environmental management plan for construction management plan for construction 8 september 2015...

Environmental Management Plan for Construction

8 September 2015 Cardno i


NZ0115065

Prepared for Jagger NZ Ltd. 8 September 2015


8 September 2015 Cardno ii

Contact Information

Cardno Ltd

Level 5 IBM Building, 25 Victoria Street, Petone,

Lower Hutt 5012

PO Box 38 098, Wellington Mail Centre, Lower

Hutt 5045

Telephone: 04 478 0342

International: +64 4 478 0342

[email protected]

www.cardno.co.nz

Author(s):

Name: Bradley Blucher

Job title: Engineer

Approved By:

Name; Ray O’Callaghan

Job title: Senior Principal

Document Information

Prepared for Jagger NZ Ltd.

Project Name

File Reference NZ0115030-CI-RP001

Construction Management

Plan.docx

Job Reference NZ0115065

Date 8 September 2015

Version Number 1

Effective Date 03 July 2015

Date Approved: 03 July 2015

Document History

Version Effective Date

Description of Revision Prepared by: Reviewed by:

1 03/07/2015 Resource Consent application Bradley Blucher Dion Mead

2 27/08/2015 Amendments to Bridge Construction Plan

Bradley Blucher Ray O’Callaghan

© Cardno. Copyright in the whole and every part of this document belongs to Cardno and may not be used, sold, transferred, copied or reproduced in whole or in part in any manner or form or in or on any media to any person other than by agreement with Cardno.

This document is produced by Cardno solely for the benefit and use by the client in accordance with the terms of the engagement. Cardno does not and shall not assume any responsibility or liability whatsoever to any third party arising out of any use or reliance by any third party on the content of this document.


8 September 2015 Cardno iii

Table of Contents

1 Plan Scope 1

2 Environmental Objectives 2

2.1 Earthworks 2

2.2 Erosion and Sediment Control 2

2.3 Flood Control 2

2.4 Stormwater Quality 2

2.5 Roading 2

3 Requirements 3

3.1 Statutory Requirements 3

3.2 Consent Requirements 3

3.2.1 Greater Wellington Regional Council Applications 3

3.2.2 Porirua City Council Consents 3

3.3 Contractual Requirements 3

4 Project Management Plan Structure 4

5 Environmental Responsibilities of Staff 5

6 Pre-Construction Requirements 7

6.1 Construction Activity plan 7

6.2 Pre-Construction site Meeting 7

6.3 Minimum notice of works prior to works commencing 7

6.4 Certification of ESC devices 7

6.5 Environmental Site Induction 8

7 During Construction 9

7.1 Inspections, Monitoring and Reporting 9

7.1.1 Daily Inspections 9

7.1.2 Weekly Site Audits 9

7.1.3 Inspection and Monitoring Schedule 10

7.1.4 Reporting of Site Audits 10

7.2 Complaints and Feedback Procedures 10

7.2.1 Public Feedback 10

8 Amendments to the Plan 11

9 Emergency Response Procedure 12

9.1 Emergency Contacts 12

10 Reporting Procedures 14

11 Environmental Impact and Risk Assessment 15

11.1 Site Description 15

11.2 Site limitations 15

11.3 Site Hazards 15

11.3.1 PCC Trunk Water Main 15

11.3.2 Gas main and Electricity/Telecom Cables 15

11.3.3 Pressurised Bulk Wastewater Main 16

11.3.4 Gravity Bulk Wastewater Main 16

11.3.5 Department of Conservation (DoC) Reserve 16

11.4 Main Construction Activities 16

11.5 Potential Adverse Effects 17


8 September 2015 Cardno iv

11.6 Erosion and Sediment Control Principals 18

11.7 Dust and Odour Control 18

11.8 Noise Control 19

11.9 Cartage of Materials and Machinery 19

11.10 Important Contractor Requirements 19

12 Project Construction Programme 21

Earthworks Construction Plan (ECP) – Stage 1 22

1 Earthworks Construction Management Plan 23

1.1 Scope 23

1.2 Earthworks Description 23

1.2.1 Purpose of Works 24

1.2.2 Site Description 24

1.2.3 Site Construction Access 24

1.2.4 Hours of Operation 24

1.2.5 General Health and Safety Provisions 25

1.2.6 Discovery of Artefacts 25

1.2.7 Programme and Methodology 25

1.3 General Erosion and Sediment Controls 26

1.3.1 Stabilised Construction Entrance 26

1.3.2 Surface Roughening and Battering 26

1.3.3 Heavy Rainfall Contingency Measures 26

1.3.4 Isolation from Floodwaters 26

1.4 Specific Erosion and Sediment Control Measures 26

1.4.1 Sediment Retention Ponds (SRP) 27

1.4.2 Pond Outlets & Discharge flow path 27

1.4.3 Pond Emergency Spillway 27

1.4.4 Silt Fences (SF) and Super Silt Fences (SSF) 27

1.4.5 Runoff Channels/Diversion Bunds (RC) 28

1.4.6 Clear Water Channels/Diversion Bunds (CW) 28

1.4.7 Stormwater Pipes/Culverts 28

1.5 Site Stabilisation 28

1.5.1 Removal of Erosion and Sediment Controls 28

1.5.2 Earthworked Areas Stabilisation 28

1.6 Maintenance and Monitoring 29

1.6.1 Erosion and Sediment Control Certification 29

1.6.2 Plan Review and Amendments 29

1.6.3 Maintenance of Erosion and Sediment Control Measures 29

1.7 References 30

BRIDGE CONSTRUCTION PLAN (BCP) 31

2 Bridge Construction Management Plan 32

2.1 Scope 32

2.2 Permanent Bridges 32

2.2.1 Description 32

2.2.2 Construction Methodology Example 33

2.3 Temporary Bridges 33

2.3.1 Description 33

2.3.2 Methodology 34


8 September 2015 Cardno v

FLOCCULATION MANAGEMENT PLAN (FMP) 35

3 Flocculation Management Plan 36

3.1 Introduction 36

3.2 Design and Management 36

3.2.1 Flocculant and Dosage Rate 36

3.2.2 Implementation and Application of Flocculant 36

3.2.3 Initial Testing 37

3.2.4 Alternatives 37

3.3 Environmental Triggers 37

3.4 Monitoring and Maintenance 38

3.4.1 Weekly Monitoring 38

3.4.2 Rainfall Event Monitoring 38

3.4.3 High rainfall contingency measures 39

3.5 Decommissioning 39

3.6 Health and Safety 39

3.6.1 Sampling 39

3.6.2 Flocculant Handling 39

3.6.3 Chemical Spills 39

3.7 Plan Review 40

3.8 Persons Responsible 40

3.9 Material Safety Data Sheets 42

Stream Diversion and Stream Works Plan 44

4 Stream Diversion and Stream Works Plan 45

4.1 Introduction 45

4.2 Stream Diversion 45

4.2.1 Pre Diversion 45

4.2.2 Diversion 45

4.2.3 Post Diversion 45

4.3 Stream Bank Remedial Works 45

Appendices

Appendix A Drawing Set

Appendix B Erosion and Sediement Control Calculations

Appendix C Environmental Effects Register

Appendix D Flocculation Management Plan updates

Appendix E Pre Construction Check List

Appendix F Erosion & Sediment Control Asbuilt documentation

Appendix G Earthworks Construction Plan Variations


8 September 2015 Cardno 1

1 Plan Scope

This Environmental Management Plan for Construction (EMPC) has been prepared for the development for

Duck Creek North at Whitby, Porirua. The EMPC, by Cardno (NZ) Ltd on behalf of Jagger NZ Ltd. is to be

approved in draft format for construction as part of the issue of consent by both Greater Wellington Regional

Council and Porirua City Council. The final documentation is to be submitted to Council(s) for final approval

post grant of consent and will reflect changes request as a request of the consenting process and will

confirm the final roles and responsibilities of various consultants and contractors.

The EMPC includes the following documents

Earthworks Construction Management Plan related to Erosion and Sediment Control,

Bridge Construction Management Plan,

Flocculation Management Plan

Stream Diversion and Stream Works Plan.

This Plan is to be read and implemented as part of the contract documentation. The greatest importance is

to be placed on adherence to the conditions of the relevant resource consents to be issued by Porirua City

Council and Greater Wellington Regional Council and the matters included within this document. Copies of

all approved plans and documentation, including, resource consent approvals are to be included as future

appendices within this document post grant of consent and subsequent approval of associated construction

plans

Duck Creek North, Whitby (The Project) is located in the sensitive catchments of Duck Creek and the

Pauatahanui Inlet. The carefully planned management of all construction activities associated with The

Project is required to ensure the effects on these regionally significant waterbodies are minimised as much

as practicable.

This EMPC aims to provide all the appropriate methodologies, processes and controls required to achieve

the environmental objectives and the requirements of resource consents granted for these works.

The consent holder shall provide a copy of this consent and any documents and plans referred to in

this document to each operator or contractor undertaking works authorised by consents within this

document, prior to the works commencing.

Any amendment proposed to this approved Environmental Management Plan for Construction shall

be submitted in writing to the Manager, Environmental Regulation, Wellington Regional Council.

Implementation of any amendment shall only occur once the amendment has been authorised in

writing by the Manager, Environmental Regulation, Wellington Regional Council.

Disclaimer:

Copyright in the whole and every part of this document belongs to Cardno and may not be used, sold, transferred, copied

or reproduced in whole or in part in any manner or form or in or on any media to any person other than by agreement

with Cardno.

This document is produced by Cardno solely for the benefit and use by the client in accordance with the terms of the

engagement. Cardno does not and shall not assume any responsibility or liability whatsoever to any third party arising

out of any use or reliance by any third party on the content of this document.



2 Environmental Objectives

The development is to be progressed in a manner to preserve and enhance the ecological integrity of the

site. In the short term, the objective is to minimise the effects of the earthmoving activity as much as

practicable by employing innovative solutions to earthworks, erosion and sediment control.

2.1 Earthworks

The earthworks as detailed on the appended plans have been designed to facilitate the construction of future

residential dwellings without the need for future site earthworks post the bulk earthworks operation. Building

platforms are to be constructed on all proposed allotments

2.2 Erosion and Sediment Control

The development shall employ the most effective means of erosion and sediment control available. These

controls shall be actively managed to ensure the deposition of silt and debris within the Duck Creek

watercourse is minimised as much as practicable.

2.3 Flood Control

The finished building platforms will be above the predicted flood water level for the 2090H storm event.

Some isolated areas of the roading networks will be floodable within a 2090H event. Please refer to the

flood modelling report submitted as part of the consent application for details on this matter.

2.4 Stormwater Quality

Specific treatment devices as to be agreed with PCC/GWRC shall be incorporated into the design of the

subdivision to provide treatment of stormwater in accordance with Low Impact Urban Design and

Development principles.

