120424 mona vale rd strategic assessment of utilities

Mona Vale Road, McCarrs Creek Road to

Powder Works Road

Strategic Assessment of Utilities Adjustment

Prepared for

Roads and Maritime Services

April 2012

Mona Vale Road, McCarrs Creek Road to Powder Works Road


120424 Mona Vale Rd Strategic Assessment of Utilities i

Cardno (NSW/ACT) Pty Ltd

Traffic and Transport

ABN 95 001 145 035

Level 9, 203 Pacific Highway, St Leonards

New South Wales 2065 Australia

Telephone: 02 9496 7700

Facsimile: 02 9499 3902

International: +61 2 9496 7700

www.cardno.com.au

DOCUMENT CONTROL

Report Title

Sub Title

Version Date Author Reviewer

Name Initials Name Initials

Draft Craig Stoddart CJS Mulavana Lakshmy ML

Final 29 March 2012 Craig Stoddart CJS Mulavana Lakshmy ML

Issue 27 April 2012 Craig Stoddart CJS

Kevin Hough (RMS)

Iain MacLeod (RMS)

Nina Kilpinen (RMS)

David Preston-Thomson

KH

IM

NK

DPT

“© 2012 Cardno All Rights Reserved. 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 without the prior written consent of Cardno.”



120424 Mona Vale Rd Strategic Assessment of Utilities ii

TABLE OF CONTENTS

1 Introduction ____________________________________________________________ 1

1.1 References ______________________________________________________________ 2

2 Background ____________________________________________________________ 3

3 Method of Review _______________________________________________________ 4

4 Impacts on Utilities ______________________________________________________ 5

4.1 General _________________________________________________________________ 5

4.2 Proposed ‘Option 6’ Section ________________________________________________ 6

4.3 Sydney Water – Sewer _____________________________________________________ 7

4.3.1 Potential Adjustment Works _______________________________________________________ 7

4.3.2 Approximate Time and Cost of Adjustment Works ______________________________________ 7

4.3.3 Future Requirements _____________________________________________________________ 8

4.4 Sydney Water – Potable Water ______________________________________________ 9

4.4.1 Potential Adjustment Works _______________________________________________________ 9

4.4.2 Approximate Time and Cost of Adjustment Works ______________________________________ 9

4.4.3 Future Requirements _____________________________________________________________ 9

4.5 Ausgrid ________________________________________________________________ 10

4.5.1 Potential Adjustment Works ______________________________________________________ 10

4.5.2 Approximate Time and Cost of Adjustment Works _____________________________________ 11

4.5.3 Future Requirements ____________________________________________________________ 12

4.6 Jemena Gas _____________________________________________________________ 13




4.7 Optus__________________________________________________________________ 14




4.8 Telstra _________________________________________________________________ 15




4.9 RMS Intelligent Transport System ___________________________________________ 17

5 Safety in Design ________________________________________________________ 18

5.1 Working adjacent to existing underground utilities _____________________________ 18

5.2 Working adjacent to relocated underground utilities ___________________________ 19

5.3 Low clearance to existing overhead services __________________________________ 20



120424 Mona Vale Rd Strategic Assessment of Utilities iii

5.4 Location of utility pits ____________________________________________________ 22

5.5 Location of utilities within the road formation _________________________________ 22

6 Recommendations _____________________________________________________ 23

Appendices

Appendix A MR 162 Mona Vale Road, Strategic Design McCarrs Creek Road to Power Works Road, Plan

and Profile

Appendix B Probable Utilities Affected by Footprint



120424 Mona Vale Rd Strategic Assessment of Utilities 1

1 Introduction

Cardno has been engaged to undertake a strategic assessment of potential utilities adjustment for the proposed

upgrade of Mona Vale Road between McCarrs Creek Road to Powder Works Road.

The scope of the assessment is as follows:

1. Review existing utilities location information provided by RMS (Dial Before You Dig, survey and MX data

files)

2. Determine constraints for each utility and plot on Strategic Design overlays

3. Determine potential for protection or relocation for each utility

4. Provide indicative timing and cost for protection or relocation for each utility

5. Provide advice on safety in design in respect of utility relocations

This Report sets out the findings of this strategic assessment and provides recommendation for the further

development of the Project.

The estimates of time and cost presented here are indicative estimates only based on the likely strategic

alignment, Dial Before You Dig utilities locations and assumed scope of relocations. These times and costs are

provided here for the sole purpose of assessing impacts on utilities when determining the alignment. These

times and costs should not be used for estimation or budgeting purposes and should not form part of any

contract.




