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Aotea Station Main Works Trees and Vegetation Delivery Work Plan

CRL-AOT-RME-LKA-PLN-800031 Revision: 001 Date: 08 May 2020

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Trees and Vegetation Delivery Work Plan Trees and Vegetation Delivery Work Plan CRL-AOT-RME-LKA-PLN-800031 This document is uncontrolled when printed. This document should be printed in colour

Revision Status Revision

Date

Version details

Prepared By

Approved By

000

05/03/2020

For issue

Lyndsey Smith

Peter Roan

001

08/05/2020

Auckland Council Approval

Approval Status Name/Title

Signature

Date

Prepared by:

Lyndsey Smith Principal Environmental Scientist (Ecologist)

05/03/2020

Reviewed by:

Fiona Davies Associate Director - Environment

05/03/2020

Approved by:

Peter Roan Link Alliance â€“ Consents Lead

05/03/2020

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Table of contents 1. Introduction ................................................................................................ 4 1.1

Aotea Station..................................................................................................................... 4

1.2

Purpose of the Trees and Vegetation DWP........................................................................ 6

1.3

Relevant Conditions .......................................................................................................... 7

1.4

DWP Review and Updates ................................................................................................. 7

2. Aotea Main Works ...................................................................................... 8 2.1

Overview of Works ............................................................................................................ 8

2.2

Programme ........................................................................................................................ 8

2.3

Construction Methodology ................................................................................................ 9

2.4

Roles and Responsibilities ................................................................................................. 9

3. Affected Trees and Vegetation ................................................................. 10 3.1

Affected Trees - Aotea Main Works ................................................................................. 10

4. Mitigation Measures ................................................................................. 12 4.1

Trees Requiring Removal / Relocation............................................................................. 12

4.1.1.

Transplanting Trees .................................................................................................. 12

4.1.2.

Permanent Removal and Replacement ..................................................................... 13

4.2

Trees not Requiring Removal........................................................................................... 14

4.2.1.

Tree Protection Zones and Crown Protection............................................................ 14

5. Consultation .............................................................................................. 17 Appendix A: Record of CLG, Independent Peer Review and Auckland Council Comments ....................................................................................................... 18 Appendix B: Aotea Stages 4 and 5 â€“ Indicative Street Tree Reinstatements .. 19 Appendix C: Tree Transplant Feasibility Assessment ...................................... 22

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1. Introduction The City Rail Link (CRL) project comprises the construction, operation and maintenance of a 3.4 km underground passenger railway, running between Britomart Station and the North Auckland Rail Line in the vicinity of Mt Eden Station. The CRL also involves the construction of two new underground stations at Aotea and Karangahape and the redevelopment of the station at Mt Eden (refer to Figure 1-1). The design and construction of the CRL infrastructure between the Aotea and Mt Eden Stations is being delivered by the Link Alliance.

Figure 1-1: CRL Route and Location

This Trees and Vegetation Delivery Work Plan (TV DWP) has been prepared in relation to the main construction works for the new Aotea Station.

1.1 Aotea Station Once completed, the Aotea Station will include platforms, lifts, escalators, rooms for housing stations and tunnel services equipment, an entrance building at Wellesley Street, two additional entrance buildings at Victoria Street, a Plenum at Kingston Street, services, internal and architectural finishings, structural fittings, utilities services diversions and connections. The location of the Aotea Station is primarily beneath Albert Street, connecting the Contract 2 (C2) cut and cover tunnels to the north and the tunnel-boring-machine (TBM) tunnels to the south. The works are approximately 380m long by 18m wide and will be excavated around 18-20m below ground level. Additional boxes branch off from the tunnel alignment at Kingston Street (to form the Plenum), Victoria Street (for two entrance buildings to the Aotea Station) and Wellesley Street (to form the main entrance building to the Aotea Station (refer to Figure 1-2 below)1. 1

Auckland Transport (AT) has obtained a resource consent for an Over Station Development (OSD) on the Bledisloe Car Park site (Council Reference R/LUC/2016/2647). The proposal involves the construction of a 24-level building comprising offices, retail and food and beverage tenancies, and public features including a plaza and a through site link. The proposed OSD is not part of the Link Alliance contract and will be progressed separately by Auckland Council / Panuku. Page 4 | Aotea Station Main Works

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Figure 1-2 Indicative Aotea Station indicating length of underground station box with the associated above-ground Main Station structure at Wellesley Street, entrance structures at Victoria Street and the Kingston Street Plenum.

