Meridian Energy Ltd Project Hurunui Wind Construction and ... · Meridian Energy Ltd Project Hurunui Wind Construction and Project Overview Construction Effects & Management Report

Meridian Energy Ltd

Project Hurunui Wind Construction and Project Overview

Construction Effects & Management Report

February 2011

Meridian Energy Ltd

Project Hurunui Wind

Construction and Project Overview

Construction Effects & Management Report

February 2011

Prepared By Opus International Consultants Limited Len Wiles Wellington Office Project Engineer Level 9, Majestic Centre, 100 Willis Street PO Box 12 003, Wellington 6144, New Zealand

Reviewed By Telephone: +64 4 471 7000 Gareth McKay Facsimile: +64 4 471 1397 Project Manager

Date: 14 Feb 2011 Reference: 5C-1604.02 Status: Final

© Opus International Consultants Limited 2011

Project Hurunui Wind Construction Effects and Management Report

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Contents

1 Introduction .......................................................................................................................... 1

2 Access Route, Turbine and Fill Site Selection ................................................................... 4

2.1 Preliminary Design Criteria ........................................................................................... 4

2.2 Geotechnical Appraisal ................................................................................................. 7

2.3 Core Site Access Route & Turbine Site Selection ......................................................... 7

2.4 Spoil Fill Site Selection ................................................................................................. 9

2.5 Assessment of Effects & General Consultation ........................................................... 10

2.6 Implementation Team Review ..................................................................................... 11

2.7 Access Options ........................................................................................................... 12

3 Core Site Construction Works .......................................................................................... 16

3.1 Overview and Site Description .................................................................................... 16

3.1.1 General Approach ....................................................................................................... 16

3.2 Land Disturbance ........................................................................................................ 16

3.2.1 Detailed Description of Core Site Access Roads ......................................................... 17

3.2.2 Access Road Formation .............................................................................................. 21

3.2.3 Turbine Platforms ....................................................................................................... 26

3.2.5 Spoil Fill Sites ............................................................................................................. 29

3.2.6 Concrete Works .......................................................................................................... 31

3.2.7 Borrow Areas .............................................................................................................. 32

3.2.8 Soil Stockpile Areas .................................................................................................... 33

3.2.9 Site Lay Down Areas .................................................................................................. 34

3.2.10 Internal Cable Reticulation ................................................................................... 34

3.2.11 Substation ............................................................................................................ 35

3.2.12 66 kV Transmission Line Connection ................................................................... 36

3.2.13 Services Building .................................................................................................. 36

3.2.14 Meteorological Masts (Wind Monitoring Towers) .................................................. 37

3.3 Discharges .................................................................................................................. 40

3.3.1 Erosion, Sediment and Dust Control ........................................................................... 40

3.3.2 Permanent Stormwater Run-off .................................................................................. 43

3.3.3 New Culverts at Stream or Gully Crossings in the Core Site ....................................... 44

3.3.4 Upgrading Existing Culverts Along Motunau Beach Road ........................................... 45

3.3.5 Culvert Construction Methodology .............................................................................. 45

4 Minor Shoulder Widening At Motunau Beach Road ........................................................ 45

4.1 Shoulder Road Widening Opposite Site Entrance ....................................................... 45

5 Geotechnical Assessment ................................................................................................ 46

5.1 Geotechnical Appraisal ............................................................................................... 46

5.2 Geotechnical Risk ....................................................................................................... 46

5.2.1 Potential Slope Instability ............................................................................................ 46

5.2.2 Seismic Hazard........................................................................................................... 47


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6 Other Proposed Activities ................................................................................................. 49

6.1 Detailed Geotechnical Investigations .......................................................................... 49

6.2 Controlled Blasting ...................................................................................................... 49

7 Indicative Construction Methodology, Noise and Lighting............................................. 49

7.1 Indicative Construction Methodology .......................................................................... 49

7.2 Construction Noise ..................................................................................................... 51

7.3 Lighting and Night Works ............................................................................................ 51

7.4 On Site Project Office ................................................................................................. 52

7.5 Bulk Fuel Storage Facility ........................................................................................... 52

7.6 On Site Batching Plant ................................................................................................ 52

8 Summary and Conclusions ............................................................................................... 53

Appendix A – Drawing Plans

A.1 – Overall Site Development Plans

A.2 – Access Road Plans & Cross Sections

A.3 – Landowner Boundary Plan

A.4 – Culvert Location Plans & Typical Details

A.5 – Typical Turbine Platform & External Turbine Transformer Details

A.6 – Hydrological Catchment Area Plan

A.7 – Substation, Underground Cabling & Transmission Line Details

A.8 – Indicative Site Office & Lay-down Area Plan

A.9 – Indicative Wind Monitoring Mast Details

Appendix B – Site Photographs

Appendix C – Typical Transport Details

Appendix D – Preliminary Geotechnical Appraisal

Appendix E – Environmental Management Plan

Appendix F – Photographs Illustrating Representative Construction Requirements

and Effects


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1 Introduction

Meridian Energy Ltd (Meridian) proposes to develop, build and operate a wind farm 66km

north of Christchurch as shown on the site location plan on Drawing Sheet 200 in Appendix

A (Appendix A.1 – Overall Site Development Plans). The proposed core site comprises five

properties, identified on Drawing Sheet 5 in Appendix A (Appendix A.3 – Landowner

Boundary Plan), covering approximately 34km2 and is bounded by:

• Reeces Road to the southwest.

• Motunau Beach Road to the northeast.

• State Highway 1 to the west.

The core site measures approximately 6km and 5km at its longest and widest points

respectively. The core site is approximately 30km south of Cheviot and approximately 34km

north of Amberley. The preferred access to the core site is from Motunau Beach Road off

State Highway 1.

The core site is primarily located along two main ridgelines running in a north-east to south

west direction with some short minor spurs running from the main ridgelines. Both of the

main ridgelines are typically characterised by sections of eastern facing escarpments. The

majority of the site is relatively steep undulating countryside interspaced with numerous

valleys and ridges. The overall site is farm land mainly covered in pasture with some

occasional tussock at higher altitudes and scrub and shrubland vegetation in some of

the gullies. The ridgelines lie between 300m and 550m above sea level. Soil depths within

the area vary typically between 0.5m and 1.0m in thickness, overlying the greywacke

bedrock. Exposures of naturally occurring bedrock are generally slightly to moderately

weathered. Road cuts have exposed some areas of moderately to highly weathered

bedrock. Rock outcrops can be found scattered throughout the site.

The core site is predominantly covered with pasture, and is used for farming. In addition to

tracks (typically 2m to 3m in width), and stock fences that have been established by the

landowners, a water mains network owned by the Hurunui District Council runs through the

project area.

The proposed Project Hurunui Wind will consist of thirty three (33) wind turbine generators

(WTGs) located within the site. The turbines being considered for this site have a

generation capacity of 2.3MW each and a rotor diameter of 101m. The maximum height of

each turbine to the tip of a rotor blade when vertical will be approximately 130.5m.

Each turbine will typically consist of the following components as illustrated in Figure 1

below:

• Foundation, typically completely buried.

• Tapered tubular steel tower.


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• Nacelle which sits on top of the tower and houses the control gear, generator and

the main rotor shaft that transmits the rotating energy from the turbine rotor to the

main gearbox.

• 3 bladed turbine rotor.

• External turbine transformer unit at ground level adjacent to the turbine tower (refer

Drawing Sheet 100 in Appendix A (Appendix A.5 Typical Turbine Platform &

External Turbine Transformer Details) for details.

Figure 1 below illustrates the various components of a typical wind turbine generator.

Figure 1: Typical Wind Turbine Generator (Project West Wind Example)

Construction of an internal core site road network of approximately 22.2km will be required

in order to construct and service the WTGs. In addition minor access tracks will be required

to construct the transmission towers supporting the transmission line between the site

substation and external 66kV transmission line. Existing farm tracks are to be upgraded

wherever possible to reduce the net earthworks required to form core site access roads

thereby minimising the overall impact of earthworks. Upgraded roads, farm tracks and new

access roads are expected to range in widths from approximately 6m wide, in the majority


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of cases, to a maximum of 10m at tight bends. In order to reduce construction effects

access road widths will be kept to a practical minimum.

At each turbine, a flat platform will be formed to provide a cranage area as well as to

contain the turbine foundation. Excavated material from these earthworks would be used

as roading fill, if suitable, while any excess material would be disposed of at appropriate

locations across the core site. Conversely, where there is a shortfall of materials for access

road construction, borrow areas will be established at suitable locations.

Other facilities required in addition to the turbines include:

• Temporary lay down areas during construction.

• Temporary concrete batching plant.

• Temporary erosion and sediment control measures.

• Temporary offices, workshops, stores and staff facilities.

• Electricity substation.

• Temporary mobile crushing plant.

• An underground transmission & fibre optic communication network between the

turbines and substation.

• Overhead transmission between the substation and the external transmission

network.

• A maintenance and operations building.

• Two Meteorological masts (wind monitoring towers).

In general, power from the site will be fed into the local Main Power 66kV Line which runs

parallel to State Highway 1 from the south before following Burrows Road. An internal wind

farm 33kV or 22kV network will be constructed to channel power generated by the WTGs to

the substation. The internal network will generally be underground, typically following the

access roads. One overhead circuit will be incorporated within the internal transmission

network to span a gully between the substation near Road D and Road A as an

underground route is impractical due to significant construction requirements.

This Construction Effects and Management Report has been prepared to support the

application for resource consent. It deals specifically with the civil and access road work

required to construct the wind farm, together with the expected management measures that

will be undertaken during construction and site rehabilitation. Transport of oversized and

overweight turbine components from the Port of Timaru to the site together with any effects

on public roads are addressed in a separate Traffic Impact Assessment report.

Drawing Sheets 1 and 2 in Appendix A (Appendix A.1 Overall Site Development Plans)

illustrates the proposed site location and layout.


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2 Access Route, Turbine and Fill Site Selection

2.1 Preliminary Design Criteria

Preliminary design criteria for road access to turbine sites and the turbine platforms are

governed by:

1. The movement of equipment and materials that are necessary for installing WTGs.

2. The size and weight of the tower sections, blades and nacelle units.

3. The mobility of the main erection crane along access roads and at the turbine

platform.

Equipment sizes and transport needs were discussed with potential turbine manufacturers,

haulage companies and cranage service providers to derive preliminary design criteria for

the access roads. Meridian has gained significant experience from the construction of

Project Te Apiti (completed in 2004), Project White Hill (completed in 2007), Project West

Wind (completed in 2009) and Te Uku (currently under construction). This experience has

also contributed to deriving the preliminary design criteria. Typical characteristics of these

plant items and indicative access road/platform requirements are described as follows:

(a) Tubular tower sections and blades

Based on data provided by New Zealand haulage companies and experience from similar

wind farm projects (Project Te Apiti, White Hill and West Wind), a minimum internal

horizontal radius of 30m has been adopted for preliminary design purposes. A road width of

up to 10m has been provided at such minimum curves.

On a straight section of road, a minimum road/running surface of approximately 6m will be

adopted to accommodate transporters hauling the tower sections and to ensure the safe

passing of other vehicles and the main erection crane as described below. This minimum

road width is adequate where the internal horizontal radius of the access road is greater

than approximately 55m. The main access road from the public road network to the core

site will be approximately 7m wide as it will be more trafficked than the internal core roads.

In addition to providing an adequate road surface width, clearance beyond the edge of the

road surface needs to be provided for the sweep of the overhanging blade where the road

is on a curve. In general, if the internal horizontal radius of the road is less than 175m, the

clearance required is examined on a case by case basis considering the following factors:

• Road width.

• Angle of departure.

• Final trailer configuration.

• Selected turbine type.

• Height of blade above ground when transported.


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Currently a minimum vertical curve radius of 200m has been adopted based on the ground

clearance of a multi-axle platform trailer with 0.5m wheel articulation. It is recognised that

this may be further reduced if the final trailer configuration permits.

Where access road grades exceed 12.5%, we envisage that haulage of the heavier turbine

components, such as tower sections and nacelles, may require additional tractor units,

dozers, or assistance by winching. An upper bound gradient of 15% has generally been

adopted. Steeper gradients may be applied at straight or broad sweeping sections if

unavoidable, subject to a maximum limit of 20%. At tighter horizontal curves, the gradient

has generally been limited to less than 12.5%.

Appendix C illustrates typical tower and blade transport configurations. Actual transport

configurations will depend on the selected turbine.

(b) Nacelle units

Depending on the turbine, nacelle units typically weigh 90 tonnes (which typically includes

an 8 tonne transport frame). Typical road transportation details/schematics (provided by

turbine manufacturers) are attached in Appendix C. An example of an off-road

configuration is also illustrated.

The minimum geometric criteria for transport of the nacelle units around the site are within

the parameters assessed for the blade and tower sections.

(c) Main erection crane

An erection crane capable of lifting the tower sections, nacelle unit and rotors to the top of

the towers (typically 80m) will need to access each turbine site. The erection crane

proposed for this project may have a crane track width of up to approximately 5m. A

photograph of a typical crane is shown on Photograph F1 in Appendix F.

An access road width of approximately 6m is expected to accommodate the main erection

crane based on its operational requirements. This width has been assumed for all roads

within the core site although further detailed design may reduce this width down to 4.5m

towards the end of roads and along spur roads depending on the final crane configuration.

Based on feedback from cranage service providers, a maximum access road grade of 17%

(5.7H:1V or 10o) is considered negotiable by a crawler crane that is unloaded with the boom

up. The crane can also negotiate road grades in excess of 17% by removing the crane’s

boom which may be required along a limited number of road sections.

(d) Turbine platform at turbine locations

The turbine platform at each turbine location is an integral part of the road access. The

turbine platform merges with the road access to enable transporters to deliver turbine

components and provide a working platform to both construct the turbine foundation and

erect the turbine components. Turbine platforms and the access roads are constructed at

the same time and therefore the preliminary design criteria for both are considered

together.

Based on experience gained at Project Te Apiti, Project White Hill and Project West Wind

together with feedback from turbine manufacturers and cranage service providers, a


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minimum platform size of between 40m x 20m and 50m x 35m will be required for turbines

depending on the specific crane selected and ridge positions.

Examples of typical foundation working platforms at Project White Hill and Project West

Wind, during the turbine component erection phase are shown on Photographs F2 to F6 in

Appendix F.

The proposed approach for rotor assembly is to fit the hub followed by the rotor blades one

blade at a time. An alternative option, also known as the single lift approach, is to assemble

the rotor and hub on the ground before lifting the assembly as one unit onto the turbine.