2.5 Roading

Road networks are formed to create a single arterial road servicing small cul-de-sacs.

To achieve these objectives, this EMPC document identifies and addresses the following matters:

> Environmental management objectives, statutory requirements and contractual requirements;

> Roles and responsibilities of all parties including training and public interaction;

> The identification of areas on the site of historical, cultural and/or ecological significance and the

preparation of an environmental effects register;

> Control of site activities and sequencing of work;

> General guidelines for erosion and sediment control on this site;

> Procedures and techniques to be used to avoid, remedy or mitigate adverse environmental effects during

construction;

> Inspection programmes, reporting, review, corrective action and contingency measures;

> Links from this EMPC to the other Management Plans.



3 Requirements

3.1 Statutory Requirements

> Resource Management Act 1991 and its amendments.

> NZS4431:1989 – “Code of Practice for Earthfill for Residential Development”

> NZS4402:1986 – “Methods of Testing Soils for Civil Engineering Purposes”

> Greater Wellington Regional Council – “Erosion and Sediment Control Guidelines for the Wellington

Region” (September 2002).

> Porirua City Council General Bylaw 1991 – Part 24 Silt and Sediment Control

3.2 Consent Requirements

3.2.1 Greater Wellington Regional Council Applications

The Greater Wellington Regional Council consent application consists of a number of permits and land use

consents. Please refer to the covering consent application for a full list of specific discharge and land use

consents being sought.

3.2.2 Porirua City Council Consents

The Porirua City Council consent application consists of a number of consents (subdivision and landuse).

Please refer to the covering consent application for a full list of specific consents being sought.

This document is prepared under the consent application and is considered approved for construction by

General Manager, Environment & Regulatory Services.

3.3 Contractual Requirements

The consent holder and contractor(s) are legally required to undertake a number of tasks before, during and

after the construction activities. The contractor is to ensure they are familiar with their obligations under this

document, the appended consent conditions and the contractor documentation.

Below is a list that details some of the requirements.

> Site specific document to be confirmed – “Specification for Earthworks”

> Monthly Contract Reports: The monthly reporting requirements include comments on environmental

management and public feedback (complaints and/or praise);

> Environmental Compliance Meetings: Being available to attend meetings where compliance with the

EMPC and other Management Plans are reviewed;

> Feedback Register: This section requires the contractor to maintain a feedback register.



4 Project Management Plan Structure

The structure of the collective Project Management Plans are shown by the diagram below: (Other plans

may be prepared by others)

This document outlines the major details of the other associated management plans which shall control the

construction and management procedures for the construction phase of the development project.

Environment Management Plan (Construction) - EMPC

Earthworks Construction Plan (ECP)

Flocculation Management Plan (FMP)

Stream Diversion and Stream Works

Bridge Construction Plan (BCP)



5 Environmental Responsibilities of Staff

There are four groups with responsibility in regard to environmental management for the project:

> Jagger NZ Ltd. as the owner of the project and holder of the resource consents;

> [ TBC ] as the project managers, designers, engineers, planners and supervisors of the development;

> Ecological experts to overview and monitor the instream water quality monitoring.

> The contractors undertaking the works;

Within the contractors group there are expected to be three major contractors: the main earthworks

contractor, the civil works (roading and services) contractor and the permanent bridge contractor. The main

earthworks contractor will be responsible for the whole site except for areas that are under the direct control

of the other major contractor. Due to the higher risk of environmental impacts during the main earthmoving

phase, the contractor undertaking these works will be required to read the EMPC and the CMP and sign a

declaration that they have read and understood them. Other contractors will be required to read and have

input into the approved EMPC and any other relevant Management Plan and sign a declaration of

understanding. The table below identifies environmental management roles on site.

Environmental Management Roles Table 5-1

Name Company Position Responsibilities

Bob Turner Jagger NZ Ltd

Director Overall responsibility for the project and the project team

TBC TBC Engineer to the Contract

Responsible for overall construction and for ensuring all activities comply with resource consent conditions.

TBC TBC Project Manager Ensuring contractor compliance with the contract documents, which will include requirement for carrying out the works in accordance with the relevant resource consent conditions.

Maintains register of documents and plans

TBC TBC Environmental Manager

Walk over survey at detailed design to assist with design and Management Plan development, assist with review of Management Plans, compile monitoring results and prepare Monthly Construction Monitoring Reports

Approval of EMPC and CMP updates.

TBC TBC Contract Supervisor Reporting to Project Manager and Engineer to the Contract on construction progress and compliance, undertakes daily site inspections with the Site Manager. Inspections of works to ensure compliance with EMPC and CMP.

TBC TBC In-stream Ecologist Reporting to Project Manager, supervises and/or undertakes the ecological monitoring on the site as required

TBC TBC Site Manager Overall responsibility for environmental management compliance and contract compliance onsite:

Reviewing environmental performance;

On-site compliance with consent conditions;

Adherence to EMPC and CMP;

Daily Inspections and monthly reporting;

Receives complaints for inclusion in the public feedback record and responds;

Ensuring training is undertaken;



Ensuring all sub-contractors know the requirements of EMPC & CMP

All contractors involved with the construction and commissioning works will be required to read the EMPC

and the CMP and sign a declaration that they have read and understood them.



6 Pre-Construction Requirements

The following tasks below must be completed by the consent holder prior to works commencing.

The contractor is to seek confirmation from the Engineer to the Contract that the tasks listed below

have been completed.

6.1 Construction Activity plan

The consent holder shall provide a detailed schedule of construction activities, management plans and

monitoring plans, to the Manager, Environmental Regulation, Wellington Regional Council, at least 5 working

days prior to the commencement of works. This schedule shall be updated at monthly intervals during the

works. The schedule shall include the details of:

1. The commencement date and expected duration of each stage of the works subject to this consent.

2. The timing of monitoring reports necessary to fulfil the conditions of this consent.

6.2 Pre-Construction site Meeting

The consent holder shall arrange and conduct a pre-construction site meeting prior to any work authorised

by this consent commencing for each stage of the works and must invite, with a minimum of 5 working days-

notice, the Wellington Regional Council and a representative from each key contractor undertaking the

works.

The matters to be covered in the pre-construction meetings are provided on the pre-construction meeting

checklist (http://www.gw.govt.nz/assets/Our-Environment/Land%20and%20soil/Earthworks-page-Pre-

constructionMeetingChecklist.pdf).

6.3 Minimum notice of works prior to works commencing

The Manager, Environmental Regulation, Wellington Regional Council, shall be given a minimum of two

working days (48 hours) notice prior to the works commencing for each stage of the works.

6.4 Certification of ESC devices

Prior to bulk earthworks commencing for each stage, the consent holder shall provide to the Manager,

Environmental Regulation, Wellington Regional Council a certificate signed by an appropriately qualified and

experienced engineer to certify that the erosion and sediment controls for that stage have been constructed

in accordance with the Earthworks Construction Plan and Flocculant Management Plan, and the current

version (at the time of submission of the ECP) of the Erosion and Sediment Control Guidelines for the

Wellington Region as a minimum standard.

Certification shall include, but not be limited to, the following:

a) Confirmation of contributing catchments, dimensions and storage volumes of sediment retention ponds,

decanting earth bunds, silt fences and diversion channels/bunds as applicable

b) As-built plans of the key erosion and sediment controls measures; and

c) Any other details that will facilitate assessment of compliance with the authorised ECP, authorised FMP

and the Erosion and Sediment Control Guidelines for the Wellington Region (September 2002).

Certification that the appropriate measures are in place shall be submitted to the Manager, Environmental

Regulation, Wellington Regional Council within 5 working days of completing the audit.

The consent holder is to complete the sediment control device as-built check sheets available on the Greater

Wellington Regional Council’s website and to submit these with the certification required under this condition.

http://www.gw.govt.nz/assets/Our-Environment/Land%20and%20soil/Earthworks-page-Pre-constructionMeetingChecklist.pdf

http://www.gw.govt.nz/assets/Our-Environment/Land%20and%20soil/Earthworks-page-Pre-constructionMeetingChecklist.pdf



6.5 Environmental Site Induction

The main contractor’s staff working on the project will be required to undertake a site induction prior to

earthworks commencing on the site. This induction will include outlining all relevant environmental

management matters and as a minimum shall include;

> Objectives and key issues of the EMPC listed in Section above

> Duty of Care and Duty to notify

> Environmental Emergency Response Procedure

> Reporting of public feedback and environmental incidents

> Conditions of Consents and Approvals

> Key site specific issues relating to the EMPC

Further inductions shall take place as new personnel, contactors and sub-contractors start works on the site.

A record will be kept of people who have undertaken the induction.

Weekly meetings shall be held by the contractor and project team. As part of these weekly meetings

environmental issues will be an agenda item. The meeting will be used to stress the importance of effective

and efficient environmental management practices. These meetings will also be structured to obtain

feedback on the project and how to improve performance. Suggestions to improve environmental

management will be actioned by the individual contract managers, site manager or construction manager.

Records of the weekly meetings are to be kept on site.



7 During Construction

7.1 Inspections, Monitoring and Reporting

7.1.1 Daily Inspections

During the main phase of earthworks, the Contractors Representative or a suitability experienced person as

nominated by the consent holder will visit the site daily to confirm works are progressing in general

accordance with the Contractors programme, the EMPC, ECP, and all relevant Resource Consents.

Daily inspections shall be conducted by both the Contractor and Client representative (as required) and shall

include, but not be limited to;

> Weather forecast

> Methodology for the days earthworks activity – cut from location ‘A’, mixing with soil from location ‘B’,

filling at location ‘C’

> Water quality observations, including downstream of the site

> Erosion and Sediment Controls relating to the methodology for the days earthworks including installation

of additional controls where required

> Dust and air quality controls

> Fuels and chemicals onsite are stored appropriately and operations surrounding these areas are

controlled

> Noise and waste are minimised as much as practicable

> Traffic movements are minimised as much as practicable

> Flora and fauna are protected

> Health and Safety measures are employed onsite, in line with current best practice

Notes on site observations and discussions between the Contract Supervisor and the Site Manager will be

taken and will form the basis of the weekly report to the Project Manager.

The contractor is to send though a record of the daily inspections undertaken on a weekly basis.

7.1.2 Weekly Site Audits

[XXXX] shall undertake weekly site audits to ensure that the erosion and sediment control methods are

being maintained in accordance with the Earthworks Construction Plan and Flocculant Management Plan.

The audits shall include:

> Date;

> Name of auditor;

> Site condition;

> Weather conditions;

> Sediment management (including identification of problem areas that are not being treated by sediment

control measures, and any measures put in place to treat these areas);

> Runoff control (check of diversion channels and check sediment retention ponds);

> Condition of sediment control measures, including silt fences, contour drains and sediment retention

ponds;

> Maintenance required and the date this will be completed by;

> The contractor responsible for the maintenance; and



> General comments.