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Trees and Vegetation Delivery Work Plan Given the nature and scale of the Aotea Station construction, works will be undertaken in a staged manner, involving: •

•

Five stages of early works (canopy removal, network utility relocation and site establishment work), being undertaken from October 2019 to March 2020 (Stages 1 to 3) and December 2019 through to August 2020 (Stages 4 and 5); these works have been authorised by separate Outline Plans (Council ref. OPW60345651 and OPW60348747); Main construction works (the ‘Aotea main works’) involving construction of the station box, associated above ground structures, mined tunnels for the rail tracks, internal finishings, structural fitout, all Mechanical, Electrical, Fire and Hydraulic (MEFH) installation, and architectural finishings2. The Aotea main works will be undertaken from early-2020 through to late-2023; Ground reinstatements (from late-2022) and urban realm improvements. These works will be described in a future Outline Plan2.

This TV DWP relates to the Aotea main works, in which the installation of diaphragm walls will require removal or relocation of 11 pōhutukawa (T34) trees situated at the southern end of Albert Street, outside the Crowne Plaza Hotel. Refer to Section 2 of the Construction Environmental Management Plan (CEMP) for a detailed description of the Aotea main works.

1.2 Purpose of the Trees and Vegetation DWP In accordance with CRL designation condition 55, this TV DWP has been prepared to identify measures that will be implemented to mitigate and manage the potential adverse effects on trees and vegetation during the Aotea main works. The objective of the DWP (designation Condition 55.2) is: • •

To avoid the removal of scheduled trees as far as practicable; and Where trees are identified for removal during surface works the Requiring Authority will remedy or mitigate the adverse effects of construction on trees and vegetation.

This TV DWP addresses the requirements of CRL designation condition 55 and will be implemented throughout the construction period. This TV DWP has been prepared in consultation with the Aotea Community and Business Liaison Group (CLG) and has undergone Independent Peer Review (IPR) prior to submission to Auckland Council (as per designation conditions 7 and 11). A record of CLG consultation outcomes and IPR review comments is provided in Appendix A.

Relevant Conditions

It is noted the architectural finishing component of works (the exterior look and feel of the Aotea Station) will occur during Phase 5 of the Aotea main works (approx. 2022 – December 2023). These finishings are still being designed and determined. Once designs are completed a separate Outline Plan and suite of DWPs will be prepared, describing the finishings and other permanent above ground public realm reinstatements. That Outline Plan package will address the relevant Urban Design related Designation conditions (condition 47 – 54, including landscaping (condition 55.3(c))). Page 6 | Aotea Station Main Works

Trees and Vegetation Delivery Work Plan Table 1-1 identifies the designation conditions relevant to this TV DWP and where they are addressed in the document. Table 1-1: Trees and Vegetation conditions and location in the TV DWP

Condition No.

Condition

55.1

A Trees and Vegetation DWP shall be prepared to manage the adverse effects from the removal of trees and vegetation during the construction of the City Rail Link or any part of it.

55.2

The objective of the Trees and Vegetation DWP is to avoid the removal of scheduled trees as far as practicable. Where trees are identified for removal in surface works the Requiring Authority will remedy or mitigate the adverse effects of construction on trees and vegetation.

55.3

To achieve the above objective the following shall be included in the Trees and Vegetation DWP and implemented as required:

1.3

Relevant section of DWP

1.2

(a) Confirmation of the trees to be removed due to surface construction works and whether it is appropriate and feasible to relocate or store these trees for replanting. The removal of scheduled trees which form a significant group should only be undertaken as a last resort;

Sections 3 and 4.1

(b) A list of trees, which due to being in proximity to construction works, have root systems and / or foliage within and / or overhanging the surface designation footprint, and the methods to be used, where practicable, to protect these trees from construction works;

Section 3

(c) Cross references to the Urban Design DWP and the proposed mitigation of any tree / vegetation removal through replanting trees at a 1:1 ratio, reinstatement of the area, and other methods. In preparing the Trees and Vegetation DWP, the Requiring Authority shall seek input from the Auckland Council Parks Department with regard to tree species / vegetation selection, tree pit construction where deemed necessary, and the positioning of replacement trees and from directly affected land owners with regards to preferences for any replacement planting for vegetation / trees removed from private property or for any replacement planting on private property;

Section 4.1.2 and Appendix B

(d) Other methods to be used to monitor and report on the management of the adverse effects from tree / vegetation removal;

Section 4.1 4.2

(e) Cross references to the specific sections in the Communication and Consultation Plan which detail how the Auckland Council Parks Department, mana whenua (see condition 8) are consulted, and communication with the general public on the management of the adverse effects relating to the removal of trees and vegetation.