The turbine platforms have been sized based on the proposed approach as the platform

area can be reduced which is beneficial given the site’s hilly terrain.

Photograph F7 and F8, from Project White Hill and Project West Wind respectively, in

Appendix F illustrate the blades being lifted and assembled on to the turbine one at a time.

Based on the above requirements, the parameters outlined in Table 1 have been adopted

for preliminary design.


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Design Aspect Preliminary Criteria Adopted

Main Construction Access

Road To Turbine A11

Approximately 7m wide with a 1.0m drainage channel.

Drainage channel to be provided on both sides in box

cuts.

Localised widening to approximately 10m at internal

radii approaching 30m.

Internal Construction

Access Roads (traversable

by crawler crane)

Approximately 6m wide with a 1.0m drainage channel.

Drainage channel to be provided on both sides in box

cuts.

Maintenance road (post-

construction)

Similar to construction access.

Pavement maintenance to 5m central strip only.

Gradient Preferred < 5%

Normal <12.5% (8H:1V)

Unavoidable ≤ 15% (6.7H:1V)

At extreme locations 20% over straight or broad

sweeping lengths (5H:1V)

Curvature Minimum internal horizontal radius = 30m

Minimum vertical radius (vertical curvature) = 200m (K

= 2)

Working platform (for

cranage and turbine

foundation)

A flat area of approximately40m x 20m up to 50m x

35m depending on cranage requirements and specific

site constraints

Table 1: Preliminary Design Criteria For Access Roads and Turbine Platforms

2.2 Geotechnical Appraisal

Geotechnical and topographic conditions have been considered in developing the proposed

road and turbine layout. Geotechnical risk, potential slope instability and seismic hazard

risks are discussed in Section 5 of this report and are based on the preliminary

geotechnical appraisal presented in Appendix D. Section 5 of this report examines the

seismic risk of the site and the potential instability along access roads and at turbine

locations.

2.3 Core Site Access Route & Turbine Site Selection

In line with operational requirements and efficiency considerations (such as minimising

turbulence and utilisation of higher mean wind speeds), turbines need to be placed clear of

localised topographic obstructions. Hence, turbines generally need to be located on ridge

tops and other clear areas. The broad, flat ridges on the site are suitable locations for WTG

placement.


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All planning and wind modelling studies leading to this final layout have focused on

achieving the maximum number of technically feasible turbine sites on the ridges based on

the design criteria, landowner consent and site geology. The design process adopted to

develop the feasibility layout is described below.

(a) Wind Model

Meridian developed initial turbine positions based on minimum turbine separation of

approximately 5 rotor diameters and 4 rotor diameters to the prevailing upwind and

crosswind direction respectively. This clearance is necessary to avoid turbulence effects

and ensure a smooth laminar air flow. When combined with the terrain/layout of the ridges,

this separation requirement places a constraint on turbine placement.

(b) Desktop Review

Initial turbine positions were reviewed against aerial photographs and 5m contour data

which were obtained specifically for the site. The primary focus of this desktop review was

to identify terrain constraints and potential encumbrances (survey trigs, transmission line,

etc) to the proposed turbine positions in view of the preliminary design criteria for access

roads and turbine platforms summarised in Table 1. Turbines which appeared to be

physically located on or near steep slopes, gullies, local depressions, watercourses, or

other potentially unfavourable terrain were noted prior to the micrositing phase which is

described below.

Other criteria and key aspects considered in developing the turbine and access road layout

included:

• Where possible, access routes were chosen to follow existing tracks, disturbed

areas such as fence lines, contours and ridgelines to reduce environmental effects

and to minimise the earthwork footprint.

• Generally a cut-to-fill approach was adopted where practicable. On steeper terrain,

a cut-to-waste approach was adopted given the difficulty of fill containment on

steeper slopes.

• Taking into account or avoiding where possible:

� Existing trigonometric stations.

� Large rock outcrops/formations or other significant natural features.

� Undisturbed watercourses.

� Damp or boggy areas.

� Areas of high ecological value.

� Steep slopes which are typically slopes > 28o (refer Figure 4 – Site Slope

Analysis Plan in Appendix D).

• Any landowner requirements.

(c) Micrositing

Micrositing involved both Opus and Meridian locating each turbine position in the field to

confirm access and turbine platform feasibility. Turbines were located in the field using a


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hand held GPS receiver with an accuracy of +/- 6 to 12m. Turbines located in unfavourable

positions as described above were moved to a more suitable position within the constraints

of optimal wind generation. Turbines which were repositioned following micrositing are

described below:

• Turbine E1 was relocated approximately 20m away from a prominent rocky outcrop

(Refer Photograph 12 in Appendix B).

• Turbine A4 was relocated approximately 20m to the west to reduce excavation and

ensure the turbine platform was integrated with Road A as indicated on Photograph

17 in Appendix B.

(d) Access Tracks

Following the site-based micrositing exercise, sections of the road that were on particularly

complex terrain were modelled to confirm feasibility. Earthworks quantities were

subsequently derived using the following approach:

• All sections of road were modelled using MXRoad (computer-aided three

dimensional road design package) to derive preliminary longitudinal alignments and

cross sections. For sidling cuts in steeper terrain, a cut to waste philosophy was

generally adopted with cross sections examined for areas of unacceptable cut or fill.

At areas of unacceptable cut or fill minor refinements to the preliminary longitudinal

alignments and cross sections were made to ensure these areas remained within

acceptable limits.

• All earthworks have been estimated using MXRoad generally using a cut-to-waste

approach including areas of gentler terrain to give an upperbound earthworks

quantity and demand on fill site capacity. Fill embankments have been adopted only

along sections of the route where longitudinal gradient and vertical curvature

requirements (refer Table 1 Preliminary Design Criteria) could not be met. However

during detailed design a cut-to-fill approach is envisaged which would result in a

reduction of cut-to-waste earthworks.

Drawing Sheets 11 to 14 in Appendix A (Appendix A.2 Access Road Plans & Cross

Sections) illustrate the proposed turbine locations and derived access road layout from

MXRoad. Roads indicated in the drawings have been identified alphabetically, while

turbines are referenced to the road on which they are located. The final access layout and

position of the turbines will be confirmed following a site survey, detailed design and the

geotechnical/foundation conditions as encountered at each site.

Approximately 22% of the proposed access roads will comprise upgraded existing tracks

(with some localised corner smoothing and widening to approximately 10m).

2.4 Spoil Fill Site Selection

Selecting fill sites for excess excavated material will be generally driven by the following

criteria:

1. Environmental- Sites suitable as fill sites include:


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• Local shallow depressions or the tops and upper reaches of natural dry gullies with

good containment are favoured for compaction, aesthetics, rehabilitation and to

reduce the risk of erosion and damming of natural drainage paths.

• Well drained, broad and gentle terrain is also suitable to ensure minimal impact to

natural flow paths. Fill material can be shaped to reinstate natural flow paths or to

create alternative drainage paths as well as blend into the terrain.

Sites not suitable as fill sites are:

• Boggy or wet areas.

• Gullies or valleys with perennial watercourses.

• Steeper areas where fill cannot be contained in particular slopes.

• Areas of high ecological value.

2. Haul Length - The haul length to and from fill sites needs to be minimised wherever

possible to maximise efficiency and to minimise plant traffic.

3. Geotechnical – Avoid obvious areas of seepage and soft, steep or unstable areas.

Several potential fill sites, near turbine positions and along proposed access roads, have

been identified within the site to accommodate the projected volume of earthworks. These

have been identified by desk top study and site visits. Photographs 50 to 58 in Appendix B

illustrate some of these potential fill sites.

The extent and final position of each fill site will be determined during the detailed design

phase and will be based on the criteria outlined above and the proposed construction

methodology. Refinement of fill site layouts will take place under the framework of the

Environmental Management Plan (EMP) for the site which is outlined in Appendix E.

As part of the process for selecting final fill sites, the design/construction team will discuss

the location, size and depth of potential fill sites with respective landowners, relevant

stakeholders (Councils or other) and the project environmental team to incorporate their

requirements. The fill site selection strategy will involve selecting sites of limited size to

control the area of disturbance and control later re-generation. The site selection strategy

will also consider visual effects by aiming to keep fill areas “internal” to the site so that they

are obscured from external view as far as possible.

2.5 Assessment of Effects & General Consultation

During the development of the preliminary engineering plans, the proposed wind farm

layout was discussed amongst Meridian's assessment of environmental effects (AEE) team

comprising transmission, ecological, noise, planning, traffic, landscape, cultural and

archaeological specialists.


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The AEE team also met on site to discuss the project layout. A key outcome of the process

was the endorsement of the identified turbine sites and road alignments by the assessment

team, in particular:

• Identification and the accurate location of any archaeological, cultural and ecological

sites of significance.

• Identifying preferred main access routes and turbine locations (if necessary) to avoid

environmentally, culturally and archaeologically sensitive areas.

• Criteria for fill site (and borrow area) selection: Avoiding (as identified in Ecological

Values and Assessment of Effects report prepared by Boffa Miskell):

� Covenanted areas such as the recently covenanted QEII land within the

Turnbull property.

� A totara forest remnant within the Batchelor property.

• Avoiding where possible (as identified in Ecological Values and Assessment of Effects

report prepared by Boffa Miskell):

� Areas of higher ecological value.

� Areas for fill sites and construction works within the Motunau and Cave

hydrological catchment areas by locating these areas in neighbouring

northern catchments. This is because the northern catchment areas have

been assessed as having less sensitive receiving environments than the

Motunau and Cave receiving environments. This is generally feasible where

these construction areas straddle both catchments.

2.6 Implementation Team Review

Meridian’s project construction implementation team completed a site visit on 15 April 2009

and 30 July 2009 to provide input and feedback on the proposed layout based on

experience from other Meridian wind farm projects including Project Te Apiti, Project White

Hill and Project West Wind.

Input from this process contributed to:

• Refining the layout of access roads and turbine positions.

• Updating construction timeframes and construction sequencing (discussed in Section

6).

• Refining the lay down area strategy and selection.

• Identifying a potential site office area and lay down areas.

• Identifying potential substation area.

• Identifying internal transmission route options.


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• Refining the criteria for fill site selection criteria as well as identifying potential fill sites.

2.7 Access Options

This section describes the access options considered for hauling wind turbine components

to the core site together from the public road network with a description of the preferred

route. A separate Traffic Impact Assessment (TIA) has been compiled to:

• Assess any impact on traffic together with any proposed means of mitigating impacts.

• Assess route options to transport components from port to site.

2.7.1 Access Objectives

The principal objectives in determining the main access from the local road network are:

• To minimise impact on the environment.

• To manage disruption to other road users and the public road network.

• To maximise the efficiency of material transport.

2.7.2 Core Site Access Options From The Local Public Road Network

This section describes the access options considered from the local public road network to

the core site.

Several potential access options were assessed as indicated below and on Drawing Sheets

3 and 4 in Appendix A (Appendix A.1 Overall Site Development Plans).

Southern Access Options via Reeces Road

1) Southern Access Road Option 1 via Reeces Road (Stevenson Property)

2) Southern Access Road Option 2 via Reeces Road (Turnbull Property)

3) Southern Access Road Option 3 via Reeces Road (Turnbull Property)

Western Access Options via SH1

1) Western Access Road Option 1 via SH1 (MacFarlane Property)

2) Western Access Road Option 2 via SH1 (MacFarlane Property)

3) Western Access Road Option 3 via SH1 (Sowden Property)

Northern Access Options via Motunau Beach Road

1) Northern Access Option 1 Road via Motunau Beach Road (Batchelor Property

2.8km from SH1)


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3.2km from SH1)


3.2km from SH1)


3.2km from SH1)

Each option is discussed below.

Southern Access Options via Reeces Road

1) Southern Access Road Option 1 via Reeces Road (Stevenson Property) – Approx

2.2km Long

This route begins at the entrance to the Stevenson’s residence on Reeces Road

approximately 5.9km from the intersection of Reeces Rd with SH1. This route utilises the

existing driveway up to the Stevenson residence, approximately 600m long, before

following a newly formed access road approximately 1.6km long to access the southern end

of Road D at turbine D1.

The majority of this southern access option route involves moderate earthworks with

minimal road cuts apart from the initial section of this route as it climbs the side of the ridge

in a sidling cut. This route was ruled out as it utilised the existing Stephenson driveway and

there are no other viable options to circumvent this section of the route.

2) Southern Access Road Option 2 via Reeces Road (Turnbull Property) - Approx

2.4km Long

This route begins at the Turnbull entrance off Reeces Road, approximately 7km from the

intersection of Reeces Rd and SH1. This route is approximately 2.4km long and generally

follows an established farm track to Road A between turbines A1 and A2.

This option involves extensive earthworks, significant geotechnical risks and environmental

concerns associated with 2 stream crossings and working along the valley floor adjacent to

a stream. This option was ruled out due to the geotechnical risks associated with the road

cuttings along the steep sided ridge to Turbine A1 and the environmental impact associated

with the stream crossings and section along the valley floor.

3) Southern Access Road Option 3 via Reeces Road (Turnbull Property) - Approx

2.7km Long

This option commences at the southwest end of the Turnbull property, approximately 7.6km

from the intersection of Reeces Rd and SH1. Rather than traverse the side of the main

ridge to reach Road A, as does the previous option, this route generally runs along the main

ridge following 2 stream crossings, both requiring culverts, at the beginning of the route.

This option was also ruled out due to extensive earthworks and the environmental impact

associated with the 2 stream crossings at the beginning of this route.


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Western Access Options via SH1

1) Western Access Road Option 1 via SH1 (MacFarlane Property) - Approx 3.1km

Long

The western access begins at the main entrance to the MacFarlane property, approximately

4.4km north from the junction of SH1 with Reeces Road. This route passes over a railway

crossing and typically follows an existing farm track which generally runs along side the

MacFarlane property’s southern boundary up to Road D between turbines D2 and D3. This

section is illustrated on Photographs 64, 65 and 66 in Appendix B.

This option was also ruled out due to extensive earthworks, the environmental impact

associated with the stream crossing at the beginning of this route and the potential issues

associated with the rail crossing.

2) Western Access Road Option 2 via SH1 (MacFarlane Property) - Approx 2.5km

Long

This option begins approximately 7.8km north from the junction of SH1 with Reeces Road

and generally follows an existing farm track to Road D between turbines D10 and D11.

Sections of this route are illustrated on Photographs 67 and 68 in Appendix B.

