Expert Witness Statement of Warwick Bishop - In the matter of Suburban Rail Loop East Inquiry and Advisory Committee Proponent: Suburban Rail Loop ...
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In the matter of Suburban Rail Loop East Inquiry and Advisory Committee Proponent: Suburban Rail Loop Authority Expert Witness Statement of Warwick Bishop Surface Water Expert of Suburban Rail Loop Authority 12 February 2022 12 February 2022
Statement Details Author: Warwick Bishop Title: Expert Witness Statement of Warwick Bishop Prepared For: Suburban Rail Loop Authority Instructed By: White & Case Lawyers Date of Statement: 12 February 2022 15 Business Park Drive Notting Hill VIC 3168 Telephone (03) 8526 0800 Fax (03) 9558 9365 ACN 093 377 283 ABN 60 093 377 283 Expert witness statement of Warwick Bishop | 12 February 2022 Suburban Rail Loop East Page 1
CONTENTS 1 STATEMENT AUTHOR 3 1.1 Statement Contributors 4 2 SCOPE OF STATEMENT 5 3 BASIS OF THIS STATEMENT 6 4 FINDINGS 7 5 ANALYSIS – REVIEW OF EES TECHNICAL CONTENTS 8 5.1 Water Quality 8 5.2 Flooding 9 5.2.1 Climate Change 9 5.2.2 Flood Impacts 9 5.3 Environmental Performance Requirements 11 6 WATER QUALITY MODELLING 14 6.1 Potential WSUD Measures 14 6.2 Water Quality Modelling 15 7 SUBMISSIONS 16 7.1 Melbourne Water (Submission 229) 23 7.1.1 Minor and Major Drainage (Flooding) 23 7.1.2 Water Quality Management 23 7.1.3 Waterway Management 23 7.2 EPRs 24 7.2.1 Kingston City Council (Submission 291) 24 7.2.2 Monash City Council 24 7.2.3 EPA (Submiussion 269) 26 7.2.4 Yarra Valley Water (Submission 272) 26 7.2.5 Monash University (Submission 262) 27 8 CONCLUSIONS 28 9 DECLARATION 29 LIST OF FIGURES Figure 5-1 Burwood, 1% AEP + Climate Change Afflux 11 Expert witness statement of Warwick Bishop | 12 February 2022 Suburban Rail Loop East Page 2
1 STATEMENT AUTHOR
Warwick Alistair Bishop
Senior Principal Engineer, Director
Water Technology Pty Ltd
15 Business Park Drive
Notting Hill, VIC 3168
Qualifications
◼ B.E. (Hons), University of Melbourne, 1993
◼ MEngSci, Monash University, 2000
Affiliations
◼ Fellow, Institution of Engineers Australia, Chartered Professional Engineer.
◼ Member, River Basin Management Society
◼ Member, Society for Sustainability and Environmental Engineering of Engineers Australia
◼ Member, Stormwater Victoria
◼ Member, Australian Water Association
◼ Member, International Association for Hydraulic Research
Area of Expertise
Key areas of expertise relevant to this statement are summarised below:
◼ Assessment of surface water engineering with a focus on drainage, flooding and water quality
management.
◼ Investigation and conceptual design of flood risk mitigation systems
◼ Expert witness for drainage, flooding and water quality related issues at environmental effects panels,
planning panels and civil hearings.
A copy of my Curriculum Vitae is provided in Appendix A.