A check sheet template is to be prepared to record the weekly site audits, which are to be sent to the Clients

representative by the Tuesday of the following week.

7.1.3 Inspection and Monitoring Schedule

The frequency of the audits may be reduced if agreed in writing by the Manger, Environmental Regulation,

Wellington Regional Council

7.1.4 Reporting of Site Audits

The results of the weekly audits shall be submitted each month to the Manager, Environmental Regulation,

Wellington Regional Council, no later than the 15th of the following month.

7.2 Complaints and Feedback Procedures

7.2.1 Public Feedback

All employees of the main earthworks contractor will be trained to report any feedback (be it complaints

and/or praise) from site visitors, neighbouring property owners or the surrounding community to the Site

Manager’s Office as soon as is reasonable practical to do so.

All feedback received in respect of the construction works will be recorded in a Public Feedback Record,

which will be maintained by the Site Manager.

The record will keep details of:

> Date of feedback;

> Name of event;

> Name and address of person providing feedback;

> Details of feedback, including weather conditions;

> Action to prevent further similar complaints;

> Date of oral response;

> Date of written response

In response to feedback that is considered a complaint, the Site Manager will be required to:

> notify the Engineer within 24 hours with an oral response, and

> within 72 hours provide a written response to the Engineer identifying what action is proposed or has

been taken to resolve the complaint.

Greater Wellington Regional Council will be notified with 24 hours of a compliant being received. Greater

Wellington Regional Council can be contacted on 0800 496 734.



8 Amendments to the Plan

Throughout the course of the project, as monitoring identifies areas where improvements can be made to

improve environmental outcomes, it is expected that these improvements can be fed through and be

included in the relevant plans.

Where changes to this Environmental Management Plan for Construction are identified these shall be

discussed with Greater Wellington Regional Council. Any amendment proposed to the authorised

Environmental Management Plan for Construction will be submitted in writing to the Manager, Environmental

Regulation, Wellington Regional Council. Implementation of any amendment shall only occur once the

amendment has been authorised in writing by the Manager, Environmental Regulation, Wellington Regional

Council.



9 Emergency Response Procedure

In the event of an Environmental Incident the emergency response procedures outlined in Section 10 should

be followed with the Emergency Contacts outlined in Section 9.1.

9.1 Emergency Contacts

Site Manager: TBC

The contractor’s site manager, will be responsible for ensuring all staff onsite are aware of the consent

requirements and shall complete the works in accordance with these requirements and approved plans

within the specified time. If unforeseen circumstances occur which are not covered in the preapproved

documents, the site manager will also be responsible for ensuring that the project manager is aware of the

issues, and that solutions to reduce the potential environmental impacts are implemented as soon as

practicable.

Phone: - Mobile: -

Engineer to the Contract: TBC

The Engineer to the Contract is responsible for resolving major environmental issues, where the issue will

cause environmental effects which are more than minor and outside the scope of the Consent document.

The Engineer to the Contract will work with the Site Supervisor and Council Staff to provide an appropriate

remedial solution to the contractor.

Phone: - Mobile: -

Contract Supervisor: TBC

The Contract Supervisor will be responsible for ensuring works covered in the Consent documents, including

all pre-approved plans, is adhered to on a daily basis. Should unforeseen environmental impacts occur as a

result of the works, the Contract Supervisor will be the liaison between the Engineer, Council Staff and the

Contractor to ensure the level of impact is minimised and a suitable remedy implemented as quickly as

possible.

Phone: - Mobile: -

Contractor: TBC

The contractor’s nominated foreman will be responsible for completing the works in accordance with the

approved documents and drawings.

Phone: - Mobile: -

Compliance Officer: TBC, Greater Wellington Regional Council

The consent holder shall notify the Manager, Environmental Regulation, Wellington Regional Council within

24 hours if any contaminants (including sediment) are released from the site and enter Duck Creek, due to

any of the following:

> Discharges from unstabilised areas that are not treated by sediment control measures required under this

discharge permit,

> Failure of any erosion and sediment control measure, or

> Any other incident which either directly or indirectly causes or is likely to cause adverse ecological effects

on Duck Creek.



Greater Wellington Regional Council can be contacted on 0800 496 734



10 Reporting Procedures

The flow chart below details the process to be undertaken when reporting site issues.

Report issues or problems to

Resolve issue/ problem.


Discuss issues or problems with

Personnel onsite: eg. Digger and Truck

drivers


Site Foreman

Site Manager:

Site Supervisor: Off Site Manager:

Consultation

Engineer: Regional and City Council Staff

Level of

Enviro

nm

enta

l Im

pact

Resolve issue/problem.



11 Environmental Impact and Risk Assessment

This section identifies the main activities associated with the construction and commissioning of the project

and the potential adverse effects. Based upon these potential adverse effects an Environmental Effects

Register has been prepared that identifies how these impacts can be avoided, remedied or mitigated. The

Environmental Effects Register is designed to ensure that awareness of potential adverse effects and their

management is maintained throughout the life of the project.

11.1 Site Description

The site for the proposed earthworks is located on the northern section of the former Duck Creek Golf course

located west of James Cook Drive.

The site is located on undulating terrain comprising relatively flat ground of the Duck Creek stream valley.

The meandering stream channel of Duck Creek leads through the site and flows through the DoC

administered scenic reserve immediately north of the site before entering into the Pauatahanui Inlet.

Around the edges of the site the topography rises up and the surrounding hills are covered in a mixture of

residential development and natural bush/vegetation.

11.2 Site limitations

Duck Creek is considered to be a regionally significant stream due to the presence of several threatened

native fish. Declining fish species of Longfin eel, Giant Kokopu, Koaro, Inanga and Redfin Bully were found

at various locations within Duck Creek during sampling.

The current streams habitat quality is reduced by bank erosion, aquatic weeds, and a lack of riparian

vegetation in some places. Therefore no construction equipment is to enter the stream unless it is for

specifically approved works in the stream, such as the placement of erosion protection rip-rap.

There are no known areas on the site of historical or cultural significance, as designated on Regional and

District planning maps.

The main focus of the Management of the Site is therefore the protection of the stream from siltation as a

result of the proposed earthworks.

The site is currently of an elevation that it is prone to flooding in a reasonable flood event, as such each

stage of earthworks will need to be undertaken to ensure the earthworks site is protected from a 1 in 5 year

flood event. Site bunding shall be constructed and stabilised using best practice techniques to ensure the

outside batter face is protected.

11.3 Site Hazards

11.3.1 PCC Trunk Water Main

Porirua City Council operates a trunk water main (200mm diameter AC) that crosses the site. The

development of the site includes the staged relaying of the main through the site. The majority of this line

will be relocated to within future legal road with a small portion within a private allotment.. The protection of

this water main during construction is an essential requirement. All work that is associated with, and adjacent

to, the water main will be carried out in close liaison with the Engineer, Porirua City Council and Wellington

Water. No earthworks, filling or excavation is to be carried out within 2m of the water main without specific

written approval of the Engineer. The 2m off-set on each side of the water main is to be shown on the site by

the erection of a warning tape (or plastic netting fence) along the length of the water main on the site prior to

any work starting on the site (i.e. as part of stage 1 establishment works).

11.3.2 Gas main and Electricity/Telecom Cables

There is a gas main and electricity/telecom cables leading west from the pump station location before

heading north up the slope towards The Crowsnest. There are also electricity and telecom cables heading



east from the pump station crossing Duck Creek and up to Observatory Close. These services are to be

relocated in conjunction with the bulk earthworks. An exclusion zone is shown on the plans to alert all parties

to the presence of these services. No work is to be carried out in the exclusion zone associated with these

services without written approval from the Engineer.

11.3.3 Pressurised Bulk Wastewater Main

In the northern portion of the site there is a pressurised bulk wastewater main (375mm diameter rising main)

leading from the pump station out to SH58. The main is primarily located under the existing access track to

the pump station from SH58. Prior to using this access track, this main must be marked out and clearance

requirements must be confirmed for heavy construction machinery as part of site establishment works

11.3.4 Gravity Bulk Wastewater Main

Currently there is a 375mm diameter AC main that leads from Discovery Drive at the southern end of the site

up to the pump station. This main passes under the stream in multiple locations and will be affected by future

lots so as part of the works it is intended to realign the main (in stages) to remove these creek crossings and

keep the alignment in public property to enable maintenance of this line without affecting private property.

11.3.5 Department of Conservation (DoC) Reserve

Immediately downstream of the site is the Department of Conservation administered scenic reserve

surrounding Duck Creek and the area where it enters into the Pauatahanui Inlet. This location is a sensitive

ecological area so the Contractor must ensure that all ESC measures are in place before before earthworks

commence and these are maintained as outlined in the ECP document.

Further information to be provided by the contractor as part of a design build tender for the bridge that will

outline in further detail the construction methodology of the bridge including associated environmental best

practice and detailed ESC etc.

Please refer to the sections below with respect to general environment protective measures.

11.4 Main Construction Activities

The main construction activities are:

Stage 1:

> Site establishment and construction of erosion and sediment controls (including SRP 1 and SRP 2);

> Construction of foundations, erection and commissioning of permanent bridge 1 at northern end of the

site;

> Bulk earthworks for Stages 1 (Including Cut Stage 1 Borrow).

> Installation of Temporary Bridge 1

> Import/Export certifiable fill and unsuitable material.

> Stage 1 of realignment of existing 200mm diameter trunk water main

> Construction of underground services;

> Formation of roads by excavating to sub-grade and sealing;

Stage 2:

> Site establishment and construction of erosion and sediment controls;

> Installation of Temporary Bridge 1 (if not completed in stage 1)

> Bulk earthworks for Stage 2

> Import/Export unsuitable material and certifiable fill.

> Stage 2 of realignment of existing 200mm diameter trunk water main




> Construction of foundations, erection and commissioning of permanent bridge 2;

> Completion of stabilisation so that sediment and erosion control pond (SRP 1) can be decommissioned

and filled up to final design surface level (if it is not to be used for future stages);


> Removal of temporary bridge 1 once permanent bridge 2 is in operation.

Note: There is a permanent stream diversion that will be undertaken at the end of Stage 2 or as an

independent stage in the following earthworks season.

Stage 3:

> Site establishment and construction of erosion and sediment controls;

> Installation of Temporary Bridge 2





> Completion of stabilisation so that sediment and erosion control pond (SRP 2) can be decommissioned

and filled up to final design surface level;


> Removal of temporary bridge 2 once permanent bridge 3 is in operation.

Stage 4:





> Completion of stabilisation so that sediment and erosion control pond (location subject to detailed design)

can be decommissioned and filled up to final design surface level;

11.5 Potential Adverse Effects

If not managed appropriately, the construction activities associated with this project can lead to adverse

effects. These effects will be avoided by the development through compliance with this EMPC and the

associated requirements outlined in Section 2.

