a new facing to the existing seawall, a waler beam and ground anchors. A rock protecting toe or concrete mattress for scour protection is also proposed.

The proposal is now to seek resource consent for both the original methodology (as submitted) and the jet grout column option for the Princes Wharf and Ferry Basin sections, so that AT has the option to implement either (but not both) of the options for each section (depending on the final methodology chosen by the appointed contractor).

In summary, resource consents are currently being sought to authorise the following seawall upgrade options:

Seawall Section Application Lodged May 2018 Addendum to Application

Princes Wharf Palisade wall Jet grout columns

Ferry Basin Post and panel wall Jet grout columns

Queens Wharf to Marsden Wharf Palisade wall N/A

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1.3 Downtown Infrastructure Development Programme

Since the time of writing the AEE (Council ref: BUN60320273), the following advancements have been made to projects which relate to the Quay Street seawall upgrade and other projects which form part of the Downtown Infrastructure Development Programme (Downtown Programme):

Resource consent (ref: BUN603020277) for the proposed seawall upgrade for the Queens to Marsden Wharf was publicly notified on 20 August 2018 with the submission close date being 17 September 2018. The hearing is scheduled for 3 and 4 December 2018;

Resource consent (ref: CST60321060) was granted on 25 July 2018 for the emergency maintenance works undertaken to repair a scour hole beneath the Ferry Building section of the Quay Street seawall. These works were completed in April 2018;

Resource consent (ref: BUN60317825) was granted on 14 June 2018 to excavate 16 trenches along Quay Street to locate and expose existing services, to assist with determining services that need to be realigned for Seawall Project. These works were completed in August 2018;

Application for resource consent (ref: CST60323353) for upgrades to the eastern Queens Wharf cruise ship berth was lodged by Panuku Development Auckland and publicly notified on 10 September 2018;

Resource consent (ref: BUN60323965) was granted on 11 September 2018 to excavate 45 trenches along Quay Street. These works are expected to start in mid-October 2018 and will assist with planning for works as part of the overall Downtown Programme;

Application for resource consent (ref: BUN60327622) was lodged on 3 October 2018 for Stage 1 of the Downtown Ferry Basin Redevelopment. This included the relocation of existing ferry services from Piers 3 and 4 to the western edge of Queens Wharf and minor modifications to the existing ferry terminal building; and

Application for archaeological authority was lodged with Heritage New Zealand Pouhere Taonga (HNZ) on 9 October 2018. This is a blanket archaeological authority for all proposed works associated with the Downtown Programme.

1.4 Consenting approach

As discussed in Section 1.1 of the AEE, each section of the seawall could be constructed as a standalone project once consented, or there may be some overlap in the construction programme, This AEE Addendum considers possible scenarios of the Princes Wharf section being constructed either as a standalone project, or overlap in the construction programme with more than one section being constructed at one time, as well as various possible combinations of seawall options being implemented (e.g., palisade wall for the Princes Wharf section and jet grout columns for the Ferry Basin section or vice versa).

This AEE Addendum sets out an alternative design and construction methodology. Resource consent is sought for both the original option (palisade wall) and the alternative option (jet grout columns) discussed here.

1.5 Proposed upgrade to the Princes Wharf section – jet grout column option

Jet grout columns are proposed to be installed landward of the existing seawall on the northern side of Quay Street, within the road reserve, for a length of approximately 105 m. The proposed jet grout column alignment will be south of the Auckland Harbour Board (AHB) Fence lighting pylons, and within the row of existing street trees. The proposed alignment of the jet grout columns will allow for Tree 18 to be retained (Refer to Appendix A for resource consent drawings).

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The concept design proposes up to five rows of 1.4 m diameter columns spaced at 1.2 m centres north-south, so that there is 200 mm overlap between the columns in that direction. In the east-west direction the columns are proposed to be spaced at 3.0 m centres. While the alignment of the columns, number of rows, diameter of the columns and spacing may change with the final design, the overall extent of ground treated with jet grout columns is unlikely to be larger than as shown on the proposed drawings.

The jet grout columns will be installed by jet grouting, which is a construction process that employs a

high kinetic energy jet in a circular motion, to break down the soil formation, erode the soil particles

into suspension and mix the in-situ soils with cement grout. Gravity grouting (also known as pre-

drilling) may also be required in areas where basalt rock is encountered as described in Section 3.3.1.

No works within the coastal marine area (CMA) are proposed in the Princes Wharf section of the Seawall Project.

Refer to Section 3 of this AEE Addendum and the Alternative Construction Methodology for Resource Consent – Jet Grout Columns (Alternative Construction Methodology Report), prepared by Downer / Soletanche Bachy (Appendix B) for further information regarding the proposed works.

The duration of works to complete the Princes Wharf section of the seawall upgrade is expected to be up to 27 weeks (up to 20 weeks for construction and up to seven weeks for mobilisation and demobilisation of the site) and includes the following:

Establishment and preparation works on Quay Street including:

pedestrian and traffic management;

establishment of construction access and laydown area;

relocation and/or protection of existing utility services;

removal of existing pavers and installation of metaled surface for plant operation;

temporary relocation of trees, light poles and other utilities; and

installation of environmental management controls.

Jet grout column installation:

Pre-drilling (gravity grouting) where basalt rock is encountered (Section 3.3.1); and

Jet grouting, involving drilling, jetting and hit and miss (in Section 3.3.2).

Reinstatement of Quay Street, including reinstating any trees that have been temporarily relocated.

The proposed jet grout columns will be located above Mean High Water Springs (MHWS) and therefore are outside of the coastal marine area (CMA). This application seeks resource consent under the Auckland Unitary Plan Operative in part (AUP), for the reasons outlined in Section 4.2 and National Environmental Standard for Assessing and Managing Contaminants in Soil (NES Soil) for the reasons outlined in Section 4.3.

1.6 Overview of resource consent requirements

The resource consents sought to enable the jet grout column option are assessed in Section 4 and listed in the tables below. The following may not be an exhaustive list and if further consent matters are identified post lodgement of the application, these should also be considered as forming part of the application.

Overall, resource consent is required from Auckland Council as a discretionary activity.

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Table 1.1: Summary of resource consents required under the AUP

Consent type AUP Rule Description Activity Status

Historic Heritage Overlay – Extent of Place (HH-EOP)

Land Use Consent D17.4.1 (A9) Modification within the HH-EOP Restricted discretionary

Land Use Consent D17.4.1 (A11) Temporary construction-related buildings within the HH Overlay

Restricted discretionary

Land Use Consent D17.4.1 (A15) Signs in Category A or B HH-EOP Restricted discretionary

Discharge of contaminants

Discharge permit E4.4.1 (A11) Discharge of contaminants onto or into land

Controlled activity

Air Quality

Discharge permit E14.4.1 (A77) Cement storage in a high air quality area

Discretionary activity

Infrastructure

Land Use Consent E26.3.3.1 (A77)

Vegetation alteration within the coastal area



Trimming of tree branches Restricted discretionary


Works within the protected root zone



Relocation of trees Restricted discretionary

Contaminated land

Land Use Consent E30.4.1 (A6) Discharge of contaminants due to disturbance of potentially contaminated soils

Controlled activity

Hazardous Substances

Land Use Consent E31.4.1 (A7) The storage and use of hazardous substances


Industrial and Trade Activities

Land Use Consent E33.4.1 (A8) Use of land for a new industrial or trade activity

Controlled activity

Natural Hazards and Flooding

Land Use Consent E36.4.1 (A55) Relocation of existing services Restricted discretionary

Business – City Centre Zone

Land Use Consent H8.6.31(2) and C1.9

Structures within Sightline 3 Restricted discretionary

Table 1.2: Resource consent required under NES Soil

Consent type NES Reg Description Activity Status

Land Use Consent Regulation 10 Disturbance of contaminated land Restricted discretionary

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2 Environmental setting

2.1 Introduction

The existing environment description provided in Section 2 of the AEE remains valid for this AEE Addendum. Additional information is also provided in the following sections to inform the jet grout column proposal.

2.2 Archaeology

A description of the archaeological setting is provided in Section 2.6 of the AEE. The Archaeological Assessment Addendum, prepared by Clough and Associates (Appendix C) provides further information regarding the recorded archaeological site – R11/2901 (the Old Hobson Street Wharf).

At the time of writing the AEE and Archaeological Assessment it was unknown whether any remains of site R11/2901 have survived subsurface. Recent excavations associated with investigation trenches in Quay Street have exposed a wharf pile on the alignment of Hobson Street which has been identified and recorded during archaeological monitoring. This has confirmed that subsurface remains are present. The pile was encountered at a depth of 1.4 m below the ground surface and was left in situ.

In addition to the wharf pile, some 20th century bluestone street kerbing was exposed in a second trench within the Princes Wharf section, but generally the trenches along the northern side of Quay Street demonstrated that the upper c.1.5 m had been very disturbed by post-1900 infrastructure.

2.3 Existing services

The proposed location of the jet grout columns is in the location of a number of services, including, but not limited to:

• Vector communications;

Chorus communications;

High voltage power cable;

Vodafone Fibre Optics;

Stormwater pipes, manhole and catchpits;

Sewer Line; and

Water supply pipe.

The locations of existing services can only be considered indicative and contractors on site will be locating these services during works. Refer to drawing 1004393-PRW-400 submitted with the AEE (Appendix C) for the existing services plan.

Since the time of lodging the AEE, resource consent (ref: BUN60317825) was granted on 14 June 2018 to excavate 16 trenches along Quay Street to locate and expose existing services, to help assist with the Seawall Project. These works have been completed. Resource consent (ref: BUN60323965) was granted on 11 September 2018 to excavate 45 trenches along Quay Street. These works are expected to start in mid-October 2018 and will also help to assist with planning for works as part of the overall Downtown Programme.

2.4 Coastal environment

Due to the proposed use of cement for the jet grout columns in close proximity to the coastal marine area (CMA), a description of the marine environment is provided below.

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The proposed works are adjacent to the coastal marine area of the Waitematā Harbour. The Waitematā harbour environment is highly modified to facilitate high volumes of marine traffic. The coastal marine habitat is subtidal, fringed by manmade structures.

The subtidal habitat has been classified as ‘soft gloopy mud’ habitat. This is characterised by soft mud and not associated with high intrinsic ecological values. This area has not been characterised as a Significant Ecological Area within the Auckland Unitary Plan. Previous work done in the wider area indicates that soft sediment benthic fauna is likely to be dominated by species that are widely distributed in New Zealand and/or exotic, and nationally ‘Threatened’ or ‘At Risk’ marine invertebrate species are unlikely to be present. Despite being of low ecological value the area is very exposed and of aesthetic value to waterfront patrons.

The existing stormwater catch pits along Quay Street discharge directly to the harbour. The nearest council water quality monitoring stations are located at Judges Bay and St Mary’s Bay, 2 km east and 1.5 km west of the works respectively. Both bays are rated high risk to human health and have no-swim warnings issued by Safeswim due to above guideline results for Faecal Indicator Bacteria. Coastal pollution in this region is primarily due to the age of combined stormwater and wastewater networks in the area and the propensity for these networks to be overwhelmed during heavy rains, displacing diluted wastewater from engineered overflow points into local waterways or directly to the coast.

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3 Description of proposed works

3.1 Introduction to proposed works

An alternative seawall design and construction methodology (the jet grout column option) is proposed as part of this AEE Addendum and is summarised in this section. This proposal is in addition to the current proposal submitted to Auckland Council.

It is proposed to install jet grout columns within the Quay Street road reserve for the Princes Wharf section of the Quay Street seawall upgrade, situated landward of the existing seawall. Refer to drawings in Appendix A. Jet grout columns are a ground improvement technique which uses a soil and grout mixture to form columns in the soil, improving structural strength.

Similar to the palisade wall proposal, site constraints have shaped the alignment of the jet grout columns. This includes the location of existing services, heritage features and street trees as well as trying to minimise disruption to all transport modes and construction noise and vibration as much as practicably possible.

The Alternative Construction Methodology Report, prepared by Downer and Soletanche Bachy included in Appendix B provides an outline of the proposed construction works which is summarised in this section of the report. It is important to note that the proposed jet grout column design is indicative, with a detailed design still to be finalised. The draft management plans included with the AEE are applicable to this alternative seawall upgrade proposal. There are also additional draft management plans applicable to the jet grout column option only, related to proposed industrial and trade activities. These management plans and a final construction methodology are to be provided to Auckland Council for certification prior to works commencing, as offered in the draft set of conditions (Appendix R).

3.2 Overview of jet grout column option

Jet grout columns are proposed to be installed landward of the existing seawall on the northern side of Quay Street, within the road reserve, for a length of approximately 105 m. The proposed jet grout column alignment will be south of the Auckland Harbour Board (AHB) Fence lighting pylons, and within the row of existing street trees. The proposed alignment of the grout columns will allow for Tree 18 to be retained.

The concept design proposes up to five rows of 1.4 m diameter columns spaced at 1.2 m centres north-south, so that there is 200 mm overlap between the columns in that direction. In the east-west direction the columns are proposed to be spaced at 3.0 m centres. While the alignment of the columns, number of rows, diameter of the columns and spacing may change with the final design, the overall extent of ground treated with jet grout columns is unlikely to be larger than as shown on the proposed drawings.

Sections A1 and A2 in Drawing No. 1004393-215 (Appendix A) show the location of the jet grout columns relative to the existing seawall as well as the anticipated depth of the columns. The final height of the jet grout columns will be at least 1200 mm below ground level to allow for the installation of tree pits and will extend to a maximum of 15 m beneath the ground surface. The grout columns will be constructed between 6 m and 36 m from the existing seawall.

The columns will be constructed by jet grouting which is a process that employs a high kinetic energy jet in a circular motion, to break down the soil formation, erode the soil particles into suspension and mix the in-situ soils with cement grout. Gravity grouting may also be required where basalt rock is encountered. These processes are detailed in Section 3.3.

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The grout mix comprises of cement (delivered by truck tanker and stored in silos) which is mixed on site by a mixing plant and is then delivered by pipe to the head of the rig. The spoil arising from the head of the holes is directed into a spoil collection box. Spoil is then pumped from the spoil collection box and discharged to a dedicated spoil pit or container. Once the spoil starts to set, it is tested and removed to an appropriate landfill.

No works within the CMA are proposed in the Princes Wharf section of the Seawall Project.

3.3 Jet grout column construction

3.3.1 Gravity grouting

A gravity grouting operation called “pre-drilling” is required for jet grouting columns located in the vicinity of the seawall, where there is the presence of basalt gravels and boulders (see Figure 3.1). It is likely that where the grout columns are close to the existing seawall, basalt boulders will be encountered. If there are no basalt boulders present, this step is not required. Gravity grouting involves two main steps described below:

Step 1: Pre-drilling with a drilling rig from the existing ground level through basalt boulders layer to identify the extent of this layer; and

Step 2: Sending a thick grout (bentonite (<5%) mix with cement and water) while extracting rods to backfill the predrilled hole and fill any voids within the basalt boulders.

The predrilling diameter shall be sufficient for the further jetting operation (approximately 200 mm diameter is proposed). The jet grouting operation has to be scheduled several days after the gravity grouting operation. This is to leave enough time for the grout in the pre-drilled hole to set and to avoid any grout mixing between holes already drilled and grouted.

Figure 3.1: Gravity grouting process (source: Downer and Soletanche Bachy)

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3.3.2 Jet grouting

Jet grouting is a construction process that employs a high kinetic energy jet in a circular motion, to break down the soil formation, erode the soil particles into suspension and mix the in-situ soils with cement grout.

The jet grouting process is outlined in Figure 3.2 below and involves four main steps:

Step 1 “Drilling”: The drilling is executed following the pre-jet method whereby water is pumped under reduced pressure from the jet grouting plant to the jetting tools (monitor and drilling tools). The water cuts the soil and lifts the drill cuttings to the surface where they are pumped to spoil pits to be treated;

Steps 2 & 3 “Jetting”: Once the final depth is reached, the jet grouting process is undertaken whereby grout is substituted for the water and the pressure is increased. The jet grout column is formed from the bottom to the top. The operator will then transfer control of the rig to the on-board computer system, which will control the upward withdrawal speed. Waste material from the process, which is a mix of soil, water and binder (referred to as spoil), is recovered at the surface and pumped to the spoil pit before being taken away for disposal (using vacuum trucks for liquid or regular trucks for solid material). This is described further in Section 3.8; and

Step 4 “Hit and miss”: For the general sequence, the jet grouting columns process is to be implemented by the “hit and miss” approach to optimise overlaps between the columns. For each row of columns the hit and miss approach involves the primary columns being installed first, allowing them to set, and then installing the secondary columns.