1.1 References

The following information was provided by RMS for the purposes of this strategic assessment:

1. Drawings Set MR 162 Mona Vale Road, Strategic Design McCarrs Creek Road to Power Works Road,

Plan and Profile (Registration Number 0162.333.SD.0002) SK56 – 60, Print Date 13/2/2012 (Appendix A)

2. MX information Received Monday 20/02 – Boundary-GENIO, Design-GENIO, Survey-GENIO




2 Background

RMS provided the Drawings Set MR 162 Mona Vale Road, Strategic Design McCarrs Creek Road to Power Works

Road, Plan and Profile (attached as Appendix A). This drawing set included:

• The current proposed alignment developed by the RMS to date (‘Option 6’) and

• RMS plotted survey and

• Utilities.

‘Option 6’ comprises a divided carriageway with two 3.5m traffic lanes in both directions with a 2.5m shoulder on

both sides. The proposed alignment is widened either side of the existing footprint.

It was agreed to use the Option 6 alignment as an indicative ‘Footprint’ given that RMS was still in the process of

developing the alignment.

The ‘Footprint’ referred to herein is the area occupied by the carriageways, shoulders and potential batters per

Option 6.

The ‘Section’ referred to herein is the section of Mona Vale Road from McCarrs Creek Road to Power Works.

Chainages referred to in this report shall relate to Chainages set out on the drawings MR 162 Mona Vale Road,

Strategic Design McCarrs Creek Road to Power Works Road, Plan and Profile.




3 Method of Review

At the time of this study there had been no investigation of the existing utilities beyond a general site inspection,

RMS survey (non-invasive) and desktop review of Dial Before You Dig information.

Craig Stoddart (Cardno Senior Project Manager) attended an inspection of the site with RMS personnel including

RMS Development Manager, David Heins and Road Designer, Andrew Jednuik. The alignment was generally

discussed and several notable environmental and heritage sites inspected.

Cardno separately obtained Dial Before You Dig information for this section of Mona Vale Road. The RMS

supplied utilities CAD files were compared with the Dial Before you Dig information. Minor differences were

noted and are discussed in the following sections of this report.

A copy of the Cardno utilities CAD files will be provided to RMS as a record of Cardno’s interpretation of the

utilities information.

Each of the utility types were separately plotted on the Option 6 ‘Footprint’ (Appendix B). The probable affected

areas where then highlighted and have been discussed further in the following sections.

There has been no direct consultation with any utility service providers during this assessment.




4 Impacts on Utilities

4.1 General

Mona Vale Road is the arterial access through the Garigal and Kuringai National Park between Terry Hills and

Ingleside. Any development of Mona Vale Road through this Section will have a heavy impact on road users

given the lack of an alternative route.

The existing alignment through this Section is generally one lane both ways and is sign posted at 70km/h. There

is very little kerb or gutter and the stormwater flows off the pavement to the verge. The surrounding topography

is undulating and the land adjacent to the existing alignment falls away steeply from the existing road formation.

The Drawings Set MR 162 Mona Vale Road, Strategic Design McCarrs Creek Road to Power Works Road, Plan

and Profile (attached as Appendix A) identified several significant ecological and heritage areas adjacent to the

existing alignment. These include the Duffy’s Forest Ecological Community, the Bahai Temple, Whale Rock and

several endangered species.

This Section of Mona Vale Road appears to convey trunk utilities for:

• Sydney Water – Sewer Rising Main

• Ausgrid 33kV Transmission and 11kV high voltage

• Optus conduits (size unknown)

• Jemena – Secondary Main

Utilities are located on both poles (electrical and communications) and underground (sewer, potable water,

communications and gas).

The area has been subject to bushfire recently and several utility poles appear to have been damaged.

Given the topography, any proposed widening of the existing alignment will require the construction of

substantial embankments, retaining structures, cuttings or bridges. This will dramatically increase the depth to

existing underground service and reduce clearance to overhead services.




4.2 Proposed ‘Option 6’ Section

The proposed Option 6 comprises a divided carriageway with two 3.5m traffic lanes in both directions with a

2.5m shoulder on both sides. RMS is still determining whether a footpath or shared path will be provided. The

absence of a footpath or shared path means that utilities will need to be located within the road corridor (ie

within the trafficable lanes or shoulder) or within a dedicated ‘off road’ utilities corridor.