These management plans will address the following potential adverse effects;

> Erosion by exposing unstable surfaces and/or through discharges of stormwater runoff,

> Deterioration of water quality in Duck Creek from the effects of sediment discharges from disturbed areas;

> Deterioration of water quality in Duck Creek from the effects of discharges associated with the

construction of the temporary and permanent bridges;

> Contamination of the air with dust;

> Excessive noise discharges;

> Loss of top soil due to poor storage and handling;

> Visual effects of open cut batters;



11.6 Erosion and Sediment Control Principals

The minimisation of erosion and active management of sediment runoff from the earthworked areas is the

main focus of earthmoving projects, particularly in sensitive environments such as Duck Creek.

The erosion and sediment control measures adopted for this project are therefore aimed at ensuring a high

level of protection against sediment discharges into Duck Creek during low to medium intensity rainfall

events, and protection against uncontrolled discharges and scour during high intensity rainfall events.

The management procedures proposed for the control of erosion and the treatment of sediment run-off, from

earth-worked areas, for this project are based on the following principles:

> Not working during inclement weather;

> Minimise disturbance;

> Staged construction;

> Protect steep slopes;

> Protect water bodies;

> Stabilise and rehabilitate exposed areas rapidly and progressively;

> Install perimeter controls;

> Employ detention devices;

> Implement an evolving CMP;

> Inspect the performance of the procedures;

> Maintain all erosion and sediment control measures to ensure maximum efficiency;

> Install additional measures prior to medium to high intensity rainfall events, where practicable.

Each of the above principals will be employed for The Project as detailed in Section 10. Site specific

solutions have been developed and will be implemented as detailed in the CMP, taking into account

construction and maintenance requirements. The solutions proposed are currently being used on most well

managed earthwork projects throughout New Zealand and are based on the methods documented in

Auckland Regional Council’s TP90 and Greater Wellington Regional Council’s, “Erosion and Sediment

Control Guidelines for the Wellington Region”.

Additional measures, not included in the above Documents, but to be employed in The Project include;

> Grit traps – similar to a small forebay to reduce flow velocities prior to discharge into either a pond, or

diversion channel;

> Filtrexx barriers (in combination with silt fences) – similar to silt fence in function, they are a compost filled

sock to trap sediment as water passes through;

> Outlet controls on Sediment Ponds – discharges from sediment ponds will, where practicable, discharge

to land rather than a water course. This will facilitate additional filtration through pasture and improve the

quality of the sediment discharge to the nearest watercourse;

> Stabilised level spreader – all sediment ponds will have a concreted level spreader to eliminate scour in

this area, and improve the overall performance of the pond.

> Baffles – all sediment ponds will have porous baffles to improve the rate of settlement for suspended

particles, increasing the efficiency of the pond.

11.7 Dust and Odour Control

Dust and odour may become a problem during certain weather conditions, causing disturbance to

neighbouring properties. Dust and odour may be generated from both works on site and the cartage of

materials from the site through adjoining streets.



If dust and odour become a problem, the contractor shall employ appropriate control measures to avoid,

remedy and mitigate any adverse effects. The following measures should be used to minimise effects of

excessive dust and odour on adjoining properties.

A water cart with sufficient water resources shall be available on short notice for the duration of the contract

works. Where the water cart is unable to mitigate any hazard, earthworks shall cease until the hazard is

removed by alternative means, as discussed in the contingency plan.

Haul roads and other areas of major dust source shall be kept damp during dry periods to minimise public

nuisance.

All storage areas, loading and unloading operations, blending or mulching processes and other activities

carried out on site shall be conducted and managed in such a manner as to ensure that all dust and

particulate emissions are kept to a practical minimum.

Where the existing landform or vegetative cover is being disturbed, ground cover is to be established

immediately following earthworks and with a minimum of delay to ensure the wind erosion of soil or other

material does not become a nuisance.

Site works shall be managed in such a manner to ensure that there shall not be any objectionable odour at

or beyond the boundary of the subject property.

11.8 Noise Control

The development of land involving earthworks will always create construction noise, mainly due to the

machinery used. All practicable measures to keep noise to an acceptable level should be implemented.

This includes but is not limited to mufflers being used on all earthworking machinery.

Heavy machinery or plant may only operate on the site between 7:00am and 6:00pm Monday to Friday and

between 7:00am and 4:00pm Saturday. The transportation of heavy machinery onto or off the site should

only occur between 8:00am and 6:00pm Monday to Friday and between 8:00am and 4:00pm Saturday.

11.9 Cartage of Materials and Machinery

The contractor shall liaise with any relevant traffic controlling authority and all entry and exit from the site will

be in accordance with the Traffic Management Plan approved for construction (by others) to minimise

congestion of traffic particularly during peak traffic flow periods.

Vehicles shall be loaded in such a manner that there is no spillage in any public place during conveyance off

the site. Pedestrians, traffic and streets shall be protected from and be free from mud and debris.

11.10 Important Contractor Requirements

The consent holder shall ensure that:

All on-site storage areas for fuels and lubricants are bunded or contained in such a manner so as to

prevent the discharge or spillages of such contaminants;

All machinery is regularly maintained in such a manner so as to minimise the potential for leakage of

fuels and lubricants;

No equipment or machinery is cleaned, stored or refuelled within 20 metres of any watercourse;

All machinery is thoroughly cleaned of unwanted vegetation (e.g. weeds), seeds or contaminants

prior to enter the site; and

No contaminants (including but not limited to oil, petrol, diesel, hydraulic fluid) shall be released into

water from equipment being used for the works.

The consent holder shall ensure that no wet concrete or concrete washwater enters any watercourse

during, or as a result of the works. The Manager, Environmental Regulation, Wellington Regional

Council, shall be notified immediately (within 12 hours) if any wet concrete or concrete washwater

enters any watercourse.



Any excess material from the construction and implementation of the works shall be removed from

site and disposed of in an appropriate manner.

If koiwi, taonga or other archaeological material is discovered in any area during the works, work

shall immediately cease and the consent holder shall contact Ngati Toa Rangatira, the New Zealand

Historic Places Trust and Wellington Regional Council within twenty four hours. If human remains

are found, the New Zealand Police shall also be contacted. The consent holder shall allow the

above parties to inspect the site and in consultation with them, identify what needs to occur before

work can resume.

Note: Evidence of archaeological material may include burnt stones, charcoal, rubbish heaps, shell,

bone, old building foundations, artefacts and human burials.



12 Project Construction Programme

The programme below provides indicative timing for key phases of the project. The programme will be

updated and submitted to GWRC monthly throughout construction.

Construction Programme Option 1 – Diversion in conjunction with Stage 2 Earthworks Table 12-1

Description Estimated Programme

Installation of ESC devices October 2015

Stage 1 Earthworks October 2015 - June 2016

Bridge 1 Construction November 2015 – February 2016

Stage 1 Roading and Services February 2016 - October 2016


Bridge 2 Construction October 2016 - December 2016


Creek Construction & Diversion January 2017 - March 2017






Construction Programme Option 2 – Diversion as independent construction season Table 12-2

Description Estimated Programme

Installation of ESC devices October 2015


Bridge 1 Construction November 2015 – February 2016





Creek Construction & Diversion October 2017 - December 2017

Stage 3 Earthworks October 2018 – June 2019







01 EARTHWORKS CONSTRUCTION PLAN (ECP) – STAGE 1



1 Earthworks Construction Management Plan

Copyright in the whole and every part of this document belongs to Cardno and may not be used, sold,

transferred, copied or reproduced in whole or in part in any manner or form or in or on any media to any

person other than by agreement with Cardno.

This document is produced by Cardno solely for the benefit and use by the client in accordance with the

terms of the engagement. Cardno does not and shall not assume any responsibility or liability whatsoever to

any third party arising out of any use or reliance by any third party on the content of this document.

1.1 Scope

This Earthworks Construction Plan incorporates the Erosion and Sediment Controls (ECP) for each phase of

the earthworks for Duck Creek North, Whitby. The ECP is to be approved prior to the commencement of

construction.

The ECP has been prepared in accordance with the current version (at the time of submission of the ECP) of

the Erosion and Sediment Control Guidelines for the Wellington. The ECP reflects the measures outlined in

the Environmental Management Plan for Construction.

This Earthworks Construction Management Plan (CMP) has been prepared for the bulk earthworks of Duck

Creek North. It is intended to undertake the earthworks within one construction season.

Emphasis is placed on the avoidance, mitigation or remediation of potential adverse environmental effects

on Duck Creek, and the residential properties to the north, as a direct result of earthworks. This Earthworks

CMP will be implemented prior to the commencement of any earthworks on site.

As earthworks sites are dynamic and site slopes are constantly changing, variations to this plan shall be

required to maintain an appropriate level of protection for sensitive downstream environments.

1.2 Earthworks Description

The proposed bulk earthworks will be undertaken in four stages, as shown on Cardno Plan NZ0115065-PL-

C120 Rev 2.

In summary, the Stage 1 earthworks involve:

the stripping of approximately 13,000m3 of topsoil from the areas to be earthworked;

excavation of approximately 23,000m3 of cut material;

the placement of all of the cut material into the fill (excluding any unsuitable material encountered);

the import and placement of approximately 35,000m3 of material from off site into the fill;

the completion of approximately 53,000m3 of fill (plus an additional allowance of 5,000m

3 for

compaction of cut material);

the respreading of approximately 4,000m3 of topsoil over the developed lots and berms;

the removal of approximately 9,000m3 of excess topsoil from the site;

the removal of approximately 11,000m3 of unsuitable material from the site that is expected to be

encountered within the earthworks operation.

The maximum height of the cut is 4m and these results in a maximum cut batter of 7.5m around the cut in

Stage 1 along the western boundary of the site. The maximum height of the fill batter is 3m but the average

depth of filling is approximately 1.9m.

The fill material is to suitable material sourced from the cut areas on site or imported from another suitable

location. No material defined as unacceptable in the Ministry for the Environment’s “A Guide to the

Management of Clean Fills” is to be deposited in any of the fill areas.



All material is to be placed and compacted to achieve the final contours shown on the plans. The completed

profile is to be topsoiled and stabilised to minimise excessive runoff. All compaction is to be in accordance

with NZS4431:1989.

No earthworks under the proposed consent, other than those subject to this Earthworks CMP, will be

undertaken without prior approval from GWRC.

1.2.1 Purpose of Works

The intent of the proposed works is to achieve uniform and gentle slopes suitable for the planned residential

development, including suitable gradients for roads.

The works will involve the installation of two temporary bridge structures on Duck Creek to allow for the

installation of a haul road to link all parts of the site during earthworks construction. The works will also

involve the construction of three permanent bridge structures on Duck Creek for permanent access to the

entire site.