This option was also ruled out due to extensive earthworks and the environmental impact

associated with the stream crossing at the beginning of this route.

3) Western Access Road Option 3 via SH1 (Sowden Property) - Approx 1.8km Long

This option begins approximately 11km from the junction of SH1 with Reeces Road and

climbs a low lying ridge to Road D at Turbine D14. This option involves less earthworks and

less environmental impacts than the other western access options described above but still

requires significant earthworks with gradients up to approximately 20% and a maximum cut

height of approximately 20m.

This option was ruled out in favour of the northern access options described below.

Northern Access Options via Motunau Beach Road

Four access options from the north were considered and are described below. The first

option considered provided the most direct route to the turbines but passed close to

neighbouring landowners the Guards and the Symmonds. Three further options were

considered following consultation with these landowners. These three options are also

described below.

1) Northern Access Option 1 via Motunau Beach Road (Batchelor Property) – Approx

2.2km Long

This route commences at the intersection of Motunau Beach Road and the Batchelor/Daly

property approximately 2.8km from SH1. The initial section of this route avoids the main

access to the Batchelor residence and nearby farm buildings by running parallel to the

existing Batchelor/Daly access before linking up with and generally following the main farm

track along an east to west running ridgeline to Road A near Turbine A11.


5C-1604.02

February 2011 15

This route has no stream crossings and the least earthworks of all the northern options

investigated. However the initial section of this route passes close to the boundaries of two

adjacent landowners (Guard and Symmonds) to the north.


2.2km Long

This route commences at the intersection of Motunau Beach Road and the Batchelor/Daly

property approximately 3.2km from SH1. This route was considered following consultation

with the adjacent landowners identified above. The initial section of this route commences

approximately 400m further south of the Option 1 above and offers a significant separation

from the adjacent landowners. The route travels west across two stream crossings and

climbs the next ridgeline south of Option 1 in deep box cuts to meet Road A at Turbine A11.

This route requires extensive cuts reaching approximately 30m and steep gradients up to

20%.

This option was ruled out due to extensive cuts, steep gradients and the environmental

impact associated with two stream crossings.


2.4km Long

This route commences at the same location of Option 2 above and was also considered

following consultation with the adjacent landowners identified above. This route also travels

west across one stream crossing but climbs another east to west running ridgeline south of

Option 2. This route requires significant earthworks and steep gradients up to 20%. The box

cuts required along this route are not as deep as Option 2 and are expected to reach

approximately 16m.

This option was ruled out due to significant earthworks and the environmental impact

associated with the stream crossing.


2.5km Long

This route also commences at the same location of Options 2 and 3 above following

consultation to provide a significant separation from the adjacent landowners. However this

route avoids the stream crossings associated with Options 2 and 3 above by following the

same ridgeline utilised by Option 1 to meet Road A at Turbine A11. To maintain a

reasonable separation between the adjacent landowners this option climbs along the

southern side of ridgeline for approximately 800m before following the same route as

Option 1 to reach Turbine A11 at Road A. The maximum gradient expected along this route

is approximately 15% and a maximum box cut of approximately 18m.

This route requires greater earthworks than Option 1 as a result of providing a reasonable

separation from the adjacent landowners but like Option 1 involves no stream crossings.

This option was selected for the following reasons:

• Provides the most technically feasible option with respect to earthworks while

maintaining a reasonable separation from adjacent landowners.


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February 2011 16

• Requires no stream crossings thereby reducing environmental impacts

• Provides access to the site from a local road rather than a State Highway

3 Core Site Construction Works

3.1 Overview and Site Description

3.1.1 General Approach

The overall access road design philosophy has been to follow existing tracks and tops of

ridges wherever possible. This minimises the volume of excavation (and hence land

disturbance), improves geotechnical conditions, reduces the risk of erosion (due to these

being the flatter areas) and generally avoids areas such as gullies and undisturbed

watercourses.

As discussed in Section 2.1 above the width of the core site access roads are largely

governed by the crane required to erect the wind turbine components, together with the

provision of safe and efficient utilisation for construction traffic. Within the core site two

access road widths have been assumed:

• 7m wide trafficable width (formation width of 8.5m) for the main access road from

the public road network to the core site.

• 6m wide trafficable width for core site access roads.

3.2 Land Disturbance

The main sources of land disturbance will arise from:

• Forming access roads and working platform areas at turbine sites.

• Disposing excess excavated material at suitable sites identified within the project

area. The identification of spoil fill areas is part of the Supplementary Environmental

Management Plan (SEMP) process (Refer Environmental Management Plan in

Appendix E).

• Establishing borrow areas at suitable locations to be identified within the project

area to extract aggregates for road construction.

• Forming turbine component lay down areas at strategic locations.

• Forming platforms for site offices and a workshop.

• Forming a platform for a concrete batching plant.

• Forming a platform for the substation.

• Laying underground cables, or the construction of overhead lines, between the

turbine sites and substations.


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February 2011 17

• Overhead transmission from the substations to the external transmission network.

• Constructing foundations for each turbine.

• Constructing wind monitoring tower foundations.

The indicative access road and site layout are shown in the drawings in Appendix A

(Appendix A.2 – Access Road Plans & Cross Sections). Drawing Sheets 6 and 7 highlight

indicative gradients along each of the access road alignments, while Drawing Sheets 8 and

9 show the approximate cross slopes along the roads and cross reference those to typical

cross sections on Drawing Sheet 10. Access road plans are also provided from MXRoad

which illustrate the construction footprint and location of road cuts and fills. These are

shown on Drawing Sheets 11 to 14 with corresponding extreme cross sections shown on

Drawing Sheets 15 to 19. Drawing Sheets 11 to 14 also identify the location of the access

roads and turbines platforms in relation to areas of higher ecological value identified in the

Ecological Values and Assessment of Effects report prepared by Boffa Miskell. These

drawing sheets illustrate how the road alignments and turbine platforms have been

designed to avoid these areas in all cases apart from the following areas:

• The beginning of Road E prior to the junction between Turbines E1 and E2.

Although Road E has been designed to avoid the majority of an area identified as

having higher ecological value, it passes through the area’s eastern side as shown

on Drawing Sheet 12. Avoiding the area completely by aligning Road E either further

to the east or to the west would involve a greater impact by significantly increasing

road cuts and earthwork volumes.

• The northern corner of the platform for Turbine A11 affects a small section identified

as having higher ecological value. The area affected may be reduced at detailed

design stage when refinements to the turbine platform will be investigated.

• One small section on Road A between Turbines A7 and A6.

The access road alignments and turbine positions as indicated are based on available

topographical and preliminary geotechnical information. During the detailed

survey/investigation and design stage, access road alignments and turbine positions will be

refined to optimise the design and suit terrain/geotechnical conditions. In this regard, it is

recognised that it may be necessary to reposition turbines within a 100m radius placement

area. The same 100m placement envelope will also apply to access roads. This approach

has been approved by the Councils and Environment Court for Project West Wind and

Central Wind. Similarly this approach has been adopted and approved by Council for

Project Mill Creek, currently awaiting an Environment Court Hearing decision.

3.2.1 Detailed Description of Core Site Access Roads

Project Hurunui Wind is sited in reasonably complex terrain and therefore turbines typically

need to be placed on the ridge tops clear of localised topographic obstructions to minimise

turbulence and capture higher mean wind speeds. While the total land holding area of this

project is approximately 34km2, only a small proportion of this is realistically available for

turbine placement due to topographic constraints.


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February 2011 18

Approximately 22.2km of internal access roads will be required to access the turbine sites.

These roads, designated alphabetically from Road A to H, have been planned with nominal

widths of 6m and 7m. Roads on which main cranes are expected to traverse fully rigged

have been planned with a nominal road width of 6m. The main access road which leads to

the core site roads has also been planned with a nominal width of 7m. Additional minor

tracks are required for construction of the transmission towers that support the transmission

line between the proposed substation and external 66kV transmission line. These will be

approximately 3.0m wide.

The 22.2km of roads comprise approximately 5.2km of upgrading of existing farm tracks

with the balance, approximately 17km, being new roads.

The northern access road is the primary internal access road into the site and links with

Road A at the northeastern section of the site. Road C provides the east to west link from

Road A to Roads D, E, F, G and H.

The layout of the roads to turbine sites will be reassessed during detailed design to align

with the final turbine positions and terrain as determined after detailed survey and

geotechnical investigations. Each core site access road is described in detail below with

references to photographs in Appendix B illustrating the location of roads and turbines in

relation to the topography. The relationship between access roads and turbine platforms to

the topography is also illustrated in the Truescape graphical attachments to the Landscape

Assessment Report prepared by Peter Rough Landscape Architects Ltd.

Northern Access Road

The northern access road, at nominally 7m wide along its entire length, will be the principal

access into site for all the construction plant, materials and WTG components. This road

commences at a new entrance off Motunau Beach Road approximately 3.2km from SH1.

From Motunau Beach Road this route runs across the Batchelor/Daly property. The initial

section of this route runs west across a flat paddock before turning north in a wide

sweeping bend adjacent to the proposed laydown area and site offices (refer Photographs

1 and 2 in Appendix B).

From this point the route runs just to the west of the Batchelor/Daly dwelling before turning

west and climbing the beginning of a gentle ridge adjacent to some farm buildings as shown

on Photograph 3 in Appendix B. From this point the route continues to ascend along the

southern side of this gently rising ridge in a series of moderate sidling and box cuts at a

gradient of approximately 11% to just prior to the forested section. The route then traverses

through the forested section in a large box cut with a maximum height of approximately

18m at a gradient of approximately 15%. This section is illustrated on Photograph 4 in

Appendix B.

The northern access road rejoins the existing track as it leaves the forested section and

follows it in a tight horizontal curve around a steep sided ridge in a sidling cut as illustrated

in Photograph 5 in Appendix B. Just prior to the bend the route steepens to approximately

16% before easing to approximately 7% as it enters the curve. Along with the section of cut

through the forest this is the most technically challenging section of the route and will


5C-1604.02

February 2011 19

comprise extensive earthworks with sidling cuts up to approximately 17m in height as

shown on Photograph 5 in Appendix B.

Once the route leaves the tight bend it continues to traverse the ridge in a sidling cut to the

ridge top at a gradient of approximately 15%. From this location the route generally follows

the ridge in a series of cuts and fills to join with Road A at Turbine A11 as shown on

Photographs 6, 7 and 8 in Appendix B.

Road A

Road A is typically 6m wide (apart from the section between Turbines A11 and A9) and

generally runs along one of the two main project ridgelines running in a north-east to south-

west direction. Road A begins in the northeast section of the site at turbine A11 and

terminates at the southwest section of the site at turbine A1.

Road A runs along gentle to moderately undulating terrain in a series of moderate cuts and

fills from Turbine A11 to Turbine A8. The maximum gradient along this section is

approximately 15% just prior to Turbine A8 with a corresponding maximum cut height of

approximately 5m. Photograph 23 in Appendix B illustrates Road A between Turbines A9

and A10 while the section just prior to Turbine A8 is shown on Photograph 13 in Appendix

B.

Between turbines A8 and A7 Road A generally descends following the ridgeline reaching a

maximum gradient of about 13% prior to leveling out at Turbine A7. Beyond Turbine A7

Road A descends at approximately 14% before rising along the ridgeline south towards

Road C and Turbine A6. The section of Road A beyond Turbine A7 is illustrated on

Photograph 14 in Appendix B.

From Turbine A6 Road A descends gradually to turbine A2 generally following the broad

ridgeline in minor cuts and fills. This section is shown on Photographs 15 to 20 in Appendix

B.

The final section of Road A from turbine A2 descends at a moderate gradient before rising

sharply to turbine A1 which is located at the top of a steep sided knoll. In order to reach

turbine A1 a box cut with a maximum cut height of approximately 7m will be required at a

maximum gradient of approximately 20%. This section is illustrated on Photographs 21 and

22 in Appendix B.

Road B

Road B follows a secondary ridgeline which branches off from Road A between turbines A4

and A3. Road B crosses the upper reaches of a gully, which will require a fill embankment

and culvert, approximately 100m from its intersection with Road A. Road B descends at a

moderate gradient reaching a maximum of 13% before leveling off to access Turbine B1.

This section is shown on Photograph 24 in Appendix B. From Turbine B2 Road B

descends for approximately 300m before climbing at a gradient of about 15% in a box cut

with a maximum cut height of 5m over a distance of approximately 100m. The remaining

section of Road B is relatively flat as it terminates at Turbine B1. Photograph 25 in

Appendix B illustrates Road B at Turbine B1 while Photograph 26 shows Road B as viewed

from Turbine A1. Road B is 6m wide.


5C-1604.02

February 2011 20

Road C

Road C links Road A with Road D as well as servicing turbine C1. Road C runs at a

relatively flat gradient from Road A and rises at approximately 15% prior to traversing the

upper slopes of a steep knoll. A maximum cut height of approximately 10m is reached as

Road C traverses this knoll to access the turbine platform for Turbine C1. Beyond Turbine

C1 Road C descends in a moderate gradient winding gently between knolls to Road D.

Road C crosses the upper reaches of a small gully, which will require culverting, just prior to

Road D. This section is illustrated on Photograph 27 in Appendix B.

Road D

Road D is approximately 6m wide and typically follows one of the main project ridgelines

(the other being Road A) running in a north-east to south-west direction. Road D begins in

the northeast section of the site at turbine D14 and terminates at the southwest section of

the site at turbine D1.

The route between turbines D14 and D13 descends at a maximum gradient of

approximately 5% before leveling at a saddle. From the saddle Road D steadily climbs to

reach the short link road to Turbine D13. A maximum gradient of approximately 20% is

expected along this section prior to the link to Turbine D13. This section is illustrated on


Road D rises gently from Turbine D13 to Turbine D12 along moderately undulating terrain.

Between Turbines D12 and D11 Road D rises in an embankment fill at a maximum gradient

of about 17% and a corresponding maximum embankment fill of approximately 5m in depth

before leveling off just prior to Turbine D11. From Turbine D11 to Turbine D10 the

horizontal alignment of the route is relatively straight and the gradients relatively flat. Minor

earthworks are expected along this section.

Between Turbine D10 and Turbine D7 Road D comprises sections of cuts and fills to

maintain acceptable gradients as it continues to follow a broad ridgeline along gently

undulating terrain. The cut heights along this section are modest and remain under 5m.

Photograph 29 in Appendix B illustrates the terrain along this section of Road D.