Figure 3.2: Jet grouting work sequence (source: Downer and Soletanche Bachy)

3.4 Proposed hazardous substances

The jet grouting plants will use and store cement within either a single 60 tonne silo or two 30 tonne silos. If required due to timeframes, there may be two jet grouting column construction projects in operation at once, doubling the cement storage quantity with a separation of approximately 100 m.

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In addition to the storage of cement, small quantities of other additives will be used as part of the plant but these are in small quantities (no more than 20 L) and therefore, are well below any of the trigger levels in the AUP and have not been considered further.

Refer to the Hazardous Substances, Industrial and Trade Activities and Air Discharge Assessment, prepared by T+ T (Appendix D) for further detail.

3.5 Timing, staging and duration of works

Construction of the proposed jet grout columns is anticipated to take up to 27 weeks to complete. This includes up to seven weeks of mobilisation and demobilisation and 20 weeks of jet grout column execution. Durations are based on one jet grouting rig and one pre-drilling rig. The construction sequence and methodology for the proposed jet grout columns is summarised below:

Site setup and enabling works (refer Section 3.7);

Hydro excavation to expose services; and realign services as required, and/or installation of PVC casing around services to protect in situ;

Pre-drilling (where required) to fill any voids between basalt boulders;

Installation of jet grout columns; and

Reinstate Quay Street (including the reinstatement of trees).

Construction may be undertaken up to 16 hours per day (7 am to 10 pm, Monday to Friday and 7 am to 11 pm, Saturday), excluding Sundays and public holidays. Construction hours will generally be limited to those hours described as “Monday to Saturday Daytime Periods” as prescribed in Rule E25.6.28 of the AUP. Exceptions to this are discussed in the addendum to the Construction Noise and Vibration Assessment (Noise and Vibration Assessment Addendum) prepared by Marshall Day (Appendix E). Any work undertaken outside of these hours would be for specific discrete activities that cannot readily be undertaken during the daytime hours outlined above.

Construction of the overall Seawall Project is expected to be undertaken during the period of April 2019 to February 2020 (18 months). Construction of the Princes Wharf section is expected to be undertaken for a period of approximately 70 days, from around June 2019 to September 2019.

The Princes Wharf section may be constructed in isolation or at the same time as one or both of the other wall sections. It is proposed to undertake the work for the Princes Wharf section in two phases, which is described in detail in the Alternative Construction Methodology Report.

3.6 Plant and equipment

The following plant and equipment is expected to be used during construction:

Jet grouting rig: 1 or 2 rigs (approximately 24 m high);

Pre drilling (gravity grouting) rig: 1 rig (approximately 24 m high);

High pressure pump: 1 per rig;

Mixing plant: 1 per rig;

Cement silos: 1 vertical silo (approximately 16 m high) of 60 T or 2 horizontal silos (approximately 7.5 m) of 30 T per rig;

Backhoe, forklift: 1 per rig;

Storage container: 1 per rig;

Generator to power the jet grouting plant;

Spoil collection box and spoil pit: 1 per rig;

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Storage / settling tanks for water management;

1 x 20 ft storage container;

1 x 20 ft office;

1 x 20 ft lunchroom; and

1 x portable toilet.

There will be a maximum of two jet grout rigs and one gravity grout rig in operation at any one time. Throughout the day there would be approximately two to six vehicle movements per day for cement delivery, and eight to 24 vehicle movements per day for spoil removal. The above numbers have been estimated based on the scenario that up to two sets of rigs and plants are located on the site. The location and positioning of the plants and rigs will be confirmed at the time of construction. Rigs will move across the site as the jet grouting takes place, the rigs will be connected to the plants via a hose which will be supplying material to the rig. The location of the plants may also change during the construction period.

3.7 Site setup and enabling works

Establishment and preparation works are required before the construction of the proposed jet grout columns commences. These works are outlined in this section below.

3.7.1 Pedestrian, cyclist and traffic management

Pedestrian, cyclist and traffic management proposed for the project is set out in the addendum to the Integrated Transport Assessment Addendum (ITA Addendum) (Appendix F), and is summarised below. It is noted that the proposed traffic management is consistent with that proposed for the palisade wall option (as the construction zone remains the same)1.

The transport management strategy relies upon maintaining the capacity along Quay Street during peak periods, for all modes. The focus is to firstly maintain bus reliability, and pedestrian access and safety. A Construction Traffic Management Plan (CTMP) is recommended as a condition of consent (refer Section 4.2 of Appendix F). It is proposed that the CTMP will include a Communication Plan, setting out how transport information will be provided to communities and road users.

The temporary works will run approximately 105 m in length. An 11 m wide construction zone is proposed to be in place for the duration of construction, running the length of the works area. The construction zone will require the temporary closure of the bi-directional cycleway, and two traffic lanes on the northern side of Quay Street. Maintaining adequate access and thoroughfare for pedestrians, cyclists and motor vehicles is a key consideration of the project and the proposed pedestrian and traffic management is set out below.

The reduction in the number of traffic lanes will commence on the southern side of Lower Hobson Street, extending to the west of the intersection with Lower Albert Street. The alignment will revert to the existing at this point, to ensure the safe operation of the Lower Albert/ Quay Street intersection can be maintained for all road users.

A dedicated cycleway (south of the construction zone) will continue to be provided during the works, with an approximately 3.4 m wide bi-directional cycleway located directly south of the construction zone (comprising 2.8 m of cycling lanes, plus two 0.3 m setbacks on either side). This exceeds the

1 The proposed pedestrian, cyclist and traffic management approach for the jet grout column option is consistent with that for the palisade wall option outlined in the AEE. On this basis, Section 3.7.1 of the Addendum AEE is unchanged from Section 3.4.1 of the AEE, but is included here in its entirety for ease of reference.

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2.5 m minimum path width set by Austroads for paths with a predominant purpose of commuting, and is the same width or wider than the existing cycling lanes.

One eastbound traffic lane and potentially two westbound traffic lanes will be provided. The provision of two westbound traffic lanes will provide resilience for bus movements through the section. There is the potential that one of the lanes could be solely dedicated to westbound buses on approach to the Lower Hobson Street, and this will be confirmed within the CTMP that is proposed to be submitted to Council as a condition of consent. It is considered at this stage the additional lane will be for buses only.

The existing bus stop outside of the PWC building (stop 1346) will be indented into the kerb space, to allow proceeding buses to pass while up to two buses use the bus stop. The existing bus shelter will be temporarily removed for the duration of works, and the existing PWC canopy will provide shelter for passengers. The indicative layout of the indented bus bay is shown on Figure 15 in the ITA Addendum in Appendix F. The kerb and bus shelter will be reinstated at the completion of construction. This aspect of the proposal does not require resource consent.

The northern pedestrian footpath, running in front of properties 131 – 139 Quay Street, will be maintained on the northern side of the construction site. The footpath will be reduced in width compared to its current provision (11 m) to 5.5 m to 6 m. At two points along this section, this will be reduced to approximately 3.1 m due to the design of the ANZ Building. Retention of the footpath on the northern side of the works enables continued access to properties, located in and around 131-139 Quay Street. It is proposed to temporarily raise the existing footpath to be the same level as the existing retail pedestrian access (131-139 Quay Street). The raised pavement will be designed to be fully compliant for mobility impaired users by way of ramps at both the eastern and western ends.

Access to Princes Wharf will be maintained during the construction stage. It is not proposed to close access for vehicles and/or pedestrians at any stage of the temporary works. General vehicle access into Princes Wharf will be maintained by way of at least one entry, in addition to one exit lane at the intersection with Lower Hobson Street.

In order to maintain access to the wharf, indicative staging suggests that the works on the western end will be undertaken in two phases:

1 Phase 1 will commence on the eastern side of the existing centre line of the Princes Wharf access. This will enable two lanes to be provided on the western side for entry and exit of pedestrians and vehicles; and

2 During phase two, the temporary works will move to the western side of the Princes Wharf access, with two traffic lanes provided on the eastern side of the current access. This staging will be confirmed by the contractor.

Throughout the temporary works period, the existing right turn into Princes Wharf from Quay Street east will be temporarily prohibited. The restriction is required as it enables sufficient space to provide adequate capacity for all modes at the intersection of Quay Street and Lower Hobson Street.

Removing the westbound shared through and right movement (movement to Viaduct and Princes Wharf) eliminates a traffic phase. This signal phase time can then be shared to other movements, increasing the capacity for all other modes through the intersection under the temporary control.

Access to Princes Wharf will be maintained via Lower Hobson Street with a dedicated shared through and left lane provided for the duration of the works. Exiting the wharf, all movements will be maintained for vehicles, that is left, right and through movements.

Refer to the ITA Addendum (Appendix F) for further details regarding traffic management during construction works.

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It is important to note in terms of the existing traffic environment in the Quay Street area that as road controlling authority AT has a wide range of powers to control traffic movements (e.g. turning directions, directions of travel) under Part 21 of the Local Government Act 1974. For example, in terms of the proposed closure of traffic lanes, and limiting the ability to turn right onto Quay Street from Commerce Street, Gore Street and Britomart Place, these traffic movements could be changed by AT without the need to obtain resource consents.

3.7.2 Trees

The proposed tree works outlined in Section 3.4.2 of the AEE applies to this AEE Addendum. This includes the retention of Tree 18, where the alignment of the proposed works and construction methodology have been designed to avoid this tree.

With regard to all other trees in this section three options are proposed in order of preference to manage the trees within the Quay Street seawall works area: (1) retain and protect, (2) temporary relocation, or (3) remove and replace. The procedures aim to provide flexibility in the management of the trees during this project. With regard to removal and replacement, a number of protocols have been developed. For Trees 19 to 21 within the Princes Wharf section, due to the conflict with the works and unknown contributing factors, the most likely reality is that preference (2), the temporary relocation of the trees, will be the procedure implemented.

Refer to Section 3.5.2 of the Arboricultural Assessment Addendum (Appendix G) for further detail. The proposed reinstatement of trees is set out in Section 3.9.1.

AT offers a condition of consent that requires the proposed tree relocation and tree protection methodologies adhere to the management processes, protocols and methodologies. These procedures, outlined in Appendix Q (Arboricultural Assessment) of the AEE are applicable to the jet grout column also.

3.7.3 Built heritage features

The proposed alignment of the jet grout columns is located south of the HH-EOP for the AHB Fence. The proximity of the jet grout column alignment to the AHB Fence as well as the WWI Memorial Beacon means that these heritage places need to be protected in situ during construction. There is no proposal to temporarily remove any heritage features during the construction of the jet grout columns. Therefore this remains the same for both the palisade wall and jet grout column option.

Details of the relocation, protection and reinstatement of heritage features will be provided Built Heritage Construction Management Plan (BHCMP) prepared by Plan.Heritage which is proposed as a condition of consent (Appendix R).

Monitoring of heritage features will also be undertaken in accordance with the Construction Noise and Vibration Management Plan (CNVMP) prepared by Marshall Day Acoustics, submitted with the AEE. This sets out the performance standards for the Seawall Project and best practicable options for noise and vibration management, which will be implemented throughout the construction period (Marshall Day Acoustics, March 2018).

Before any construction works commence, the following heritage enabling works are proposed to be undertaken:

Undertake a pre-works survey for the heritage features in close proximity to construction works (AHB Fence and WWI Memorial Beacon);

Isolation and redirection of utilities serving built heritage structures if required in this instance e.g. harbour fence lighting pylons; and

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Temporarily protect built heritage features in close proximity to construction works, such as with temporary physical barriers, in accordance with the Built Heritage Construction Management Plan (BHCMP) prepared by Plan Heritage.

Refer to Section 3.9.2 of this AEE Addendum and Appendix H for proposed remediation works to heritage features once the seawall has been constructed.

3.7.4 Site preparation and construction access

A number of activities will occur to prepare and establish the site before any construction works commence. The site will be enclosed by a solid timber hoarding (which will also act as an acoustic barrier), approximately 2.4 m high. Existing concrete pavers will be lifted and stored offsite to be re-laid on completion of works, and a metalled surface of 0.4-0.5 m thick laid to provide a level area for plant to operate on.

An 11 m wide working space and lay down area will be established in the vicinity of the proposed works area. This will allow construction traffic to enter the site at the western end and proceed through the site, exiting at the eastern end. An internal access lane is to be provided for trucks to manoeuvre to the appropriate location within the site. Where construction traffic enters and exits the site, they will be crossing the cycle lane, with traffic control being required each time a vehicle crosses the cycle way.

It has been estimated that daily truck movements of between ten and 38 is likely. During peak periods, it is estimated that this would equate to between one to a maximum of three truck movements per hour.

Construction trucks will travel via Lower Hobson Street and enter the site from Quay Street west. This will provide good access from the State Highway network and will restrict the number of construction vehicles passing through the city.

It is not anticipated that an office will be provided in the construction area on Quay Street. It is more likely that a site office will be sought in close proximity to the construction area. A maximum of 22 staff working at the site at any one time is expected.

A contractor’s yard (comprising a lunchroom, portable toilet, storage container etc.) will be established within the fenced construction area, and will likely be relocated within the area as works progress.

Before construction works commence, procedures will be established for erosion and sediment control, stormwater and groundwater management and the management of hazardous substances. Refer to Section 3.8 for detail on the establishment of these environmental controls.

3.7.5 Relocation of services and utilities

Separate to the Seawall Project, a common utilities trench is proposed along Quay Street to allow for the relocation of some major and minor services in this area. This includes services such as Chorus, Vector and Vodafone infrastructure in this area. This work will be covered under a separate resource consent application proposed by AT which is expected to be lodged in October 2018. In the event that services are not re-located to a common utilities trench at the time of construction, the jet grout column design can be adapted to be located around the majority of the existing services, and / or services can be relocated in general accordance with the detail proposed in this AEE Addendum.

During services relocation or identification, working areas up to 100 m in length will need to be established, requiring temporary diversion of both traffic and pedestrians. Plant such as 10-12 tonne excavators would be required as well as hydro excavation where working around live services. This proposed services relocation work is currently being developed with the relevant service providers.

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Where the jet grout columns are proposed to interface with the common utilities trench (if it is in place at the time of construction), similar measures and construction methodologies will need to be developed to ensure all relocated services are protected.

All utility providers will be consulted to agree the design and construction of any utility diversions and/or protection measures. Refer to Appendix N for the consultation log for discussions with service providers regarding the jet grout column option.

A number of other utilities may also require temporary relocation. This includes lighting columns, way-finding signs, seating, rubbish bins, up lights and emergency telephones. These will be reinstated at the completion of works.

3.8 Environmental Management Controls

Environmental management controls are set out in detail in the Environmental Management Response Plan (EMRP) prepared by Downer and Soletanche Bachy, dated October 2018 (Appendix I). Below is an overview of the proposed controls for erosion and sediment controls, water management and hazardous substances. These control are also designed to avoid hazardous substances being discharged onto land or into water. The EMRP also includes a draft Spill Response Plan (SRP) and Environmental Management Plan (EMP) in accordance with requirements under Chapter E33 (Industrial and Trade Activities) of the AUP. An Erosion and Sediment Control Plan (ESCP) is included as Appendix A of the EMRP.

3.8.1 Erosion and sediment control

Erosion and sediment (including spoil) controls are to be put in place around the jet grout construction works. These are outlined below:

An asphalt bund is to be installed around the perimeter of the site to prevent clean stormwater entering the site;

Impervious asphalt is to be maintained at all entrances and exits and vehicles will use an identified vehicle route. This will include regular monitoring;

A spoil collection box will be installed to capture the spoil from the head of the drill string. Spoil will then be pumped from this collection box to the spoil pit for drying prior to discharge. It is proposed to use retrofitted shipping containers in series to store and treat the spoil prior to off-site disposal. The containers will have tarpaulin covers as required to prevent rainfall entering the containers. The spoil (once settled) will be loaded into sealed trucks or vacuum trucks for appropriate disposal off site;

Any material that needs to be stockpiled will be stored in a bunded area; and

Dust will be managed through visual inspection and surface dampening with water when required.

3.8.2 Water management

Water management of both stormwater around the site and dewatering during works is required. These practices are outlined below:

Stormwater catch pits will have Enviropods (or similar) installed to capture sediment prior to discharge; and

Water arising on site as part of the jet grouting process needs to be collected for treatment and settling prior to discharge to sewer as trade waste (subject to permitting). In the event that a trade waste consent is not issued, all dewatered material will be captured on site and removed via tanker for appropriate disposal.