Figure 4-1 (below) is a theoretical arrangement for utilities (per the Streets Opening Conference) Plotted against

the typical section for Option 6. Figure 4-1 shows that, without the provision of a footpath (or similar), utilities

within the road corridor will need to be located within the live traffic lanes and the shoulder. It should also be

noted that the utilities would, in some section, be installed well above the existing ground levels, meaning that

these utilities could not be installed until the road formation has been partially constructed.

4-1 Theoretical utilities arrangement on 'Option 6' section

The given the lack of cycleway of footpath, the utilities would need to be located within the travel lane and the

shoulder. Utility authorities are likely to oppose this as it poses a significant risk to service personnel accessing

given the proximity to live traffic.

The presence of pits in the shoulder can also serve to weaken the pavement by allowing water ingress. Conduits

within the shoulder can clash with other infrastructure such as stormwater drainage, reinforced earth wall

straps, etc. Austroads Guide to Road Design Part 6B: Roadside Environment provided at 4.5.3:

It is generally undesirable to locate utilities under road pavement... although this may be unavoidable in some

circumstances.

RMS should investigate an ‘off road’ utilities corridor where possible to eliminate these risks.

Utilities to be located within the road corridor will need to be constructed during road construction as the design

vertical alignment of proposed utilities will be above existing surface levels in several sections.




4.3 Sydney Water – Sewer

Refer to Probable Utilities Affected by Footprint – Sewer Rising Main (Appendix B).

Sydney Water has a Pressure Main (Rising Main) running the length of the section on the northern side of the

existing carriageway. The pipe consists of a 300 DICL (Ductile Iron Cement Lined), 300 GRP (Glass Reinforced

Polyester) and single and double 300 PVC. The double 300 PVC section commences at CH 3180 (just prior to the

intersection with Powder Works Road).

The principle constraint here is the Sydney Water requirement for approximately 1m of separation to other

services in a very tight corridor.

4.3.1 Potential Adjustment Works

The pressure main is impacted by the Footprint at:

• CH 45 – CH 320: It would be preferable to relocate this section to the north of the Footprint. This would

require construction near or within Duffy’s Forest Ecological Community. Alternatively the pressure

main could be relocated within the new carriageway. This would require steel reinforced concrete

encasement to create a ‘maintenance free’ pressure main. Sydney Water will require that any encased

rising main is reconstructed with new pipe to maximise the life of the main.

• CH 2685 – CH 2760: It is possible that a detailed investigation would find that this section of the

pressure main would not be impacted by the Footprint. However, it is likely that a short section would

need to be relocated to the north (into the Heritage / Duffy’s Forest Area) or concrete encased to create

a ‘maintenance free’ pressure main. Sydney Water will require that any encased rising main is

reconstructed with new pipe to maximise the life of the main.

• CH 2920 – CH 3000: It is possible that a detailed investigation would find that this section of the

pressure main would not be impacted by the Footprint. However, it is likely that a short section would

need to be relocated to the north (into the Heritage / Duffy’s Forest Area) or concrete encased to create

a ‘maintenance free’ pressure main. Sydney Water will require that any encased rising main is

reconstructed with new pipe to maximise the life of the main.

4.3.2 Approximate Time and Cost of Adjustment Works

Time for relocation is approximately:

• Design 6 months

• Construction 3 months (subject to staging and access)

• Commissioning 1 month

• Connection up to 3 months (at SWC discretion)




Cost for relocation will be in the order of $250k - $750k depending on extent of works undertaken by others and

the length of pipe relocated.

4.3.3 Future Requirements

It is likely that future developments would require additional sewer mains to be installed in the area. Liaison

with Sydney Water is required to determine their future requirements.

It is recommended that a corridor is allocated for the installation of any future watermains within the proposed alignment in accordance with the provisions of the Streets Opening Conference - Guide to Codes and Practices for Streets Opening, 2009.

It is also recommended that road crossings are installed at the location of future developments to avoid

excavation of the new pavement.




4.4 Sydney Water – Potable Water

The only potable water shown in the Section is a short section (approximately 10-20m) of 100mm CICL (Cast Iron

Cement Lined) pipe extending from McCarrs Creek Road to CH 75. The water main does not appear to be

impacted by the Footprint.


It is not likely that the existing watermain will require significant adjustment.


Any adjustments to the existing watermain would be quickly undertaken at minimal cost (in the order of $25k).


It is likely that future developments would require additional water mains to be installed in the area. Liaison

with Sydney Water is required to determine their future requirements.

It is recommended that a corridor is allocated for the installation of any future watermains within the proposed alignment in accordance with the provisions of the Streets Opening Conference - Guide to Codes and Practices for Streets Opening, 2009.