The topography changes between Turbines D7 and D2 where the ridgeline narrows and

undulates sharply constraining Road D to run in a succession of sidling cuts and saddle fills

to achieve acceptable grades and alignments. Photograph 30 illustrates the section of

Road D between Turbines D7 and D5 while Photograph 31 shows the section of Road D in

the vicinity of Turbine D5. In order to ease the gradient of Road D prior to Turbine D5 a fill

embankment is proposed across a narrow saddle as shown in Photograph 31. The

maximum height of this fill embankment is approximately 16m and it is expected that

suitable material from nearby road cuts will be used as structural fill. From Turbines D5 to

D4 Road D descends along the sharply undulating ridgeline reaching a maximum gradient

of approximately 15%. The maximum cut height along this section is approximately 10m

which represents the largest road cut along Road D. Between turbines D4 to D2 the

ridgeline, although narrow, is less undulating and road D descends in a series of modest

cuts and fills reaching a maximum gradient of 15% over a length of approximately 300m.

Photograph 32 shows this section of Road D between turbines D4 and D3 while

Photograph 33 shows Road D between Turbines D3 and D2.


5C-1604.02

February 2011 21

The route between Turbines D2 and D1 is relatively flat with minor earthworks expected.

Road D comprises gently undulating broad ridgelines at the northeast and southwest ends

of this route but more complex and technically challenging terrain along the middle section

as described above.

Road D1

Road D1 provides access to Turbines D6 and D7 and runs along gently undulating terrain.

Minor earthworks are expected along this route which is shown on Photographs 38 and 39

in Appendix B. This road is approximately 6m wide.

Road D2

Road D2 comprises a short section of road to access Turbine D9. This route is relatively

flat and only minor earthworks are expected. Road D2 and Turbine D9 are shown on


Road E

Road E at approximately 6m wide commences at the intersection with Road D between

Turbines D5 and D7 and circles around the outside of steep sided localised ridge in both

sidling and box cuts to a point where both Turbines E1 and E2 can be accessed along

alignments with reasonable gradients. The maximum cut height is approximately 7m with a

corresponding maximum gradient of approximately 15% as Road B circles outside a steep

sided ridge. Road E is shown on Photographs 34 and 35 in Appendix B.

Road F

Road F runs along a spur running approximately perpendicular to Road D near turbine D11.

A series of moderate cuts and fills characterise Road F as it descends along moderately

undulating terrain to reach turbine F1. Road F is approximately 6m wide.

Road G

Road G is approximately 6m wide and services turbine G1 which is located along a spur

running perpendicular to the Road D ridgeline as shown on Photograph 36 in Appendix B.

This route descends from Road D in a moderate sidling cut reaching a maximum down

slope gradient of about 12% before leveling off in a fill embankment across a narrow

saddle. Road G rises at a gentle gradient of approximately 5% from this saddle in a

shallow box cut to reach turbine G1. The maximum cut height along Road G is

approximately 6m.

Road H

Road H descends along a gently undulating spur running in a southeast direction

perpendicular to Road D. The majority of the earthworks are concentrated at the latter

section of this route where a maximum cut height of approximately 6m is expected. Road H

is shown on Photograph 32 in Appendix B. Road H is approximately 6m wide.

3.2.2 Access Road Formation

Typical Cross Sections and Extent of Cuts


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February 2011 22

Table 2 indicates the typical access road cross sections for the different terrain types with

cut slopes expected in the region of 1H:2V to 1H:4V. Fill slopes, where applied, are

expected to be in the region of 2H:1V as tabulated in Table 3. Typical cross sections are

illustrated on Drawing Sheet 10. Drawing Sheets 8 and 9 illustrate the sections of access

road where these typical cross sections apply. The longitudinal extent of cuttings (length

along the access roads) can be approximated to the linear length of each section identified.

Side Slope at Road Location Typical Cut Slope Typical Cut Height

Road running on ridgeline, in shallow

box cut, or relatively flat land.

(Section A – Drawing Sheet 10)

None

through to 1H : 4V.

Up to approximately

1.5m.

Road in sidling cut with side slopes up

to 20% (1V:5H)

(Section B – Drawing Sheet 10)

1H:2V 2.5 to 3.5 metres.

Road in sidling cut with side slopes up

to 40% (1V:3H)

(Section C – Drawing Sheet 10)

1H:2V

5 to 6 metres.

Box cuts on ridges, or in sidling cut

situations. (Drawing Sheet 10)

1H:2V

1.5 to 6 metres.

Table 2: Typical Cut Slope and Height

Side Slope at Road Location Typical Fill Slope Typical Fill Depth

Road running on relatively flat land or

gentle slopes.

(Typical Section in Fill – Drawing

Sheet 10)

2H:1V Varies, up to 5m

Table 3: Typical Fill Slope and Height

Typical cut heights of 2.5m to 6m described in Table 2 will be similar in scale to some of

those visible along the existing tracks. Photograph 6 in Appendix B illustrates such a cut on

the existing track following the proposed alignment of the northern access road.

Photographs F9 (taken at project Te Apiti) and F10 and F11 (taken at Project West Wind) in

Appendix F illustrate road cuts with approximate heights between 7m to 8m.

Table 4 summarises sections where extremities of cut height are expected (ie batter heights

greater than or equal to approximately 6m.


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February 2011 23

Location

(approx)

Approx. Maximum

Batter Height of Cut (m)

Approx. Length of Individual Extreme Cuts (m)

Approx. Maximum

Earthworks Width & Location

Indicative Section in Drawing

Sheets 15 to 18 T

yp

ical C

ut

Slo

pe

Northern Access Road (1.0km

from Motunau Beach Road) 18 350 31m @ 1300m Section 1

1H

:2V

(B

enchin

g a

t 5m

inte

rvals

)

Northern Access Road (1.5km

from Motunau Beach Road) 17 140 20m @ 1550m Section 2

Road A (Between A1 & A2) 7 130 14m @ 350m Section 3

Road A (Between Road C & A2) 7 40 19m @ 50m Section 4

Road A (Between Road C & A2) 8 100 19m@890m Section 5

Road A (Between Road C & A11) 8 40 18m @ 2300m Section 6

Road A (Between Road C & A11) 7 70 19m @2710 Section 7

Road C 10 150 19m @ 580m Section 8

Road D (Between D1 & D3) 9 60 15m @ 480m Section 9






Road E (Between Road D & E1) 7 50 14m @ 120m Section 15

Road E (Between Road D & E1) 7 70 14m @ 290m Section 16

Road G (Between Road D & G1) 6 100 13m @ 550m Section 17

Table 4: Extremities of Cut Height (Batter Cut Heights >= 6m)

The cumulative length of sections where the cut height is greater than or equal to 6m is

approximately 1.6km, which equates to approximately 7% of the proposed total access road

network. In this respect, sections with cut heights greater than 6m only occur along a relatively

small proportion of the entire access road network. We note that preliminary geotechnical

investigations suggest that cut faces greater than 5m height should be benched at 5m intervals.

Therefore these sections identified in Table 4 will be benched.

The maximum batter height referred to in Table 4 is represented as the height of the cut face from

the toe of the cut to the top of the batter. This measurement is illustrated in Figure 2 below.


5C-1604.02

February 2011 24

Figure 2 – Batter Height of Cut

Table 5 tabulates sections where fill depths are expected to exceed typical depths. Typical

cross sections at these extremes are illustrated in Drawing Sheets 15 to 18. The total

length of road with cuts greater than or equal to 6m is 1.58km.

Location

(approx)

Approx. Maximum

Fill Depth(m)

Approx. Length of Individual

Fill Sections (m)

Approx. Maximum

Earthworks Width & Location

Indicative Section in Drawing Sheet 18

Typ

ical F

ill

Slo

pe

Road D (Between D1 & D3) 6 50 60m @

STA1370 Section 21

2H:1V Road D (Between D3 & D7) 16 170 13m @ STA

2250 Section 22

Road E (Between Road D & E1) 5 40 22m @ STA

50 Section 23

Table 5: Extremities of Fill Depth (Fill Depths >= 5m)

Geotechnical investigations and observation during construction will also identify any areas

of cutting with a potential for seepage, such as any areas with high groundwater pressure

within the bedrock. Where seepage is likely to occur, measures such as horizontal

drainage, or subsoil drains can be provided to control erosion. However, given the geology

of the formation and observations on site, groundwater is unlikely to be of significant

concern.

As the works progress, the aim will be to rehabilitate (as appropriate) exposed cut and fill

slopes as soon as is reasonably practicable. A requirement to this effect will be included in

the construction contract documentation and will be included as part of the proposed

conditions of consent. Rehabilitation for cuts in soil and fill slopes will use the most

practical and effective re-vegetation techniques available at the time the work is required.

Revegetation techniques are discussed in more detail in the Ecological Values and

Assessment of Effects report prepared by Boffa Miskell and incorporated in the

Environmental Management Plan prepared by Tonkin and Taylor.


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February 2011 25

Estimated Cut Volumes

The pessimistic volume of earthworks associated with formation of the access roads, based

on the preliminary investigations to-date, is summarised in Table 6 below. The pessimistic

earthworks volumes are calculated as 15% over and above the “most likely” earthworks

volumes determined from MXRoad (computer-aided three dimensional design package).

The volumes presented represent the upper bound of materials as we have assumed that

earthworks will be undertaken on a cut-to-waste approach. Actual excess excavated

material will be lower given that a cut-to-fill approach will be applied during detailed design.

Table 6 below also shows that approximately 5.2km of access roading comprise of existing

tracks which equates to approximately 22% of the total length of access roads.

Road Approximate

Length (km)

Approx portion

comprising upgraded

existing tracks (km)

Cut Only

(m3)

Northern Access Road 2.5 1.8 123,000

Road A 5.8 1.4 98,000

Road B 1.9 17,000

Road C 1.4 30,000

Road D 7.3 1.8 121,000

Road D1 0.5 6,000

Road D2 0.3 4,000

Road E 0.9 11,000

Road F 0.6 4,000

Road G 0.8 16,000

Road H 0.5 0.2 5,000

Project Total 22.5 5.2 435,000

Table 6: Estimated Access Road Excavation Volumes

Access Road Surfacing

Access roads will typically be unsealed with a basecourse running surface. Roads will be

categorised as to the level of construction traffic on them with an expected design depth of

basecourse between 100mm and 200mm depending on traffic levels and ground

conditions.

Initial geotechnical investigations suggest that material sourced within the project area from

excavations for the access roads, working platforms and foundations is unlikely to be of

sufficient strength to provide an adequate source of basecourse. We have observed that

the quality of bedrock is variable (ranging from fresh and unweathered to exposed and

weathered). Further detailed geotechnical investigations will be required to confirm

whether on-site material is suitable for use as a basecourse. In the event suitable material

is available on site excavated materials can be stockpiled at localised processing areas


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February 2011 26

where a mobile crushing plant will be employed to produce the required grade of

basecourse material. This is discussed in more detail in Section 3.2.8 on borrow areas.

In some circumstances, where longitudinal grades of principal roads exceed 15-18%, it is

possible that the 5m central portion of the road may be sealed to improve traction and

reduce maintenance needs. Any pavement seal is likely to comprise chip seal depending

on the maintenance strategy developed during the detailed design stage.

3.2.3 Turbine Platforms

While the maximum foundation base is expected to be approximately 16m to 18m in

diameter (depending on final turbine and ground conditions), a larger flat area is required to

accommodate the main tower and turbine erection cranes. Drawing Sheet 80 of Appendix

A.5 shows generic requirements for a flat working platform. The area required will depend

on the final crane configuration and any site specific constraints.

The pessimistic volume of excavation associated with platform construction based on an

upper bound 50m x 35m platform is summarised in Table 7.

Road Nos. of Turbines Cut (m3)

Road A 11 84,000

Road B 2 11,000

Road C 1 13,000

Road D 12 69,000

Road D1 1 6,000

Road D2 1 2,000

Road E 2 20,000

Road F 1 3,000

Road G 1 10,000

Road H 1 7,000

Project Total 33 225,000

Table 7: Estimated Turbine Platform Excavation Volumes

A maximum excavation depth of approximately 1.5m to 3m is typically required at sites on

flat to gently rolling terrain to create the required platform area. However, sites with more

undulating terrain require excavation greater than or equal to approximately 5m to create

the required working platform area and/or to interface with the access road. Table 8

summarises approximate average and maximum turbine platform excavation depths where

the maximum platform cut height is expected to equal or exceed 5m. The approximate

maximum cut depth presented, which represents the maximum height of cut that is likely to

occur at the respective platform location, is illustrated in Figure 3 for three typical terrain

types.


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February 2011 27

Photographs F12 and F13 in Appendix F show a turbine foundation at Project West Wind

before and after concreting and backfilling. Photographs F14 and F15 in Appendix F show

a turbine foundation and platform at the operational stage of Project White Hill.

Hillside cut

Ridge cut

Saddle cut Ap

pro

x M

ax

Cu

t

Ap

pro

x M

ax

Cu

t

Ap

pro

x M

ax

Cu

t

Figure 3: Approximate Maximum Cut Depth Definition


5C-1604.02

February 2011 28

Road Turbine

Approx. Cut Depth (m)

Average Maximum

Road A

A2 4 7

A3 4 10

A7 3 8

A8 4 5

A9 3 5

A10 5 10

A11 3 6

Road B B1 3 5

Road C C1 5 9

Road D

D5 2 6

D6 3 5

D7 3 5

D10 3 5

D12 4 5

D14 4 7

Road E E1 5 7

E2 4 5

Road G G1 3 5

Table 8: Turbine Platforms - Excavation Expected to Equal or Exceed 5m in Height

3.2.4 Construction Footprint of Roads & Turbine Platforms

The construction footprint of core site access roads including turbine platforms calculated

from MXRoad and illustrated on Drawing Sheets 11 to 14 in Appendix A (Appendix A.2

Access Road Plans & Cross Sections) is shown in Table 9 Below.


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Road Approximate

Length (km) No. of Turbines

Const.

Footprint

(m2)

Northern Access Road 2.5 33,000

Road A 5.8 11 82,000

Road B 1.9 2 21,000

Road C 1.4 1 9,000

Road D 7.3 11 111,000

Road D1 0.5 2 8,000

Road D2 0.3 1 4,000

Road E 0.9 2 13,000

Road F 0.6 1 6,000

Road G 0.8 1 11,000

Road H 0.5 1 7,000

Project Total 22.5 33 305,000

Table 9: Construction Footprint of Core Site Roads and Turbine Platforms

3.2.5 Spoil Fill Sites

During the earthmoving operation excess excavated material will be placed at clearly

defined spoil fill sites. These locations will be selected during detailed design/construction

in accordance with the criteria outlined in Section 2.4. In some locations material may also

be utilised to aid localised shaping of the adjacent ground to blend in the construction

works.