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3.8.3 Management of hazardous substances

The jet grout method will include the use of hazardous substances (as discussed in Section 3.4). Management of hazardous substances is outlined below:

Cement will be stored on site in silos, measures to minimise cement dust include attendance during cement delivery, maximum flow rates identified, venting of the silo, regular cleaning and maintenance of the silos, sensors installed to prevent overfilling and inspection of area by site supervisor;

Jet grout spillage will be avoided where practicable through minimisation of hose length. Where spillage does occur this will be contained using silt socks and other physical barriers, daily maintenance checks will be undertaken;

Oils and lubricants will be held in small quantities and stored in a bunded area on site; and

Diesel will be required for fuelling the equipment, refuelling will take place as far from stormwater catch pits as practicable and all fuelling will be attended. In addition a SRP has been prepared and included in the EMRP.

3.8.4 Other controls

In addition to the management controls outlined above, other aspects of the project require management controls. This includes the management of construction noise and vibration, which will be managed in accordance with the CNVMP.

3.9 Reinstatement

Upon completion of the construction works, previous ground levels will be restored and paving taken away during the enabling works will be reinstated. Where possible, the bedding sand and pavers that were removed during enabling works will be reused, in response to a request from mana whenua. Street furniture will be reinstated, as well as any other utilities which are required to be reinstated (e.g. rubbish bins and light poles etc.).

3.9.1 Trees

As described in Section 3.7.1, it is likely that Trees 19 -22 will be directly affected by the line of works and will need to be temporarily uplifted, stored outside the work areas and reinstated in their existing locations once the jet grout columns have been installed.

The final height of the jet grout columns will be at least 1200 mm below ground level to allow for the installation of tree pits. As discussed in Section 3.8.1 of the AEE, consultation with Auckland Council’s Community Facilities in the design of the tree pits is proposed. The tree pits will allow for drainage, automated irrigation, appropriate soil volume to allow for a large mature tree and a load bearing pavement, which may require structural soil cells or similar. In most cases, the tree pit will be designed with a soil volume that reflects the potential size of the tree at maturity, though this measure should be negotiable dependant on site requirements. At any stage through the transplant process, if the tree declines and replanting will not be successful or the tree dies, an equivalent transplantable specimen tree will be supplied and planted.

3.9.2 Built heritage features

The following heritage remediation works are proposed following the construction of the jet grout columns. This relates to the heritage features in close proximity to constructions works:

Remove temporary structures protecting built heritage places, in accordance with the BHCMP;

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Carry out post-works visual condition survey of built heritage places close to the construction works; and

• Make good any damage to built heritage places or carry out routine cleaning/ maintenance to built heritage places close to the construction works (if required).

A BHCMP is recommended as a condition of consent, as well as other conditions relating to the protection of historic heritage features. Refer to Appendix H for further detail.

3.10 Consideration of alternative options

3.10.1 RMA context

Under the RMA an assessment of alternative methods and locations is required for activities likely to have any significant adverse effects (Clause 6(1)(a) of Schedule 4). Section 5 of this document concludes that the actual and potential effects associated with the Princes Wharf section are more than minor but they are not significant. Section 3.9 of the AEE outlines alternative options that have been considered based on the Project Context and Options Assessment (Options Report). As part of the jet grout column proposal, an addendum to the Project Context and Options Assessment Report (Options Addendum) has been prepared (Appendix M) and is summarised in this section.

Section 105 of the RMA also requires an assessment of possible alternative methods for discharges and this is provided in Section 6 of this AEE Addendum.

3.10.2 Jet grout column option

The 2014 and 2017 Multi-Criteria Assessment considered jet grout columns as a potential solution. An area where jet grout columns did not score well was ‘construction plant type and availability’ as there is limited equipment available in the New Zealand market to perform the works. It was also considered in the Options Report that the jet grout option could result in potential greater adverse effects in relation to water quality. The Options Report states that jet grouting was excluded as an option for the Ferry Basin section due to constructability issues below sea level and potential contamination of the harbour.

In June 2018 AT engaged Downer and Soletanche Bachy to provide Early Contractor Involvement (ECI) services, with a view to them completing the physical works. Soletanche Bachy have specialist expertise and equipment in relation to jet grout columns.

Downer and Soletanche Bachy have prepared an Alternative Construction Methodology Report and an EMRP, which addresses concerns raised in the Options Report, to minimise adverse effects on the environment, including effects on water quality. Given the availability of specialist equipment, and knowledge now available to the team, the option of jet grout columns was assessed and compared directly to the originally preferred options.

The evaluation considered the 2017 Multi-Criteria attributes in the revised context of the project as of July 2018. The assessment concluded that for the Princes Wharf and Ferry Basin sections of the wall, jet grout columns was a solution with considerable merit, to the extent that AT wanted to seek resource consent for it as an option for implementation.

3.10.3 Refinement of preferred options

Following the decision to proceed with seeking resource consent for the alternative solution as an option, AT progressed with concept design, construction planning and assessment of effects for the jet grout column alternative. These activities were undertaken in parallel, with iterative adjustments made to determine the design for which resource consent is being sought.

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Particular refinements and considerations included in the current design include:

Jet grout columns have been located to avoid one of the trees (labelled Tree 18 on the resource consent drawings);

Lowering of the finished height below ground of the jet grout columns to accommodate tree roots when trees are reinstated; and

Accommodation of temporary traffic requirements (as advised by the project transportation specialist) in determining the alignment of the wall.

3.10.4 Conclusion

With new specialist equipment and expertise available to AT, a jet grout column design solution has been assessed and compared to the previously preferred solution considering multi-criteria attributes. It is considered to be a solution for the Princes Wharf and Ferry Basin sections of seawall with sufficient merit that AT has decided to seek resource consent for jet grout columns as an option for these two sections.

The design of the jet grout columns has been refined in consultation with technical specialists and the ECI contractors to determine the design for which resource consent is sought.

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4 Resource consent requirements

4.1 Introduction

The requirements for resource consent are determined by the rules in both the AUP and the regulations in the NES Soil.

Section 4.1 of the AEE is applicable to this AEE Addendum, including zoning and planning limitations provided in Table 4.1. It is noted however that since the lodgement of the AEE, the Regional Coastal Plan component of the AUP is now operative (as of 31 May 2018). Accordingly, we have not assessed the proposed jet grout column option against the Auckland Regional Plan: Coastal (Coastal Plan) as the provisions are no longer operative and have no weighting.

Resource consent is being sought to enable the proposal (as described in this AEE Addendum) and the application intends to include all necessary consents for those activities to occur. The following may not be an exhaustive list and if further consent matters are identified post lodgement of the application, these should also be considered as forming part of the application.

4.2 Auckland Unitary Plan – Operative in part

Resource consent requirements for the jet grout column option under the AUP are provided in Table 4.1 below. An assessment against the relevant standards is provided in Appendix O. Overall, the activity status under the AUP is a discretionary activity.

Table 4.1: Resource consents required under the AUP

Rule reference/description Proposed activity/assessment Activity status

D17 Historic Heritage Overlay

D17.4.1 Activity Table (A9)

“Modifications to, or restoration of, buildings, structures, fabric or features of a scheduled historic heritage place, except where provided for as a permitted, controlled or restricted discretionary activity in another rule in this overlay”, is a restricted discretionary activity.

Modifications within the HH-EOP

Minor works may extend slightly into the HH-EOP for the AHB Fence during construction. This may include removal of the existing pavement within this area. There are no applicable standards.

Restricted discretionary activity

D17.4.1 Activity Table (A11) and C1.9(2)

“Temporary buildings and structures, including structures accessory to temporary activities”, within the HH – EOP for Category A and B places, are permitted, subject to compliance with the standards in D17.6.

Temporary construction-related buildings within the HH Overlay

Temporary buildings and structures may include construction fences, acoustic walls, traffic management barriers, erosion and sediment control devices, porta cabins, and other construction-related structures.

As the buildings and structures will be in place longer than 21 consecutive days in any 60 day period (standard D17.6.6(c)), resource consent is required as a restricted discretionary activity in accordance with C1.9(2).


D17.4.1 Activity Table (A15) “Signs not otherwise provided for

Signs in Category A or B HH-EOP Restricted discretionary activity

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as a permitted activity” is a restricted dictionary activity.

It is likely there will be temporary signage to direct traffic within HH-EOP. There may also be other signage (i.e. noticeboards) to inform the public of the project. Identification and safety signs are permitted under A13, however it is possible that not all permitted activity standards under D17.6.7 will be met. This relates to signs exceeding 0.5 m2 and signs being attached to heritage features. Accordingly, a conservative approach is being taken and resource consent is sought as a restricted discretionary activity.

E4 Other discharge of contaminants

E4.4.1 Activity Table (A11)

“Discharge of water and/or contaminants (including washwater) onto or into land and/or into water from any of the following:

(b) construction, repair, maintenance, upgrade or removal of network utility infrastructure;” is a controlled activity.

Discharge of grout into land and water

Grout is considered a contaminant under the definition provided in the RMA.

Standards under E4.6.1 will be complied with.

Controlled activity

E14 Air Quality


“Cement storage, handling, redistribution or packaging” is a discretionary activity in the “High air quality – dust and odour control area” is a discretionary activity.

Cement storage

The works proposed will be within a high air quality – dust and odour control area.

The activity falls under Rule A77 as cement will be stored on site.


E26 Infrastructure

E26.3.3.1 Activity Table (77)

“Vegetation alteration or removal that does not comply with Standards E26.3.5.1 to E26.3.5.4” is a restricted discretionary activity.

Relocation of trees

There are trees within the road within the ‘coastal area’ that will likely need to be altered and/or temporarily relocated for the duration of the works. Standard E26.3.5.2 will not be complied with due to some trees exceeding 6m in height and/or 600 mm in girth.

This rule was identified as relevant to street

trees in Quay Street by Adrian Lamont

(consultant arborist advising Council) during

processing of resource consent application

BUN60323965 to excavate 45 trenches along

Quay Street. We understand that Council's

internal interpretation team is reviewing

applicability of the rule as there is uncertainty

about whether it applies to street trees. We


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acknowledge the uncertainty but have taken

a conservative approach and included this

rule as a reason for consent.

E26.4.3.1 Activity Table (A84)

“Tree trimming or alteration that does not comply with Standards E26.4.5.1” is a restricted discretionary activity

Trimming of tree branches

Through the relocation process trees may require pruning to be undertaken. There is a possibility that pruning may not meet the permitted activity standard at all times (E26.4.5.1). Accordingly, consent is applied for as a restricted discretionary activity.



“Works within the protected root zone not otherwise provided for” is a restricted discretionary activity.

Works within the protected root zone

If any of the trees can be retained during construction, it is likely works will be within the dripline of the tree, in particular Tree 18. It is likely that Standard E26.4.5.2 will not be met and therefore does not meet permitted activity standard E26.4.3.1 (A87). Accordingly, consent is conservatively applied for as a restricted discretionary activity.



“Alteration or removal of trees 4 m or more in height and/or 400 mm or more than girth”* is a restricted discretionary activity.

*(PC4 – see modifications)

Relocation of trees

There are three trees within the road (at least 4 m in height) that will likely need to be altered and/or temporarily relocated for the duration of the works. It is proposed to reinstate any trees that have been relocated once works are completed. Consent is sought to relocate Trees 19-21.

(Tree 22 is less than 4 m and can be removed as a permitted activity).


E30 Contaminated land


“Discharges of contaminants into air, or into water, or onto or into land not meeting permitted activity Standard E30.6.1.1; E30.6.1.2; E30.6.1.3; E30.6.1.4; or E30.6.1.5” is a controlled activity.

Discharge of contaminants due to disturbance of potentially contaminated soils

The proposed work involves the disturbance of potentially contaminated soils. The discharge of contaminants from land not used for rural production activities is permitted under Rule A4 provided the standards in E30.6.1 are met. The Ground Contamination Report (submitted with the AEE)indicated that all soil acceptance criteria is met under Table E30.6.1.4.1, however previous testing in the area has indicated that there are localised hotspots of contamination. Therefore, as a precaution this activity is assessed as a controlled activity standards. All of the controlled activity standards under E30.6.2 will be met.

Controlled activity

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E31 Hazardous substances


“Hazardous facilities that store or use hazardous substances above the specified thresholds for controlled activity and restricted discretionary activity status in the activity tables or are not otherwise provided for” is a discretionary activity.

The storage and use of hazardous substances

The storage and use of hazardous substance during construction will be within the road reserve which is not listed in Table E31.4.3. Therefore, the storage and use of cement is a discretionary activity under Rule E31.4.1 (A7) as it is not otherwise provided for.


E33 Industrial trade activities


“Use of land for a new industrial or trade activity listed as high risk in Table E33.4.3” is a controlled activity.

Use of land for a new industrial or trade activity

The activity of preparing and using the grout for column formation has been considered as “Cement, lime, plaster and concrete products” in Table E33.4.3, which would categorise an activity area of less than 1,000 m2 as moderate risk, and an activity area of greater than 1,000 m2 as high risk. The total activity area is calculated as greater than 1000 m2 and therefore is a high risk activity. Permitted and controlled activity standards under E33 are met.

Controlled activity

E36 Natural hazards and flooding


“Operation, maintenance, renewal, repair and minor infrastructure upgrading, of infrastructure in the coastal erosion hazard area, coastal storm inundation area, and overland flow paths that does not comply with Standard E36.6.1.13” is a restricted discretionary activity.

Relocation of existing services

It is expected that the relocation of services necessary to allow for the construction of the seawall will comply with the majority of standards. However it is possible that re-alignment of services may be greater than 2 m from the existing location and therefore will not comply with Standard E36.6.1.13 (1)(a)(i).


H8 Business – City Centre Zone

Standard H8.6.31(2) – Street sightlines and C1.9

“(2) Buildings or structures must not locate within the sightlines identified in Appendix 9 Business – City Centre Zone sightlines, except as otherwise provided in Table E26.2.3.1 Activity table in E26 Infrastructure”.

Structures within sightlines

Structures associated with the construction phase of works will be located within

Sightline 3 as identified in Appendix 9. Standard H8.6.31(2) is therefore not complied with, with resource consent required as a restricted discretionary activity pursuant to Rule C1.9.

Standard H8.6.31 is located with H8 Business

– City Centre Zone section of the AUP. While

Quay Street is not zoned, and there is nothing

in the rule itself that suggests it is intended to


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control temporary construction structures

within the road, the definition of structure in

the AUP includes temporary and permanent

structures. On this basis, a conservative

approach has been adopted and resource

consent is sought pursuant to this rule for

temporary construction structures located

within the road reserve which may be located

within the sightlines.

4.3 NES for assessing and managing contaminants in soil

As discussed in Section 4.3 of the AEE, the Ground Contamination Report (Appendix P of the AEE) identifies that past land uses/activities are included on the Ministry for the Environment’s (MfE’s) Hazardous Activities and Industries List (HAIL). These activities potentially pose a risk to human health and the environment (refer Section 2.10 of the AEE). NES Soil regulations apply to proposals to change the use or disturb soils at the site. Table 4.2 below outlines the resource consent requirements for the proposed works under the NES Soil.

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Table 4.2: Resource consents required under the NES Soil

Regulation Proposed activity/ assessment Activity status

10 Restricted discretionary activities

(1) This regulation applied to an

activity in any of regulation

5(2) to (6) on a piece of land

described in regulation 5(7)

or (8) that is not a permitted

or a controlled activity.

(2) The activity is a restricted

discretionary activity while

the following requirements

are met:

(a) a detailed site

investigation of the piece

of land must exist;

(b) the report on the detailed

site investigation must

state that the soil

contamination exceeds

the applicable standard in

regulation 7;

(c) the consent authority

must have this report;

(d) conditions arising from

the application of

subclause (3) if there are

any, must be complied

with.

A Ground Contamination Assessment containing a Detailed Site Investigation (DSI) has been completed and was submitted with the AEE (which also applies to this AEE Addendum). While previous studies have suggested the area is not contaminated there is data to suggest that there are hotspots of contamination. Soil disturbance will exceed permitted volume and duration.

Conditions in subclause (3) will be able to be met through implementation of the Site Management Plan (SMP) prepared by T+T, dated June 2018submitted with the section 92 response, dated 11 July 2018.


4.4 Permitted activities

The activities in Table 4.3 have been identified as permitted activities under the AUP. An assessment against the relevant standards is provided in Appendix O.

Table 4.3: Permitted activities relevant to the proposed activity under the AUP and Coastal Plan

Rule Proposed activity Comment on compliance

AUP Rules

E4 Other discharge of contaminants

E4.4.1 Activity Table (A1(b))

“Discharge of water and/or contaminants (including washwater) onto or into land and/or into water from any of the following activities: drilling (excluding bore development and testing)” is

Pre-drilling through basalt boulders as described in Section 3.3.1.