Statement of Expertise
With my qualifications and experience, I believe that I am well qualified to provide an expert opinion on
drainage, flooding and water quality matters relative to the Suburban Rail Loop East Environment Effects
Statement.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 3
1.1 Statement Contributors Bertrand Salmi Principal Engineer Water Technology Pty Ltd 15 Business Park Drive Notting Hill, VIC 3168 Qualifications ◼ Bachelor (Hons) of Ecological Sciences (Environmental Sciences), University of Edinburgh 2006 ◼ Master of Sciences, Water Resource Engineering Management, Heriot Watt University 2007 Area of Expertise Key areas of expertise relevant to this statement are summarised below. ◼ Assessment of flood and stormwater management; ◼ Application of GIS. Scope of contribution Bertrand assisted in the preparation of the statement, including data review and figure preparation, under my supervision. Expert witness statement of Warwick Bishop | 12 February 2022 Suburban Rail Loop East Page 4
2 SCOPE OF STATEMENT
In September 2021 I was instructed by White & Case on behalf of the Suburban Rail Loop Authority to conduct
an independent peer review of the surface water reports (existing conditions and impact assessment) prepared
for the Suburban Rail Loop East (SRL East) Environment Effects Statement (EES).
In November 2021, I was instructed by White & Case on behalf of the Suburban Rail Loop Authority to give
evidence in respect of the environmental effects of SRL East relevant to my area of expertise, including
reviewing and responding to submissions relevant to surface water. My instructions to prepare this witness
statement are set out in Appendix B.
In particular, I have been instructed to prepare an expert witness statement in which I:
◼ Set out my background and relevant expertise;
◼ Briefly describe and summarise the peer review report of the Surface Water Impact Assessment and
Existing Conditions reports prepared in support of the EES and my role in preparing it;
◼ Detail whether there is anything in the peer review report that I disagree with or wish to elaborate on and
set out any additional information that I consider necessary to include, including any additional
assumptions or further work undertaken since exhibition of the EES; and
◼ Consider submissions that are relevant to my area of expertise and respond to any relevant issues raised
My review has been based on a desktop review of the EES and supporting documents, considering standard
industry practices and standards.
I have prepared this expert statement in accordance with the Planning Panel Victoria’s Guide to Expert
Evidence.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 5
3 BASIS OF THIS STATEMENT
This statement is based on the following sources of information:
◼ Suburban Rail Loop East – Technical Appendix Q.1 - Surface Water Existing Conditions, prepared by
AJM (Rev 01)
◼ Suburban Rail Loop East - Technical Appendix Q.2 - Surface Water Impact Assessment, prepared by
AJM (Rev 01)
◼ Memorandum regarding 5% Annual Exceedance Probability (AEP) including Climate Change Impact
Summary, prepared by AJM (February 2022)
◼ Memorandum regarding EES MUSIC Modelling, prepared by AJM (February 2022)
◼ Review of additional available information, including:
◼ LiDAR (survey) and VicMap data
◼ Submissions to the EES that raise issues relevant to my area of expertise, as provided by White and Case
Lawyers
A copy of the 5% AEP flood modelling memorandum is provided in Appendix C and a copy of the water quality
modelling memorandum is provided in Appendix D.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 6
4 FINDINGS
A review of the EES surface water reports for existing conditions and impact assessment is documented in
my previous report “Peer Review – Hydrology and Flooding”, October 2021 (Appendix E to Technical
Appendix Q.2).
I adopt my peer review report as the basis for my evidence before the Suburban Rail Loop East Inquiry and
Advisory Committee. There are no departures from the findings or opinions expressed in my peer review
report, save to the extent they are supplemented in this statement. The peer review report is complete and no
circumstances or assumptions adopted in it have changed that would effect the opinions I express in it.
Based on review of the submissions and further consideration of the Environmental Performance
Requirements (EPRs), I consider the two following minor adjustments to the EPRs could be considered.
SW7 Develop and implement a water quality monitoring program
◼ I recommend that, in addition to pre-construction and during construction, post construction monitoring for
a minimum period of 2 years should be undertaken to confirm water quality conditions are maintained for
the operational phase of the project.