Section 5

DWP Review and Updates

This TV DWP is a live document that will be reviewed at least annually, or as a result of a material change to the project, or to address unforeseen adverse effects on trees and vegetation arising from construction, or unresolved complaints. Any material changes to this TV DWP must be approved by Auckland Council prior to any on-site activity reliant upon the change commencing. Refer to the CEMP for further detail on the review and updating process.

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Aotea Main Works 2.1 Overview of Works

The Aotea main works will involve three main phases of work. Each phase of work involves multiple construction activities which will be undertaken throughout the Aotea project site. The phases associated with the Aotea main works involve; • • •

Foundation works to form the perimeter walls of the station box and underground running tunnels. This involves diaphragm wall construction, roof construction, piling and jet grouting; Construction of the Aotea Station platforms, main station structure, concourse, entrance structures and Plenum, and; Structural fitout of the Aotea Station including MEFH installation, and internal and architectural finishings.

The works require the operation of a Construction Support Area (CSA) within the Bledisloe House car park site and a portion of Mayoral Drive. Equipment used to undertake these works will be predominantly situated in the CSA. Upon completion of the Aotea main works, the area will be repurposed in preparation for public realm reinstatement works2. The methodology for the construction of the Aotea Station is predominantly based on a ‘top down’ and ‘bottom up’ approach. The ‘top down’ approach relates to the southern end of Albert Street (south of Durham Street) and involves the installation of the ‘roof structure’ early on, which enables a limited number of traffic lanes to operate concurrently with the construction of the station, which occurs beneath. This approach reduces the construction effects on traffic flow within the city centre. The tunnel alignment on the northern end of Albert Street (north of Durham Street) will be constructed using a ‘bottom up’ methodology. A detailed description of the Aotea main works is included in the CEMP and includes; • • •

an overview of the works including indicative timeframes in Table 2-1. the construction sequencing including equipment and earthworks volumes for the works in Table 2-2. further detail of the CSA in Section 2.6.2 of the CEMP. Drawings indicating the staging of the construction activities and proposed layout of the CSA is provided as Appendix B.

It is noted that public realm reinstatement works (including tree replacement) and details of architectural finishings for the Aotea Station (Condition 47 – 54 of Designation 2500-1), will form part of separate Outline Plan packages to be prepared in the future prior to the commencement of the respective works2.

2.2 Programme The Aotea main works are anticipated to take approximately 45 months to complete, occurring from April 2020 to December 2023 (approximately) as detailed in Table 2-1 in Section 2.2 of the CEMP. Some construction activities outlined in each phase of the Aotea main works will occur in parallel.

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2.3 Construction Methodology The Aotea main works will be divided into stages as described in the CEMP.

2.4 Roles and Responsibilities The key personnel responsible for this TV DWP are identified in Table 2-1. All site personnel are also responsible for following the requirements of the TV DWP. Refer to the CEMP for further detail on roles and responsibilities. Table 2-1: Key Personnel

Role

Name

Aotea Station Project Manager

Matt Sinclair

Aotea Station Construction Manager

Hunter White

Environmental and Sustainability Manager

Sarah Sutherland

Aotea Station Environmental Advisor

Marie Aguiar

Link Alliance Communications and Engagement Manager

Rachel Blundell

Project Arborist

Matt Paul

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3. Affected Trees and Vegetation A Tree Assessment3 was prepared in August 2012 and formed part of the original Notice of Requirement (NoR) for establishing the CRL designations. The assessment found that there are scheduled trees within or near the construction footprint of Aotea Station and the construction worksite. Two TV DWPs have been prepared for the relocation of utilities prior to the construction of Aotea Station and its associated tunnels. The working areas for these enabling works overlap with the Aotea main works. Therefore, the majority of trees within the project area will have already been removed prior to the commencement of Aotea main works construction. The TV DWP prepared for Stages 1 to 3 and Stages 4 and 5 details where tree removal is required. It was identified in the Stage 4 and 5 TV DWP that an outline of future street tree reinstatements for Aotea Station would be provided in this current DWP, to provide an early indication of how the CRL project will mitigate for the loss of tulip trees along Mayoral Drive. This is presented in Appendix B.