Based on observations of the site, the majority of spoil fill sites will occupy areas of pasture.

The total area required to dispose of the pessimistic earthworks cut volumes, within the site

assuming a conservative average fill depth of 2.5m, would be in the order of 250,000m2

(0.25km2). This represents just under 1% of the total land holding area of the site (34km2).

Given the landform’s potential to provide well contained sites, the fact that earthworks

quantities are likely to be lower than the pessimistic value quoted and the sites are

generally capable of holding greater than 2.5m depth of fill, the total area of potential fill

sites is expected to be smaller than the figure estimated above. Photographs 50 to 58 in

Appendix B provide examples of typical well contained fill sites throughout the core site.

The criteria for avoiding areas of high ecological value (areas not suitable for spoil fill sites)

have been assessed in the Ecological Values and Assessment of Effects report. The

detailed design/construction team will consult landowners and other relevant stakeholders

in the process of identifying and selecting the location and number of fill sites in accordance

with the process outlined in the draft Environmental Management Plan (EMP) in Appendix


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E. The extent and fill depths for each site will also be confirmed on the ground with

landowners/relevant stakeholders prior to construction and included within the

Supplementary Environmental Management Plan.

It is expected that the following typical measures would be incorporated into the design and

construction of the fill sites, as appropriate:

• Strip topsoil and soft materials from the ground surface and stockpile.

• Bench slopes as required to key in fill.

• Install subsoil drainage in the base of gullies with branches to areas of observed

seepage

• Prepare surface drains within and on the periphery of the site to prevent erosion and

mitigate run-off as applicable.

• Compact the fill adequately to ensure sufficient strength for stability and minimise

settlements.

• Adopt an appropriate fill profile for stability by considering the nature of the material

and proposed fill height. The outer profile of the fill may vary between 3H:1V to

2H:1V.

• Where appropriate, surface cut off drains will be formed around the head of fill sites.

Such drains are to have controlled outlets in stable locations clear of the fill area and

any areas of hillside instability.

• Shape final surface of the fill to blend into the landform.

• The surface of the fill will generally be covered in topsoil (which has been previously

removed and stockpiled) and vegetated with suitable and appropriate ground cover.

The plant species shall be consistent with the species in the immediate vicinity of

the exposed area, replacing “like with like”. Generally the site is covered in pasture

and this is expected to be the predominant ground cover, with some areas of silver

tussock.

• Sediment control measures, as discussed in Section 3.3, will be installed to manage

sediment run-off during construction and until ground cover is established.

Examples of fill sites at other Meridian Wind Farm Projects are provided in Appendix F.

These are described as follows:

• Photograph F16 illustrates a fill site being prepared with benched slopes at Project

White Hill.

• Photographs F17 and F18 show fill sites being prepared at Project West Wind.

• Photograph F19 shows a disposal fill site at Project West Wind under rehabilitation.


5C-1604.02

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• Photograph F20 illustrates a rehabilitated fill site at Project Te Apiti.

3.2.6 Concrete Works

Two foundation types may be used within the site depending on bedrock competency and

the depth of any overburden. These are a standard gravity pad or a rock anchor solution.

Specific foundation details will be developed during the detailed design in conjunction with

detailed geotechnical investigations and site specific testing. Indicative reinforced concrete

foundation concepts are illustrated in Drawing Sheet 80 in Appendix A (Appendix A.5

Typical Turbine Platform & External Turbine Transformer Details). The pessimistic volume

of reinforced concrete associated with the gravity pad and rock anchor solution,

respectively, is estimated to be approximately 400m3 and 120m3 per foundation.

In order to provide an indication of resource inputs to the foundation construction a

conservative scenario based on the use of standard gravity pad foundations at all sites has

been adopted. Table 10 below summarises the approximate total volume of concrete and

the total number of concrete truck trips required based on this foundation type. We have

assumed that concrete trucks will only be 75% full due to the gradients present (ie 4.5m3

per truck).

Volume of Each Pad (m3) Total Volume of 33

Pads (m3) (Including

site concrete)

No. of Trucks

per pad

Total No. of

Trucks

400 13,200 94-96 3,200

Table 10: Concrete Pad Foundation Volumes and Truck Trips

At these production volumes it is envisaged the contractor will establish an on-site concrete

batching plant to minimise the number of truck movements on the public road network and

increase efficiency, i.e. fewer larger trucks delivering cement and aggregate. Such an

approach on Project Te Apiti, White Hill and West Wind has demonstrated these benefits.

Employing concrete batching plants is discussed in more detail in Section 7.

We have assumed concrete aggregates will be sourced off site. Potential sources of

concrete aggregates have been identified from quarries at local rivers such as the Hurunui

to the north/northwest and the Waipara to the south.

Subject to approval from the Hurunui District Council, water supply for the batching plant

may be sourced from the mains water supply network located throughout the site.

Otherwise water will be delivered to site by tankers(Refer to section 3.2.17 for further

information).

It is estimated that 72,000 litres (72m3) of water will be required for each 400m3 foundation.

Based on 33 gravity pad foundations, Table 11 indicates the average demand on resources

during turbine foundation construction.


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February 2011 32

Concrete

Component

Estimated Demand

(Turbine

Foundations)

Estimated

Demand Per

Pour (Same

Day)

Approximate

Indication of Average

Demand

Cement 3,200 tonnes 94 tonnes 3 x 23 tonne bulk

carriers per day

Sand and

Aggregate

27,000 tonnes 800 tonnes 13 x 23 tonne trucks

per day

Water 2.4 million litres 72,000 7 tankers (10,000 litre

capacity) per day

Table 11: Indicative Batching Plant Demand on Materials

We envisage that measures to contain any dust, spillage and wash down of plant or trucks

will be outlined in the contractor’s management plan. Such measures are likely to include

cement storage within a silo, aggregate storage bins, a temporary concrete slab beneath

the loading area and containment bunding around the plant.

3.2.7 Borrow Areas

Basecourse material may be sourced within the project area from excavations for the

access roads, working platforms and foundations wherever practicable. Basecourse

material may also be sourced from borrow areas within the site. However, an appraisal on

the availability of suitable material on-site for processing roading and platform basecourse

would be undertaken at the detailed design phase to determine whether suitable material is

available on site.

In the event that locally won materials will be suitable for road construction, borrow areas

would be established at locations within the site which meet the same criteria established

for fill sites (outlined in Section 2.4). Extracted materials will be stockpiled at localised

processing areas where a mobile crushing plant will be used to produce the required grade

of basecourse material. Material may also be extracted from these borrow areas for

roading fill where there is a shortfall of suitable material excavated from road construction.

The total pessimistic volume of basecourse required for roads, turbine platforms and

laydown areas is approximately 41,000m3. Assuming this involves approximately 90% of

the equivalent volume in overburden to extract this material and an average borrow site

depth of approximately 3m the following construction footprint expected is approximately

25,000m2. These details are summarised in Table 12 below.

Total Volume of

Basecourse (m3)

Equivalent Volume

of Overburden (m3)

Total Combined

Volume (m3)

Construction

Footprint (m2)

41,000 35,000 76,000 25,000


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Table 12: Potential Basecourse Volumes and Borrow Areas

Should all basecourse be sourced on site the potential construction footprint would be

approximately 25,000m2. This is minimal compared to the construction footprint of 285,000

m2 estimated for disposal fill areas associated with core site access roads and turbines

(less than 10%).

We expect the following activities and typical measures would be incorporated into the

identification, design and operation of borrow areas, as appropriate:

� A site appraisal by the design/construction team, in consultation with landowners

and other relevant stakeholders, to identify suitable borrow areas in line with the

EMP. Areas of ecological value, particularly around rocky outcrops, as described in

the road layout and fill site selection (Sections 2.3 and 2.4), will be avoided.

� Detailed soil investigation involving deep boring and trial pits at identified locations

to confirm suitability for material extraction.

� Initial establishment of borrow area by site clearance followed by stripping and

stockpiling topsoil.

� Establishing a mobile crushing plant. A typical mobile crushing plant comprises a

hopper, jaw crusher, conveyor and screen attached to a tracked wheel vehicle. An

excavator generally fills the hopper with material for processing into basecourse.

� Excavation, processing and stockpiling of materials.

� Fill of excess or unwanted materials at suitable fill site locations.

� Mitigation to control run-off and sedimentation. Sediment control measures, as

discussed in Section 3.3 below, will be provided to manage sediment run-off during

operation and until ground cover is established after rehabilitation of the borrow

area..

� Reshaping the borrow areas to blend in with the surrounding terrain, re-topsoiling

(with material which has been removed and stockpiled) and re-vegetating. Measures

will be discussed and agreed with landowner. Note that the overburden material

extracted from borrow areas and other surplus material from the civil works may be

used to fill in borrow areas prior to topsoiling.

At Project West Wind a mobile crushing plant was established on site at a borrow area near

Oteranga Bay to produce materials for core site access roading and turbine platform

basecourse. This mobile crushing plant and borrow area is illustrated on Photograph F21

in Appendix F.

3.2.8 Soil Stockpile Areas

Topsoil will be stockpiled throughout the site for re-topsoiling fill sites, platform areas and so

on. Long-term stockpiles will be temporarily stabilised by hydroseeding or hydro-mulching,

if necessary, to reduce erosion and sediment generation.


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3.2.9 Site Lay Down Areas

WTG components will be delivered from port to site ahead of installation. Therefore lay

down or stockpile areas will be required for temporary storage of turbine components, as

well as other materials such as electrical cables. Rather than creating multiple large lay

down areas for the bulk storage of turbine components, Meridian proposes to store turbine

components near turbine locations using the turbine platforms and storage lay-bys adjacent

to access roads where possible. This is to allow for sufficient components/materials to be

stockpiled on site to meet the demand of construction crews as well as to accommodate the

arrival of several large shipments of components. Photographs F2 to F6 in Appendix F

show how turbine platforms have been used to store turbine components while being lifted

and assembled at both Project White Hill and Project West Wind. Photograph F22 shows a

typical lay down area to store turbine blades at Project West Wind.

The optimum and most strategic locations for storage lay-bys will be dependent on a more

detailed study of the construction and installation sequences. At this stage potential

storage lay-bys have been identified at the following locations:

� Near Turbine A9 along existing air strip as shown on Photograph 23 in Appendix B.

� Adjacent to the initial section northern access road as shown on Photograph 2 in

Appendix B.

3.2.10 Internal Cable Reticulation

A 33kV or 22kV and fibre optic internal cable reticulation system is required to link the

turbines to the substation. The internal cable layout developed for this project is a series of

separate cable strings leading from the substation connecting all turbines along each main

access road. These cables will generally be placed in trenches running along the formed

access roads. It may be necessary to adopt some overhead reticulation to avoid hard,

unstable or boggy ground or avoid a longer underground route only where the overhead

line can be masked, or hidden from the skyline. For example an overhead line will be

required to span a gully between Road D and Road A. Note this overhead line is internal to

the site and any overhead reticulation would be constructed from monopole structures no

taller than 20m.

Typical trench dimensions could be 400mm to 600mm wide and 800mm to 1000mm deep.

Where two cables run along a common road trenches will be located on either side of the

road. Where off-road routes are required, trenching operations may require a working

corridor of up to 5m (to form a cable trench) depending on the number and type of cables.

Cable trenches will typically have a granular backfill to meet required thermal resistivity and

engineered fill with pavement or topsoil (material which has been removed and stockpiled)

layer above as appropriate.

Where overhead routes are employed, routes will be selected to follow the access road and

existing tracks/fencing corridors where possible. In the event a cross country route cannot

be avoided, it is envisaged that overhead line construction will require the establishment of

an appropriate corridor including access to any transmission poles.


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February 2011 35

Indicative cable trenching details are illustrated on Drawing Sheet 102 in Appendix A

(Appendix A.7 Substation, Underground Cabling & Transmission Line Details). Photograph

F23 in Appendix F shows a typical buried cable being constructed.

3.2.11 Substation

Substation Platform

A substation will be required to connect the turbines to the Transmission grid. The

proposed location for the substation is just south of Turbine D11 on the western side of

Road D as shown on Drawing Sheets 81, 82 and 83 in Appendix A (Appendix A.7

Substation, Underground Cabling & Transmission Line Details). The substation compound

area will occupy an area approximately 79m by 46m. A maximum cut height of

approximately 5m will be required on the edges of the construction footprint to create a

single level platform for this substation as shown on Drawing Sheet 83. The indicative

construction footprint, including batter slopes, and the pessimistic volume of excavated cut

are shown in Table 13 below.

Indicative Substation Footprint (m2) Cut (m3)

5,000 16,000

Table 13: Substation Construction Footprint and Cut Volumes

Although detailed geotechnical assessment of the site has not been completed at this

stage, ground conditions are unlikely to present any problems. Once the substation site is

established, the surrounding area that has been disturbed will be re-vegetated as

appropriate.

Substation Buildings & Construction Activities

The following activities will be required at this substation:

� Construction, maintenance and use of a substation switch room for housing a

switchgear suite and associated equipment. The dimensions of the switchgear

building are approximately 14m long, 11m wide and a height of no more than 6m.

The switchgear building will be located within the substation perimeter fence.

� Construction, maintenance and operation of a switchyard located within the

climb/predator/pest-proof fenced substation area. The switchyard will include

switching gear, insulators, circuit breakers and a main transformer, lightning

protection masts up to 20m tall), communication equipment and other associated

equipment. The communication equipment will consist of either a maximum of two

dishes mounted on the side of the substation building or on a 5m mast beside the

building.

The transformer will be oil filled and located within appropriately designed bunds to retain

any oil leakage and avoid any contamination of the stormwater runoff in the unlikely event

of an oil spillage. As such, it is envisaged that a low concrete bund will be provided around


5C-1604.02

February 2011 36

the transformer together with a concrete ground slab. Oil-water interceptor tanks will be

constructed below the bunded area to separate and collect any spilt oil from rainwater.

The substation switching gear, insulators, circuit breakers and main transformers will be

less than 7m in height.

A boundary stock proof fence (approximately 1.2m high wire mesh) will be constructed

around the perimeter of the substation site and an internal 2.3m high wire mesh security

fence at a distance of 10m within the boundary fence.