It is also recommended that road crossings are installed at the location of potential future developments to avoid





4.5 Ausgrid

Refer to Probable Utilities Affected by Footprint – Electricity (Appendix B).

Ausgrid has Low Voltage and Street Light (415V), High Voltage (11kV) cables and Transmission (assumed to be

33kV) feeders in this Section along the length of the Section on both sides of the existing alignment. Direct

consultation with Ausgrid is required to confirm the voltages of the various cables.

A Transmission Feeder (assumed to be 33kV) enters the Section from the south at Kimbriki Road. The Feeder

crosses the existing alignment and then extends along the northern side of the existing alignment (outside the

Footprint) to CH 3000 where it skews across the existing alignment to the south/eastern side. The Feeder

remains on the south/eastern side to the limit of works at Powderworks Road. The Transmission Feeder poles

are supported by stay poles and cables at various locations including CH 2700 where the stay cable crosses the

existing alignment.

It was observed during the site inspection that several electrical poles had been threatened by recent bushfires in

the area. It is likely that Ausgrid will be keen to relocate overhead services to underground through this Section

to minimise the exposure to bushfires.

As noted elsewhere, electrical poles in this Section also support communications cables.


The Transmission Feeder is impacted by the Footprint at:

• CH 825 (Kimbriki Road): The Feeder approaches

from the south (along Kimbriki Road) and

crosses the existing alignment of Mona Vale

Road. The pole on the south eastern corner of

the intersection with Kimbriki Road is well

within the Footprint and will need to be

relocated. There is also 11kV, Low Voltage and

Street Light cables mounted on this pole.

Ausgrid requires that an approved Accredited

Service Provider be engaged to undertake the

design of this relocation. The relocation of the

pole will be more involved than simply moving

the pole. Works would include the

construction of a stay pole and cable, jointing

of the new cable, testing of the new cable and commissioning. The approval of Transmission Feeder

designs can take several months. Cut over of Transmission Feeders is usually restricted to ‘cut over

windows’ and Ausgrid will require extend notice of intention to cut over.

• CH 3000 – CH 3060: The Transmission Feeder skews across the existing alignment from the

north/western to the south/eastern side. It is possible that a detailed investigation would find that this

road crossing is sufficiently outside the Footprint and could be retained. It is recommended that the

4-2 Electrical transmission approaching from

Kimbriki Rd




Footprint be aligned (both vertically and horizontally) to avoid having to relocate the Feeder at this

location if possible.

• Generally: Clearance to the Transmission Feeder appears to be very low at many locations (including

over the pedestrian way in the vicinity of Addison Streeet and at CH 3000) throughout the Section. This

is likely to impact on potential construction access points, haul roads, etc. The low clearance may also

impact on the construction of any proposed off road cycleway. This is further discussed in Section 5

Safety in Design.

The Low Voltage, Street Light and High Voltage (11kV) cables are generally impacted by the Footprint. The Low

Voltage, Street Light and High Voltage (11kV) will be impacted throughout the Section and the majority will

require relocation. Ausgrid requires that an approved Accredited Service Provider be engaged to undertake the

design of these relocations. Some (if not all) of the cables will need to be relocated into a services corridor either

within the road corridor or ‘off road’.


Both time and cost are highly dependent upon the amount of works required. Ausgrid approval of the electrical

design will take several months and construction will be limited by ‘cut over windows’ extended notice periods

and testing and commissioning.

The cost to relocate the Low Voltage, Street Lighting and 11kV will be in the order of $2 -$4m. The cost to

relocate the Transmission Feeder at Kimbriki Road will be upwards of $0.5m depending on the required scope of

relocation (length of cable replaced, number of poles, etc).

4-3 Electrical transmission and low voltage cables skew across existing alignment at CH 3000





It is likely that future developments would require additional electrical transmission and distribution cables to be

installed in the area. The risk of bushfire in the area is also likely to encourage Ausgrid to relocate the existing

overhead cables to underground. Liaison with Ausgrid is required to determine their future requirements.

Generally transmission feeders are relocated to within the travel lanes of the carriageway. In the absence of

relocating the feeder cables it would be worth considering installing the conduits and jointing pits (as a

minimum) to avoid major excavation of the new pavement should the cables be installed at a later time. The

conduits and pits would need to be designed by an Accredited Service Provider acceptable to Ausgrid.