3.1 Affected Trees - Aotea Main Works As the majority of trees initially identified within the construction footprint will be removed during the Stages 1 to 3 and Stages 4 and 5 utility relocation works, the only additional trees to be affected by the Aotea main works are 11 pĹ?hutukawa (T34) trees situated at the southern end of Albert Street, outside the Crowne Plaza Hotel. The location of the impacted trees is shown in Figure 3-1 and Figure 3-2. Table 3-1 provides a summary of the trees that will be impacted by the Aotea main works, and proposed mitigation measures. Figure 3-1: Illustrating trees T34. Image from Google Maps (2019).

Boffa Miskell. (2012). City Rail Link Tree Assessment. Report prepared for Auckland Transport, dated August 2012. | Aotea Station Main Works

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Figure 3-2: Trees (T34) on Albert Street which will be impacted by the Aotea main works. Note that Trees T30 to T33 have been assessed as part of Stage 1 to 3. Table 3-1: Identified Trees Impacted by Aotea main works

Tree ID

Common name

Botanical name

Scheduled

Overall condition

T34*

Pōhutukawa x11

Metrosideros excelsa

Good

Estimate height (m) 6

Project effect

Mitigation measures

Removal

Transplant trees (if practicable); refer to Section 4.1.1. Otherwise trees to be replaced as part of public realm reinstatement.

* = T34 refers to 11 separate trees (all pōhutukawa).

None of the trees detailed in Table 3-1 are scheduled under the Auckland Unitary Plan (Operative in part). Despite this, consideration has been given to the feasibility of relocating all trees planned for removal. Link Alliance Project Arborist, Matt Paul, provided a Tree Transplant Feasibility Assessment to assess the 11 pōhutukawa in terms of their suitability for transplant; this assessment is provided in Appendix C. The following conclusion was drawn from the Tree Transplant Feasibility Assessment; “The restricted root zone and current condition of the trees coupled with their disproportionate height in relation to root zone area determines that they are not suitable for transplant. Furthermore, their current height and potential transplanted size would make them difficult to transplant and ultimately Page 11

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Trees and Vegetation Delivery Work Plan support, either in a temporary location or as part of a permanent solution. Extensive under and above ground support would be required, which would be difficult to install and safely maintain in a public realm environment.”

As it has been concluded that the 11 pōhutukawa trees are unable to be transplanted, they will be replaced as part of public realm reinstatement works in accordance with designation condition 55.3(c).

4. Mitigation Measures As identified above, the Aotea main works will affect the 11 pōhutukawa trees on Albert Street. In order to mitigate the effects of tree removal on the local streetscape and prevent further loss or damage to impacted trees, the following mitigation measures will be implemented during the works. CRLL and the Link Alliance are maintaining a Tree Register for the entire CRL project which, for the purposes of the current TV DWP, includes a record of all trees removed as a result of the Aotea Station construction works.

4.1 Trees Requiring Removal / Relocation As outlined in Section 3.1, the 11 pōhutukawa trees will require removal during the Aotea main works. This work will be undertaken by a suitably qualified and experienced arborist.

4.1.1. Transplanting Trees If transplantation of the trees were deemed to be feasible, this would be undertaken in a manner that allows them to be replanted within the designation area following the completion of main construction works or at another suitable location to be determined in consultation with Auckland Council’s Senior Advisor Urban Forest. Tree relocation methodologies generally follow a set process and shall be informed by the Project Arborist. This process should consider the following: • •