1.2.2 Site Description

The site is the northern part of the former Whitby Golf Course off Discovery Drive (West of James Cook

Drive), Whitby. The proposed residential subdivision is to be situated on the mostly flat to gently sloping land

near Duck Creek to the south of where Duck Creek discharges to the Pauatahanui Arm of the Porirua

Harbour. Duck Creek runs through the site and several permanent crossings will need to be constructed to

maintain access to all areas of the site.

Notable aspects of the site that influence the construction include the presence of the 200mm diameter AC

Trunk Water Main and 375mm diameter AC bulk sewer main crossing the site that will need to be relocated

during the works.

The trunk water main crossing the site will be realigned between the eastern and western boundaries of the

site to ensure that the main is located in the road corridor to enable future maintenance of this line. This

realignment will be undertaken in two stages. The first stage will be undertaken in conjunction with the Stage

1 earthworks on the western side of the creek, constructing a new 200mm diameter line shifting the trunk

main away from the western boundary into the future road corridor. The second stage will then connect into

the new line and cross permanent bridge 2 before connecting into the existing main adjacent to the eastern

boundary. A portion of the first stage realignment will be abandoned upon completion of the second stage as

it will be no longer required.

No work is to be carried out in the vicinity of the water main or wastewater main without written approval from

the Engineer.

The development requires the construction of three permanent bridges to access all areas of the site. The

design is such that the deck undersides are clear of the required flood events as detailed in the Flood

modelling report.

1.2.3 Site Construction Access

Access to the site is currently from the northern end of the site off SH58 along the access track to the

wastewater pump station. This will only be used for site access until the permanent bridge is constructed,

provided access to the site from James Cook Drive.

Aside from when the earth working machinery is brought to the site and the arrival and departure of workers

from the site at the beginning and end of a working day, the number of vehicle movements to and from the

site is to be kept to an absolute minimum.

While bridge 1 is under construction the importing and removal of material from site will be via the SH58

access. Please refer to the prepared traffic management plan for construction – prepared by others that

details the requirements for entering and exiting the site during this phase of works.

1.2.4 Hours of Operation

Hours of operation for the works on the site, including machinery warming up, shall be as follows:

Monday to Friday 7.00am to 6pm



Saturday 8am to 4pm

No work is to be carried out on Sundays or public holidays. Machinery warm up must be within the above

start times.

Heavy machinery or plant may only access/ exit the site and operate on the site between 8:00am and

6:00pm Monday to Friday and between 8:00am and 4:00pm Saturday.

The exception to the above hours being that any emergency remedial works required for example, in relation

to slips or general safety issues on the site or adjoining sites relative to the proposed earthworks or silt

control installations, including repair after heavy rainfall, will not be subject to these restrictions.

1.2.5 General Health and Safety Provisions

The contractor shall comply with all relevant health and safety regulations and adopt best practice guidelines

for activities occurring on and off site which are directly related to the nature of works required.

These measures shall include the provision of appropriate signage and fencing where necessary to ensure

public safety during the period of works.

1.2.6 Discovery of Artefacts

If koiwi, taonga or other archaeological material is discovered in any area during the works, work shall

immediately cease and the consent holder shall contact Ngati Toa Rangatira, the New Zealand Historic

Places Trust and Wellington Regional Council within twenty four hours. If human remains are found, the New

Zealand Police shall also be contacted. The consent holder shall allow the above parties to inspect the site

and in consultation with them, identify what needs to occur before work can resume.

Note: Evidence of archaeological material may include burnt stones, charcoal, rubbish heaps, shell, bone,

old building foundations, artefacts and human burials.

1.2.7 Programme and Methodology

The earthworks are planned for earthworks construction season 2015/16. The bulk earthworks for Stage 1

will take approximately 5-6 months to complete and will follow the steps outlined below.

The earthworks will be carried out in a sequence that achieves a satisfactory progress, whilst achieving the

desired management of surface water runoff to ensure appropriate management of erosion and sediment

control. The key activities are shown below.

The key aspects of the methodology are:

Install E & S Control devices (including SRP 1 and 2);

Commence construction of permanent bridge 1 off James Cook Drive;

Construction of temporary bridge 1 to provide access to Future Stage 2;

Progressively stripping topsoil from areas 1A, 1B and cut borrow area and stockpiling in Stage 2

location;

Initiate filling in area 1A with a combination of imported material and cut from onsite (from area 1B

and borrow area), including shaping haul road to protect pressurised main at toe of the hillside.

As area 1A is progressed, commence cut to fill in the area 1B with ensuring that exposed area

remains under 3Ha and the flow path to SRP 1 is maintained throughout the operation;

The proposed road corridor in area 1A is to be stabilised with crushed concrete/metal as it is brought

up to grade.

Complete the construction of the permanent bridge and the bridge approach works. This is expected

to be completed in late 2015;’

Complete the cut to fill in phase 1A area and complete stabilisation. This is expected to be

completed in late 2015;



As area 1A is completed and area 1B is being progressively stabilised, area 2 can be opened up for

cut to fill.

Complete cut to fill in area 1B, area 2 and the cut borrow area and complete stabilisation of these

areas.

Stabilisation will be completed on the final areas, which is expected to be completed in June 2016;

The programme set out above is an indicative programme. Where earthworks can proceed in different areas

without reliance on earlier implementation of sediment controls this may be undertaken concurrently rather

than consecutively.

1.3 General Erosion and Sediment Controls

1.3.1 Stabilised Construction Entrance

A stabilised construction entrance shall be installed at a suitable location between the entrances from SH58

and James Cook Drive and the construction site ensuring that all truck movement use the aggregate pad.

Design and maintenance of the stabilised construction entrance shall be in accordance with the Greater

Wellington Guidelines. A wheel wash facility shall be provided if required.

1.3.2 Surface Roughening and Battering

Surface roughening shall be undertaken by machinery tracking after completion of the slopes. Benches shall

be used to break up steep slopes and bunding shall be constructed at the top of the slopes. Methodology

and maintenance shall be in accordance with the GWRC Guidelines.

1.3.3 Heavy Rainfall Contingency Measures

If heavy rain is forecast or can be reasonable foreseen measures shall be taken on site to reduce the

potential for erosion or discharge of sediment laden water. These steps shall be especially prudent where

the heavy rainfall event is due to be greater than the design event of the control devices.

All stockpiles shall be covered in straw mulching (or similar approved method) or geotextile fabric where it

can be sourced in sufficient time.

All earthworks areas shall be compacted and surfaced roughened to the extent that is practicable taking into

account the slopes, stage of earthworks, equipment available and time prior to the occurrence of the rainfall

event.

All control devices shall be checked to ensure they will be operating effectively during the rainfall event.

Additional decanting grit traps shall be placed if practicable to reduce the loading on the permanent sediment

controls.

1.3.4 Isolation from Floodwaters

The sediment control devices are designed to cater for up to a 5-year event and therefore should be

protected from at least such a flood event. Greater flood events will not affect the sediment controls which

shall already be operating over capacity. The flood level to be protected against shall be the level of the 10-

year flood as per the modelling carried out for the Cardno Flood Model Report. Depending on the extent of

the earthworks and flood protection measures this may correspond with a rainfall event higher than a 10-

year rainfall event so should provide more than sufficient protection and freeboard in the events where the

device is still going to be functioning. The theoretical stream level in the modelled event is less than the

earthworks levels and the top of the SRPs, therefore no mitigation measures are required.

1.4 Specific Erosion and Sediment Control Measures

The following proposed measures are indicative of the locations and types of measures required for this site.

As the earth working operation progresses, the Site Foreman, Engineer, Project Manager or Regional

Council may request that these measures need to be moved, altered, or removed to ensure sediment runoff

from the site is kept to an absolute minimum, without unduly affecting the surrounding environment.



Note: Preliminary calculations for the proposed Sediment Retention Ponds and main Runoff Channel

leading to SRP 1 have been included in this draft report. Additional detail and calculations will be provided in

the ESCP for approval following detailed design.

1.4.1 Sediment Retention Ponds (SRP)

Two sediment retention ponds shall be used during the earthworks to control sediment. They have been

sized in accordance with the Greater Wellington Regional Council Guidelines, Clause 5.1, and are

summarised in the Table below. Ponds are shown on Cardno Plans NZ0115065-PL-C201 – C204, attached

in Appendix A (or within the supplied plan set)

Table 1-4 Pond Summary

Pond ID Catchment Area (Ha)

Volume (m³) Length (m) Width (m) Decants Pipe Outlet (m)

Emergency Spillway Width (m)

SRP 1 2.98 1100 57 17 2 300 6

SRP 2 1.23 455 41 13 1 100 4

The ponds have been sized on the basis of 370m³ of retention volume per hectare of earthworks area. The

pond volume ensures that the pond has the capacity for a five year event. Both ponds shall have a forebay

of 10% of the volume to increase the efficiency of the pond and shall be flocculated in accordance with the

Flocculation Management Plan.

The spillway width is designed for 100-year event minus the flow in through the decant and primary spillway

outlet pipe.

In addition to being a standard flocculant pond it is proposed that each of the ponds will also have 5 porous

baffles, constructed from Propex Landlok 300, a turf reinforcement mat supplied by Cirtex (positions to be

confirmed), to increase the rate of settlement in the ponds further increasing their efficiency. These will be

installed to seek an improved performance in the reduction of sediment through the device prior to

discharge. The arrangement and design of the baffles is to be based on information presented in the

research paper “Optimisation of baffles for sediment retention ponds” published from the University of

Auckland.

The contractor is also responsible for ensuring that the sediment retention ponds are fit for purpose from a

health and safety perspective. All ponds are to be fenced off and signboards erected to deter unauthorised

access into the ponds. All weather access must be provided to the decants and outlet chamber so that water

quality monitoring can be safely undertaken during/following heavy storm events. Contractor also to provide

a solution that enables the decants to be raised in a safe manner without entering the pond (ie rope and pully

system).

1.4.2 Pond Outlets & Discharge flow path

The sediment pond outlets are indicated on the erosion and sediment control plans for each stage. SRP 1

shall have two decants discharging via a central outlet manhole to a 300mm diameter pipe. Pond SRP 2

shall have a single decant to a 100mm diameter pipe. The outlet shall discharge through a bubble up sump

to a vegetated dispersal zone bounded by silt fences with regular check dams along its length. This will allow

clean water from the pond to be discharged at low velocities to land and some reasonable mixing to occur

prior to reaching watercourses.

1.4.3 Pond Emergency Spillway

The emergency spillway for SRP1 will discharge into the vegetated dispersal zone (detailed above) before

flowing down the bank to Duck Creek. The emergency spillway for SRP2 will be directed by the overflow

channel to discharge into Duck Creek. Erosion protection will be used to maintain a stabilised channel.