The standards under E4.6.1 will be complied with.

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a permitted activity, subject to compliance with E4.6.1.

E7 Taking, using, damming and diversion of water and drilling


Dewatering or groundwater level control associated with a groundwater diversion permitted under the AUP is permitted, subject to compliance with standards E7.6.1.6.


Diversion of groundwater caused by any excavation is permitted, subject to compliance with standards E7.6.1.10.

Dewatering of excavation trenches (for service relocation if required)

The groundwater diversion is permitted under A27 and the water take meets the standards to be permitted. Of particular note, the diversion is exempt from standards E7.6.1.10(2)-(6): piles up to 1.5 m in external diameter, and diversions for network utilities and road network linear trenching activities where any part of the trench is open for no longer than 10 days.

E11 Land disturbance – Regional


“The temporary diversion and damming of surface water and the discharge of treated sediment laden water from any land disturbance that complies with all relevant permitted activity standards” (E11.4.2).

The temporary discharge of treated sediment laden water

The rules in Activity Table E11.4.2 specifies the activity status for damming, diversion and the discharge of treated sediment laden water from any land use pursuant to section 14 and 15 of the RMA.

The general standards under E11.4.2 will be complied with.

E24 Lighting


Activities that comply with all the relevant permitted activity standards is a permitted activity.

Lighting during construction Construction lighting will comply with permitted activity standard E24.6.1.

E25 Noise and vibration

E25.4.1 (A1)

Activities that comply with all the relevant permitted activity standards are a permitted activity.

Construction noise and vibration Construction noise and vibration from work within the road will comply with permitted activity standards E25.6.

E26 Infrastructure


Earthworks up to 2,500 m2 within the Sediment Control Protection Area other than for maintenance, repair, renewal, minor infrastructure upgrading is a permitted activity (subject to

Earthworks (rp)

Earthworks will be less than 2,500 m2 (estimated at 300 m2)

General standards under E26.5.5.2 are met.

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compliance with E26.5.5.2 General Standards).

E26.5.3.1 Activity Table (A95 and A96)

Earthworks up to 2,500 m2 and 2,500 m3, other than for maintenance, repair, renewal, minor infrastructure upgrading is permitted (subject to compliance with E26.5.5.2 General Standards).

Earthworks (dp) Earthworks will be less than 2,500 m2 and 2,500 m3 (estimated at 2,400 m3)

General standards under E26.5.5.2 are met.

E36 Natural hazards and flooding


Construction, operation, maintenance, renewal and repair of road network activities within the legal road or road formation width in the coastal erosion hazard area, coastal storm inundation area, and overland flow paths is permitted. There are no applicable standards.

Reinstatement of pedestrian and road surfaces within the legal road, in the:

coastal erosion hazard area;

coastal storm inundation 1 per cent annual exceedance probability (AEP) plus 1 m sea level rise area; and overland flow paths

This activity is permitted.


Infrastructure within roads is a permitted activity, subject to compliance with permitted activity standards E36.6.1.13.

Infrastructure within the road The seawall in the legal road is permitted and meets relevant permitted activity standards.

E40 Temporary activities


Temporary activities associated with building or construction, (including structures and buildings that are accessory activities), for the duration of the project, or up to 24 months, whichever is the lesser are permitted, subject to compliance with E40.6 standards

Construction activity The standards will be met.

F2 Coastal – General Coastal Marine Zone

Rule F2.19.7 Activity Table (62)

Discharges into the coastal marine area, which are not covered by another rule in the Unitary Plan and not covered by the Resource Management (Marine Pollution) Regulations is a permitted activity, subject to compliance

Discharges into the coastal marine area during construction

Standards will be complied with, through mitigation measures as discussed in Section 5.13.

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with standard F2.21.1 and F2.21.8.6.

4.5 Other requirements

4.5.1 General archaeological authority

As described in Section 4.5.1 of the AEE, an archaeological authority is required to cover all proposed earthworks associated with the Seawall Project. Since the date of lodgement a decision has been made to apply for a blanket archaeological authority for all proposed works associated with the Downtown Programme.

This covers all recorded archaeological sites, as well as allows for any unrecorded sites during construction.

An application for this blanket archaeological authority (HNZ ref: 2019/260) was lodged with HNZ on 9 October 2018.

4.5.2 Signage Bylaw 2015

Signs that will be required during construction will comply with the Signage Bylaw 2015. No dispensation is required.

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5 Assessment of effects on the environment

5.1 Introduction

The following assessment identifies and assesses the types of effects that may arise from the proposed works. This assessment also outlines the measures that the applicant proposes to avoid, remedy or mitigate any potential adverse effects on the environment. The assessment takes into account the relevant standards, matters of discretion and assessment criteria associated with the rules described in Section 4 above; refer also to Appendix O (assessment of planning standards) and Appendix P (matters of discretion and assessment criteria) that have been used as a guide in the following assessment.

Actual and potential effects on the environment have been identified as including:

Positive effects;

Transportation effects;

Construction noise and vibration effects;

Historic heritage effects;

Archaeological effects;

Cultural effects;

Effects on trees;

Landscape and visual amenity effects;

Geotechnical and groundwater diversion effects;

Contaminated land effects;

Marine and groundwater quality effects;

Land disturbance and water quality effects;

Hazardous substances, industrial and trade activities and air discharge effects; and

Scale of effects.

This chapter draws on information provided in the technical reports contained within Appendices C to L.

5.2 Positive effects

The positive effects of the proposed seawall upgrade are outlined in Section 5.2 of the AEE and are applicable to this AEE Addendum. In summary, the proposal to upgrade the seawall to Importance Level 4 (IL4) with a robust design life of 100 years will provide significant resilience for the city’s transport and utility infrastructure. This resilience is in terms of seismic events. This will mitigate potential risks of ground surface subsidence and instability in a seismic event, limiting lateral deformations.

Other potential positive effects resulting from the project include:

For any tree temporarily relocated, new tree pits will be created that will allow for drainage, automated irrigation, appropriate soil volume to allow for a large mature tree and a load bearing pavement, which may require structural soil cells or similar. In most cases the tree pit will be designed with a soil volume that reflects the potential size of the tree at maturity. This will enhance the potential for trees to grow to a greater maturity;

Removal of some contaminated soil from the city and further information about the material in the reclamation area, which may potentially assist future projects in the area; and

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There also may be an improved opportunity to access and inspect heritage buildings and other structures in the vicinity, to undertake emergency stabilisation, and repair of damage prior to any subsequent event, by limiting displacement. The importance of rapid accessibility for such assessment and stabilisation to prevent further damage was keenly demonstrated during the 2011 Christchurch earthquake (and subsequent seismic events).

5.3 Transportation effects

5.3.1 Approach to transportation effects assessment and mitigation

An addendum to the Integrated Traffic Assessment has been undertaken by Flow Transportation Specialists, this ITA Addendum is contained in Appendix F. Details related to the existing traffic environment (including current construction projects) as outlined in the ITA are applicable to this assessment of effects. It is noted that the construction zone remains the same for the palisade wall option and jet grout column option.

5.3.2 Effects on pedestrians

Pedestrian facilities on both the northern and southern sides of Quay Street will be provided, with the pedestrian footpath in front of properties 131-139 Quay Street being maintained and reduced from 11 m to 6 m. This will be reduced further in some isolated locations (down to 3.1 m at its narrowest due to existing street furniture). Pedestrian access is maintained on the southern side of Quay Street, and remains unchanged.

Access to Princes Wharf will be maintained during the construction stages, with pedestrian access also being maintained, vehicle access being provided via Lower Hobson Street from the south approach and retained for all facilities and restaurants on the northern side of Quay Street.

An adequate level of crossing will be provided at Lower Hobson Street/ Quay Street intersection, with a pedestrian crossing across Princes Wharf access, pedestrian and cycle shared crossing to centre median at the intersection, and another shared crossing across Lower Hobson Street. Overall, the pedestrian accessibility and safety should not be compromised with the works.

The adverse effects of the proposal on pedestrians are assessed as minor.

5.3.3 Effects on cyclists

The existing bi-directional cycleway will be maintained throughout the temporary works, and shifted further south of its current location. A 2.8 m width cycleway with 0.3 m setbacks on either side will be provided. Maintaining the cycleway, with its current widths and separation from traffic, ensures the safety, ease of access and cycle patronage of this well used facility.

A pedestrian footpath will be provided on the northern side of the construction zone, which removes the conflicts with cyclists traveling along Quay Street. The separation of facilities is considered adequate and will potentially attain an increased Level of Service (LOS) for cyclists.

The adverse effects of the proposal on cyclists are assessed as less than minor.

5.3.4 Effects on public transport

The connection to public transport services will not be affected during construction, with accesses to both bus, train and ferry services maintained.

A 3.2 m westbound bus lane is provided to safeguard bus travel times and reliability. The provision of the bus lane will separate buses from general traffic, reducing the influence of any delays that maybe incurred.

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Bus stops associated with each of the bus routes are unchanged and remain in their current location, the bus stop at the PWC office (stop number 1346) will remain however indented into the existing kerb. Pedestrian access to the bus stops will enable similar levels of accessibility thus ensuring bus patronage is maintained.

The adverse effects of the proposal on public transport are assessed as less than minor.

5.3.5 Effects on property access

For the properties located on the northern side of Quay Street through the Princes Wharf section, no changes to property access will result as a consequence of the temporary works.

Access to Princes Wharf will be maintained for general vehicles with one lane in one lane out maintained during the temporary works. Pedestrian access will remain as currently provided for.

Property access to the southern side of Quay Street will remain as currently provided for pedestrians. Vehicle access to properties will be maintained however vehicle access points associated with properties 196-200, and 188 Quay Street along with the PWC laneway will be restricted to left in left out during the temporary works. This is put forward to ensure delays are minimised for buses and general traffic, in addition reducing pedestrian conflicts.

The adverse effects of the proposal on property access are assessed as minor.

5.3.6 Vehicle traffic effects

Travel times are predicted to increase by approximately two minutes or less over the length of the Customs and Quay Street corridors as well as the other key corridors in the city centre.

In the evening peak hour, Quay Street travel times are predicted to increase by some two minutes in the eastbound direction largely as a result of the single lane from Lower Hobson Street into Quay Street.

The predicted changes in travel time along the remaining corridors through the network are also considered minor increases, with less than half a minute changes noted.

With regard to changes to traffic flow, modelling indicates that relatively modest changes in traffic patterns are predicted in both directions on Quay Street and Custom Street. The traffic capacity of Quay Street is shown to remain comparable to the base situation, and minimal traffic flow changes are predicted elsewhere on the network within the CBD.

The effects of additional truck movements along Quay Street are considered minor and manageable, as only approximately three construction truck movements per peak hour are estimated.

Overall, it is considered that the effects related to vehicle traffic times and queuing is a minor adverse effect.

5.3.7 Cumulative traffic effects

Cumulative traffic effects have been assessed, assuming that the Princes Wharf, Ferry Basin and Queens Wharf to Marsden Wharf sections are constructed concurrently. It further assumes the section of Quay Street in front of the Ferry Building is also restricted by the works. This is considered a worst-case scenario. The traffic modelling to assess cumulative effects also takes into consideration known construction activities within the broader city centre area (i.e. City Rail Link (CRL), 36th America’s Cup (AC36), and Commercial Bay.)

In regard to network operation, if all seawall sections are constructed concurrently the predicted travel times along Quay Street and Customs Street are as follows:

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In the morning peak hour:

Eastbound: general vehicle travel times are predicted to be reasonably unaffected; and

Westbound: general vehicle travel times are predicted to increase by about one minute 50 seconds on Quay Street and increase by about one minute on Customs Street.

In the evening peak hour:

Similar to the existing situation, congestion at the intersection of Fanshawe and Nelson Streets is predicted to spill back onto both Lower Hobson and Fanshawe Streets, with large traffic flows travelling towards the SH1 Fanshawe Street on-ramp;

In the westbound direction, travel times are predicted to increase by one to one minute 20 seconds on Quay Street and Customs Street respectively. The westbound constraint on Quay Street is the merge from two general traffic lanes to one traffic lane to the east of Britomart Place;

Bus travel times are predicted to be relatively unaffected as a result of the dedicated westbound bus lane between Tangihua Street and Commerce Street; and

Quay Street travel times are predicted to increase by about three minutes in the eastbound direction, with the constraint being only a single lane from Lower Hobson Street to Quay Street.

In both peak periods, other key corridors in the city centre are likely to be relatively unaffected as the extent of delays along Quay Street is relatively minor.

In regard to traffic flow patterns, if all seawall sections are constructed concurrently the predicted traffic flow changes are as follows:

Relatively modest changes are predicted in both directions on Quay Street due to the capacity of the corridor remaining relatively similar to the existing corridor. Traffic flow changes are in the order of 100 to 250 vehicles per hour per direction, which equates to between 10 % and 25 % reduction per hour;

Minimal changes to traffic flow on Customs Street are predicted. Rather, modest traffic flow rerouting is likely throughout the city centre and state highway system; and

Minimal traffic flow changes are predicted on Customs Street, with the modest traffic flow rerouting likely through the city centre and state highway system.

The cumulative adverse effects of the proposal on general vehicle travel times and queuing are assessed as minor.

5.3.8 Summary of transport effects

The proposed transport management measures will maintain bus reliability, pedestrian connectivity, and property access, and will maintain the well-used cycleway facility.

The main transportation effects and proposed management/mitigation are summarised as follows:

The pedestrian facilities on both northern and southern sides of Quay St will be provided. Pedestrian accessibility is maintained with appropriate levels of service provided ensuring safety and access to public transport and properties are maintained through the works;

Maintaining the cycleway ensures the cycleway patronage is maintained, ensuring a separate cycleway is provided maintain cyclists safety, while providing a viable alternative to the car with the extension of the Quay Street east and Nelson Street cycleway;

Provision of a westbound dedicated bus lane maintains bus travel times, and bus reliability. Bus stop locations are maintained in their existing positions to reduce confusion and to

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maintain patronage throughout the works period. No reductions in bus layover facilities are envisaged with the works;

Access to properties in close proximity to the works will be maintained throughout the works for both pedestrians and vehicles;

Vehicle capacity through the works site is maintained close to existing capacities, this reduces the probability of traffic transferring to alternative routes which are already experiencing delays. It is predicted some vehicle queueing will occur in specific areas, however, in general, the vehicle delays predicted and predicted journey times along the Quay Street, and wider CBD cross routes, will be maintained to an acceptable level;

The proposed temporary works will not shift during the period in place, thus consistency in the layout will result in efficiency gains, and minimise confusion to users of Quay Street. Construction traffic associated with the works is considered minimal with a maximum of two trucks predicted to be generated in the peak hours and these are to utilise main routes to access Quay Street;

If the Princes Wharf, Ferry Basin and Queens Wharf to Marsden Wharf sections, in addition to the known consented construction activities within the vicinity of the Seawall Project area are constructed concurrently, the increased congestion and travel times on Quay and Customs Streets is considered to be minor, with the greatest predicted delay being about three minutes on Quay Street in the eastbound direction. As traffic delays will be within the ten-minute threshold described in Section 5.3.1, the effects on general traffic will be no more than currently authorised in the Quay Street environment over the prescribed routes. Bus travel times on Quay Street and congestion on other key corridors in the city centre are likely to be relatively unaffected; and

As traffic delays will be within the ten-minute threshold described in Section 5.3.1, the effects on general traffic will be no more than currently authorised in the Quay Street environment over the prescribed routes.

5.4 Construction noise and vibration effects

An addendum to the Construction Noise and Vibration Assessment Report has been prepared by Marshall Day Acoustics and is included in Appendix E. The Noise and Vibration Assessment Addendum assesses the potential construction noise effects from the proposed jet grout column work only. Other construction activities required for the alternative methodology, such as hydro vac, concrete cutting, excavation and rock breaking, are already addressed in the Construction Noise and Vibration Assessment and are therefore not duplicated in the addendum. The findings of the Noise and Vibration Assessment Addendum are summarised below.

5.4.1 Noise

5.4.1.1 Project Standards for construction noise

The project standards for construction noise set out in Section 5.4.1.1 of the AEE remains valid for this AEE Addendum.

5.4.1.2 Predicted noise levels

The Construction Noise and Vibration Assessment Addendum outlines the key construction activities and their predicted airborne noise levels.

The assessment indicates that there is likely to be intermittent exceedances of the recommended daytime Project Standards during pre-jet drilling, which is the highest noise activity. Other jet grouting activities are predicted to generally be below the daytime Project Standard of 75 dB LAeq,

33



although there is the potential for marginal exceedances. Such exceedances are common for inner city civil works projects due to the proximity and scale of buildings in the immediate environment.