•

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Timing of works – removal should ideally occur outside of active growth stages, after flowering or before flower budding, if practicable. Temporary storage site – this will need to be identified prior to removing the trees. The site must have a hardstand area large enough to house the trees, with a water connection; and be in or near the CBD to allow easy transport. Preparation – prior to being dug out, the trees may need to be pruned and selected branches tied back to protect them during the relocation process, foliage may also need to be sprayed with anti-transpiration prior to works. A trench will need to be dug around the root balls, the dimensions of which will be at the discretion of the arborist, and outer roots trimmed as required. The trench will need to be deep and wide enough to allow the root balls to be undercut at a 45-degree to allow its extraction. Transport – the root balls will need to be covered in damp hessian/burlap to keep as much of the root balls and soil intact during transport. The trees will need to be removed using a digger or small crane and transported, in an upright position, using a flatbed truck. Storage – the trees will need to be transferred to temporary planter boxes large enough to contain the root ball and support the tree during storage. The planter should be kept in a cool, shaded place and the roots kept moist until it can be replanted. Aged mulch and high fungal compost will be added to the planter. | Aotea Station Main Works

Trees and Vegetation Delivery Work Plan •

Replanting – once the relocation site has been identified, replanting will need to be undertaken within a similar window in which the tree is ‘dormant’. The replanting locations and aftercare maintenance should be included in the replanting plans prepared as part the Urban Design DWP4.

It has been assessed that these trees cannot be relocated, therefore, they will need to be replaced in accordance with the criteria described in Section 4.1.2.

4.1.2. Permanent Removal and Replacement It has been assessed by the Project Arborist (refer Appendix C), that the 11 affected pōhutukawa trees will require removal (as opposed to relocation) prior to the commencement of the Aotea main works. The method for removal of these trees will be informed by a qualified arborist in accordance with site observations, such as the proximity of surrounding buildings, tree size and overall condition, and expert knowledge. The methodologies used may include the following: • • •

Staged removal whereby the outer limbs are removed first, followed by inner limbs and the main trunk. As the trees are within planters it will be investigated whether all the tree roots are contained within the planters, therefore, avoiding underground services. Removed tree debris will either be mulched onsite or removed for mulching off-site, depending on which is more practicable.

The Link Alliance will ensure that Council’s Senior Advisor Urban Forest is made aware of any tree felling, including being kept informed of the proposed time and date of tree felling before it takes place. All trees permanently removed as part of the Aotea main works will need to be replaced to address adverse effects on amenity and the local streetscape. If the future public realm reinstatement design allows, replacement trees for those removed from Albert Street will be planted within the same or a nearby area, as part of the site’s reinstatement. If this is not possible, replacement trees will be planted in an appropriate location elsewhere within the CRL designation. The location of replacement trees will be included in a replanting plan prepared as part the Urban Design DWP for the Aotea Station public realm reinstatement. The Urban Design DWP will be prepared in the future (approx. late 2021 / early 2022) and replanting plans will consider the following in accordance with designation Condition 55.3(c): • • • •

Replanting of removed trees at a ratio of at least 1:1. The species and characteristics of replacement trees will be determined following input from Auckland Council’s Senior Advisor Urban Forest. Design for re-instatement of Albert Street, including opportunities to replace removed trees with appropriate native species. Document input from the Auckland Council with regard to tree species / vegetation selection, tree pit construction and positioning of replacement trees.

Relates to Reinstatement of the Albert Street public realm (streetscape). This will occur on completion of the main construction works, confirmed through a sperate OPW. This separate OPW package will address relevant Urban Design related Designation conditions (Condition 47 – 54). Page 13 | Aotea Station Main Works

Trees and Vegetation Delivery Work Plan •

•

An outline of the maintenance periods and responsibilities for care of the trees (i.e. maintenance is to be undertaken by the Requiring Authority for a period of five years for specimen trees and 3 years for all other landscape planting). Any consultation undertaken in relation to the replacement planting (refer to Section 5 of this TV DWP).

4.2 Trees not Requiring Removal As outlined in the TV DWP Aotea Utility Relocation Works - Stages 4 and 5, two trees in close proximity to the CSA (Mayoral Drive) will be retained in situ during the CSA site establishment works (these trees identified as T51 and T52, refer Figure 4-1 below). During the Aotea main works, construction works will continue to occur in close proximity to these trees; there is therefore potential for these trees to be impacted as a result of large vehicle movements and other construction activities.

Figure 4-1: Tulip Trees T51 and T52 to be protected during the Aotea main works.