1.4.4 Silt Fences (SF) and Super Silt Fences (SSF)

Silt fences and super silt fences provide control around pond areas and small areas where runoff channels

cannot capture sediment laden runoff. The fill batter slopes will be controlled by Super Silt Fence as the only

control device as the levels do not allow drainage into the SRPs. Fences are placed within the requirements



of Clauses 5.3 and 5.4 of the Greater Wellington Regional Council Guidelines for Erosion and Sediment

Control.

Regular returns on the silt fences are to be installed during the installation of the silt fence to ensure the

returns trap run off and avoid longitudinal flow through to a possible low point.

1.4.5 Runoff Channels/Diversion Bunds (RC)

Sediment laden water shall be directed to ponds via RC’s. All RC’s are trapezoidal shaped and have been

sized for their respective flows in a 20-year, 10 minute rainfall event. The 10 minute rainfall duration was

calculated based on the short catchment lengths and the lack of vegetation cover.

RC’s are shown on the plan in their starting position, generally along the cut/fill boundary. Once earthworks

are sufficiently established the RC can move to the top of the fill batter to maximise the sediment laden

catchment area of the ponds.

Stabilisation of all RC’s is recommended and will be considered at time of detailed design. Aspects that will

be considered will include; soil type, grade, catchment, flow rate, location.

Stabilised channels, as with all channels, will be visually inspected along the entire length after each storm

event with maintenance occurring where required.

1.4.6 Clear Water Channels/Diversion Bunds (CW)

Where possible the earthworks area is to be isolated from runoff originating uphill of the site by diverting the

clear water around the site using Clearwater Channels/Diversion Bunds, which shall be used in accordance

with clause 4.1 of the Erosion and Sediment Control Guidelines for the Wellington Region (the Guidelines).

The majority of runoff from uphill of the site shall be collected during all stages of the earthworks and

directed around the earthworks area for discharge to their respective gullies and/or stormwater pipes. By

this manner the sediment runoff catchment boundaries shall be clearly defined and maintained, and the

majority of ‘clear’ stormwater runoff shall be restricted from entering the earthworks area. Where the grade

of the channel is required to be over 2%, they will be armoured with suitability size rock. All CW have been

sized for their respective flows in a 20-year, 20 minute rainfall event. The 20 minute rainfall duration was

determined from the time of concentration which is higher due to on the long catchment lengths and the high

level of vegetation cover.

All clearwater bunds shall be formed by means of a cloth wrapped bund (or similar or approved by the

engineer / GWRC). The cloth shall be A14 Bidem cloth securely wrapped around the bund.

1.4.7 Stormwater Pipes/Culverts

For the Stage 2 earthworks a stormwater pipe will be required to be constructed over the creek between

Stages 1 & 2, as shown on Cardno Plan NZ0115065-PL-C202, in order to carry dirty water from Stage 2

over to SRP 1. This pipe will need to be appropriately anchored and protected to ensure it is not damaged or

washed away during flood flow events. We note the elevation of this pipe will be higher than the existing

sewer pipe that crosses Duck Creek immediately downstream of the proposed location.

1.5 Site Stabilisation

1.5.1 Removal of Erosion and Sediment Controls

No Sediment Control structure is to be removed from the site until the earthworks area above has been

stabilised appropriately. The Engineer is to direct when removal is to occur, and it may only be done with the

approval of Greater Wellington Regional Council. The area of the pond, channel or bund is to be stabilised

by grassing following removal.

1.5.2 Earthworked Areas Stabilisation

The means of stabilisation of the site will depend on the nature of the area being stabilised. Rock faces left

visible after removal of cut material will not require stabilisation.



The majority of slopes and flat areas left after cut and fill operations shall be topsoiled and hydroseeded.

The application of hydroseed depends on the soil material, the weather and the nature of the slope. Some

areas shall have a 30mm down topcourse applied which shall provide a stabilised surface.

Areas which require to be stabilised quickly in order to meet one of the hold points will use straw-matting,

terraflex hydroseed, polymer (strike) with grass seed (5% application) or alternative as approved by Greater

Wellington Regional Council.

Areas which are to form the subbase for future road alignments will have rotomillings or metal, including

30mm down, applied to them. Where steep sections of slopes are to be applied with rotomillings or metal,

contour channels shall be placed at 20m intervals, or as appropriate, to reduce the flow across the metalled

surface and reduce the risk of scour or erosion of the surface.

1.6 Maintenance and Monitoring

1.6.1 Erosion and Sediment Control Certification

Certification that the Erosion and Sediment Controls have been constructed in accordance with the above

shall be issued prior to bulk earthworks commencing.

Certification shall include the following:

> Confirmation of contributing catchments, dimensions and storage volumes of sediment retention ponds,

decanting earth bunds, silt fences and diversion channels/ bunds as applicable.

> As-built plans of the key erosion and sediment control measures; and

> Any other details that will facilitate assessment of compliance with this plan, the Flocculation

Management Plan and the Erosion and Sediment Control Guidelines.

1.6.2 Plan Review and Amendments

There shall be weekly meetings between contract supervisor and the contractor to discuss works on site and

management issues. In the event that there is a conflict between works on site and the Plan, a review of the

Plan shall be undertaken accordingly.

If deemed necessary a review of the plan shall be undertaken with consultation from all appropriate persons.

The revised plan shall be approved by Greater Wellington Regional Council prior to implementation.

1.6.3 Maintenance of Erosion and Sediment Control Measures

All maintenance of the sediment control features to be employed on the site is to be in accordance with

GWRC Guidelines. Specifically:

Sediment Retention Ponds and Decanting Earth Bunds

> Inspect ponds every day, before forecasted rainfall event, and after every rainfall event.

> Immediately repair any damage.

> Repair perimeter fence as required.

> Clean out ponds (and forebays) before volume of accumulated sediment reaches 20% of total

pond/forebayvolume

> Clean out using sludge pumps or excavators containment areas created using 500mm high mulch bunds.

The sediment laden water will filter through the mulch bunds and be treated prior to discharging at a slow

rate over land. Following a treatment period of up to three weeks the remaining sediment laden water will

be pumped back into the pond and the solids will be taken to the dump.

> All sediment removed must be disposed of responsibly to an approved receiving facility, such as mixing

with temporary unsuitable earthworks stockpiles for drying and use as non-engineered filling on future

earthworks sites.



> It should be noted that pond sizes are based on the predicted flow from a 1 in 5 year storm. Storm events

larger than this may result in pond failure and therefore these items must be thoroughly checked and

additional measures installed when heavy rain is forecast.

Runoff Diversion Channel and Bund

> Inspect channels and bunds regularly and after each rainfall event to check for accumulated sediment

which may cause overtopping or for any signs of breaching.

> Check any discharge points for signs of scouring and install further armouring or other stabilisation if

scouring is evident.

> All sediment removed must be disposed of responsibly to an approved receiving facility, such as mixing

with temporary unsuitable earthworks stockpiles for drying and use as non-engineered filling on future

earthworks sites.

Super Silt Fences

> Inspect fences at least once a week and before and after each rainfall event.

> Make any necessary repair when bulges occur or when sediment accumulation reaches 20% up the

fabric height. Remove sediment deposits as necessary to the stockpile.

> Any areas of ineffectiveness need to be removed and replaced so that they are effective.

Stabilised Construction Entrance

> Maintain the stabilised construction entrance in a condition to prevent sediment from leaving the

construction site. After each rainfall inspect any structure used to trap sediment from the stabilised

construction entrance and clean out as necessary.

> When wheel washing is also required, ensure this is done on an area stabilised with aggregate which

drains to an approved sediment retention facility.

> Where mud is tracked onto the public road, it shall be cleaned at the end of each day.

1.7 References

1. ARC (1999), 'Erosion and Sediment Control: Guidelines for Land Disturbing Activities in Auckland

Region', Auckland Regional Council Technical Publication 90.

2. Farjood, A., Melville, B. W., and Shamseldin, A. Y. "Optimisation of Baffles for Sediment Retention

Ponds" Proceedings of International Conference on Stormwater, 2015 Asia Pacific Stormwater

Conference

3. GWRC (2006), ‘Erosion and Sediment Control Guidelines for the Wellington Region’.



02 BRIDGE CONSTRUCTION PLAN (BCP)



2 Bridge Construction Management Plan

2.1 Scope

It is proposed to construct two temporary bridges and three permanent bridges across Duck Creek within the

Duck Creek North development to gain access across Duck Creek for both construction and permanent

access once the lots are created there.

This document is considered a draft and a final BCP will be prepared that address specific consent

conditions and contractor construction methodology.

2.2 Permanent Bridges

2.2.1 Description

Three permanent bridges are required to gain access to all of the proposed lots in Duck Creek North. The

proposed bridges are shown in Cardno Plans NZ0115065-PL-C411 to C417.

2.2.1.1 Bridge 1

The proposed permanent Bridge 1 is located at the northern end of the site creating an access point on to

James Cook Drive. The bridge will be 34m long and 9.6m wide and have two spans over a central pier.

A bore hole has been drilled approximately 35m south of the western abutment of the bridge to confirm

depth to solid rock for the piles. The test hole confirmed that good bearing rock was present approximately

6.6m below ground.

As shown by the drawings, the abutments are clear of the 100 year 2090H flood event.

A contractor will be engaged in late 2015 and will be required to adhere to the EMP(C) and will prepare in

detail with reference to the granted consent conditions a site specific construction management plans for

approval by GWRC prior to commencement of physical works. The construction of the bridge will also be the

subject of a building consent (yet to be applied for) from PCC.

2.2.1.2 Bridge 2

The proposed permanent Bridge 2 is located between Stages 1 & 2 of the site below Observatory Close. The

bridge will be 17m long and 8.5m wide.

A bore hole has been drilled at the western abutment of the bridge to confirm depth to solid rock for the piles.

The test hole confirmed that good bearing rock was present approximately 6.7m below ground.

As shown by the drawings, the abutments are clear of the normal stream flow but will become inundated in

higher flood events. The wingwalls and abutments will be designed to provide erosion protection to the

stream banks and appropriately sized riprap will be used to protect the channel and abutment foundations

against scour

2.2.1.3 Bridge 3

The proposed permanent Bridge 1 is located at the northern end of the site creating an access point on to

James Cook Drive. The bridge will be 17m long and 7.6m wide. The top of the deck slab will be at a

minimum RL of 4.5m and the underside of the bridge deck will be at a minimum level of RL 3.6m. The

existing high tide level at the bridge location in Duck Creek is RL 1m and the predicted water level for the

100 year event occurring in 2090 with a high climate change scenario is RL 3.1m. The bridge therefore has a

clearance between the underside of the deck and the 100 year flood event for the 2090H predicted water

level is 0.5m.

A bore hole has been drilled approximately 35m south of the western abutment of the bridge to confirm

depth to solid rock for the piles. The test hole confirmed that good bearing rock was present approximately

6.6m below ground.