The works are predicted to exceed the daytime Project Standard at the following receivers as they cannot be effectively screened by the barriers:

ANZ building upper floors (131-139 Quay Street): occupancies on the most exposed façade are primarily commercial offices on the upper floors. Based on the façade construction, it is predicted that internal noise levels from the jet grouting would be 45 – 55 dB LAeq during approximately 12 of the 20 weeks of works for the Princes Wharf section. Noise levels would reduce for subsequent works further away;

NZ Maritime Museum first floor (149 Quay Street): the first floor at the eastern end of the NZ Maritime Museum is occupied by the Spirit of Adventure Trust offices and the Maritime Room bar/restaurant. This façade is clad in corrugated metal with two small openable window sets. Assuming that the windows are closed during the jet grouting works, internal noise levels are predicted to be up to 50 – 60 dB LAeq during the closest jet grout columns in the Princes Wharf section, and dropping away as the jet grouting progresses east; and

PWC Building first floor café: noise levels at the façade of 75 – 80 dB LAeq are predicted. This may cause annoyance for occupants, but is unlikely to result in any long-term disturbance.

Prior consultation with representatives from the ANZ Building and NZ Maritime Museum building will enable an understanding of noise and vibration sensitive spaces and periods of use. Furthermore, regular communication during the works to inform occupants of scheduled works will be critical to manage the noise effects (e.g. advanced warning and timing of activities to enable alternative scheduling of meetings in offices overlooking the works).

Further afield, or for other quieter activities, noise levels of up to 75 – 80 dB LAeq at commercial sites such as the PWC and HSBC buildings would typically result in annoyance for building occupants during the day, but are unlikely to result in any long-term significant disturbance.

Noise levels are predicted to be 70 – 75 dB LAeq at the upper floors of the M Social building and PWC building during the loudest jet grouting works. At receivers further afield, such as the Ferry Building and HSBC building, levels are predicted to be below 70 dB LAeq, which is comparable to the existing noise from road traffic in the vicinity.

Incident noise levels of 70 – 75 dB LAeq may be audible for occupants but are unlikely to cause annoyance. Noise barriers are predicted to be effective in shielding ground floor occupancies such as the M Social restaurant, resulting in noise levels in the order of 60 – 65 dB LAeq.

Noise levels of 75 dB LAeq and below from jet grouting works would likely be noticeable, but generally similar in character and slightly louder than the existing road traffic in the vicinity.

5.4.1.3 Cumulative noise effects

It is anticipated that two jet grouting rigs could operate on each section of the Seawall Project simultaneously. Given the work site space constraints, close proximity of receivers and sequencing, any activities that exceed the noise limits would be dominated by the closest jet grouting rig. This would also be the case when considering concurrent downtown construction including construction of other sections of the Quay Street seawall, CRL and AC36. While the ambient noise level may increase due to concurrent construction projects, the cumulative noise level during any exceedance would generally increase by less than 1 – 2 decibels. This is an indiscernible change in level. What may be apparent is that high construction noise levels are more frequent or regular.

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5.4.1.4 Construction Noise and Vibration Management Plan

The draft CNVMP included within the application remains valid for this AEE Addendum, as does the discussion of the CNVMP in Section 5.4.1.4 of the AEE.

5.4.1.5 Summary of noise effects

Construction noise is predicted to generally comply with the relevant limits. Some activities are predicted to exceed these limits for brief periods at occupied buildings, primarily pre-jet drilling, rock breaking and concrete cutting activities. With the mitigation measures in the CNVMP, it is considered that the airborne noise associated with construction can be appropriately mitigated to ensure that any adverse effects on sensitive receivers are minor.

5.4.2 Vibration

Jet grouting produces very little vibration in comparison to other piling methods. This is due to use of an auger/drill instead of an impact or vibro hammer. Vibration from the jet grouting rig and associated equipment is negligible and is predicted to be imperceptible at nearby receivers, and therefore, has not been considered further.

5.5 Historic heritage effects

The proposed jet grout column works have the potential to affect several historic heritage places. These effects may be physical, setting-related, direct or indirect, and temporary or permanent in nature. There may also be cumulative effects arising where there are several concurrent or planned future projects to consider. An addendum to the Built Heritage Impact Assessment (the BHIA Addendum), prepared by Plan.Heritage is provided in Appendix H and is summarised below.

5.5.1 Physical effects on built heritage

During construction works there is a potential risk for accidental damage to occur to existing built fabric of heritage value. Scheduled or listed built heritage places which are in close proximity to the works and which may be affected are the existing Quay Street seawall; the AHB Fence pylons, the WWI Memorial Beacon and the Maritime Museum/Launchman’s office Building.

This risk can be avoided or mitigated through the adoption of a Built Heritage Construction Management Plan (BHCMP), a draft version prepared by Plan.Heritage (submitted with the AEE) which identifies and protects built heritage features through screening, hoarding, use of kickboards or scuff boards, etc. Larger structures can be screened with temporary Heras Fencing or similar where space permits.

The pre-drilling of jet grouting columns will physically affect the basalt rock foundations of the existing sea wall at the western section of the works, but not the wall itself. The Harbour Seawall is not scheduled, but forms a component of the historic harbour area (HNZ List ref 7158). No other physical effects to scheduled, listed or recorded built historic heritage places will occur as a result of the proposed works.

As noted in Section 5.4.2, vibration from the jet grouting rig and associated equipment is assessed as negligible. Nevertheless, vibration effects on heritage features will be monitored in accordance with the CNVMP.

5.5.2 Effects on the setting of built heritage

There will be a temporary change to the setting of the built heritage places within the Princes Wharf section as a result of the enabling and construction works, which will have no long-term adverse effects. Short term adverse effects will be managed through implementation of the BHCMP.

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5.5.3 Long-term effects of built heritage

Once works are completed, the Quay Street seawall will continue to serve the same function as it does now, although with improved resilience to a seismic event. The proposal will not result in any adverse long-term change of use, or generate long-term adverse effects, on the built heritage places within the vicinity.

5.5.4 Cumulative effects

Due to the staging of the works, there is potential for cumulative adverse effects to occur in regard to the temporary relocation of the AHB fence and Eastern and Western Ferry Shelters, which are proposed as part of the Queens Wharf to Marsden Wharf and Ferry Basin Section works. These can be effectively managed through the adoption of a BHCMP, recommended as a condition of consent.

However, the Princes Wharf proposal will not contribute to these cumulative effects, as all elements of the AHB Fence will remain in situ for the Princes Wharf Section. There may be cumulative effects to heritage features if cosmetic damage occurs as a result of construction vibration, or other form of accidental damage. Again, this can be appropriately managed through adoption of controlled working practices and remediation protocols.

The setting of built heritage will be adversely affected through the erection of site compounds. However, as they are temporary in nature the cumulative effects are assessed as acceptable.

5.6 Archaeological effects

An addendum to the Archaeological Assessment has been prepared by Clough and Associates, and is provided in Appendix C. A summary of the effects is included below.

The construction of the proposed jet grout columns on the landward side of the existing Quay Street seawall will not affect the existing 20th century seawall. It will have some adverse effects on an area of early 20th century reclamation, removing any intact reclamation deposits within the seawall footprint and possibly also removing features or items at the interface between the reclamation deposits and the original sea floor.

The proposed jet grout columns will also impact on remains of the old Hobson Street Wharf (R11/2901). The jet grout columns will affect a strip approximately 6.2 m wide in the north-south direction in part of the location of the former wharf, which would have extended a further c.120 m south to near the junction of Hobson Street and Customs Street. Other wharf remains are therefore likely to be present subsurface to the south of the proposed jet grout columns and would remain unaffected, but the wharf pile noted during investigation trenching and any other remains within the

footprint of the jet grout columns will be destroyed.

However, there would be no possibility of establishing whether additional wharf piles will be affected, or recovering any archaeological information relating to the early wharf, 20th century reclamation deposits or potential archaeological material on the seabed, as the construction methodology would not allow any observations to be made. The historic heritage significance of site R11/2091 is assessed as having limited knowledge potential but moderation historical and contextual value.

Early 20th century rail lines are known to be present in some parts of Quay Street just beneath the road surface. The rail lines were located more centrally within Quay Street in areas not affected by the proposed jet grout columns, but it is possible that rail lines turning into the wharf may be present and affected by the proposed jet grout columns. If so, this would represent only a small proportion of the original rail system.

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Overall, in view of the extent of previous modification for roading and service installation within Quay Street, and the limited footprint of the proposed works compared with the extent of the early 20th century reclamation areas, the adverse effects of the proposed jet grout columns in the Princes Wharf section on historic heritage values will be acceptable. Archaeological mitigation (monitoring and recording) will not be possible for the jet grout columns themselves, but can be undertaken for the associated works, comprising trenching for utilities relocation.

5.7 Cultural effects

The Waitematā Harbour and land surrounding the harbour area holds cultural significance to a number of local iwi. Engagement with Māori is an important principle of the Seawall Project, recognising that Tikanga Māori encompasses a complex system of customs and values to conserve, manage and protect natural and physical resources.

AT holds monthly hui with iwi through its Mana Whenua Engagement Framework to discuss a range of major projects. A hui was held on 15 August 2018 where the jet grout column option for the Seawall Project was discussed. A number of iwi indicated they have kaitiakitanga responsibilities within the Seawall Project area, and expressed an interest to be involved in the project. A summary of this consultation and matters discussed is contained in Section 8 of this report. The matters discussed were predominantly in relation to further clarification of the jet grout column methodology.

In Maori culture, the mauri (or life force) of water is sacred. The mauri of a waterbody can be adversely affected through the degradation of water quality. The effects on water quality are considered to be less than minor as the coastal water will be protected from sediment discharge, contamination and hazardous substances used during construction. (Refer to Sections 5.12 and 5.13).

Engagement with mana whenua will continue throughout the project lifecycle through the AT Mana Whenua Engagement Framework. Through this ongoing engagement, if any potential adverse cultural effects are identified from the proposal, these will be appropriately managed to ensure this level of effect is acceptable.

5.8 Effects on trees

AT has proposed a hierarchy of three management procedures to manage the trees associated with the construction of the seawall, in order of preference; retain and protect, temporarily relocate, or remove and replace. Due to the construction requirements, many of the trees will require temporary relocation. Tree 18 is proposed to be retained and protected for the duration of the works.

The management procedures proposed are the same as proposed for the palisade wall option. Accordingly Section 5.8 (Effects on Trees) of the AEE is applicable to this AEE Addendum. An addendum to the Arboricultural Assessment Report (Arboricultural Assessment Addendum) prepared by Arbolab is provided in Appendix G and is summarised below.

The proposed relocation of trees is a short-term loss that will be mitigated with the reinstatement of the trees in a similar position from where they were uplifted following the installation of the grout columns. As they are proposed to be uplifted, maintained for the duration of the works, planted back into new specifically designed planter pits and provided aftercare maintenance thereafter, it is expected that the vitality and vigour of the trees will not be adversely affected long-term. If for an unforeseen reason the trees decline or die during the translocation or storage they will be replaced with an equivalent sized transplantable tree. This may have a minor adverse loss through the benefits that mature trees provide, however, using the most equivalent sized replacement tree available, the long-term potential adverse effects are likely to be negligible.

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Trees being retained on site will be protected through a tree protection methodology and physical barriers such as a temporary fence / wooden structure around the tree. The works will be retained outside the sensitive rootzone and the tree maintained for the duration of the works. There are no foreseen, unmitigated actions that are likely to adversely affect the health and safety of the trees.

The proposed work is likely to affect five trees growing in the road reserve within the vicinity of the Princes Wharf jet grout columns. It is likely that Trees 19, 20 and 21 will need to be temporarily relocated due to the work requirements. Tree 22 is growing within an existing relocatable planter box and can be easily stored outside the works site until such time as it can to be brought back. Tree 18 is to be retained and protected for the duration of the works.

Overall, considering the management proposal, tree protection methodology and relocation methodology, the long-term overall effects are considered to be acceptable and appropriately managed.

5.9 Landscape and visual amenity effects

An assessment of the potential landscape and visual amenity effects anticipated from the proposed jet grout column option (LVA Assessment Addendum) has been undertaken by Boffa Miskell and is included in Appendix J. The assessment contained in the addendum to the Landscape and Visual Amenity Assessment relates to the visual effects of removing street trees and temporary construction works and considers both temporary, permanent and cumulative effects.

5.9.1 Temporary landscape effects

5.9.1.1 Construction effects

No physical effects are anticipated on the harbour or distant landforms, however during construction, the appreciation and views of these features will be affected, and in turn, the character of the street, and its relationship with these features.

It is important to note that this change in character would not be restricted to Quay Street and its immediate environments, but would also capture Lower Hobson Street, where views are attained through the viewshaft down the street particularly from the pedestrian overbridge and from the footpath on the eastern side of the street. It is however recognised that the works take place within a transport corridor, and it can be reasonably expected that construction activities may be present in such areas, and therefore such activities form part of the ever-changing character of these environments.

Hoarding is proposed to be erected during the construction phase of this section of works. Construction hoarding would be approximately 2.4 m in height and constructed out of timber. The presence of hoarding would result in adverse landscape and visual effects due to the reduction in sea views for viewing audiences at street level, presence of structures associated with construction located in the pedestrian environment, and the change in the landscape character of the street.

These temporary adverse effects could be minimised by treating the hoarding panels with artwork, interpretive media, viewing panels and/or visually permeable materials.

Overall, it is considered that the level of change able to occur within the wider landscape character is

limited. Effects at a localised level would however be greater, however, these temporary effects are

considered to be minor.

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5.9.1.2 Tree works

Temporary effects are those effects which are not only associated with the construction works of the project, but also those interim effects which are generated until all trees are reinstated. Four trees are proposed to be temporarily relocated and reinstated and therefore no trees would be permanently removed from the site.

With consideration to the effects on the character of the immediate vicinity, it is recognised that the trees, which are proposed to be temporarily relocated, are of a smaller size to Tree 18 (which will be retained). They do however contribute to the amenity and character of the road reserve and are a valuable landscape feature of the streetscape. Nevertheless, it is recognised that this is a period of construction during which people will not be able to view or access and enjoy this section of harbour edge streetscape in the way they do at present, which will mean for most people the absence of those trees to be temporarily relocated during this period will not be missed.

In terms of the wider character context, and as noted above, the site is largely contained visually from any distant public locations to the south, and with distant public locations to the north being restricted to Tree 18. Furthermore, any visibility from the east being typically confined to the adjoining section of Quay Street, or the vicinity of the Lower Hobson Street intersection. The level of change able to occur, within the immediate vicinity and wider landscape character is therefore very limited and is considered to result in very low adverse effects. After construction, if the trees have yet to have been reinstated, it is considered that the temporary landscape effects would be less than minor until such time as they are reinstated. Overall, the actual and potential effects are considered to be acceptable.

5.9.2 Temporary visual effects

During construction, it is considered that the works associated with the seawall upgrade would result in the greatest change in views, rather than the absence of trees. Views from buildings to the north of the site, such as 139 Quay Street, would have their views of the city centre interrupted, principally due to the presence of the rigs and plants in close proximity. It is also acknowledged that up to two jet grout rigs, one gravity grout rig, and two plants could be located within the site.

Overall it is considered that construction activities, and the appearance of large scale construction is a largely anticipated activity, and as such the sensitivity to these activities is lessened. It is therefore concluded that no more than minor visual effects would be brought upon viewing audiences in buildings to the north of site, during construction.

Views from locations to the south of the site, such as the M Social Building and PWC Tower, are generally focused towards the harbour waters. Construction operations and elements which are limited in height, are unlikely to substantially affect their existing outlook due to the elevation of many viewing audiences. However, for some of the lower floors (such as Beast and Butterflies in the M Social Building), views towards the harbour would be interrupted.

Notwithstanding this, throughout the duration of construction it is considered that there would be some degree of visual interest created by the presence of this uncommon construction equipment and activities. Furthermore, apart from construction hoarding standing 2.4 m in height, views of the harbour would remain attainable between the construction equipment towards the harbour. Overall it is considered that adverse effects that would be acceptable for these viewing audiences to the south of the site.

Views from some nearby ground floor restaurants (Burger Boy, Gourmet Burger and Brew Kitchen, Wildfire and Beasts and Butterflies) would experience works directly in front of their premises. Construction hoarding would help screen the construction work, however this would not mitigate the scale of the machinery required. It is however considered that construction activities, and the

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appearance of large scale construction can be expected from time to time within these city centre environments, and as such the sensitivity to these activities is lessened. In combination with the absence of the trees within these viewing audiences foreground (to be temporarily relocated during construction), it is considered that the adverse effects would be minor.