Drawing Sheet 84 in Appendix A (Appendix A7 Substation, Underground Cabling &

Transmission Line Details) shows indicative layout details of the substation facilties

together with the services building discussed below.

3.2.12 66 kV Transmission Line Connection

A multi span single line 66 kV overhead connection is proposed to connect the substation to

the Mainpower 66kV Line, which runs adjacent to the western side of the project. The

proposed transmission line is approximately 2.7km long and supported on 12 transmission

line structures. The transmission line structures proposed are concrete double pole

structures, known as Pi Poles, no greater than 22m high. Indicative details on the layout

and the proposed structures are shown on Drawing Sheets 85 and 103 in Appendix A

(Appendix A.7 Substation, Underground Cabling & Transmission Line Details). The

majority of pole structures will be supported by guy wires to reduce the size of the pole

foundations. We expect each pole foundation will comprise a bored hole approximately

800mm in diameter and approximately 2 metres deep filled with concrete. It is likely the

foundations supporting the guy wires will also be concrete filled bored holes. The total

volume of concrete per pole structure is expected to be minimal at approximately 10m3.

The potential effects of the proposed transmission line route and structures have been

minimised by:

• Reducing visual impact by avoiding ridgelines.

• Avoiding constructing access roads to each transmission structure by locating the

transmission structures near existing established farm tracks.

• Reducing the number of structures by reducing the number of turn angles

Within the substation a single gantry no greater than 20m high will provide the overhead

link to the main 66kV transmission line. Photograph F24 in Appendix F shows a typical

gantry structure (Project White Hill) similar to the one proposed for this project. It is

important to note that the gantry structure shown in Photograph F24 is a double gantry

whereas this project proposes a single gantry structure.

3.2.13 Services Building

A permanent services building, including car-parking, for post construction maintenance is

required. The services building will house a workshop, control room (for managing

turbines) and amenities. The dimensions of the services building are approximately 33m x

11m. The services building will be single story portal frame structure with steel cladding.


5C-1604.02

February 2011 37

The maximum height of the services building is 7m. The services building will be serviced

for water, sewerage and stormwater as described above for the switchgear building. The

Services building will also support some communication equipment for operation of the

wind farm site. This equipment may include up to two communications dishes mounted on

the side of the building.

The services building will be serviced in the following manner:

� Water supply: It is likely the building will rely on a rainwater collection system with

on-site storage tank or tanks, or use the local mains supply if authorised by the

Hurunui District Council.

� Sewerage: Any foul water will be directed to a septic tank located within the site

area. Foul water flows are expected to be minimal, being generated from a single

toilet, washbasin and kitchen area. Flows are likely to be managed easily by the

soakage field contained within the site. Prior to design a soakage test will be

undertaken to confirm the size of soakage field required.

� Stormwater: Runoff is expected to be minimal given the intention to collect rainfall

runoff. Excess rainwater will be directed on to land/adjacent undisturbed areas.

3.2.14 Meteorological Masts (Wind Monitoring Towers)

Two wind monitoring towers up to approximately 80m in height will be installed on the site

to provide wind data for operational purposes. The proposed location of the wind monitoring

masts are shown on Drawing Sheet 1 in Appendix A (Appendix A.1 Overall Site

Development Plans).

The wind tower is likely to comprise a steel truss structure on a concrete foundation pad of

approximately 8.6m x 8.6m x 1m thick. Indicative wind monitoring tower details of a lattice

tower is presented on Drawing Sheet 101 in Appendix A (Appendix A.9 Indicative Wind

Monitoring Mast Details). Guyed towers may also be utilised.

The position of the wind monitoring tower is determined by the location of the turbines and it

may be necessary to reposition the wind monitoring tower within a 150m radius of the

indicated placement area.

Construction of the tower will require the preparation of a flat working platform of

approximately 12m x 12m to accommodate a crane and other construction vehicles. The

sites as indicated have been selected in view of their relatively gentle grades in order to

minimise earthworks. Working platform preparation and rehabilitation is envisaged to be

similar to that for turbine platforms (but minor in comparison) as described in Section 3.2.3

above.

3.2.15 Estimated Earthwork Volumes & Construction Footprint - Summary

The pessimistic estimate of the all land disturbing activities within the core site is

summarised in Table 14 below.


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Land Disturbing Activity Cut (m3)

Footprint

(m2)

Footprint/

Landholding

Area (34km2)

Core Site Access Roads 435,000 305,000 0.90%

Turbine Platforms 225,000

Substation & Services Building 16,000 5,000 0.01%

Lay down Areas & Site Office 9,000 26,000 0.08%

Trenching & New Tracks for Transmission Line 12,000 6,000 0.02%

Borrow Areas 76,000 25,000 0.07%

Spoil Fill Sites n/a 309,000 0.91%

Erosion & Sediment Controls at Spoil Fill Sites n/a 15,000 0.04%

Project Total 773,000 691,000 2.03%

Table 14: Summary of Pessimistic Excavation Volumes within Core Site

3.2.16 Construction Footprint in Relation to Hydrological Catchment Areas

Drawing Sheet 22 in Appendix A (Appendix A.6 Hydrological Catchment Area Plan)

identifies the various hydrological catchment areas which encompass the project area. This

drawing illustrates the proportion of the project footprint to the catchment area and the

remoteness of the project footprint to streams within each catchment area. Table 15,

below, complements this drawing and shows:

• Pessimistic earthworks cut volumes generated within each hydrological catchment

area based on a pessimistic earthworks cut-to-waste volume of 683,000m3 derived

from Table 14.

• Corresponding disposal fill areas from earthworks cut volumes within each

hydrological catchment area based on an average fill site depth of 2.5m.

• The construction area footprint within each hydrological catchment area.

• The percentage of construction area to catchment area including the overall

construction area to catchment area.


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Hydrological

Catchment

Catchment

Area (km2)

Cut-to-Waste

(m3)

Disposal Fill

Area (From

Cut-to -

Waste

Material)

(m2)

Construction

Area (Turbine

Platform,

Construction

Road & Other

Footprint (m2)

Total

Area (m2)

Total

Area/Catch

ment Area

(%)

1 (North) 6.16 72,000 40,000 39,000 79,000 1.28%

2 (Tipapa) 3.79 107000 25,000 40,000 65,000 1.72%

3 (Cave) 6.89 196,000 45,000 89,000 134,000 1.94%

4 (Motunau

East) 4.32 48000 28,000 21,000 49,000 1.13%

5 (Motunau

Upper) 12.11 210000 79,000 105,000 184,000 1.52%

6 (West) 4.26 17000 28,000 9,000 37,000 0.87%

7 (North

West) 9.96 123,000 65,000 78,000 143,000 1.44%

Project Total 47.49 773,000 310,000 381,000 691,000 1.46%

Table 15: Earthworks Volumes and Areas Summarised by Catchment Area

Table 15 illustrates that the proportion of the total construction footprint area to hydrological

catchment area is very minor and overall represents approximately just 1.34% of the total

hydrological catchment area. However Table 15 also identifies that hydrological catchment

area No.3 (Cave) has the highest proportion of construction footprint area to catchment

area followed by No.2 (Tipapa) and No.5 (Motunau Upper). Where possible the

construction footprint area has been redirected from the more ecologically sensitive areas

such as Cave and Motunau Upper to the less sensitive northern catchment areas including

Tipapa. At detailed design more refinement to the road alignments and turbine platforms

should result in more of the construction area positioned in the less sensitive catchment

areas.

A large fill site is proposed at a saddle along Road D just north of Turbine D5. This site will

be a combination of structural fill to form the core of Road D as well as spoil fill to form the

batters. This fill straddles the northwest catchment area and the more sensitive Motunau

Upper catchment. Specific controls at this fill site will be required to manage sediment

particularly where sediment run-off is within the Motunau Upper catchment.

Measures to avoid, remedy or mitigate the potential adverse effects from discharges,

including sediment run-off are discussed in the next section and in Appendix E (draft

Construction Environmental Management Plan).


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3.2.17 Water Demands

As discussed in section 3.2.6 a water supply will be required to supply any onsite concrete

batching, together with other site construction activities including dust suppression,

stabilization and re-vegetation, pavement construction and for any mobile crushing plant.

Indicative estimates of potential water demand are summarised below in table 16.

Activity Peak Daily Demand (m3)

Maximum Total Water

Demand (m3)

Time Period

Dust Suppression (non potable) 80 17,000 26 days per month for 8 months

Stabilisation & Revegetation (non potable)

15 3,100 26 days per month for 8 months

Pavement Construction (non potable) 10 1,300 26 days per month for 5 months

Mobile Crushing Plant (non potable) 5 1,000 26 days per month for 8 months

Turbine Foundations & Other Concreting (potable)

80 2,600 2 per week over 4 months

Total 190 25,000

Table 16: Indicative Estimates of Potential Water Demand

Preliminary discussions with Hurunui District Council (HDC) suggest that a significant

proportion of this demand may be met via supply from the HDC water mains. Water supply

from the mains and permitted abstraction rates will need to be negotiated with HDC at the

appropriate time, however it is envisaged that temporary water storage tanks would be

established on site to enable the buildup of water storage volume.

Any shortfall in water requirement can be met via tanker delivery from offsite, from the

creation of temporary stock ponds, or by stream abstraction within any consented or

permitted limits.

3.3 Discharges

3.3.1 Erosion, Sediment and Dust Control

We recognise that the construction of this wind farm will require extensive earthworks.

However, the potential impact from erosion, sediment run-off and dust emissions are likely

to be minor given the environmental management measures that will be applied. Details on

the environmental management measures are discussed in detail in Appendix E (draft

Environmental Management Plan) while the impact from erosion, sediment run-off and dust

emission is addressed in the Ecological Values and Assessment of Effects report prepared

by Boffa Miskell. One of Meridian’s prime objectives for the construction of this wind farm is

to ensure that any potential adverse effects on the environment from any erosion, or

sediment and dust discharges are avoided, remedied or mitigated. To achieve this

Meridian will:

� Ensure that environmental management is a core requirement in the management

process.


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� Prepare and implement a robust EMP and site specific SEMPs.

� Ensure a partnership approach between Meridian and the contractor(s).

� Ensure adequate resourcing of environmental management activities.

� Monitor and audit the project works to determine the effectiveness of the

environmental management activities being undertaken.

� Ensure all incidents are reported to the Project Environmental Manager.

The following outlines the approach that Meridian will implement to mitigate the impact of

construction activities on the environment.

a) Contract Requirements

Although Meridian will be ultimately responsible for ensuring EMP and consent condition

compliance, the construction contract will place specific responsibilities on the contractor for

environmental management. The contract will require the contractor to:

� Comply with the Environmental Management Plan (EMP) and Supplementary

Environmental Management Plans (SEMPs). Refer to Appendix E for details on the

EMP and SEMPs process.

� Have read and comply with resource consent conditions.

� Take all necessary measures to ensure no adverse effects arise from dust

discharges.

� Attend environmental compliance meetings.

� Ensure all plant and equipment is clean and well maintained.

� Foster an environmentally responsible attitude on behalf of the contractor and his

employees.

� Follow Meridian’s Accidental Discovery Protocol for archaeological or cultural

remains.

b) Erosion, Sediment and Dust Control Plans

The main tool for avoiding or mitigating potential adverse effects from erosion, sediment

and dust discharges is by preparing and implementing SEMPs for each major component of

the work. There are four steps in preparing and implementing each SEMP:

Plan Preparation

Separate SEMPs will be prepared for specific locations and activities (as outlined in the

EMP). To get construction underway as soon as possible, plans for partial sections of

works may be prepared.


5C-1604.02

February 2011 42

The first stage in plan preparation will be a walk over of the area to be covered by the plan.

The walk over will involve the contractor, Meridian’s Construction Manager, Meridian’s

Engineer, Meridian’s Environmental Manager, and an Environment Canterbury

representative/s and Hurunui District Council representative/s (for some components). The

purpose of the walk over is to identify the measures needed for minimising erosion and

sediment generation, e.g. cut off drains and treatment options for storm water runoff such

as silt ponds, grit traps and so on. Based upon these discussions a draft SEMP will be

prepared by the contractor assisted by Meridian’s Environmental Manager.

The SEMP will include the following:

� A method statement covering health and safety matters, construction method,

monitoring and contingencies.

� A plan or series of plans showing spoil areas to be used, cut off drains, culverts,

surface water control works, silt ponds and any other sediment control measures.

� Inspection and reporting schedule particularly in response to adverse weather

conditions.

� A list of maintenance activities.

In addition, the SEMP will cover revegetation requirements, storage and handling of fuel,

and management of waste.

There are five location specific SEMP areas proposed for this project. At this stage an

indicative SEMP plan for one of these areas has been prepared demonstrating the intended

approach for such plans. Details on the SEMP area boundaries and the indicative SEMP

plan are provided in Appendix E.

Review

The draft SEMPs will be submitted to both Environment Canterbury and Hurunui District

Council as well as Meridian's Engineer and Environmental Manager for review. Comments

from the review will be provided to the contractor who will finalise the plan. The final plan

will be provided to the regional and district councils for their information and to satisfy any

resource consent requirements.

Implementation & Monitoring

Implementing the SEMPs will be the responsibility of the contractor. Where required the cut

off drains, silt ponds and other similar works will be installed in advance of earthworks

commencing.

The construction works will be monitored on a regular basis by Meridian or Meridian’s

advisors. The frequency of this monitoring will be dictated by the work programme. A

summary of the inspection will be copied to Meridian's Engineer. Work will only commence

once Meridian’s Construction Manager is satisfied that appropriate measures to avoid

potential adverse effects are in place or planned to be implemented. Examples of erosion

and sediment control measures proposed for this project are detailed in the draft EMP in


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Appendix E. Erosion and sediment controls will be designed and installed in accordance

with Environment Canterbury's Erosion and Sediment Control Guidelines (2007).

Auditing

Ensuring an audit of compliance with the SEMPs will be the responsibility of Meridian’s

Environmental Manager. It is proposed the audit will involve an inspection of site works and

a meeting that involves the contractor, Meridian’s Construction Manager and Environmental

Manager. Environment Canterbury and Hurunui District Council will be invited to be part of

this audit process.

A programme for the audit meetings will be set once the construction programme is known.

Any recommendations resulting from the audit process will be recorded and used to modify

the current and subsequent SEMPs.

(c) Reporting

Initially, a weekly report shall be prepared by the contractor to identify the erosion, sediment

and dust control activities undertaken, to provide comment on their effectiveness, and to

identify any improvements which are required. This report will be reviewed by Meridian's

Engineer. The reporting timetable will be reviewed on an ongoing basis as the project

progresses.