Transmission feeder conduits are subject to minimum cover (typically 750mm to the top of concrete protection

slab) and maximum depths to avoid overheating during operation. This ‘vertical envelope’ needs to be

understood by road designers as it impact on proposed road levels during design and construction. An Accredited

Service Provider will be required to advise on the extents of the ‘vertical envelope’.

The ‘vertical envelope’ also causes significant constraints on intersecting utilities, especially gravity fed utilities

such as sewer and stormwater. Intersecting utilities (existing and proposed) need to be identified and allowed

for in the design of the transmission feeder longsections to avoid clashes during construction. Where possible

these intersecting utilities should be installed (or at least blocked out) prior to the completion of the feeder

conduits. This will significantly reduce the risk of clashes or damage to the feeder during construction.

Transmission feeders also require very large pits at regular intervals (300 – 600m) for jointing, drawings, etc.

These pits can encroach on other utilities and adjacent stormwater drainage pits. The pits should be plotted to

check for clashes. An Accredited Service Provider will be required to advise on the extents of the size and

spacing of pits.

It is recommended that a corridor is allocated for the installation of Low Voltage, Street Lighting and High

Voltage within the proposed alignment in accordance with the provisions of the Streets Opening Conference - Guide to Codes and Practices for Streets Opening, 2009.

It is also recommending that road crossings are installed at the location of future development to avoid





4.6 Jemena Gas

Refer to Probable Utilities Affected by Footprint – Gas (Appendix B).

Jemena has a 250mm diameter Secondary Main (1050 kPa - High Pressure) running through the Section. The

Secondary Main extends below the existing pavement until CH 150 where it crosses to the northern side of the

existing alignment. The Secondary Main departs the corridor to the north at approximately CH 400 before

returning to the northern side of the existing alignment CH 2190 (Tumburra Street). The Secondary Main crosses

to the southern side of the existing alignment at CH 2270 and follows the southern side to the end of the Section.

Jemena requires that 1200mm cover is provided to high pressure mains within the carriage way and that there is

1000mm separation from other services. Jemena also places limits on the construction loadings that can be

applied to the mains and limits machine excavation to 300mm from the main.

Refer to Jemena Guidelines for construction activities over Jemena Gas Networks Assets.


The Secondary Main is impacted by the Footprint at:

• CH 00 – CH 220: detailed investigation of the Secondary Main is required to indentify the extent that

would be impacted by the footprint. It is likely that at least a short section (~150m) of the Secondary

Main will need to be relocated or protected at this location. Relocation of this section of the Secondary

Main will reduce risk of a gas leak during construction and eliminate several potential clashes with

other utilities and stormwater.

• CH 2270 – 3110: the majority of the existing Secondary Main is located within the proposed area for

widening to the south and east of the existing carriageway. It is likely that the Secondary Main will

clash with the preferred alignment for relocated utilities, stormwater or retaining wall footings. It is

also likely that the construction of the widened road formation will dramatically increase the depth to

the Main rendering it unserviceable. This section of Secondary Main will need to be relocated either to

the north of the Footprint or within the carriageway of the proposed alignment.


Both time and cost are highly dependent upon the amount of works required. Costs will be in the order of $0.5 –

$2m. Jemena undertakes their own design of their assets so timeframes will be determined by Jemena. It is

anticipated that the time for design will be in the order of 3 – 6 months.


It is likely that future developments would require additional gas mains to be installed in the area. Liaison with

Jemena is required to determine their future requirements.

It is recommended that a corridor is allocated for the installation of any future gas mains within the proposed alignment in accordance with the provisions of the Streets Opening Conference - Guide to Codes and Practices for Streets Opening, 2009.




It is also recommended that road crossings are installed at the location of future development to avoid


4.7 Optus

Refer to Probable Utilities Affected by Footprint – Optus (Appendix B).

It is not clear from the Optus Dial Before You Dig information and the RMS

survey information whether the Optus cables are above or below ground (or

both). The Optus Dial Before You Dig information does not provide

information about the type or size of the cables. There are Optus

underground cable markers indicating that there are extended sections of

cable underground, possibly in ‘others’ conduits. The Optus Dial Before You

Dig information does not provide information about the type or size of the

cables.

A detailed survey of the Optus cable is required to determine the precise

location and determine whether the cable is located within ‘others’ conduit

on suspended from a common pole (with electrical).


The Optus cable route generally appears to be away from the Footprint and

thus significant relocation of the cable is not likely. However, relocation of the Optus cable may be required if

the common pole or ‘others’ conduit in which it is installed is required to be relocated.


It is not likely that the existing Optus cable will require significant adjustment. Time and costs are therefore not

likely to be significant.