As shown by the drawings, the abutments are clear of the normal stream flow but will become inundated in

higher flood events. The eastern abutment will be affected by a 10 year flood event while the western

abutment and shared footpath will be inundated in the 2090H flood event. The wingwalls and abutments for

this bridge will be designed to provide erosion protection to the stream banks and appropriately sized riprap

will be used to protect the channel and abutment foundations against scour.

2.2.2 Construction Methodology Example

The bridge shall be constructed by the following method:

1. Survey set out of the bridge;

2. Install safety fencing around the construction area;

3. Install Super Silt Fences around the extent of the abutment works. No work shall take place beyond

this delineation;

4. Site preparation;

5. True right bank - Drilling the foundation piles for the bridge abutments;

6. True right bank - - Placing of reinforcing cages and pouring concrete in 1m lifts for the foundation

piles;

7. True left bank - Drilling the foundation piles for the bridge abutments and central pier for Bridge 1;

8. True left bank - Placing of reinforcing cages and pouring concrete in 1m lifts for the foundation piles;

9. Construct the abutments on each side of the bridge;

10. Placement of the deck beam structure and internal ducts;

11. Pouring the concrete bridge deck and kerbing;

12. Construct the wing walls at each of the 4 corners of the bridge where required;

13. Installing the guard rails on either side of the bridge;

14. Construction of bridge approaches as required including backfilling of the abutments;

15. Construct the settlement slabs on each side of the bridge and finish backfilling over the settlement

slabs;

The bridge construction will take a total of approximately 10-15 weeks to complete assuming average

weather patterns.

The contractor shall ensure that no construction materials, wet concrete or concrete washwater enters any

watercourse during, or as a result of the works. The Manager, Environmental Regulation, Wellington

Regional Council, shall be notified immediately (within 12 hours) if any wet concrete or concrete washwater

enters any watercourse.

2.3 Temporary Bridges

2.3.1 Description

Two temporary bridges are required during development to provide access across Duck Creek during the

construction of the permanent bridges. The proposed bridge locations are shown in Cardno Plan

NZ0115065-PL-C411. A further temporary bridge may also be provided off James Cook Drive and next to

the construction of the permanent Bridge 1. This is an option to assist traffic management issues at SH58.

The first temporary bridge is required to enable the transportation of machinery and material between Stages

1 & 2. This bridge will be constructed during the Stage 1 earthworks to enable the use of Stage 2 for

stockpiling topsoil. It is anticipated that it will be in use for approximately two years while the earthworks,

roading, services and permanent bridge 2 are constructed. Following the completion of permanent bridge 2

the first temporary bridge will be decommissioned and removed.

The second temporary bridge will be located further south between Stages 3 & 4. This bridge is required to

provide access to Stage 3 following completion of Stage 1 but prior to the completion of permanent bridge 3.



This bridge will be constructed at the start of the Stage 3 earthworks and it is anticipated that it will be in use

for approximately 11 months while the earthworks, roading, services and permanent bridge 3 are

constructed. Following the completion of permanent bridge 3 the first temporary bridge will be

decommissioned and removed.

The proposed temporary bridge (as used with previous stages in Duck Creek South) is 15.4m in length, 3m

wide and has abutments set back from the stream edge by approximately 2m – 3m, see Cardno Plan

NZ0115065-PL-C420 for details. The underside of the bridge is well above the daily stream flow, and has

sufficient freeboard to accommodate a reasonable storm event.

The bridge is formed by steel beams creating a frame, holding up a single steel plate. The bridge abutments

will be formed using concrete blocks, soil from on site and rock rip rap, with silt fences located between the

abutment and the stream channel. The approximate area of earthworks for each bridge abutment and the

approach road to the bridge is 70m2 (14m long and 5m wide) giving a total earthworks area of approximately

140m2, these areas are grade and elevation dependent.

Silt fences will be installed between the abutments and Duck Creek to prevent sediment entering Duck

Creek. These fences will be installed prior to the works commencing so that Duck Creek is protected during

the construction of the temporary bridge foundations. They will remain in place and be monitored during the

construction phase.

2.3.2 Methodology

The installation of the bridge crossing shall be by the following methodology:

1. Install silt fences between bridge foundation pads and the stream as shown on Cardno Plan

NZ0115065-PL-C420;

2. Construct the temporary bridges foundations;

3. Lift the temporary bridge frame into position;

4. Lift the steel plate surface of the bridge into place and fix it to the frame;

5. Install handrails to the surface of the temporary bridge;

6. Complete Earthworks, Roading, Services and Permanent Bridge construction via the bridge;

7. Decommission the temporary bridge;

8. Remove the temporary foundations with a digger;

9. Grass all exposed areas associated with the temporary access.

No works shall take place in the bed of the stream while the temporary bridge is installed.



03 FLOCCULATION MANAGEMENT PLAN (FMP)



3 Flocculation Management Plan

3.1 Introduction

This Flocculation Management Plan (FMP) has been prepared for the bulk earthworks at Duck Creek North,

Whitby. Flocculation of the ponds is to be carried out under this Flocculation Management Plan.

3.2 Design and Management

3.2.1 Flocculant and Dosage Rate

The flocculant to be used on site shall be PAC type flocculant. RST Environmental Solutions completed

testing of sample runoff water from samples of soil from the site in Duck Creek South, to determine the most

appropriate flocculant for the site and the applicable dosage rates as part of the management of earthworks

in the upstream catchments. It is anticipated that the previous does rates used on the site will be appropriate

for Duck Creek North. However, prior to the construction of the earthworks, additional testing will need to be

undertaken in accordance with Greater Wellington Regional Council guidelines to confirm that the dosing

rates are appropriate for the soils on that area of the site. The performance of the ponds will be monitored

and that might lead to some refinement of the dose rates.

3.2.2 Implementation and Application of Flocculant

RST have determined that either a PAC system or HaloKlear system will work on this site.

The flocculant can be added by rainfall activation via an inflow measurement. The flocculant will be stored

securely inside the flocculation shed designed as per the Greater Wellington Regional Council Guidelines.

RST has confirmed that an Electronic Dosing Device (EDD) would be the preferred system to use for this

site. The system is flow activated so whilst there is water running in to the pond whether from rain fall or from

a pump EDD will dose the water. It can add any type of flocculant system and can run dual polymers if

necessary.

EDD will also monitor rainfall on site and rainfall intensity and can measure the volume of water that passes

through the pond. It can send a text message if any preset limits are reached or when the flocculant is low in

the tank

Add on’s to the system include measuring total suspended solids at the inlet and outlet of the pond, pond pH

plus there is provision to install other devices. EDD has telemetry so we can transmit live data to a web site.

EDD’s systems mean that it is very easy to calibrate for any catchment size or chemical dose rater. The

monitoring system means that there is less maintenance or any requirement to check the ponds and the

feedback system allows for easy management.

The flocculant which is held in a separate tank next to the unit is pumped in to the water flow by a series of

dose pumps. This then settles the sediment out of the water in the same way that the old system did. EDD

has 2 x 12v battery packs in it which are recharged by a solar panel that run the PLC, sensor and dose

pumps. The unit can dose several different flocculants at once if required. It monitors the amount of

flocculant used and has sensors on the dose tanks which will advise when the level is low.

EDD has plug in sensors that can measure water quality as the water runs through the weir and as it leaves

the pond. It can measure but is not limited to total suspended solids (TSS), pH, temperature, flow rate

volume of water treated. These are optional on any unit. All of this data is stored on the unit and can be

down loaded on to a lap top or can be transmitted via cell phone back to a web site. It also has a warning

function system that can transmit text messages to individuals when any pre-set limit is reached such as rain

fall or tank low levels.



3.2.3 Initial Testing

After the ponds are installed, the first rainfall event of [XXXXmm] peak intensity, or rainfall in which the pond

discharges via the decant, will initiate sampling. Samples shall be taken from the inflow, pond and decant

outlet (if a discharge occurs). Each sample shall be tested for the following parameters:

> pH

> temperature (pond only)

> turbidity

> suspended solids

The results shall be recorded and the dosage rates of the flocculant shall be fine-tuned accordingly. An

Advisory Note shall be submitted to Greater Wellington Regional Council within [XXXX] days, outlining the

results and analysis of the testing.

Testing of these parameters will be carried out after each subsequent rainfall event, and/or when a discharge

occurs via the decant, as part of the overall ongoing site monitoring to achieve the best sediment control

performance practicable.

3.2.4 Alternatives

If monitoring of the ponds shows that the flocculation measures are not reducing sediment concentrations to

the satisfaction of Greater Wellington Regional Council, then alternative flocculation measures shall be

considered.

The alternatives are:

> Use of a dose pump to calculate the flow into the pond and release a measured dose of PAC flocculant;

> Use of Magnasol as an alternative flocculant.

The alternative methodology can be achieved within a day if practicable.

3.3 Environmental Triggers

Although the pond will be actively managed until it is decommissioned at the completion of the earthworks,

there may be a need to enhance sediment treatment prior to discharge if the discharge is likely to cause

adverse environmental effects.

If the pH of the pond drops below [XXXX] and/or if NTU values increase above [XXXX] in the pond

discharge, then the following steps shall be undertaken:

1. Dosing of the pond shall cease immediately and Greater Wellington Regional Council shall be

informed. It is the responsibility of both RST Environmental Solutions and the Client’s Environment

Manager to alert Regional Council. Greater Wellington Regional Council can be contacted on 0800

496 734.

2. The management of the pond and surrounding sediment controls shall then be reviewed by both the

Clients Environmental Managers representative and RST Environmental Solutions to ensure erosion

of the soil is minimised and all practicable steps to improve the efficiency of the pond are being taken.

If practicable, the pond decants shall be raised to store sediment runoff within the pond, rather than

discharge over land downstream. The header tank will also be checked to see if it needs to be

emptied, as this may cause overdosing of flocculant.

3. If the pH is below [XXXX], the pond may be dosed with lime to raise the pH levels back to neutral.

This will be achieved by first determining the volume within the pond, to determine the dose rate for

lime.

4. If there are high NTU levels in the main pond (above the average determined from previous testing)

then, if practicable, the decants shall be raised to increase the dead storage in the pond and reduce

the volume of discharge.



3.4 Monitoring and Maintenance

3.4.1 Weekly Monitoring

The following parameters will be monitored on a weekly basis with samples taken from the inflow, forebay,

pond and decant outlet (if a discharge occurs):

> temperature

> pH;

> turbidity (NTU);

> dissolved aluminium is to be tested if an aluminium based flocculant is used (ie: PAC flocculant);

> suspended solids (g/m³) (inflow and outflow only).

The results shall be recorded. Routine monitoring shall continue until the sediment pond catchment has

become completely stabilised. The testing equipment to be used on site is listed in Table 3-1 below.