4.2.1. Tree Protection Zones and Crown Protection Tree Protections Zones around any remaining trees shall be established around each tree to ensure the trunks, roots, canopy and branches are protected during the Aotea main works. The Tree Protection Zone encompasses the root and crown area of the tree that would need to remain isolated from construction disturbance to maintain tree health. The height of the Protection Zone is dictated by the height of the tree and the width (or radius) around the tree is typically calculated by multiplying the tree’s diameter at breast height (DBH) by 12 (AS 4970-2009): Tree Protection Zone = DBH x 12 The Tree Protection Zone will not be less than 2m nor greater than 15m, except where crown protection is required. If a tree is multi-stemmed at 1.4m above the ground (refer to Figure 4-2) the Australian Standard (AS4970-2009) indicates that in this situation the following equation should be used to determine the DBH, which would then feed into the equation above to calculate the Tree Protection Zone:

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Figure 4-2: Tree forks below 1.4m where the arborist would measure DBH (AS4970-2009).

The information needed for this calculation has not been collected within the original arboricultural assessment of trees (Boffa Miskell, 2012), therefore, a site visit will be completed to obtain the measurements needed to determine the Tree Protection Zone. Crown protection will also be required to ensure that the trees do not receive injury from machinery such as excavators, drilling rigs, cranes, trucks and hoarding installation. Crown protection will be located 1m outside of the perimeter of the crown, which may be within the Tree Protection Zone.

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Figure 4-3: Indicative Tree Protection Zone (AS4970-2009).

The following activities will not be permitted in the Tree Protection Zones: • • • • • • •

Mechanical excavation on the road, footpath or any public space. Stockpiling of building materials, debris or soil. Vehicular traffic except on existing paved surfaces. Installation of service pits or hatches. Vehicular crossings. Severing of tree roots with a diameter greater than 30mm. Alteration of soil levels and structure.

The Link Alliance will coordinate a site walk over between Auckland Council’s Aotea Station Environmental Advisor, the Project Arborist, contractors undertaking the works and site compliance officer, to ensure all protection measures are in place for trees requiring protection. Ongoing monitoring will be undertaking by the Aotea Station Environmental Advisor to ensure the trees that are located outside of the area of works are being monitored and where necessary, protected for the duration of the site work. Any issues raised will be directed to the Link Alliance Project Arborist, whom will ensure correct mitigation measures are implemented.

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5. Consultation The Aotea main works Communication and Consultation Plan (CCP) (Appendix G of the CEMP) outlines the engagement to be undertaken with Auckland Council and Mana Whenua. It also details the communications that will be undertaken with the general public (through the CLG) on the management of the adverse effects relating to the removal of trees. Refer in particular to Sections 6 and 7 of the CCP.

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Appendix A: Record of CLG, Independent Peer Review and Auckland Council Comments A1. CLG Comments An Aotea CLG meeting was held on the 19 November 2019 to discuss the Aotea main works and for the CLG to provide comments / feedback on the CEMP and sub-plans, including this TV DWP. No comments were received.

A2. Independent Peer Review Comments Page no.

DWP section

Paragraph/ sentence

Comment

4.1.1

Preparation – prior to being dug out, the trees will need to be pruned and any remaining branches tied back to protect them during the relocation process. A trench will need to be dug around the root balls and outer roots trimmed as required. The trench will need to be deep and wide enough to allow the root balls to be undercut at a 45-degree to allow its extraction.

Resolution

“trees may need” “pruned and selected branches” The foliage may need to be sprayed with anti-transpiration prior to works. Dimensions of the rootball will be at the discretion of the arborist.

Preparation – prior to being dug out, the trees may need to be pruned and selected branches tied back to protect them during the relocation process, foliage may also need to be sprayed with anti-transpiration prior to works. A trench will need to be dug around the root balls, the dimensions of which will be at the discretion of the arborist, and outer roots trimmed as required. The trench will need to be deep and wide enough to allow the root balls to be undercut at a 45-degree to allow its extraction.

4.1.1

Storage – the trees will need to be transferred to temporary planter boxes large enough to contain the root ball and support the tree during storage. The planter should be kept in a cool, shaded place and the roots kept moist until it can be replanted.

Aged mulch and high fungal compost could also be added to benefit the plant

4.1.1

Replanting – once the relocation site has been identified, replanting will need to be undertaken within a similar window in which the tree is ‘dormant’. The replanting locations should be included in the replanting plans prepared as part the Urban Design DWP.