It should be noted that even small optic fibre cables may be subject to limitations on cut over (ie private fibres,

nurse call services, etc) that may lead to an extended time for cutting over to a new cable.


It is likely that future developments would require additional communications cables and conduits to be installed

in the area for Optus and other potential communications providers, including the National Broadband Network.

Liaison with Optus (and other communications providers) is required to determine their future requirements.

It is recommended that a proposed alignment is allocated for the installation of communications conduits (for all suppliers including the NBN) within the corridor in accordance with the provisions of the Streets Opening Conference - Guide to Codes and Practices for Streets Opening, 2009.

It is also recommended that road crossings are installed at the location of future development to avoid


4-4 Optus underground cable

markers




4.8 Telstra

Refer to Probable Utilities Affected by Footprint – Telstra (Appendix B).

The Telsta Dial Before You Dig information shows that the Telstra cables are underground along the northern

side of the existing alignment from CH 00 to CH 405. There is an ‘Pillar/cabinet’ located on the southern side of

existing alignment within the proposed Footprint. There is a discrepancy here between the Dial Before You Dig

information (confirmed by observation on site) that shows the Telstra cable on a common pole and the utilities

CAD file provided by RMS.

The cable then crosses the existing alignment overhead and continues on ‘Shared Poles’ until CH 1185 where the

cable again crosses the existing alignment overhead and departs the alignment to the north. The cable re-enters

the alignment underground on the northern side at Addison Road and remains on the northern side until the end

of the Section (per RMS survey information).

The Telstra cable appears to serve local properties (small optic fibre only) only and does not appear to be a trunk

main between exchanges. This would need to be confirmed with Telstra.

There are several heavy ‘bundled’ cables suspended

on poles throughout the Section. These cables

don’t appear to correlate with the Dial Before You

Dig information provided for Telstra (or Optus). It is

possible that these cables are for Pay TV (Optus or

Foxtel). This will require further investigation to

confirm.

Pay TV cables require a low voltage power supply

for the associated hubs. This would need to be

included in the design of any electrical relocation

works.


The Telstra assets are impacted by the Footprint at:

• CH 00 – CH 405: The underground cable is shown within the Footprint and will require relocation.

Ideally, relocation would be to the southern side of the proposed alignment in a dedicated

communications trench or outside the northern boundary of Footprint. This would require construction

near or within Duffy’s Forest Ecological Community.

• CH 405: The ‘Pillar/cabinet’ shown at this location is potentially within the Footprint. Relocation of

‘Pillar/cabinets’ can be expensive and can take some time to undertake, and should avoided if possible.

• CH 405 – CH 1185: The poles through this section are well within the Footprint and will require

relocation. Ideally, relocation would be to the southern side of the proposed alignment in a dedicated

communications trench. The pole on the south/western corner of Kimbiki Road may possibly be left in

4-5 Bundled cables




place, minimising impacts to the cables that follow Kimbriki Road to the south of the Footprint. This

pole would probably require a stay pole to be located to the north.

• CH 2690 – CH 3110: It is possible that a detailed investigation would find that this section of the Telstra

cable would not be impacted by the Footprint. However, any relocation would require construction near

or within the heritage items and Duffy’s Forest.


The existing Telstra cables appear to be local distribution cables only and thus relocation should be relatively

inexpensive and undertaken quickly. Telstra undertakes their own design and relocation of their assets so

timeframes will be determined by Telstra.

Construction of any permanent way communications conduit bank within the Footprint would be mostly done

during construction of the road formation. It should be noted that Telstra requires Telstra approved contractors

install their conduits.

Relocation costs for the likely impacted area (CH 00 – CH1185) would be in the order of $500k - $750k depending

on extent of works undertaken by others and the length of cable relocated.

Construction of a permanent way communications conduit bank within the Footprint would cost in the order of

$500k - $1.5m depending on the extent of works undertaken by others the arrangement and the length and

arrangement of the conduit bank. It is anticipated that the time for design will be in the order of 3 – 6 months.

It should be noted that even small optic fibre cables may be subject to limitations on cut over (ie private fibres,

dedicated fibres, nurse call services, etc) that may lead to an extended time for cutting over to a relocated

cabled.


It is likely that future developments would require additional communications cables and conduits to be installed

in the area for Telstra and other potential communications providers, including the National Broadband Network.

Liaison with Telstra (and other communications providers) is required to determine these future requirements.