Testing Equipment Table 3-1

Parameter Testing Equipment Detection Limit

Temperature (C) Eutech 300 series pH meter -10C - +110C

pH Eutech 300 series pH meter -2 -16pH

Turbidity (NTU) Hanna Portable turbidity meter 0 NTU – 1,000 NTU

Aluminium (g/ m3) Sample to be sent to the laboratory

(ELS) 0.002 g/m

3

3.4.2 Rainfall Event Monitoring

Automated notification is triggered by rainfall events of [XXXX] mm in one hour peak intensity (measured at

the [XXXX] rain gauge) and/or a rainfall event that exceeds [XXXX] mm in a 24 hour period. This alert can

be used to inspect the pond forebay and flume areas and, if necessary, clean out to maintain maximum

storage capacity in the forebay. Any blocks, cages or flumes on the level spreader which have been

damaged shall be removed and replaced.

During the inspection the ponds will also be checked for integrity and effectiveness. Instructions to fix or

remedy defects shall be given to the contractor as required.

The following parameters will be monitored with samples taken from the inflow, forebay, pond and (if a

discharge occurs) decant outlet:

> pH

> temperature (pond only)

> turbidity (NTU)

> dissolved aluminium (g/m3)

> suspended solids (g/m³)

The monitoring will be undertaken within 24 hours of notification as required in consent. The testing

equipment to be used is listed in Table 3-2 below.

Rainfall Event Testing Equipment Table 3-2

Parameter Testing Equipment Detection Limit

Temperature (C) AQUAMETER AM-200 Aquaprobe AP-2000

-5C - +50C (±0.5C)

pH AQUAMETER AM-200 Aquaprobe AP-2000

Optical Dissolved Oxygen (%) AQUAMETER AM-200 Aquaprobe AP-2000

0% – 500% (±1%)



Turbidity (NTU) AQUAMETER AM-200 Aquaprobe AP-2000

0 NTU – 3,000 NTU (±2%))

Total Suspended Solids (g/m3) INSITE IG Model 35L Sensor 0 g/m

3 – 1,500 g/m

3 (±1% or ±2mg/L)

If testing equipment varies from the above this will be detailed in the floc management plan

submitted to GWRC for approval prior to construction

The results will be recorded and sent to GWRC within 10 working days.

3.4.3 High rainfall contingency measures

Arrangements are to be made for additional flocculant to be stored onsite in a locked shed to allow batch

dosing of the ponds if the flocculant in the shed runs out and RST staff are unable to reach the site to refill

the chemical reservoir.

Batch dosing, if required, will only be undertaken by persons suitably trained to handle the flocculant.

3.5 Decommissioning

The sediment ponds and other erosion control devices are to remain operational until the sediment pond

catchments have become completely stabilised. Ponds cannot be removed until GWRC has signed off that

the earthworks are complete and pond is ready to be decommissioned.

Accumulated sediments from the ponds will be excavated. The sediments are not suitable as fill material, but

may be mixed with other material to be used as topsoil.

The flocculant sheds, decant manholes and flumes will be removed from the site and the ponds will be filled

to design surface level.

No measure will be removed without prior approval of the Manager, Environmental Regulation, GWRC.

3.6 Health and Safety

3.6.1 Sampling

Possible sampling locations are:

> Inflow

> Forebay

> Pond

> Discharge outlet into stream

Sampling is to be carried out during daylight hours. Safe access shall be provided to the sampling locations

identified above, or modified accordingly if access is identified as an issue following sampling.

3.6.2 Flocculant Handling

Many flocculants are hazardous substance and precautions are required. Safety Data Sheets for the

proposed flocculants will be supplied to the Contractor and shall be kept onsite at all times.

All flocculant onsite shall be within the flocculant socks, or in a Chemical Reservoir within a locked flocculant

shed. If a Chemical Reservoir is used then a small bund shall be created around the shed to contain spills.

3.6.3 Chemical Spills

In the unlikely event of a chemical spill, the area shall be ventilated (if indoors) and RST Environmental

Solutions shall be contacted.

If there is a spill of PAC onto the ground it will be immediately contained using earth bunds to prevent it

entering water. The spilt PAC should be recovered if possible and placed in polyethylene containers. If the

spilt PAC cannot be recovered, it should be mixed with a volume of soil equal to at least ten times the

volume of spilt PAC, and buried in dry soil.



If there is a spill of PAC into ponded water, discharge from the pond to natural water should be prevented.

The pH of the water should be tested and if below pH5.8 treated with lime to increase the pH before

discharge.

If there is a spill of PAC into flowing water:

> GWRC should be advised immediately.

> The volume of the spill should be recorded.

> If possible the water and spilt PAC should be pumped into a bund or pond until all the spilt PAC has been

removed from the watercourse.

> If the PAC cannot be removed from the watercourse any downstream users should be identified and

advised. In association with GWRC an action plan will be developed.

No chemicals shall be stored onsite, other than that contained in the chemical reservoir. A small bund will be

constructed around the flocculation shed to ensure all spills are contained.

The flocculation shed will have a Hazchem sign attached to the outside, with appropriate information clearly

visible including a 24hr emergency phone number.

Robert Coulson, RST Environmental Solutions Ltd , 06) 355-3625 or 021-661-258

3.7 Plan Review

There shall be meetings between the contract supervisor and the contractor as required to discuss works on

site and management issues. In the event that it is identified that this plan is not providing sufficient

management of the flocculation, a review of the Plan shall be undertaken accordingly.

If deemed necessary a review of the plan shall be undertaken with consultation from all responsible persons

listed in Section3.8 below. Plan updates are to be inserted into applicable appendix and a new revision of the

Plan issued.

3.8 Persons Responsible

Setting of the Flocculant including dosage rates

Person Responsible: Robert Coulson, RST Environmental Solutions Ltd

Contact Number: 021 661 258

RST Environmental is responsible for installation of the flocculation measures and setting of the dose rate

following testing.

Initial and Weekly Pond Monitoring

Person Responsible: Robert Coulson, RST Environmental Solutions Ltd

Contact Number: 021 661 258

RST Environmental is responsible for monitoring and maintenance of the flocculation measures on a weekly

basis.

Rainfall Event Monitoring

Person Responsible: [Client Environmental Rep (or consultant)]

Contact Number: [XXXX]

[XXXX] is responsible for ensuring that monitoring the pond is undertaken following a rainfall triggered event.



Reporting to Greater Wellington Regional Council

Person Responsible: [Client Environmental Rep (or consultant)]

Contact Number: [XXXX]

[XXXX] is responsible for reporting to Greater Wellington Regional Council as per the consent conditions

and Management Plan requirements.



3.9 Material Safety Data Sheets

INSERT MATERIAL SAFETY DATA SHEETS HERE



04 STREAM DIVERSION AND STREAM WORKS PLAN



4 Stream Diversion and Stream Works Plan

4.1 Introduction

This Stream Diversion and Stream Works Plan has been prepared for the stream works to be undertaken as

part of the development at Duck Creek North in Whitby. Design and Management

4.2 Stream Diversion

The sections below outline the main steps to be undertaken at each stage of the stream diversion works.

4.2.1 Pre Diversion

> Install applicable water diversion bunds and silt control fences

> Construct new creek high flow channel

> Inspection by Engineer and Ecologist

> Set out and construct low flow meander

> Confirm Riffle/Run/Pool locations

> Construction low flow creek

> Inspections by Engineer and Ecologist during construction

> Creek Asbuilts

> Stabilisation (Flex-Terra and Applicable Matting)

> Ecologist advisory notice to GWRC confirming suitability for fish passage

4.2.2 Diversion

> Remove downstream coffer dam

> Divert creek into new alignment

> Fish capture and reporting of old alignment by Ecologist

> Transfer of creek gravels from existing channel to new creek bed at direction of Ecologist

4.2.3 Post Diversion

> Associated inspections and post diversion reporting to GWRC

> Ongoing consenting requirement with respect to diversion

4.3 Stream Bank Remedial Works

The locations identified for channel stabilisation or erosion protection shown on Cardno Plan NZ0115065-PL-C251 have been identified as areas of risk from the flood modelling; see the flood modelling report for more detail. This work involves lining the channel bed and sides with rock armouring wrapped in a geotextile. This will be keyed in at the bed with a 1 m gravel substrate place within the bed. The rock will be placed from the bed of the stream up to top of the banks and covered in a layer of topsoil. In locations where the banks are incised/undermined these will be battered back to an appropriate slope prior to armouring and stabilisation.



APPENDIX

A DRAWING SET



REFER TO PROVIDED PLAN SET. PLANS WILL BE INSTERED IN THIS APPENDIX FOR ISSUE TO CONTRACTOR.



APPENDIX

B EROSION AND SEDIEMENT CONTROL CALCULATIONS



APPENDIX

C ENVIRONMENTAL EFFECTS REGISTER



CONSTRUCTION ACTIVITY

ASPECT OF CONSTRUCTION

IMPACT CONTROL MEASURES

Establishment onsite

Clearing and grubbing Destroying native vegetation

- Set-out of earthworks to include limits of vegetation clearance

- Site inductions

Topsoil removal Erosion and sediment runoff

- Install sediment controls prior to beginning associated earthworks operation

Maintenance and refuelling of plant

Fuel spill into Duck Creek - Ensure all areas for storing and refuelling machinery are adequately bunded

Bulk Earthworks including excavation of unsuitable and cut material, mixing and placement of fill

Sediment runoff into water courses

Smothering stream beds Damage to stream and harbour ecology Damage to neighbouring properties

- Follow the Earthworks Construction Plan (ECP) and actively manage the site in consultation with Cardno and Council

Application of flocculation to sediment ponds

Contaminated discharge into water courses

- Frequent monitoring and maintenance

Dust Nuisance to neighbouring properties Dust on roads

- Have water cart available onsite at all times

- Stabilised construction entrance

- Watch weather forecast and dampen dry dust prone areas when windy days are forecast.

- Stockpile material away from site boundaries

- Establish ground cover as soon as levels are on grade

Haul Road Source of Dust Noise

- Water cart available onsite at all times for wetting dust sources as required

- Vehicles shall not be overloaded

- Working hours governed in EMPC

Bridge and Culvert works

Works within the active stream bed

Loss of habitat Sedimentation

- Isolate work area using sheet piling and sediment controls



APPENDIX

D FLOCCULATION MANAGEMENT PLAN UPDATES



INSERT FLOC MANAGEMENT PLAN UPDATES HERE



APPENDIX

E PRE CONSTRUCTION CHECK LIST



APPENDIX

F EROSION & SEDIMENT CONTROL ASBUILT DOCUMENTATION



INSERT EROSION AND SEDIMENT CONTROL ASBUILT DOCUMENTATION HERE



APPENDIX

G EARTHWORKS CONSTRUCTION PLAN VARIATIONS



Amendments to this Earthworks Construction Plan to be filled here:

DATE SUMMARY OF AMENDMENT MADE AMENDMENT SENT TO GWRC

AMENDMENT APPROVED BY

.