A section for aftercare maintenance should be added.

4.1.2

Depending on the location of utility lines, tree stumps shall either be dug out or ground in situ.

The trees are in a raised planter box, which is also likely to be removed.

• As the trees are within planters it will be investigated whether all the tree roots are contained within the planters, therefore, avoiding underground services.

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A3. Auckland Council Comments DWP section

Comment

Resolution

4.3

Condition 55 will need to be adhered to as outlined with the 1:1 replacement of a suitable sized new tree and that the new trees will receive a minimum of 5 years aftercare maintenance to ensure successful establishment prior to handed over to Auckland Council.

The Link Alliance are currently confirming the processes, information requirements and engagement needed to inform the Urban Design DWP. Meetings with the Link Alliance Urban Design team (who will be leading this process) are currently underway. The Link Alliance will be meeting with Auckland Council within the next couple of weeks to brief them on this process, and this will include how and when the Link Alliance intend on engaging with Auckland Council’s Parks department in relation to tree mitigation (location, number, size, species, tree pits etc).

The Link Alliance should work with council’s parks specialist to start the process of selection and contract growing of the tree stock that will be necessary for the replacement plantings. The Urban Design work plan needs to be urgently developed to show locations for replacement planting 4.1.2

4.2.1

The tree removal work is going to attract public attention and it is important that a consistent set of messages are developed by the Link Alliance communication team to answer public concerns over tree removal. Prior notification of the date for tree removal is requested from the Alliance to Auckland Council representatives prior to works taking place.

The Link Alliance will coordinate between the contractors, comms team and planning team, to ensure Auckland Council is made aware of important matters relating to tree felling.

There is a need to ensure that the tree protection measures for trees directly outside of the area of work are adhered to by the contractors undertaken utility relocation work. In addition, I would request an opportunity for council arborist to walk over the area of works with the contractors where trees are identified as being affected along with their project arborist to ensure that the measures outlined for tree protection are being implemented.

The Project Arborist for the Aotea Station is Matt Paul of Peers Brown Miller. The Link Alliance will coordinate a site walk over between Auckland Council’s Arborist, the Link Alliance Project Arborist, contractors undertaking the works and site compliance officer, to ensure all protection measures are in place.

Ongoing site attendance by the project arborist is recommended as being necessary to ensure the trees that are outside of the area of works are being adequately monitored and where necessary protected for the duration of the site work.

The TVDWP has been updated to include the advance notification of the Council arborist.

The TVDWP has been updated to include this as a step required to be followed by the construction team. Ongoing monitoring will be undertaking by the Link Alliance Site Compliance Officer to ensure the trees that are located outside of the area of works are being monitored and where necessary protected for the duration of the site work. Any issues raised will be directed to the Link Alliance Project Arborist, whom will ensure correct mitigation measures are implemented. The TVDWP has been updated to include this as a step required to be followed.

Appendix B: Aotea Stages 4 and 5 – Indicative Street Tree Reinstatements As a result of CSA establishment works during the Aotea Utility Relocation Works - Stages 4 and 5’ (herein referred to as the ‘Stage 4 and 5 works’), 14 scheduled tulip trees which provide a boulevard effect along Mayoral Drive, will require removal (refer to the ‘Stage 4 and 5 TV DWP’). Through Page 19

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Trees and Vegetation Delivery Work Plan discussions with Auckland Council’s Senior Advisor Urban Forest during the preparation of the Stage 4 and 5 TV DWP, it was agreed that an initial (indicative) plan for reinstatement of street trees would be provided in the Aotea main works TV DWP.

Future street tree reinstatements at Aotea Station Link Alliance Urban Designers have indicated that the main design intent to mitigate the loss of 14 street trees along Mayoral Drive, is to reinstate a boulevard of evenly spaced (6-8 m) tulip trees (Figure B-1).

Figure B-1: Mayoral Drive Tulip Tree Re-instatement

To enable replacement planting to occur the design will need to allow for 15m³ tree pits with adequate drainage and irrigation. Two options for pits are currently being considered: •

•

extending the tree pits under the road to achieve the space required for each tree to reach maturity, without conflicting with services. The pits would be similar to the detail approved for the C2 package (Figure B-2). combining the pits into a single trench in which all trees are located, with a vertical stacking of services located adjacent to the trees.