It is recommended that a proposed alignment is allocated for the installation of communications conduits (for all suppliers including the NBN) within the corridor in accordance with the provisions of the Streets Opening Conference - Guide to Codes and Practices for Streets Opening, 2009.




4.9 RMS Intelligent Transport System

RMS will look to install conduits for an Intelligent Transport System (ITS) ‘backbone’ through the Section. The

ITS conduits need to be installed in close proximity to the trafficable lanes given that they will serve traffic

signals, variable message boards, etc. As such, provision will need to be made for ITS conduits and pits

(electrical and communications) within the road corridor.

The location of the ITS conduits is generally flexible and the conduits can cross the road at intersections if

required. Given this flexibility, and RMS’s control of the design, the ITS conduits will generally be designed after

other utilities have been designed. It is, however, recommended that the ITS is designed as part of the detailed

design for the roadworks and not left to the roadworks contractor to design.




5 Safety in Design

The following outlines the risks associated with working adjacent to utilities.

5.1 Working adjacent to existing underground utilities

Existing utilities should be investigated to at least a ‘Quality Level B’ investigation, including the application of

geophysical methods such as electro-magnetic and ground penetrating radar, to confirm location utilities.

5-1 Ground penetrating radar with 3D survey location

In areas of high risk, and in areas recommended in this Report, further investigation using physical location

including potholing (‘Quality Level A’) should be undertaken to provide accurate location of significant existing

utilities.

5-2 Vacuum truck potholing to physically locate service

The utility location information should then be plotted in 3D to allow review of analysis of clashes, construction

staging, relocation and protection, and this information provided to contractors. Contractors should be required

to utilise a rigorous ‘Permit to Excavate System’ during construction.




Refer to:

• Workcover Guide Work Near Underground Assets (2007)

• Ausgrid Electrical Safety Rules (September 2011)

• Ausgrid NS 156 Working Near or around Underground Cables (August 2010)

• Jemena Guidelines for construction activities over Jemena Gas Networks Assets.

5.2 Working adjacent to relocated underground utilities

Relocated utilities present a significant additional risk as the location of each may not yet be recorded on utility

asset databases, including Dial Before You Dig. Packaging utility relocation works with the road works contract

reduces the risk of damage to relocated utilities as the road contractor has control of the relocation process and

subsequent road construction works.

Other risk control measures include the use of sand backfill to readily identify the utility trenches and the use of

marking tape. It is recommended that detectable marking tape is used to increase the ease at which utilities can

be located. Detectable marking tape includes either foil or wire that is detectable with electro-magnetic

detection equipment.

Intensive as-executed surveys should be undertaken of each relocated utility. The survey information should

include physical location in three dimensions, conduits size and arrangement and conduit bank extents for

multiple conduit banks.




5.3 Low clearance to existing overhead services

It was observed during the site inspection that there

is minimal clearance to overhead cables at several

locations. The minimal clearance presents an

increased risk of the cables being struck by

construction vehicles and plant (refer Figure 5-4

Typical plant items proximity to Ausgrid

minimum clearances), and can act as a constraint

to road widening or the alignment of a cycleway.

The overhead cables should be surveyed and the

safety clearances plotted for the various cable types

to determine the potential constraints to road

widening and the risk during construction.

The risk of striking cables can be eliminated by

relocating the cables or avoiding low clearance

locations when planning site accesses, haul roads,

stockpile sites, etc. Risk mitigation controls such as

‘tiger tails’, signage and spotters can be implemented

to control the risk of striking cables during

construction.

Refer to:

• Workcover Code of Practice Work Near Overhead Power Lines (2006)

• Ausgrid Electrical Safety Rules (September 2011)

• Ausgrid NS209 Operating Cranes & Plant in Proximity to Overhead Power Lines (February 2008)

5-3 Low clearance to existing overhead cables




5-4 Typical plant items proximity to Ausgrid minimum clearances




5.4 Location of utility pits

Both existing and proposed utility pits need to be located such that each can be safely accessed both during

construction and operation. This includes locating the pits away from live traffic lanes and heights (eg retaining

walls or steep batters). Relocating the utilities into corridors away from the road corridor will significantly

reduce these risks.

Pit depth should also be considered as changes in surface levels will increase existing pit depths. Deeper pits

are difficult to access safely and efficiently and may require the use of confined space access equipment and

procedures.

5.5 Location of utilities within the road formation

Several of the utilities identified in this Section are likely to remain or be relocated to within the new road

formation (ie. electrical transmission, street lighting, high pressure gas and ITS).