SW9 Develop and implement an Integrated Water Management Strategy
◼ In accordance with SW9 the development and implementation of an Integrated Water Management
Strategy, will be undertaken “..in consultation with EPA Victoria, Melbourne Water and relevant local
councils in general accordance with approach outlined the Integrated Water Management Framework for
Victoria (DELWP, 2017).” Reference to water corporations such as Yarra Valley Water and South East
Water and the need to include them and consult with them is an explicit component of the DELWP
Integrated Water Management Framework, and hence is implicit within this EPR. Recognising that these
organisations have an integral role in the Integrated Water Management Framework for Victoria, the
wording of this EPR could be modified to include specific reference to water corporations, which would
reinforce this aspect.
Key risk issues and impacts are identified in Section 5 of this statement along with how they have been
addressed within the EES. Surface water impacts have been addressed through a combination of qualitative
and quantitative assessments. The proposed EPRs cover how the detailed project design will comply with the
necessary requirements to minimise, avoid or mitigate impacts.
I consider the surface water assessments within the EES have adequately defined existing conditions and
identified potential impacts of the project and how these can be minimised, avoided or mitigated. The proposed
EPRs, with minor modifications, are appropriate to guide the design of surface water management measures
to produce an appropriate project outcome.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 7
5 ANALYSIS – REVIEW OF EES TECHNICAL CONTENTS
I have been previously instructed to:
◼ Review all reports, maps and appendices provided and provide opinions and recommendations based on
the outcomes detailed; and
◼ Produce a Peer Review Report in accordance with instructions from White & Case Lawyers on behalf of
the SRLA.
In this section, I briefly describe and summarise the key issues with respect to the EES Surface Water Existing
Conditions and Surface Water Impact Assessment reports and associated Technical Advisory Notes.
5.1 Water Quality
The EES considered potential impacts of the SRL East project on water quality, in three stages:
a. Baseline (existing) conditions were established, using available water quality data from a range of sources,
including Melbourne Water, Environment Protection Authority (EPA) Victoria and Waterwatch monitoring
sites for the receiving waterways, including Elster Creek, Mordialloc Creek, Scotchmans Creek, Mile
Creek, Gardiners Creek and Koonung Creek:
i. Desktop assessment was supplemented with values in conditions identified for the relevant
catchments in Melbourne Water’s Healthy Waterways Strategy;
ii. These data were compared with relevant water quality guideline values, including the EPA’s
environmental reference standard (ERS) objectives along with the General Environmental Duty
(GED), to evaluate existing water quality.
b. A qualitative assessment (for each catchment) was conducted to investigate the potential water quality
impacts during the construction of the project. This desktop assessment identified likely source-pathway-
receptor linkages and subsequently considered impact on water quality, flow regime or bed and bank
stability before and after standard controls are implemented.
i. The surface water management plan – to be developed in accordance with EPA Victoria guidelines -
would identify suitable mitigation measures for the construction stage;
ii. It would be complemented with a water quality monitoring program to confirm the effectiveness of the
environmental controls provided.
c. A qualitative assessment (for each catchment) was conducted to investigate the potential water quality
impacts during the project operation. This desktop assessment identified that any impact can be mitigated
through the implementation of “Integrated Water Management measures and Water Sensitive Urban
Design assets”:
i. It is expected that a quantitative assessment, using the Model for Urban Stormwater Improvement
Conceptualisation (MUSIC) software, will be undertaken as part of future design to size water quality
treatment assessments and ensure best practice objectives are met. I note that, subsequent to the
EES exhibition, a memorandum “SRL EES MUSIC Modelling” February 2022 has been produced by
AJM that includes preliminary MUSIC modelling of water quality treatment performance for sites
where there is a net increase in impervious area resulting from the Project. The results of the MUSIC
modelling demonstrate that objectives set out in the EPA guidance on stormwater treatment levels
can be met.
ii. The implementation of WSUD features to provide the level of treatment likely to be required is
expected to be achievable within a relatively small footprint, through the use of efficient treatment
measures such as tanks and rain gardens. This provides flexibility in the ultimate design to be
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 8
accommodated within each site. It is not anticipated that any significant barriers to this being achieved
exist.