To determine if there is sufficient space to deliver the tree boulevard at Aotea Station, trial pits will be dug (early 2020) to confirm the location of existing utilities. The Urban Design proposal indicates the reinstatement of 12 tulip trees to offset the loss of trees locally, with the aim of delivering a tree boulevard effect. If spacing allows, and agreement with Auckland Council is obtained, this could potentially include replacement planting along sections of Mayoral Drive outside of the CRL designation boundary.

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Trees and Vegetation Delivery Work Plan

Figure B-2: Cantilevered Tree Pit Page 21

| Aotea Station Main Works

Trees and Vegetation Delivery Work Plan

Appendix C: Tree Transplant Feasibility Assessment

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| Aotea Station Main Works

Memorandum DATE

5 March 2020

Maria Aguiar – CRL Environmental Advisor, AOTEA Station

FROM

Matthew Paul – CRL Consultant Arborist

SUBJECT

Tree Transplant Feasibility Assessment – AOTEA Station Works

1.0

Introduction

In order to undertake the CRL AOTEA Station works, a number of existing trees will be impacted. The purpose of this memorandum is to assess a particular grouping of trees growing within the bounds of the proposed works area, in terms of their suitability for transplant.

2.0 Trees to be assessed The majority of trees standing within the AOTEA station works area were removed in December 2019 and January 2020. An assessment was undertaken, prior to removal, to assess their viability for transplant. No trees were determined to be suitable for transplant, due to a number of factors which included restricted growing location, the cost of service relocation, along with other arboricultural factors that deemed them unsuitable for transplant. Additional trees within the designated works area have also been retained and will be protected during the construction phase, in accordance with best arboricultural practice. The purpose of this memorandum is to provide an assessment of a row of 11x Pohutukawa trees (Metrosideros excelsa) (identified as T24 in the applicable TVDWP, dated 8 November 2019, referenced as CRL-AOT-RME-LKA-PLN-800023). These subject trees stand adjacent to the Crown Plaza Hotel (128 Albert Street), within Road Reserve. The eleven trees stand in a heavily modified environment, being encased in an above ground planter pit that is constrained on all sides by a masonry wall. It is noted that the planter is split into two levels, with an additional wall separating the two levels. The width of the pit in which the subject trees are located is approximately 1.0m.

Link Alliance – Level 3, 12 Morgan Street, Newmarket, Auckland 1023

Figure 1 – subject Pohutukawa row as viewed from the northeast

3.0 Assessment of Transplant Feasibility 3.1 Overall Health At the time of the inspection, undertaken on the 12/2/2020, the trees were in poor-moderate health. The majority of the trees, with the exception of the tree at the northern end of the planter, were exhibiting drought stress. This was evident by the loss of internal canopy growth and condition, manifested by dead leaves and the loss of typical canopy density.

Figure 2 – view of internal canopy, noting canopy sparseness and decline Link Alliance – Level 3, 12 Morgan Street, Newmarket, Auckland 1023

When selecting trees for transplant, it is important to consider the likely severe stress a tree is subjected to as part of the actual transplant works. The majority of a treeâ€™s root zone would typically be severed, with the required root ball for such a tree being typically 2.0m-3.0m in circumference. As such, it is considered that the subject trees would not tolerate such stresses, when considering their current condition. 3.2 Physical transplant and replacement works When considering the viability of a tree/group of trees for transplant, it is important to consider both the ability to remove the tree while still maintaining and ensuring its current and future health. The subject trees stand in a very confined environment, with tight root system associations and intertwining of roots created between the subject trees. The trees have also grown very tall in considering their allowable root zone area, in the pursuit of sunlight. Further to this, the complete dismantling of the planter and wall would be required.

4.0 Conclusion In conclusion, the restricted root zone and current condition of the trees, coupled with their disproportionate height in relation to root zone area determines that they are not suitable for transplant. Furthermore, their current height and potential transplanted size would make them difficult to transplant and ultimately support, either in a temporary location or as part of a permanent solution. Extensive under and above ground support would be required, which would be difficult to install and safely maintain in a public realm environment.

Link Alliance â€“ Level 3, 12 Morgan Street, Newmarket, Auckland 1023