The utility authorities are likely to require that these utilities (especially those under trafficable lanes) are

reconstructed to be ‘maintenance free’. ‘Maintenance free’ generally requires concrete encasement of the

utility. This significantly increases the cost of the relocation but may be a more acceptable alternative to

installing in other locations. Whilst constructing the utility to be ‘maintenance free’ reduces the likelihood that

the road pavement will need to be damaged to access these utilities in the future, the encasement does create a

significant obstacle to the installation of future intersecting services.

However, any utilities located within the road formation footprint are at risk of being struck during construction

or future maintenance and the risk mitigation measures described above should be considered. Utilities within

the road formation are also subject to increased risk during underboring operations. Installation of redundant

conduits at future development sites reduces the likelihood of future underboring.




6 Recommendations

The following actions are recommended.

1. Further detailed investigation of existing utilities is required to confirm location and type of existing

utilities and requirements for protection or relocation. This should include Quality Level B location of all utilities and Quality Level A location of high risk utilities identified herein.

2. Survey overhead cables to determine impacts on design and construction.

3. Confirm which utilities are mounted on common poles as both utilities will need to be relocated if the pole is to be removed.

4. Liaise with utility authorities to confirm the location and status of existing utilities, discuss potential requirements for protection or relocation and determine future requirements. RMS should develop a preferred road and utilities alignment prior to liaison with the utility authorities.

5. Need to investigate an ‘off road’ utilities corridors where possible, particularly at CH 0 – CH 465 and CH 2550 – CH 3000.

6. Need to consider an alignment and typical section for utilities within the road corridor (ie within the

shoulder or otherwise) where an ‘off road’ alignment is not available and for utilities that are required within the road corridor (ie ITS, street lighting power, etc). Provision of a footpath or shared path may alleviate this in some sections.

7. Plot existing and proposed utilities in 3D to serve as a base for road design, clash analysis and construction staging.

8. Given the narrow corridor width and the importance of this route as the only thoroughfare through the area, it is generally recommended that future utilities are installed during the construction of the road.

9. If possible allocate a corridor for the installation of any future utilities within the corridor in accordance with the provisions of the Streets Opening Conference - Guide to Codes and Practices for Streets Opening, 2009.

10. Install road crossings, at the location of future developments, to avoid excavation of the new pavement. 11. Review the approval process and requirements for utility works within the National Parks 12. Review the current Memoranda of Understanding with utility authorities to determine cost sharing

opportunities (ie Sydney Water)

APPENDICES

Appendix A MR 162 Mona Vale Road, Strategic Design

McCarrs Creek Road to Power Works Road,

Plan and Profile

Appendix B

Probable Utilities Affected by

Footprint

PROBABLE UTILITIES AFFECTED BY FOOTPRINT - SEWER RISING MAIN SHEET 1 OF 2MONA VALE ROAD

29 MAR 2012600342-0020(1)

PROBABLE UTILITIES AFFECTED BY FOOTPRINT - SEWER RISING MAIN SHEET 2 OF 2MONA VALE ROAD

23 FEB 2012600342-0021(1)

PROBABLE UTILITIES AFFECTED BY FOOTPRINT - GAS SHEET 1 OF 2MONA VALE ROAD

29 MAR 2012600342-0022(1)

PROBABLE UTILITIES AFFECTED BY FOOTPRINT - GAS SHEET 2 OF 2MONA VALE ROAD

29 MAR 2012600342-0023(1)

PROBABLE UTILITIES AFFECTED BY FOOTPRINT - OPTUS SHEET 1 OF 2MONA VALE ROAD

29 MAR 2012600342-0024(1)

PROBABLE UTILITIES AFFECTED BY FOOTPRINT - OPTUS SHEET 2 OF 2MONA VALE ROAD

29 MAR 2012600342-0025(1)

PROBABLE UTILITIES AFFECTED BY FOOTPRINT - TELSTRA SHEET 1 OF 2MONA VALE ROAD

29 MAR 2012600342-0026(1)

PROBABLE UTILITIES AFFECTED BY FOOTPRINT - TELSTRA SHEET 2 OF 2MONA VALE ROAD

29 MAR 2012600342-0027(1)

PROBABLE UTILITIES AFFECTED BY FOOTPRINT - ELECTRICITY SHEET 1 OF 2MONA VALE ROAD

29 MAR 2012600342-0028(1)

PROBABLE UTILITIES AFFECTED BY FOOTPRINT - ELECTRICITY SHEET 2 OF 2MONA VALE ROAD

29 MAR 2012600342-0029(1)

120424 mona vale rd strategic assessment of utilities

Documents