I conclude that the water quality assessment appropriately considered the impacts of the project at a qualitative
level, with preliminary quantitative modelling demonstrating an appropriate level of performance for this
approach. The impacts of the SRL East project can be addressed through the design of appropriate Water
Sensitive Urban Design (WSUD) features, consistent with the concepts outlined and modelled to date. These
can be finalised through the detailed design process, in accordance with the Environmental Performance
Requirements (EPRs).
5.2 Flooding
Flooding at each of the new stations or interchanges has been assessed for pre-development (existing) and
post-development conditions. The assessment was based on detailed hydrological and hydraulic modelling.
The technical details of the hydrology and hydraulic model setup and parameterisation which are described in
the “Technical Advisory Note – Hydrology and Hydraulics Modelling”, for each site. The hydrologic and
hydraulic investigations have been guided by Australian Rainfall and Runoff 2019 (ARR), along with Melbourne
Water’s Technical Specifications for flood investigations. The investigations also considered climate change
impacts, as discussed in Section 5.2.1. This general approach is considered consistent with industry best
practice and will streamline the process of compliance with Melbourne Water needs.
I consider the approach applied to the flood impact analysis appropriate and acceptable for the EES. It should
provide a sufficiently robust outcome that will give confidence that any significant project impacts, in terms of
surface water management, have been identified and are able to be mitigated through the application of
appropriate Environmental Performance Requirements during detailed design.
5.2.1 Climate Change
The SRL flood impact assessments considered current climate conditions as well as projected future climate
change conditions over the Project design life, in accordance with Environmental Performance Requirement
SW4. The modelling allowed for an increase in the adopted design rainfall intensity, to reflect projected change
in storm severity due to climate change in 2150. This is in line with the principles of the Victorian Climate
Change Act 2017 and is a more conservative approach usual for design. However, the investigators noted the
long expected design life of the project to justify the approach. I believe this is a sound basis for incorporating
flood-related climate change risks into the project.
Melbourne Water’s flood specifications recommend a rainfall intensity increase to 2100 of 18.4% (based on
extrapolating the RCP 8.5 scenario projection). A value of 23.4% was adopted for this project, to reflect the life
of the proposed infrastructure. I understand that this value of 23.4% was adopted based on simulations using
SimCLIM software, which is an appropriate tool for this purpose.
The climate change modelling scenarios used exceed the requirements of Melbourne Water. For this reason,
I considered that an appropriate assessment of the potential impacts of climate change have been incorporated
into the EES.
5.2.2 Flood Impacts
The EES considered potential impact of the SRL East project on the 1% AEP flood risk during three stages:
a. Construction and Early Days Stage:
i. Modelling of potential mitigation measures was undertaken and documented for each location. The
modelling suggests that any significant afflux (increase in flood levels) is contained within each of the
project sites.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 9ii. This provides confidence that potential adverse impacts can be mitigated as part of the detailed
design.
b. Operation:
i. Each location was considered, with detailed hydraulic modelling undertaken. The detailed hydraulic
modelling appropriately demonstrates that any impacts from the development (hazard, afflux) are
within Melbourne Water’s acceptable limits, apart from upstream of the Burwood Highway at
Burwood.
1. Flood impacts at Burwood Station are further discussed in Section 5.2.2.1.
ii. Melbourne Water has provided “In-principle Non Objection” for the flood analysis for each of the sites.
Each of Melbourne Water’s responses contain comments or conditions that may require further
resolution during the design process. None of these are of a level of significance that cannot be
resolved or would prevent the project from proceeding.
Analysis of flood impacts would typically be undertaken over a broad range of flood flows, in addition to the
extreme flood case. Melbourne Water guidelines suggest the 20%, 10%, 5% and 2% AEP design floods, as
well as the 1% AEP plus climate change scenario should be simulated. No impact for the 1% AEP design
storm does not guarantee that all design flood magnitudes will similarly have no impact. It is acknowledged,
however, that if a mitigation solution is possible at the 1% AEP flood level, then mitigation for less intense
storms will most likely be feasible with limited modification to the design. This can be addressed with Melbourne
Water as the project design progresses in accordance with EPR SW3.