3.3.2 Permanent Stormwater Run-off

Access roads

Stormwater runoff control through cut sections of road will consist of unlined open side

drains at the base of each cut. Depending on the ground conditions at any steep sections

of access road, there may be a need to incorporate short lengths of concrete lining to limit

erosion. On steeper sections, it is envisaged that stormwater flow velocity will be controlled

(to minimise scour) with the use of rip-rap dissipaters or other similar devices.

Water from the side drains will be discharged by either 300mm (approximately) diameter

culverts under the access roads and fluming to gullies, or by fluming direct to gullies as

appropriate. Given that the access roads are generally located at the upper reaches of

catchment areas, water from most side drains will be discharged on to land in dry gullies.

However, where existing streams are present, such as that indicated by existing culverts,

water will be discharged into the stream.

Riprap or other similar stabilisation measures will be utilised at points of discharge. The

position and intervals of the culverts will be determined during detailed design. The aim is

to retain run-off within the existing natural catchment area.

Turbine platforms

Given the general nature of platform areas (e.g. small areas at the top of catchments), no

particular permanent stormwater drainage measures are envisaged other than ensuring


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that platform areas around the basecourse hardstand areas are backfilled with top soil with

a slight cross fall, and regrassed to avoid erosion.

Drainage provision may be provided to the foundation excavation by way of a trench or filter

drain with suitable stabilised outlet.

Fill sites and lay down areas

The proposed treatment for fill sites is discussed in Section 2.4. Finished ground profiles

will be shaped to ensure that natural drainage paths are maintained. On completion of

construction, these sites will be re-topsoiled (with material which has been removed and

stockpiled) and re-vegetated as appropriate with runoff direct onto grassed land on

surrounding catchments.

Lay down areas will have a general crossfall, allowing stormwater run off in the direction of

the general slope of the land. Sedimentation and erosion control measures as described in

Section 3.3.1 above will be applied. On completion of construction, lay down areas will be

rehabilitated in the same manner as fill sites.

3.3.3 New Culverts at Stream or Gully Crossings in the Core Site

No stream crossings have been identified within the core site however there are locations

where upper gully crossings and existing open channel drain crossings will require culverts.

Table 15 below summarises the proposed culverts identified along core site access roads.

Culvert sizes have been based on flows for flood return periods of 20 years with provision

for secondary flow paths across purposely lowered sections of the access road (for

overtopping for longer return periods).

We envisage no gully crossings in addition to those tabulated given the layout of the access

roads are generally close to or on ridge tops where the terrain is relatively gentle. However,

where new culverts are required per the detailed design (consequent to adjusting the

turbine platforms and access roads within a 100m radius placement area), culverts will be

sized as described above.

The approximate height of the embankment at the culvert inlet of the majority of all culverts

is less than 1m apart from one culvert on Road D which has an embankment height of

approximately 1.5m at the culvert inlet. Given the embankment heights at culvert inlets are

not significant no locations have been identified where an embankment fill could essentially

form a ‘dam’ across upper valleys. However, if a significant embankment fill arises

consequent to adjusting the turbine platforms and access roads (within a 100m radius

placement area) the culvert will be sized on flows for flood return periods of 100 years to

address the effects of ‘heading up’ associated with culverts with significant embankment

fills.

Based on this design criteria, the required culvert sizes are indicated in the following table.

The final size of the culvert, where required, will be determined during the detailed design

stage. This table also identifies a range of characteristics associated with each culvert.


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An ecological assessment of these locations is discussed in the Ecological Values and

Assessment of Effects report prepared by Boffa Miskell.

Road Culvert

ID

Indicative

Culvert Size

(mm dia.)

Indicative

Culvert

Length (m)

Approx

Catchment

Area (Ha)

Approx Height of

Embankment at

Inlet (m)

(from ground

level)

Northern

Access Road

A1A 375 15 4 ≤1.0

A1B 375 14 4 ≤1.0

Road A A1 300 15 1.2 ≤1.0

A2 450 14 3.0 ≤1.0

A3 600 13 3.8 ≤1.0

A4 300 11 0.7 ≤1.0

A5 300 11 0.5 ≤1.0

Road B B1 375 13 2.1 ≤1.0

Road D D1 300 20 1.1 1.5

D2 300 18 0.3 ≤1.0

D3 300 20 0.7 ≤1.0

Road G G1 600 14 4.4 ≤1.0

Table 17: Culverts at Gully Crossings within the Core Site

The culvert location plan is shown on Drawing Sheets 23 to 26 while typical culvert details

are shown on Sheet 27 in Appendix A (Appendix A.4 Culvert Location Plans & Typical

Details).

3.3.4 Upgrading Existing Culverts Along Motunau Beach Road

One culvert along Motunau Beach Road, just south of the proposed site entrance, will

require lengthening to accommodate the proposed widening of the road shoulder along this

section. The existing 450 diameter concrete culvert, which serves an open channel drain

from within the Batchelor/Daly property will require lengthening on the eastern side of

Motunau Beach Road as shown on Drawing Sheet 205 in Appendix A8.

3.3.5 Culvert Construction Methodology

Installing culverts will involve bed preparation, laying of pipe culverts, construction of

headwalls and backfilling/compaction. There are no stream crossings therefore stream

diversions will not be required.

4 Minor Shoulder Widening At Motunau Beach Road

4.1 Shoulder Road Widening Opposite Site Entrance

Directly opposite the proposed site entrance the shoulder of the southbound lane will be

widened approximately 3m to provide an overall sealed width of approximately 6m from the

centerline as shown on Drawing Sheet 205 in Appendix A8. The widening is provided to

facilitate vehicles turning right into the site from the south. The proposed widening will


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February 2011 46

extend over an existing road culvert which will need to be lengthened as described in

Section 3.3.4 above.

The existing permanent stormwater network of side drains will be maintained on the eastern

side of Motunau Beach Road by forming a new side drain at the toe of the proposed

widened section. This side drain will also discharge into the existing open channel drain just

east of Motunau Beach Road. On the western side the existing side drain will follow a new

side drain formed at the site entrance and will discharge into the existing open channel

drain in the Batchelor/Daly property.

The widened area will be formed with minor quantities of compacted basecourse and

sealed with chipseal or harder wearing asphaltic concrete surfacing to match the existing

surfacing.

5 Geotechnical Assessment

5.1 Geotechnical Appraisal

A preliminary geotechnical appraisal of the site was completed in 23 August 2009 and is

presented in Appendix D. This appraisal primarily examined the seismic risk of the site and

the potential slope instability along access roads and at turbine locations. Seismic risk and

potential instability are discussed below.

5.2 Geotechnical Risk

5.2.1 Potential Slope Instability

Slopes observed in the preliminary geotechnical appraisal visits were considered to be

stable. The site reconnaissance did not identify any areas of deep-seated instability in the

areas proposed for use as access roads or turbine sites. Shallow seated slides (up to 1.0m

deep) and creep-type failures within the overburden material on slopes were observed at

localised areas throughout the site but restricted to slopes over 28 degrees. Turbine sites

and access roads are setback from steep slopes, generally located on ridge tops (where

the overburden is relatively thin). Construction activities will be outside the areas of shallow

seated slides and creep-type failures and therefore unlikely to be affected by any slope

instability.

Where road cuttings are close to, or down slope of turbine foundations, roads are

positioned so that cuttings are adequately set back from the base of the foundations. This

is to reduce the risk of undermining turbine foundations. Access routes have been chosen

to follow existing tracks, ridge lines and to generally avoid steep slopes (slopes equal to, or

greater than 28 degrees in the project area) to minimise the potential for creating instability

due to slope undercutting. Avoiding areas with steep side slopes also serves to minimise

the height of cuts, and therefore maximise stability. Drawing Sheet 10 in Appendix A

(Appendix A.2 Access Road Plans & Cross Sections) shows the typical cross slopes along

each road length. In addition, Figure 4 in Appendix D demonstrates that all turbine

platforms and the vast majority of all access roads avoid slopes equal to, or greater than 28

degrees. However any access roads which run through these areas will typically be


5C-1604.02

February 2011 47

assigned an acceptable risk profile of “low” at the detailed design stage and special

measures taken to reduce the risk of instability. Therefore the construction effects of this

project on shallow seated instability will be no more than minor.

Siting the turbine foundations will involve detailed geotechnical investigation of each

platform to refine each turbine’s position and setback from any adjacent slopes. Such siting

will ensure there is a very low risk for any natural slope instability to undermine a turbine

foundation. For road cuttings geotechnical investigation will ensure global stability of

cuttings through appropriate batter design. Some small localised material loss from the

face can be tolerated given the low accessibility of the roads beyond the construction

period.

Existing farm access tracks were typically at grade, with some generally low height (1.0 –

1.5 m) cuts. In general the low height cuts stand at close to vertical. Deeper existing road

cuts range in height between approximately 3.0m to 4.5m high at slope angles

approximately 63 degrees (1H:2V). The bedrock was observed to be stable at these slope

angles up to heights of about 8m. No obvious rock failures were observed in existing cuts.

Photograph 6 in Appendix B shows a cut slope on an existing track ranging up to

approximately 4m to 5m cut height.

In view of such observations of the site, the process proposed, and based on knowledge of

proposed road and turbine positioning, the risk of landslides, or large scale soil movement

being mobilised by the proposed works is considered low. This preliminary assessment of

slope failure risk is also affirmed by the generally shallow depth of surficial soils overlying

the more stable (barring bedding planes) bedrock. Final cut batter angles, or requirements

for benching will be adjusted as necessary during detailed design to suit any geotechnical

recommendations.

Local bearing capacity can affect the feasibility of turbine sites in some situations. Since

these turbines are typically located on ridge tops where the bedrock is relatively shallow,

bearing capacity of the soil/rock is unlikely to constrain turbine positioning.

Detailed geotechnical investigations at the detail design stage and on-site assessment

during construction will be undertaken to confirm the above preliminary conclusions and to

establish appropriate cut slopes around the road network. We recognise that some

ongoing maintenance of steeper cut slopes may be necessary during the life of the wind

farm.

5.2.2 Seismic Hazard

With reference to the preliminary geotechnical appraisal in Appendix D, the seismicity of the

site is governed by the presence of the following faults:

• Omihi Fault (borders the northwest of the site)

• Kaiwara Fault (5 km to the north of the site)

• Hurunui Bluff Fault (15 km to the northwest of the site)


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• Hope Fault (45 km to the north of the site)

• The southern Alpine Fault (95 km northwest of the site)

• Pegasus Bay Fault (an offshore fault, which lies approximately 30km to the

southeast of the site)

Other minor faults are mapped within the wind farm area, some of which may be active.

Fault Rupture

Based on geological evidence, the recurrence interval for the Omihi and Kaiwara Fault is

2000 to 5000 years, having last ruptured more than 10,000 years ago. The southern Alpine

Fault has a recurrence interval of 500 years and evidence suggests it last ruptured between

340 and 410 years ago. The Hope Fault is considered to have the shortest recurrence

interval of 120 years, with the last rupture 121 years ago. Records of the Hope fault

earthquake indicate magnitudes greater than 7.

An interim guideline to assist resource management planners in New Zealand “Planning for

Development of Land on or Close to Active Faults”, Ministry for the Environment, 2003

defines the fault avoidance zone as a zone that extends 20m on either side of the active

fault line, shown on a plan as an active fault trace. The guideline requires that structures

with special post disaster functions (Building Importance Category 4 structures) are not built

in the fault avoidance zone. For this project, all turbines will be located at distances

substantially larger than 20m from active faults and therefore are not expected to be

adversely affected by rupture of the known faults. In addition to separation from fault

zones, wind loading and operational fatigue dominate the foundation design for the

turbines. Therefore, the risk of damage to wind turbines associated with fault rupture is

assessed to be low. Roads and cables crossing the fault rupture zones would be affected,

but these can be readily repaired and reinstated following such an event.

Ground Shaking

Wind turbines are designed to withstand the large wind forces imposed by extreme wind

storms that may occur during the life of the turbines. Therefore the turbines have a large

reserve of strength available to resist the forces imposed by earthquake ground shaking,

including shaking resulting from rupture of any of the faults listed above.

Liquefaction

There is no possibility that the ground beneath the turbine foundations will liquefy under

earthquake as they will be founded on rock.

Earthquake Induced Slope Failures

Earthquake-induced failures (in the form of debris flow and slips) can be expected in the

weaker overburden materials, but such failures would not affect the wind turbine

foundations, as all the wind turbines will be founded on the bedrock, or set back from slope

edges.


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6 Other Proposed Activities

6.1 Detailed Geotechnical Investigations

As part of the detailed design investigations there will be a need to undertake more

comprehensive site investigations and testing to determine site specific geotechnical design

parameters for road and turbine platforms as well as turbine foundations. Types of intrusive

testing that are likely to be employed include:

• Trial pits and borehole investigations in the vicinity of potential borrow areas, large

cuts, embankments, the substation location and at turbine sites.

• Borehole and possible rock anchor pullout tests to confirm detail design

assumptions for turbine foundations.

• Trial pits to test the suitability of material for thermal bedding / backfill for

transmission cables

6.2 Controlled Blasting

Based on visual inspection of the site, together with the preliminary geotechnical appraisal,

excavation is most likely to be achieved by the use of hydraulic excavators, large bulldozers

with ripping attachments, and motor scrapers.

In the event that harder material (particularly moderately/slightly weathered or intact rock) is

encountered it may be necessary to utilise controlled blasting operations to achieve

economic working rates.

If employed, it is anticipated that small amounts of explosives will be used to break up rock

masses into more manageable pieces. Rock drilling to plant the explosives will also be

required. Management measures and methodologies for controlled blasting operations will

be documented in the contractor’s management plan in advance of any work commencing.

This will set out management measures, OSH requirements, blast design, methods, site

protocols, storage requirements, warning systems, and noise monitoring requirements as

required under current HSNO Regulations.

7 Indicative Construction Methodology, Noise and Lighting

7.1 Indicative Construction Methodology

The project implementation timeframe, based on experience from other wind farm projects

(Te Apiti, White Hill and West Wind) is likely to be in the order of 18 months depending on

the sequencing adopted and weather conditions.

The initial construction priorities are likely to focus on civil earthworks for the key access

route (Northern Access Road), platforms and the substation. Following on from the initial

construction phase the construction priorities are likely to focus on turbine foundation

construction and erection as well as civil earthworks on the remaining access roads


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sequenced over the project implementation timeframe. The likely sequence of construction

for the site is:

• Site mobilisation including establishment of temporary site offices, workshops,

stores and other facilities.