With regard to adverse effects on pedestrians, cyclists and road users that typically transit through the site, it is considered that the presence of construction activities, particularly when viewing the site from locations along the southern side of Quay Street and lower Hobson Street, would be minor. Overall, temporary visual effects are considered to be acceptable.

5.9.2.1 Street sightlines under the AUP

As discussed in the Landscape and Visual Amenity Assessment Addendum, the project site is located within Sightline 3 identified in Appendix 9 Business - City Centre Zone sightlines of the AUP. Accordingly, consent is required under Rule H8.6.31(2) and C1.9 of the AUP (refer Section 4.2).

While nothing in the rule itself suggests it is intended to control temporary construction structures within the road, the definition of structure in the AUP includes temporary and permanent structures and therefore consent is sought under this rule for the temporary construction structures.

Sightline 3 is located to the east of the site and focused along the axis of the street towards the Ferry Building. The AUP does not provide specific commentary around each of these sightlines, however it is noted that the former Auckland District Plan central area (‘DP’) identified ‘focal elements’ and ‘contextual elements’ for each sightline.

The DP indicates that the focal elements of the sightline are the Ferry Building, red port gates and the port. The context elements were listed as the America’s Cup boat mast (currently removed), and the viaduct harbour which now includes the developing backdrop of Wynyard Quarter buildings beyond.

The works would be taking place to the west of the listed focal elements of red port fence and Ferry Building at a distance of over 540 m from the eastern edge of the extent of works. This will preserve views of the focal points of the sightline. Given the works are focussed to the northern side of the road corridor, a visual connection to the distant viaduct elements would remain.

In summary, the affected street sightline is located some distance from the site and extent of works, such that visibility of the red port fence, ferry building and viaduct harbour are retained. Furthermore, the focal and context elements are observed within a heavily built environment along a road corridor which is subject to the presence of permanent and transient elements and activities which together, visually compete with the views. Overall it is considered that the works, although being noticeable, are unlikely to affect views in anything but a largely inconsequential sense. It is therefore considered that the actual and potential visual effects would be acceptable for the duration of construction.

5.9.3 Permanent landscape and visual amenity effects

As discussed above, the effects on the trees are principally considered to be temporary in nature. Once the project is complete, the trees will exist much as they were previously (in regard to location and appearance), as they would have either been retained and protected during the construction period, or reinstated to the same, or similar position. Given the proposal results in the permanent retention or reinstatement of all the existing pōhutukawa trees, the proposal avoids any permanent landscape or visual effects, being essentially benign with no or very little change to the character of the existing streetscape and waterfront context.

It is recognised however that with any construction works taking place within the vicinity of a tree, and additionally any tree reinstatement (after temporary relocation), there are risks. These risks

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include tree damage, poor health or death. If tree replacement is required, it is proposed that a suitably equivalent transplantable specimen will be planted for any tree failure.

The permanent effects associated with the reinstatement of the existing trees is concluded as less than minor. In addition, the permanent effects associated with the jet grout columns is nil, as the wall is under the road and therefore there will be no long-term visual effects.

5.9.4 Cumulative landscape and visual amenity effects

Construction across the entire project would physically affect up to 16 pōhutukawa trees along the northern side of Quay Street. The effects on the trees would vary and involve a combination of ‘retain and protect’, or ‘temporary relocation’ and ‘remove and replace’ measures. There is no permanent loss of any of these 16 trees proposed as part of the Seawall Project.

Pōhutukawa trees are not a rare occurrence in coastal locations within Auckland, however it is the urban setting in combination with their representative and scenic value which contributes to their cumulative landscape value in this setting. The temporary cumulative effect upon the landscape character of the area is considered to be less than minor during construction and minor until all trees are reinstated.

In addition, there could be up to three rigs and two plants across the Ferry Basin and Princes Wharf sections to support the proposed jet grouting construction method. This would be in addition to the rigs and equipment required for the construction of the palisade wall for the Queens Wharf to Marsden Wharf section.

The presence of this construction activity along the three sections of Quay Street would result in greater effects than those anticipated for this section of works only. Nevertheless, it is acknowledged that if the three sections were under construction concurrently, the overall duration of works would be reduced. Construction activities occupying large portions of the northern side of the Quay Street would change the character of the street however this would be relative to the extent of the street and spread across a wider area. Furthermore, works would continue to occur within a transport corridor, of which along much of the northern side encompasses a working port environment featuring large elements and structures such as ships, cranes, containers and vehicles.

From sightline 32, temporary construction equipment within the Ferry Basin and Princes Wharf section would be restricted to the northern side of the road, and beyond the Ferry Building would be seen as distant features within the view. It is noted that hoarding and construction equipment along the Queens Wharf to Marsden Wharf Section would temporarily interrupt views of a portion of the red port fence, and the lower portion of the Ferry Building. It is however acknowledged that as the red fence continues along the length of Quay Street (toward the sightline origin), this element would still in part be visible within the view. Furthermore, it is acknowledged that the Ferry Building would still be attainable from within the road corridor. As the sightline view would still afford a view of the Ferry Building and appreciation of the red fence, it is considered that the adverse effects on the sightline would be minor.

It is considered that many viewing audiences within the site are stationary. Pedestrians, cyclists, and road users on the other hand would have the opportunity to view the entire extent of the project along Quay Street. In regard to the visual effects resultant from the effect on trees specifically it is considered that viewing audiences would experience less than minor visual effects during construction as their focus would be upon the construction activities rather than the temporary

2 It is noted that the construction structures for the Ferry Basin section fall within Sightline 3 and 16. Accordingly, there are no cumulative effects in relation to Sightline 16 since it is only applicable to the Ferry Basin section.

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absence of the trees. After consideration, until all trees are reinstated, it is considered that the temporary adverse effects would be minor.

Overall, the proposal avoids any permanent landscape or visual effects, being essentially benign with no or very little change to the character of the existing streetscape and waterfront context.

5.10 Geotechnical and groundwater diversion effects

An addendum to the Geotechnical and Groundwater Effects Report (Geotechnical and Groundwater Effects Addendum) has been undertaken by T+T to assess the actual and potential geotechnical and groundwater effects of the proposed jet grout column option and is contained in Appendix K. The construction and operational effects are summarised as follows.

5.10.1 Construction effects

The geotechnical risks associated with constructing jet grout columns are primarily associated with mixing grout in situ with soil at high pressure below the ground surface, potentially inducing ground deformations and instability. These risks are considered to be minor to negligible and can be managed through appropriate construction techniques.

Based on the Alternative Construction Methodology Report, the extent that grout is mixed with the soil is controlled during construction. In the jet grouting process, the soil formation is broken down and grout mixed in situ with the soil in a circular motion. That is, grout is not intended to be mixed with soil outside the specified design diameter. It is expected that some mixing of grout with the soil may occur outside the specified diameter in certain ground conditions (generally softer and/or looser materials). However, the extent of this mixing outside the specified diameter is not expected to be large and the small extent of area that individual jet grout columns are treating combined with the hit and miss construction approach (i.e. immediately adjacent columns are not installed at the same time as the initial column is allowed to set before the adjacent column is installed) means that overall the geotechnical effects on the surrounding ground should be minor to negligible.

The Alternative Construction Methodology Report states that trial jet grout columns can be undertaken to adjust and validate jet grouting parameters such as pressure and flow rate of the water and grout, and rotation, withdrawal speed, and diameter of the jet grout nozzle.

The controlled construction of the jet grout columns, outlined in the Alternative Construction Methodology Report, means that the risk of potential instability of the existing seawall (primarily at the western end of the Princes Wharf section) and surrounding ground is low to negligible. A draft Ground Settlement Monitoring and Contingency Plan (GSMCP) (submitted with the section 92 response) has been prepared to manage any residual risk of ground or existing seawall deformations.

Spoil will be retrieved during the jet grouting process and this spoil will be monitored to ensure appropriate mixing of the grout with the in situ soils. If grout is found to not be mixing appropriately then mitigation measures, such as pausing the jetting process, modifying the jet grout mixing parameters, and adjusting the depth of mixing, can be undertaken to avoid potential effects on soil outside the jet grout columns and the potential to induce ground and existing seawall deformation.

There is potential for groundwater levels to be affected during the jet grouting process. During the jetting step, water is used at high pressure to cut through the soil so that grout can then be mixed in situ. The introduction of water at high pressure below the ground surface could raise groundwater levels in the surrounding ground, potentially inducing instability. Also, some water may be extracted when spoil is retrieved during the jet grouting process, which could lower groundwater levels in the surrounding ground, potentially inducing instability of surrounding ground. However, the small extent of area that individual jet grout columns are treating combined with the “hit and miss”

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construction approach means that groundwater should recover to normal operating levels in a short timeframe.

Updates to the draft GSMCP will be made to allow for groundwater monitoring during construction to help manage for the potential groundwater effects, as outlined in the Geotechnical and Groundwater Effects Addendum.

Finally, there are potential geotechnical effects during construction due to large machinery (jet grout rigs and grout mixing plant) positioned on top of or adjacent to the existing seawall. As indicated in the resource consent drawings, the columns are set back behind the existing seawall. Loading of the existing seawall during construction will be considered as part of the design process and can be managed through appropriate design and construction practice. Measures can be taken to distribute machinery loads if necessary to limit the effects, such as situating the rig on beams that span a larger distance or steel plates that can spread the load onto a larger area. On this basis, the geotechnical effects on the stability of the existing seawall can be appropriately managed.

5.10.2 Operational effects

Operationally, the proposed jet grout columns in the Princes Wharf section improves stability and resilience of Quay Street, particularly mitigating any potential effects of ground surface subsidence and instability in a seismic event. The stability of the existing seawall is less than what would be required for a new structure under static conditions and is likely to fail during a design seismic event. The proposed jet grout columns will be designed to mitigate large scale lateral spread during a seismic event and improve seismic protection for the assets in Quay Street.

Improvement of the seismic stability of Quay Street also provides a consequential improvement to the resilience, particularly seismic resilience, of surrounding buildings and infrastructure on Quay Street. By mitigating large scale lateral spreading in order to protect Quay Street and the services within it, the buildings and infrastructure on Quay Street, including those on the southern side, can have limited displacements in a seismic event.

In relation to groundwater, the potential operational geotechnical effect of the proposed jet grout columns is restriction of the flow of groundwater. Groundwater landward of the proposed jet grout columns may become elevated due to the inclusion of the columns. However, the rows of jet grout columns will be separated in the direction parallel with the existing seawall to allow groundwater to flow through the jet grout column alignment so that any potential elevation in groundwater is expected to be small. The GSMCP allows for the monitoring of groundwater before, during, and after construction to manage potential groundwater effects. Overall, the operational geotechnical effects of the proposal are acceptable.

5.11 Contaminated land effects

An addendum to the Ground Contamination Report (Ground Contamination Assessment Addendum) has been prepared by T+T, and is included in Appendix L. The addendum finds that the potential effects of the jet grout column option are consistent with those described in the Ground Contamination Assessment report in regard to the potential effects of contaminated land disturbance on human health and the environment. The assessment included in Section 5.12 of the AEE is included here for ease of reference.

A revised SMP (dated June 2018) was submitted to Auckland Council as part of the response to the section 92 further information request (dated 11 July 2018). The procedures set out in the SMP are appropriate for managing the potential ground contamination effects associated with the jet grout column option.

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An assessment of the potential effects of the jet grout column option on groundwater and marine water quality is also provided in the Ground Contamination Assessment Addendum, and is addressed in Section 5.12 below.

5.11.1 Effects of contaminated soil disturbance on human health

The potential risks associated with contaminated material to human health include the potential of contaminants entering the body through inhalation, ingestion or skin absorption during the works.

The measures outlined in the SMP in relation to human health and safety include:

Training undertaken by contractors to outline risk and site safety;

Protective equipment including full length clothing, impermeable gloves, dust masks and splash/water proof coveralls will be used on site by those undertaking excavation activities;

Personal decontamination before eating, drinking and smoking;

Eating, drinking and smoking to be undertaken in designated areas only;

Hand to mouth and hand to face contact to be avoided;

Additional emergency procedures will be established prior to works commencing; and

Decontamination will occur during completion of works including cleaning or disposing equipment.

The potential effects on human health from the disturbance of contaminated soils are considered to be less than minor with the mitigation in place and the unlikelihood of unearthing contaminated material.

5.11.2 Effects of contaminated soil disturbance on the environment

The potential risks associates with the contaminated material on the environment include uncontrolled discharges of contaminated surface or ground water and the inappropriate handling or disposal of contaminated soils or water.

The measures outlined in the SMP in relation to management of the contaminants in the environment include:

All excavated material will be treated as contaminated and a Contaminated Land Specialist will be consulted to confirm it is suitable to be reused on site;

Where possible, spoil should be located directly onto trucks (or sealed transfer bins);

Where temporary stockpiling is required this should be kept to a minimum, away from any water systems and covered when site is not active. Contaminated materials should be segregated and managed separately from clean materials;

Trucks should be loaded where management of potential spills and dust can be managed, wheels swept/washed before leaving site, and be covered during transport;

Details of truckloads shall be recorded;

Unusually coloured or odorous soil/ fill identified should be notified to Auckland Transport’s project manager and if necessary a Contaminated Land Specialist will be contacted;

Disposal shall meet criteria within the SMP Table 8.1;

No debris or spoil generated shall be discharged to storm water or CMA;

Erosion and sediment will be managed following Council’s guidelines and other applicable legislation;

Maintain damp conditions, minimize stockpiling and apply with council guidelines and other relevant legislation to control dust; and

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All equipment will be decontaminated before it leaves site.

Soil that is imported and used on site will be sourced from a suitable source as outlined in the SMP. This is not expected to have any negative effect on the surrounding environment or human health.

The SMP may be updated throughout the works and must be notified and approved by Auckland Transport to cater for the changes in understanding of ground contamination and/or best operational practice and/or regulations. The contractor is responsible got reviewing new work elements and assessing possible new hazards and how to eliminate, isolate or minimise these.

The potential effects on the environment and human health from the disturbance of contaminated soils are considered to be less than minor with the mitigation in place and the unlikelihood of unearthing contaminated material.

5.12 Marine and groundwater quality effects

5.12.1 Runoff of exposed soil to stormwater

The jet grout option results in relatively limited exposure of soil at surface as the method comprises drilling a 200 mm pilot hole to approximately 1.2 m depth before development of the larger diameter columns commences. The spoil is returned to surface via the pilot hole and is captured and pumped to a dedicated spoil pit or container to cure prior to disposal to landfill. Therefore as long as the management procedures set out in the SMP (in particular Sections 7 and 8.3 to 8.7) are implemented the contamination effect of discharges are expected to be less than minor.

5.12.2 Spoil management

As described in Section 3.8 spoil is returned to surface via the pilot hole and is captured and pumped to a dedicated spoil pit or container to cure prior to disposal to landfill. Therefore the contamination effects associated with the spoil are expected to be less than minor as long as the management procedures set out in the SMP (in particular Sections 7 and 8.3 to 8.7) are implemented. Surplus spoil should be disposed of in accordance with the procedures set out Section 8.2 of the SMP.

Water arising on site as part of the jet grouting process needs to be collected for treatment and settling prior to discharge to sewer as trade waste (subject to permitting). In the event that a trade waste consent is not issued, all dewatered material will be captured on site and removed via tanker for appropriate disposal.

With the implementation of appropriate mitigation measures, the adverse effects are considered to be less than minor.

5.12.3 Potential effects on groundwater quality

Groundwater level monitoring has shown that the groundwater level in the reclamation fill is similar to and follows tidal fluctuations, with a lag behind the tidal level of approximately 20 minutes. Therefore the groundwater is expected to have a high level of connectivity to the sea.

In considering the permitted activity standards related to discharge of water and/or contaminants (refer Table E4.4.1 of the AUP) the discharge must not, after reasonable mixing, give rise to:

A change to the natural temperature of the receiving water by more than 3 degrees Celsius; and

A change in the natural pH of the water by more than 1 pH unit.

The grout will result in a small increase in temperature in the immediate vicinity of the columns due to the exothermic nature of the grout curing process. This effect will be similar to any construction

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concrete pour that occurs below groundwater (such as basement excavations). In addition the highly alkaline nature of the grout will also result in a localised change in pH in the immediate vicinity of the columns. However, considering the thermal mass and buffering capacity available in the surrounding groundwater, these changes are not expected to be measurable once reasonable mixing occurs within the receiving environment. Further, as a result of the apparent connectivity with, and proximity to, the CMA, the interaction between groundwater and the sea are likely to further mitigate potential effects, via tidal pumping and dilution, in this instance. Accordingly the groundwater quality effects are assessed as less than minor.

5.12.4 Potential effects on the marine environment

Injecting grout could have potential effects on the marine environment if grout (and entrained contaminated soil) is able to break out and discharge into the CMA. However, it is considered unlikely that these effects will occur, or if they do occur they can be managed in a way that the effects will be less than minor, as follows:

1 Grouting only occurs from a depth of approximately 1.2 m below ground level, below the elevation of most services, thereby reducing the potential for break out via these pathways;

2 The construction methodology includes the following control and mitigation measures:

a The jet grouting occurs in three phases: pre drilling; pre jet and finally jet grouting. Only water is used during the two first phases allowing the operator to monitor water loss prior to commencing grouting;

b The jet grout process results in a circular motion mixing soil and grout rather than forcing cement into or through the soil formation; and

c Observation of spoil return is undertaken at ground level. If continuous return is lost, grout loss or plugging could be occurring. In the case of a loss, the column works will be stopped and a visual assessment undertaken over the seawall. If any impact is observed spill response measures will be implemented. If no impact is occurring, the column will be filled with thick grout and re-drilled after curing (generally the next day, this process is known as gravity grouting or pre-drilling). The above process is repeated as necessary.

As a result of the mitigation measures in place, the potential ground contamination effects on the marine environment from jet grout method will be acceptable.

5.13 Land disturbance and water quality effects

In addition to the contaminated land and associated water quality effects described in Section 5.11, there are additional effects associated with general land disturbance and silt generation during construction works and the management of these effects. As described in Section 3.8, the EMRP proposes environmental controls to appropriately manage effects related to land disturbance and water quality. These effects are summarised as follows.

Erosion and sediment control measures to manage any silt generation on site. This includes measures such as a stabilised entrance and exit point, perimeter bunding and stockpile management. The implementation of these measures will mitigate the risk of sediment-laden water entering the existing stormwater network in the road corridor and potential discharge directly from the construction area into the harbour marine environment.

Stormwater catch pits within the construction site will be managed through the installation of an Enviropod insert (or similar) during construction to capture sediment prior to discharge as a mitigation measure. The Enviropods will be inspected and maintained on a weekly basis with any accumulated sediment being deposited into the spoil pit for off-site disposal. Stormwater and water

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in the harbour will be continuously observed throughout construction to monitor the effectiveness of erosion and sediment control measures.

With the implementation of appropriate mitigation measures, the adverse effects on water quality are considered to be less than minor.

5.14 Hazardous substances, industrial and trade activities and air quality

An assessment has been prepared by T+T, titled Hazardous Substances, Industrial and Trade Activities and Air Discharge Assessment – Jet Grout Option, and is contained in Appendix D. The effects associated with the use of hazardous substances, industrial and trade activities and potential air discharge are summarised below.

5.14.1 Hazardous substance effects

The main hazards that have been identified in the above-mentioned report which could result in off-site effects include accidental release associated with a leakage or rupture of the mixing plant equipment through plant or connection failure or through release during operation and recharging of the cement silo.

Cement will be completely contained within the silos and mixing plant and will have specific controls, through design, examination, testing and certification for pneumatic equipment under the Health and Safety at Work (Hazardous Substances) (HSW-HS) Regulations 2017. Standard operating procedures and emergency response procedures will be in place to include recharging operations and plant operation.

The hazardous substance risk assessment provided in Appendix D has assessed the risks to be low. While the sensitivity of the receiving environment has been identified as being high, due to the assessed risk being low, and considering the design and operational procedures, the effects associated with the use and storage of cement will be acceptable.

5.14.2 Industrial and trade activity effects

The main hazards of the jet grout mixing plant and associated activities include those covered above in Section 5.13.1 as well as container leak or rupture during unloading of cement at the site, grout entering stormwater or directly discharged overland to the harbour.

The jet grout plant will be bunded with all stormwater drains either sealed or covered. In addition, the works areas where jet grouting is being undertaken will be bunded to contain any spills or leaks in addition to containing the runoff from the spoil which is conveyed from the rig’s spoil collection box to spoil tanks prior to removal off-site.

The risk of overflow from the spoil tanks will be controlled though procedures for management of the tank levels and disposal, cover of drains in the immediate area, bunding of the site and SRP’s.

All waste from the process will be collected, stored and disposed of at an appropriate landfill. With these controls in place the potential effects to the surrounding environment posed by the jet grout mixing plant will be appropriately managed.

5.14.3 Discharges to air

The only discharge to air is dust associated with the storage and handling of cement. The cement will be completely contained within the silos and mixing plant, and delivery of cement will be conveyed through sealed connections and pneumatic pumps, resulting in no avenue for loss of cement dust to the air. The silos will also be fitted with fabric filters to minimise any discharges to air from the cement silos during filling.

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Dust generation during construction of the jet grout columns is anticipated to be negligible due to the slurry nature of the grout and spoil. Conditions will be monitored by the Site Superintendent during high risk conditions (e.g. high winds, extended dry periods), and surface dampening measures will be deployed where dust discharges are identified.

Taking into consideration the controls listed above, the potential effects associated with discharges to air from the jet grout mixing plant will be acceptable.

5.15 Scale of effects

The scale of the potential effects of the proposed works has been assessed taking into account the expert reports prepared in relation to the jet grout column option, together with matters relating to the importance of the area, the sensitivity of the area and surrounding users, cumulative effects and combined effects. Each of these matters is discussed below.

5.15.1 Importance of the area

The importance of the area, as assessed in Section 5.13.1 of the AEE remains valid to this AEE Addendum.

5.15.2 Sensitivity of the area and surrounding users

Impacts to sensitive areas and users are usually more significant than impacts to those that are relatively resilient to impacts.

It is considered that there are sensitivities associated with the proposed location and particulars of the works that differentiate it. In particular, this relates to:

Noise and vibration – due to ongoing long term construction activities in the area, associated with the construction of CRL and Commercial Bay;

Temporary loss of trees – due to previous loss of trees in Quay Street, there is the potential for greater sensitivity to loss of trees in this area, temporary or otherwise; and

Temporary hoardings and large plant and equipment during construction (silos, rigs etc.) potentially obscuring views of heritage features and potential for damage to heritage features –due to the high profile nature of the historic heritage in the broader area (including the Ferry Building and the AHB Fence), and due to previous permanent loss of heritage features in this area, there is the potential for greater sensitivity to effects on heritage features in this area.

These sensitivities have been taken into account when assessing the combined effects of the proposed works.

5.15.3 Cumulative effects

Cumulative effects are the accumulation of impacts over time and space resulting from the combination of effects from a number of activities. Cumulative effects can be greater in significance than any individual effect.

Cumulative effects have been assessed in relation to each individual effect, in particular transportation, noise and vibration, trees, landscape and visual amenity and heritage.

For each of these individual effects, it is concluded that the cumulative effects will be minor or less than minor.

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5.15.4 Combined effects

The combination of effects can result in effects of greater significance than any individual effect from an activity.

In this case, each individual effect has been assessed as “minor” or “less than minor”, and each individual cumulative effect has been assessed as “minor” or “less than minor”. However, when added together, and taking into account the additional significance added to the effects due to the importance of the area, and the sensitivities, it is considered that the potential temporary adverse effects on people’s use and enjoyment of the area may be more than minor.

In particular, this assessment is based on the combined effect of the impacts on people and organisations use and enjoyment of the area due to noise, vibration, restrictions to pedestrian, vehicle and property access, large scale plant and equipment reducing the character and amenity of the area, temporary loss of seating and walking areas at the waterfront, temporary loss of trees and temporary hoardings that will be in place to protect heritage features. This assessment takes into account the sensitivities discussed and the potential cumulative duration of construction (approximately 18 months).

It is not considered that these adverse effects will be significant as there are other stretches of waterfront within the CBD, including the Viaduct Harbour and Wynyard Quarter that people can access to use and enjoy the waterfront location, and no permanent loss of features that contribute to the amenity values of the area is proposed.

5.16 Summary of effects

The construction of the proposed jet grout column option for the Princes Wharf section of the Quay Street seawall will provide a number of positive effects including seismic resilience for the city’s transport and utility infrastructure in this location.

Construction of the Princes Wharf section has the potential to give rise to a range of adverse environmental effects within the vicinity of the proposed works and these have been covered in the preceding assessment. AT proposes conditions as part of this resource consent application in order to avoid, remedy or mitigate the adverse effects of the construction activities as appropriate. These conditions require a suite of management plans to be developed or updated, including an overarching Construction Environmental Management Plan (CEMP), which will set out final details of methodology and staging, the contact and communication arrangements, site management procedures, health and safety matters, and environmental management requirements (including all of the management plans required by the conditions of consent).

Transportation effects are considered to be minor, subject to implementation of proposed traffic management measures. In particular, pedestrian, cycle and public transport access will be provided for and the effects on general traffic will be no more than currently authorised in the Quay Street environment.

It is considered that, while some exceedances of noise limits are predicted to occur, overall effects arising from construction noise on sensitive receivers and on heritage features can be appropriately managed so that they are minor, through implementation of the CNVMP and the BHCMP. In particular, communication with sensitive receivers and pre and post condition surveys of heritage features will be important.

Effects on heritage features are considered to be minor, subject to the implementation of the BHCMP. Potential effects on trees and landscape and visual amenity are considered to be minor during construction and less than minor following construction. In particular, effects on trees can be

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appropriately managed through the implementation of tree management procedures, including in relation to protection in situ, relocation and reinstatement or replacement.

It is considered that any potential geotechnical and groundwater effects will be less than minor. Potential effects associated with erosion, soil mobilisation, sedimentation to receiving water bodies and stormwater discharges will be temporary in duration and will be appropriately avoided or mitigated via measures outlined in the EMRP.

Although there was no contaminated soil found during investigations, a SMP has been prepared to manage potential adverse human health and environmental effects during earthworks and to also provide mitigation for unexpected discovery of contamination during earthworks.

Effects associated with use of hazardous substances, industrial and trade activities and potential air discharge is assessed as less than minor. Appropriate management practices are proposed, including the adoption of an EMP and SRP to manage the industrial and trade activity. Operational procedures will ensure that any environmental risk is appropriately mitigated.

Notwithstanding the above conclusions that each actual or potential adverse effect is minor or less than minor, it is considered that the combined potential temporary adverse effects of construction may be more than minor.

In particular, this assessment is based on the combined effect of the impacts on people and organisations use and enjoyment of the area due to noise, vibration, restrictions to pedestrian, vehicle and property access, the use of large scale plant and equipment during construction, loss of seating and walking areas at the waterfront, and loss of trees. This assessment takes into account the importance of the area, the sensitivity of surrounding uses and the potential cumulative duration of construction (approximately 18 months).

It is not considered that the combined potential temporary construction adverse effects will be significant. Following the completion of construction, it is considered that the potential adverse effects over the life of the works will be less than minor.

Taking into account the positive effects, and in particular the benefits of the improved seismic resilience for Quay Street and the proposed conditions of consent attached as Appendix R, it is concluded that the actual and potential effects of the proposed Princes Wharf section works are able to be appropriately managed and mitigated.

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6 Statutory assessment

6.1 Introduction

This section of the AEE Addendum assesses the proposed Princes Wharf section works against the

key provisions of the RMA in Section 6.2 and comments on other relevant legislation in Section 6.3.

An assessment of the proposed Princes Wharf section against the relevant statutory and non-

statutory policy statements and plans is contained in Section 7.

6.2 Resource Management Act 1991

6.2.1 Part 2 – Purpose and principles (sections 5 to 8)

Part 2 of the RMA sets out the purpose and principles of the Act. These matters have been fully

canvassed in the AEE. The proposed jet grout option is considered to be consistent with that

assessment, which concluded that the proposed upgrade to the seawall is in accordance with Part 2

of the RMA.

In particular, the jet grout column option is considered to be consistent with the direction in section

6 ‘Matters of national importance’, including section 6(h) ‘the management of significant risks from

natural hazards. To reiterate, the intent of the works is to make the existing Quay Street seawall

more resilient and effective in a seismic event, as the existing seawall does not meet current design

standards for seismic performance.

6.2.2 Public notification (section 95A)

For clarity, the application requests public notification of this AEE Addendum in conjunction with the

main AEE report under section 95A. In accordance with section 95A(2)(a) and 95A(3)(a), public

notification is therefore mandatory.

6.2.3 Matters relevant to certain applications (section 105)

Section 105(1) of the RMA provides for matters that consent authorities must have regard to when

considering discharge or coastal permit applications that would contravene section 15 or 15B of the

RMA. The proposal contravenes section 15 and therefore section 105(1) applies. Section 105(1)

requires the consent authority to have regard to the nature of the discharge and the sensitivity of

the receiving environment, the applicant’s reasons for the proposed choice and possible alternative

methods of discharge. These matters have been addressed throughout this report.

In particular, Section 2 describes the receiving environments and Section 5 assesses the effects on

the environment, concluding that the adverse effects of the discharges will be less than minor

provided that appropriate mitigation is in place.

As discussed in Section 5.13, the only discharge to air is dust associated with the storage and

handling of cement. Dust generation during construction of the jet grout columns is anticipated to

be negligible due to the slurry nature of the grout and spoil. Conditions will be monitored by the Site

Superintendent during high risk conditions (e.g. high winds, extended dry periods), and surface

dampening measures will be deployed where dust discharges are identified.

As discussed in Section 5.11 water arising on site as part of the jet grouting process needs to be collected for treatment and settling prior to discharge to sewer as trade waste (subject to permitting). In the event that a trade waste consent is not issued, all dewatered material will be captured on site and removed via tanker for appropriate disposal. Jet grouting could have potential

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effects on the marine environment if grout is able to break out and discharge into the CMA. This is considered unlikely, or if they do occur they can be managed in a way that the effects will be less than minor as outlined in Section 5.11. This is due to the management procedures in place as outlined in the EMRP (Appendix I).

6.2.4 Matters relevant to discharge permits (section 107)

Section 107 restricts the granting of discharge permits in certain circumstances, namely if, after reasonable mixing, the contaminant or water discharged (either by itself or in combination with the same, similar, or other contaminants or water), is likely to give rise to all or any of the following effects in the receiving waters:

c The production of any conspicuous oil or grease films, scums or foams, or floatable or suspended materials;

d Any conspicuous change in the colour or visual clarity;

e Any emission of objectionable odour;

f The rendering of fresh water unsuitable for consumption by farm animals; and

g Any significant adverse effects on aquatic life.

The effects of the discharge are considered in Sections 5.11 and 5.12 of this AEE Addendum. Discharges during construction will be managed in order to avoid the adverse effects set out in section 107. Overall it is concluded that the discharge would meet the tests set out in section 107(1)(c) to (g).

6.2.5 Conditions and consent duration and lapse (sections 108, 123 and 125)

In accordance with section 108, an updated set of suggested consent conditions is provided in

Appendix R and summarised in Section 9 of this report. These suggested conditions request the

same lapse and duration date as set out in the AEE. While the duration of works is anticipated to be

shorter in duration if the alternative jet grout column option is implemented, there is potential for

the works to commence after the AC36 and APEC events in 2021 if there are delays. Therefore, AT

requests:

An unlimited duration, for the land use consents being sought, under section 123(b);

A duration of 15 years, for the regional consents being sought, under section 123(d); and

A lapse period of 10 years, for all resource consents sought.

6.3 Heritage New Zealand Pouhere Taonga Act 2014

The purpose of the HNZPTA is to promote the identification, protection, preservation, and

conservation of the historical and cultural heritage of New Zealand.

Since the date of lodgement an application for a blanket archaeological authority for all proposed works associated with the Downtown Programme has been submitted to HNZ. This covers all recorded archaeological sites, as well as allows for any unrecorded sites during construction.

An application for this blanket archaeological authority (HNZ ref: 2019/260) was lodged with HNZ on

9 October 2018.

6.4 Statutory assessment summary

The actual and potential effects on the environment of the jet grout column option for the Princes

Wharf section will be temporary in nature and can be managed via the measures outlined in Section

5 of this AEE Addendum. Overall, the proposed works are considered to be consistent with the

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statutory assessment undertaken in the AEE, which considered that the proposal achieves the

purpose of the RMA, and that the works are considered to be consistent with the policy direction (as

set out in Section 7).

An Archaeological Authority from Heritage NZ is currently being sought for the Seawall Project under

the HNZPTA.