• Installing erosion & sedimentation control measures.

• Upgrading key access routes to core site.

• Preparing initial fill sites and haulage routes. Haulage routes will typically follow the

proposed access routes and existing access tracks, as appropriate.

• Excavating and forming access roads with any surplus cut material transported,

placed and compacted at fill sites.

• Upgrading existing and constructing new culverts.

• Preparing lay down areas and substation platform.

• Constructing the substation.

• Constructing the overhead transmission line from the substation to existing external

66kV transmission line.

• Constructing cranage and turbine platforms.

• Progressive excavation and construction of reinforced concrete turbine foundations,

as platforms become available.

• Cut/fill slope and fill site rehabilitation (this will be undertaken on a progressive

basis).

• Progressively installing internal transmission network (cables) typically along the line

of formed access roads, or across country as appropriate.

• Progressively delivering turbine towers and generators.

• Progressively installing and commissioning (turbines and substation).

• Removing temporary services and site offices, rehabilitating lay down areas and

general site reinstatement.

Figure 4 below shows an indicative project implementation timeline, with broad construction activities, over an 18 month period. A more detailed programme will be developed by the Meridian Implementation Team prior to construction.


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Figure 4: Indicative Construction Timeline

7.2 Construction Noise

Typical plant likely to be employed for the construction work may include:

• Hydraulic excavators.

• Scrapers and dumpers.

• Bulldozers (with ripping attachments).

• Mobile crushers for processing basecourse.

• Main and assistant turbine erection cranes Graders and rollers.

• On-site batching plant with concrete mixer trucks.

• Portable generators.

• Drilling rigs for detailed geotechnical investigations, possible installation of rock

anchors and testing.

Construction noise may also result from blasting if employed.

Construction works will require a noise management plan in accordance with NZS

6803:1999 to manage noise emissions from construction activities involving the above

types of plant and activities. Potential noise impacts are assessed and discussed in the

Project Hurunui Acoustic Assessment report by URS.

7.3 Lighting and Night Works

Certain works may take place at night (outside regular working hours). In this respect, it is

envisaged that work may progress on a 24 hour basis for turbine sites and access roads

remote from any dwellings while complying with the recommended noise limits at any

neighbouring dwellings.

Where works after sunset or night works are permissible, portable lighting rigs will be

employed.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Site Establishment/Civil Mobilisation

Civil Earthworks/Roading

Concrete Batching

Substation & O/H Transmission

Construction

Turbine Foundation Construction &

Turbine Installation

Turbine Commissioning

Site Rehabilitation

End Project

Construction ActivityConstruction Period (Months)


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7.4 On Site Project Office

The location of the main project site office including stores and initial lay down area is

proposed in the front paddock of the Batchelor/Daly property adjacent to the initial section

of the Northern Access Road. The layout of any other temporary site offices, workshops,

stores and other construction facilities, such as the concrete batching plant, will be

determined following further detailed investigations of the construction and installation

strategy.

One security gatehouse will be located just in from the Northern Access Road, off Motunau

Beach Road, to control access in and out of the site.

An indicative main site office layout is shown on Drawing Sheet 203 in Appendix A

(Appendix A.8 Indicative Site Office & Lay-down Area Plan). This drawing shows the

indicative dimensions and layout of the proposed structures which make up the temporary

site office facilities. In general the site office structures will comprise single storey sandwich

panel prefabricated structures with a combined area of approximately 380m2. These

structures are typically 2.8m high (not including the footings) and come in two standard

colours, green and white. Allowance has been made for a communication mast

(approximately 6m high), diesel generator and diesel fuel tank. The diesel generator and

fuel tank will be located in a bunded area to retain any fuel leakage. Sewerage and waste

water will be directed to a holding tank and removed off site. At completion of the

construction phase these temporary buildings will be removed off site.

7.5 Bulk Fuel Storage Facility

A bulk storage facility will be located at or near the site offices or close to the active

construction area. The bulk storage facility will provide fuel to specialist mini tankers that

will service all vehicles on site. In special circumstances where mini tanker access is not

possible, a towable tanker will be used to service the vehicles. This facility is discussed in

more detail in the EMP in Appendix E of this report.

7.6 On Site Batching Plant

The contractor will require a concrete batching plant to minimise the number of truck trips

on the public road network and increase efficiency. Photograph F25 in Appendix F shows

the concrete batching plant established at Project West Wind. This photograph illustrates

an indicative layout and the structures which comprise a typical concrete batching plant

proposed for this project.

The likely structures and facilities which comprise a typical concrete batching plant

including indicative dimensions are:

• Control room and storage building (6m long, 2.8m high, 2.4m wide).

• Prefabricated office and amenities structure (4.8m long, 2.8m high, 3m wide).

• Mobile batching plant unit which includes, but is not limited to, hoppers, aggregate

storage bins, compressor, cement silos and conveyors (18m long, 4m wide, 7m high

(highest point)).


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February 2011 53

• Water tank.

• Aggregate stockpile area (50m x 20m).

• Truck washdown area.

A concrete batching plant occupies a relatively small area for a relatively short duration

(approximately 5 months) of the construction period as the plant is only on site during the

foundation construction stage of the construction programme. The concrete batching

process proposed under this application is a dry batching process which involves mixing

dry materials in the batching plant. The dry material is then transferred into a normal

concrete mixing truck and only then is water added. Minor dust discharges potentially arise

from the transfer of materials into the plant and again, into the mixing truck. It is envisaged

that measures to contain any dust will be outlined in the EMP or relevant SEMP. Such

measures are likely to include cement storage within a silo and aggregate storage bins.

Given that the concrete is mixed in the truck, rather than in the batching plant, the wash

down requirements associated with conventional concrete batching plants are significantly

reduced. The dry batching process ensures that there are no requirements to wash down

wet concrete within the batching plant. Measures to contain any dry cement spillage in the

event of a batching plant failure will be outlined in the EMP or relevant SEMP. Such

measures are likely to include a temporary concrete slab beneath the loading area and

containment bunding around the plant incorporating a 2 stage settling pond or sediment

control pond. The concrete batching plant will not be located within 100m of any

permanent watercourse.

On completion of the works the site office areas and batching plant areas will be stripped of

any basecourse, re-topsoiled (with material which has been removed and stockpiled) and

ground cover replanted as appropriate.

8 Summary and Conclusions

Construction of the civil works elements for Project Hurunui Wind will require excavation; fill

site creation; potential on-site extraction; potential crushing and processing of basecourse

pavement materials; construction of culverts; substation and transmission line construction;

internal site cable trenching and placement; concreting works and site regeneration.

The key measure we have proposed to minimise the overall environmental effect of

construction is to adopt the general design philosophy of following existing tracks and tops

of ridges wherever possible. Following this general design philosophy will typically

• Minimise the volume of excavation.

• Avoid gullies & undisturbed watercourses.

• Improve geotechnical aspects.


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This report has demonstrated that potential effects within the site resulting from

construction activities typically include:

• Site stability issues.

• Discharges to land and water from sediment run-off.

• Stormwater discharges.

• Flooding within the catchments affected by road embankments incorporating

culverts.

• Visual effects.

• Local traffic effects.

• Dust & noise nuisance.

The potential effects and measures proposed to avoid, remedy or mitigate these effects are

summarised as follows:

Potential Effects Measures to Avoid, Remedy

or Mitigate Effects

Comments

Land disturbance

at the recently

covenanted QEII

within the Turnbull

property and the

totara forest

remnant within the

Batchelor/Daly

property

Avoid construction works within

these areas.

These two areas are recognised as having

significant natural features. However these

areas are outside the construction

footprint.

Site Stability of

Roads, Turbine

Platforms,

Substation,

Transmission and

Met Masts

Avoid large slips and steep

slopes.

Avoid sidling fill situations on

steep cross slopes.

Avoid access roads undercutting

turbine platforms.

Ensure detailed geotechnical

investigations are carried out at

detailed design.

Natural slopes and existing cuttings in the

project area are generally observed to be

stable. In this respect the risk of

landslides or large scale soil movement is

considered low.

Damp (soft) ground is not expected to be

an issue as turbines and roads have been

placed to avoid these areas.

Road, Turbine & Substation Platforms

Typical cut slopes to form roads and

platforms are not typically expected to

exceed 6m in height. Extreme cut heights

of between 6m and 18m account only for

approximately 7% of the total road length

Site Stability of

Disposal Fill Sites

Avoid steep areas.

Select sites to suit depressions,


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or tops of natural gentle sided

small or shallow valleys with

good containment.

Key and compact fill into

surrounding land.

Install subsoil drainage.

in the core site area (24km). Based on

materials observed on site, cut slopes of

1H:4V are expected to be stable up to

1.5m in height and cut slopes of 1H:2V are

expected to be stable up to 5m in height

and stable beyond this provided benching

is employed at 5m intervals.

Further geotechnical investigation and

observation will be completed during

detailed design to confirm design

parameters.

Disposal Fill Sites

Fill site selection and design will follow a

structured approach, as suggested in this

report and will take place under the

framework of the Environmental

Management Plan (EMP) and

Supplementary Environmental

Management Plan (SEMPs). There is

sufficient fill site capacity to accommodate

the pessimistic earthworks cut volume.

Overhead Transmission to 66kV Main

The construction effects of the connection

to the 66kV Mainpower Line on

undisturbed land are expected to be minor

and will remain within proposed

transmission line construction envelope.

Internal 33/22 kV cable reticulation

Apart from one overhead section all

33/22kV cables are expected to be

installed under the access roads. As

trenching works are typically undertaken

within the road corridor, underground

cabling is not expected to cause any

additional land disturbance.

Site Stability –

Seismic Risk

Locate wind farm site away from

major active faults.

Given the active faults are outside the

wind farm area, no structural or foundation

failure is expected in relation to rupture of

any of the faults

Discharges to

Land & Water

Staged construction.

Revegetation and site

A layer of basecourse will be provided to

roads and platforms during construction.

At steeper road sections, a sealed


5C-1604.02

February 2011 56

rehabilitation throughout the

construction phase.

Environmental Management

Plans to control erosion and

treat sediment run-off.

pavement may be provided. This will

provide a clean running/working surface

as well as minimise erosion.

Turbine platforms will be rehabilitated upto

the edge of basecourse hardstand areas

with appropriate ground cover after

construction.

Some potential fill areas and lay down

areas will involve the removal of existing

topsoil and vegetation. The measures

outlined in this report will ensure that these

fill sites and lay down areas are blended

back into the existing environment

following their rehabilitation.

In the likely event that an on-site batching

plant is deployed, an SEMP will be

developed to outline measures to manage

any dust, sediment, cement and wash

water discharges. Such measures are

likely to include cement storage within a

silo, aggregate storage bins, a temporary

concrete slab beneath the loading area

and containment bunding around the

plant.

Appropriate substation design such as

bunding and interceptor tanks will ensure,

in the unlikely event of transformer oil

spillage, that the risk of oil discharge is

low.

Sewerage and waste water from the

services building will be directed to a

septic tank. Flows are expected to be low.

Sediment Run-off

Discharges to the

Cave and Motunau

Catchment Areas

Avoid where possible by

redirecting works and/or

discharges from sediment

control structures to northern

(including Tipapa) catchments

assessed as having lower

comparable ecological values.

Ensure specific erosion and

sediment controls at fill site just

north of Turbine D5, in particular

In areas where the construction works

border catchments, road alignments and

fill sites can be adjusted to remain within

catchments with lower comparable

ecological values.

The draft SEMP details specific measures

at this area.


5C-1604.02

February 2011 57

where run-off is directed within

the Motunau Upper catchment.

Flooding Within

Catchments

Affected by

Culverts

Provide for overflows.

Select road alignments which

minimize catchment areas.

Stormwater

Discharges From

Roads and Turbine

Platforms

Provide permanent stormwater

runoff management.

Provide unlined open side

drains, sumps, culverts &

flumes.

Direct discharges to land or

adjacent undisturbed areas.

Retain runoff within each

existing natural catchment area.

Appropriate roadside drainage design

employing measures such as fluming and

riprap will reduce the risk of scouring and

erosion. Roadside drains will generally

discharge on to land. However, roadside

drains may discharge into existing streams

(ephemeral or otherwise) if located

nearby.

Measures as described in this report to

mitigate stormwater run-off from turbine

platforms, fill sites and lay down areas will

ensure that natural drainage paths are

maintained and erosion minimised. As

platforms will be graded to the fall of the

land, runoff will generally discharge

directly into undisturbed land.

As most new roads are close to or on

ridge tops, new roads generally do not

cross any streams or dam gullies. Where

natural flow paths are affected by new

roads, appropriate cross culverts will be

provided to ensure that drainage paths are

maintained.

Visual Effects of

Roads, Disposal

Fill Sites &

Substation

Select fill sites in areas “internal”

to the site.

Select substation site in low

lying areas internal to the site.

Utilise internal access roads and

farm tracks as much as

possible.

Select alignments of new roads

and platforms to be visible

internal to the site as much as

possible.

Some potential fill areas and lay down

areas will involve the removal of existing

topsoil and vegetation. The measures

outlined in this report will ensure that these

fill sites and lay down areas are blended

back into the existing environment

following their rehabilitation.


5C-1604.02

February 2011 58

Avoid rocky outcrops, significant

natural features and areas of

higher ecological value

Local Traffic

Effects of

Construction

Works

Reduce truck trips by exploring

potential to source on site

materials for roading

basecourse.

Reduce truck trips by utilising on

site concrete batching plant.

Dust & Noise

Nuisance

Adopt environmental control

measures under the framework

of the Environmental

Management Plan (EMP) and

Supplementary Environmental

Management Plans (SEMPs).

Appropriate requirements will be

incorporated into the construction works

documents to manage noise emissions

from construction activities, including, but

not limited to, preparation of a noise

management plan in accordance with NZS

6803:1999 to manage emissions from

construction activities.

We recognise that works to create Project Hurunui Wind will result in visible cuttings, soil

disturbance, vegetation clearance as well as associated discharges to land and water.

However, most of the construction effects are short term as opposed to long term, and

potentially adverse effects resulting from such construction effects can be mitigated by the

approach to design/construction and application of measures identified in this report.

.

Meridian Energy Ltd Project Hurunui Wind Construction and ... · Meridian Energy Ltd Project Hurunui Wind Construction and Project Overview Construction Effects & Management Report

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