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7 Relevant planning documents

7.1 Introduction

Sections 7.2 to 7.5 below assess the relevant provisions of planning documents required by section

104(1)(b) of the RMA, which in this case are:

National Environmental Standards for Assessing and Managing Contaminants in Soil to Protect Human Health (NES Soil);

New Zealand Coastal Policy Statement (NZCPS);

Hauraki Gulf Marine Park Act 2000 (HGMPA);

Regional Policy Statement (AUP); and

Regional Coastal Plan, Regional Plan and District Plan provisions of the AUP.

This assessment largely relies on the assessment of planning provisions undertaken in the AEE, with additional analysis provided where there are notable distinctions between the two construction methodologies in relation to the policy direction.

7.2 National Environmental Standards

The NES Soil is the only National Environmental Standard relevant to this application. One of its key

features is to provide national planning controls that direct the requirement for consent or

otherwise for activities on contaminated or potentially contaminated land. All territorial authorities

are required to give effect to and enforce the requirements of the NES (Soil) in accordance with their

functions under the RMA relating to contaminated land. The resource consent requirements under

the provisions of the NES (Soil) are discussed in relation to the jet grout column option under Section

4 above. Resource consent is required under Regulation 10(3) as a restricted discretionary activity.

An assessment against the matters is included in Section 5 of this AEE Addendum.

7.3 New Zealand Coastal Policy Statement

The NZCPS sets policy direction for management of the coastal environment of New Zealand and is

relevant to the proposal. A brief assessment against the NZCPS provisions is set out in the AEE.

Overall, the proposed works are considered to be consistent with the NZCPS, given the intent of the

proposed works to help provide for the social and economic wellbeing of the surrounding

community and ensure built development is protected.

While the jet grout option is not immediately adjacent to the CMA, the provisions of the NZCPS have

been considered in relation to this construction methodology. In particular, Policy 22

(Sedimentation) has been considered. Appropriate erosion and sediment control measures will be

put in place to mitigate sedimentation of the CMA, and these will be assessed and monitored

throughout the works period, as set out in Section 5.13 of this AEE Addendum.

7.4 The Hauraki Gulf Marine Park Act

The site is located in the Hauraki Gulf and is governed by the HGMPA. The overall purpose of the

HGMPA is to improve the environmental management of the Gulf, its islands and catchments. For

the coastal environment of the Hauraki Gulf, sections 7 and 8 of the HGMPA must be treated as a

New Zealand coastal policy statement.

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The installation of the jet grout columns will maintain and enhance the resilience of the downtown

area and its ability to support the social and economic well-being of the people and communities of

the Hauraki Gulf and New Zealand.

7.5 Auckland Unitary Plan – Operative in Part

The AUP became operative in part on 15 November 2016. Since the lodgement of the AEE for the

palisade wall option, the Regional Coastal Plan component of the AUP is now operative (as of 31

May 2018). Accordingly, the jet grout column option has not been assessed against the Auckland

Council Regional Plan: Coastal.

In addition, some of the AUP provisions are affected by Plan Change 4. This is largely an

administrative plan change and is not considered to have any substantive effect on the relevant

provisions to this project.

The relevant objectives and policies of the AUP are assessed in Sections 7.5.1 and 7.5.2 below.

7.5.1 Chapter B regional policy statement

Relevant Regional Policy Statement (RPS) provisions are included in full in the AEE. Having assessed

these provisions, the AEE considers the proposal to be consistent with the direction of the RPS.

Having reviewed these provisions, it is considered that the jet grout column option remains

consistent with the RPS provision as assessed in the AEE, including the provisions contained in B3.2

Infrastructure. These provisions direct that:

Infrastructure is resilient, efficient and effective;

The benefits of infrastructure, along with the functional and operational needs of infrastructure and the value of investment in existing infrastructure, are recognised; and

Development, operation, maintenance and upgrading of infrastructure is enabled in an efficient manner, while avoiding, remedying and mitigation adverse effects.

The construction period will be undertaken as efficiently as possible to enable the works to be

completed in sufficient time to allow for other planned development to occur prior to key events in

2021. The efficiency of options for upgrading the seawall was considered during options

identification and assessment (see Project Context and Options Assessment attached to the AEE as

Appendix E, and the Options Report Addendum attached as Appendix M to this AEE Addendum).

The jet grout column option, along with the palisade wall option, are both appropriate

methodologies proposed for the upgrade of the Princes Wharf section of the seawall.

As set out in Section 3.10 above and in the Options Report Addendum, jet grouting was originally not

a preferred option due to lack of construction plant type and availability and potential greater

adverse effects in relation to water quality. As set out in Section 3.10 above, these issues have been

resolved as a result of Early Contractor Involvement (ECI) and as such, jet grout columns are

considered to be an appropriate alternative option which can enable the efficient upgrade of Quay

Street.

Provisions relating to air quality, hazardous substances and industrial and trade activities, and

contaminated land are relevant to the jet grout column option, in addition to all the other provisions

assessed as part of the AEE. These additional provisions are attached and assessed in detail in

Appendix Q. Effects relating to these provisions are assessed in Section 5.14.

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7.5.2 AUP Regional Plan and District Plan provisions

The relevant objectives and policies of the AUP provisions are assessed in full in Appendix Q of the

AEE. Overall, the jet grout column option is considered to be consistent with the assessment of

objectives and policies of the AUP contained in the AEE.

In relation to that assessment, it is noted that management of risks of discharge into the coastal

environment will be managed differently for the different methodologies. Therefore, in addition to

the commentary set out in relation to the provisions of ‘Chapter E11 Land Disturbance – Regional’

and ‘Chapter E12 Land disturbance – District’, it is noted that the Environmental Management

Response Plan (EMRP) (Appendix I) sets out additional erosion and sediment control principles

relating to the jet grout column option, including:

Minimise disturbance;

Protect watercourses (in this case, stormwater outlets which discharge directly to the Waitematā Harbour);

Install perimeter controls and devices;

Employ sediment retention devices;

Training/experienced operators;

Adjust the Erosion and Sediment Control Plan as required; and

Regular assessment and adjustment of erosion sediment control measures.

A draft Erosion and Sediment Control Plan (ESCP) relating to the jet grout column option is attached to the EMRP.

In addition, the provisions of Chapters ‘E14 Air quality’, E31 Hazardous substances’ and ‘E33 Industrial and trade activities’ are relevant in relation to the alternative jet grout column option. The main hazardous substance associated with jet grouting is cement, which has potential to discharge to air during unloading of the silos, as set out in Appendix D. Industrial and trade activities associated with jet grouting include cement storage, jet grout plant and injection, and spoil handling and storage.

The relevant provisions of Chapters ‘E14 Air quality’, E31 Hazardous substances’ and ‘E33 Industrial and trade activities’ are addressed in Appendix Q of this AEE Addendum. In summary:

The discharges to air associated with the jet grout option can be managed in a way that avoids offensive and objectionable effects. It is considered that the emission control and management practices set out in Section 5.14 of the AEE Addendum and Appendix D, are appropriate to the scale of the discharge and potential adverse effects, taking into account the type of emissions and the proximity of commercial activity and vehicular and pedestrian traffic on Quay Street to the works;

A hazardous substance risk assessment has been undertaken for the storage and handling of cement, and this has assessed the risks to be low. While the sensitivity of the receiving environment has been identified as being high, due to the assessed risk as being low and considering the design and operational procedures the effects associated with the use and storage of cement is less than minor; and

The main potential effects of the jet grout plant and associated industrial and trade activities include discharges of hazardous substances, container leak or rupture during unloading of cement at the site, grout entering stormwater or directly discharged overland to the harbour. These will be prevented by bunding the jet grout plant and works areas, sealing or covering all stormwater drains, and removing all waste from the process from site, or minimised by risk controlling overflow from the spoil tanks though procedures for management of the tank

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levels and disposal (see Section 9.2 of Appendix D). A draft environmental management plan, including a SRP, is included in the EMRP (Appendix I).

Overall, the jet grout option is considered to be consistent with the provisions of Chapters ‘E14 Air

quality’, E31 Hazardous substances’ and ‘E33 Industrial and trade activities’ of the AUP.

7.6 Other matters (Section 104(1)(c))

An assessment of documents which are considered relevant under section 104(1)(c) (‘any other matter the consent authority considers relevant and reasonably necessary to determine the application’) is provided in Section 7.5 of the AEE. This also applies to the jet grout column option and therefore should be referred to for the purposes of this report. This includes an assessment of the:

City Centre Master Plan;

Waterfront Plan;

Waterfront Auckland Sustainable Development Framework 2013;

Waterfront Refresh 2017; and

Conservation Management Plan for the Auckland Harbour Edge Area.

In addition, the Auckland Plan 2050 was released on June 2018, after the AEE was lodged with Auckland Council. This supersedes the Auckland Plan 2012, which was assessed in the AEE.

The Auckland Plan 2050 is our long-term spatial plan which sets out the big issues facing Auckland, and sets out a strategy for Auckland to grow in a way that will meet the opportunities and challenges of the future. The Seawall Project responds to a number of the outcomes set out in this plan as follows:

Belonging and participation: Supporting the Downtown Programme public space projects, which are consistent with Focus Area 1 ‘Create safe opportunities for people to meet, connect, participate in and enjoy community and civic life.’

Māori Identity and Wellbeing: Having regard to Direction 3, Mana Whenua have been engaged through AT’s Mana Whenua Engagement Framework, which has been set up in a manner consistent with the principles of the Treaty of Waitangi.

Transport and Access: The Seawall Project is consistent with the directions and focus areas set out in relation to the transport and access outcome, which is the most directly relevant outcome to this project. In particular, the project will assist AT in developing a sustainable and resilient transport system (Focus Area 7).

Environment and Cultural Heritage: The project is generally consistent with Direction 1, ‘Ensure Auckland’s natural environment and cultural heritage is valued and cared for’ and Direction 4, ‘Ensure Auckland’s infrastructure is future-proofed’. As set out in Section 5 of the AEE and this AEE Addendum, environmental and cultural effects associated with both construction methodologies are considered to be appropriate and manageable. The proposed upgrade will improve the resilience of the seawall to seismic events, enhancing the ability of this critical transport link into the future.

Overall, the project is considered to be consistent with the strategic direction contained in the Auckland Plan 2050.

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8 Consultation and feedback

8.1 Introduction

Engagement with identified stakeholders (outlined in section 8 of the AEE) is ongoing, which includes discussions around the jet grout column option.

Of particular note is meetings held in August 2018 with Auckland Council, Mana Whenua and HNZ as outlined below. Engagement and consultation will continue during the design, consenting and construction phases of the project.

For the purpose of this AEE Addendum, consultation undertaken for the jet grout column option for both the Princes Wharf section and Ferry Basin section has been captured together.

A consultation log and other consultation documentation related to the jet grout column option is included in Appendix N.

8.2 Auckland Council

A number of meetings have been held with AC’s resource consent team, including meetings with AC’s Principal Project Lead, and the assigned processing planner to discuss the jet grout column option and provide information to AC’s teams of experts. This has enabled AT to gain an understanding of the Resource Consent team’s information requirements.

Specific discussions have been held between experts advising AT and the experts for AC, which have further added understanding of information requirements.

8.3 Māori engagement

Engagement with Māori is an important principle of the Project, recognising that Tikanga Māori encompasses a complex system of customs and values to conserve, manage and protect natural and physical resources.

AT holds monthly hui with iwi through its Mana Whenua Engagement Framework to discuss a range of major projects. A hui was held on 15 August 2018 where the jet grout option for the seawall upgrade was discussed. AT and its consultants presented information on the project and its context, listened to feedback, and responded to questions. The table below summarises the questions asked at the hui and the responses provided by the project team. Representatives of the following iwi/ Māori organisations were in attendance at the hui:

Ngāti Maru (Geoff Cook);

Ngāti Te Ata Waiohua (Metiria Kaihau); and

Te Akitai Waiohua (Adrian Pettit).

Table 8.1: Questions and responses during Māori engagement

Question/ feedback from iwi Project team response

Will the jet grouting work given the variable composition of the reclamation?

The contractor noted that they had worked on other projects along Quay Street in similar material and had encountered no problems. Also trials will be done on the seawall site.

It was noted that jet grouting was a less intrusive method with small diameter holes at the surface. There was no need for a trench and capping beam.

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Question/ feedback from iwi Project team response

What centres the grout columns would be placed?

The columns would overlap by 200 mm forming a solid wall.

Would scour from the large number of ferries and ships be accommodated?

It was noted that various scenarios had been investigated.

What was being done about drains coming out of the existing seawall. The original idea of post/panel wall was to install filters over the stormwater pipes. Is this still the case?

It was mentioned that this was not part of the scope of this project. This would be accommodated in the Downtown Public Space project.

Where rocks be sourced from for the rock protecting scour.

Various sources are being considered.

It was noted this is a highly contaminated area due to previous reclamation in area.

The contractor noted that the process would be similar to CRL but not using sodium bentonite.

Adrian queried how shotcrete would be applied on the seaward side of the seawall.

The contractor replied that precast panels would be fixed below water level and shotcrete above water level from a hanging platform.

8.4 Heritage

A meeting was held on 2 August 2018 with HNZ and the Auckland Council Heritage Unit to present information and provide updates on the Downtown Programme, including the alternative jet grout column methodology for the seawall upgrade.

It was discussed that a brief summary on the proposed methodology had been provided to Council specialists for comment. During the discussion, matters were raised by AC’s heritage specialists, including:

Interest regarding the impact on heritage features through the construction process. It was clarified that the alternative methodology would have no other effects to heritage features than originally proposed in the AEE; and

Interest regarding the disturbance of archaeological remains. It was noted, similar to the above, that there would be no additional effect to archaeological remains than what was proposed in the AEE.

8.5 Service Providers

A meeting was held with Chorus on 12 August 2018 which included a discussion on the jet grout option. Chorus advised they were happy with the jet grout option so long as care is taken around their assets.

Fortnightly meetings are being held with Vector to discuss the jet grout construction methodology and the interface with their assets. These discussions are ongoing.

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9 Proposed conditions of consent

This AEE Addendum includes an updated set of draft conditions (Appendix R) to include the jet grout column option in addition to the palisade wall option. The draft conditions proposed by AT capture all of the mitigation measures and management plans addressed in the specialist reports and assessment of effects. This includes additional management plans (SPR and EMP) applicable to the jet grout column option. These suggested conditions request the same lapse and duration date as set out in the AEE.

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10 Conclusion

This AEE Addendum has been prepared on behalf of AT to accompany a resource consent application to AC for the upgrade of the Princes Wharf section of the Quay Street seawall.

The proposed works require consent as a discretionary activity under the AUP and NES Soil.

This AEE Addendum draws the following conclusions:

The works are consistent with Part 2 of the Resource Management Act 1991. In particular, the works are consistent with section 6(h), the management of significant risks from natural hazards. The works will make the existing Quay Street seawall more resilient and effective in a seismic event, reducing the risk of seawall failure and providing better support to the Quay Street reclamation. In relation to section 6(f), risks to historic heritage features will be managed, and once complete, the works will ultimately protect historic heritage features by providing a more resilient seawall which supports these items;

The works are consistent with the relevant objectives and policies of: the New Zealand Coastal Policy Statement; the Hauraki Gulf Marine Park Act; the Regional Policy Statement, Regional Plan and District Plan provisions of the AUP; and the NES Soil; and

The actual and potential effects of the proposed works include a number of positive effects, and any adverse effects are able to be appropriately managed and mitigated, subject to the implementation of the proposed conditions of consent.

AT requests that the resource consent application, comprising the AEE lodged on 18 May 2018 and this AEE Addendum, for the Princes Wharf section of the Seawall Project be publicly notified. In accordance with section 95A(2)(a) and 95A(3)(a), public notification is therefore mandatory. AT also requests that the owners/ occupiers of adjoining properties and all stakeholders and interested parties, who have requested to be kept updated as part of the consultation process, are served notice of this application.

An updated suite of draft resource consent conditions proposed by AT is included in Appendix R.

11 Applicability

This report has been prepared for the exclusive use of our client Auckland Transport with respect to the particular brief given to us, and in accordance with our Letter of Engagement dated 31 August 2018. It may not be relied upon in other contexts or for any other purpose, or by any person other than our client, without our prior written agreement.

We understand and agree that Auckland Transport will submit this report to Auckland Council in support of an application for resource consent for the development described herein and that Auckland Council will rely on this report for the purpose of assessing that application.

Tonkin & Taylor Ltd

Environmental and Engineering Consultants

Report prepared by: Report prepared by:

.......................................................... ...........................….......…...............

Alexandra Scouller Sarah McCarter Planner Senior Planner

Technical review by: Authorised for Tonkin & Taylor Ltd by:

.......................................................... ...........................….......…...............

Jennifer Carvill Richard Reinen-Hamill Technical Director – Planning Project Director

26-Oct-18

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