Following my peer review, I recommended that additional 5% AEP design storm modelling and impacts
assessment be undertaken for the operational scenario. The purpose of this request was to understand the
effectiveness of mitigation measures for a more frequent design storm magnitude than the 1% AEP.
The selection the operational scenario represents the long-term potential impact of the project. The inclusion
of the 5% AEP design storm assessment provides an indication of system performance for a range of flows
without necessarily analysing the full suite of design storms. This provides additional confidence in the
robustness of the proposed mitigation measures.
The 5% AEP design storm is large enough to promote overland flow and test the performance under a more
frequent flood scenario. A more frequent design storm than the 5% AEP (10% or 20% AEP for example), would
more likely reflect the underground drainage system capacity and little if any overland flow behaviour would
be observed. For this reason I consider the 5% AEP is an appropriate design condition to assess system
performance under more frequent flooding than the 1% AEP design storm.
Subsequently, since the EES exhibition, additional flood modelling and impact assessment has been
undertaken by AJM for the 5% AEP design storm at each site. This work shows that impacts are confined to
the boundaries of each site, with the exception of Burwood. Similar to the 1% AEP design storm case, some
afflux is predicted by the modelling immediately upstream of the Burwood Highway in the mitigated scenario.
For the 5% AEP design storm there is also an area of afflux on the east side of Gardiners Creek, south of the
site boundary that may impact private land. The magnitude of afflux at these locations is small and generally
consistent with the 1% AEP design flood behaviour.
I consider the critical aspect for the impact assessment is to determine whether feasible mitigation strategies
exist to mitigate those impacts identified by the EES modelling. The results presented, and Melbourne Water’s
in-principle support, provide confidence that mitigation solutions can be achieved for all sites. The details for
each site will be finalised as the project design progresses. In the case where some residual afflux remains,
assuming the mitigation solution is not at its maximum limit, the solution can be refined and resolved through
the detailed design process in compliance with Melbourne Water’s requirements. Some level of residual afflux
could also be discussed with and accepted by the relevant authority or any affected property owners.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 105.2.2.1 Burwood Station
The detailed hydraulic modelling shows no significant increase in peak flood levels outside the site location
boundaries, apart from Gardiners Creek at Burwood, for the operational case with climate change (Figure 5-1).
I considered, as part of my peer review, that this afflux would need to be addressed. This could be done either
through additional optimisation in the design of the mitigation measures to reduce this afflux to acceptable
levels or to obtain permissions from the relevant stakeholders. I noted there may be capacity to provide
additional flood storage in part of the area occupied by the two sports ovals to the east of Gardiners Creek.
This area is higher than the creek and would require extensive excavation. There could also be services or
other constraints. However, the area has the potential to provide additional flood storage and could be
combined with an integrated water management outcome such as water harvesting for irrigation of parklands.
Whilst it is recognised that naturalising a section of Gardiners Creek will provide substantial benefits to the
community in terms of amenity and ecological values, the design solution must also manage flood impacts. I
believe these issues can be resolved through the detailed design process.
Figure 5-1 Burwood, 1% AEP + Climate Change Afflux
5.3 Environmental Performance Requirements
The Environmental Performance Requirements (EPRs) as described in Section 9 of the “SRL East – Impact
Assessment – Surface Water” report provide measures intended to ensure any potential impacts are managed
appropriately. The EPRs are a mechanism to reinforce and scope the commitment to resolve any impacts on
the environment resulting from the project. The EES has been informed by mitigation modelling at the concept
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 11(or reference) design phase to establish that mitigation solutions for surface water impacts are achievable at
each location.
The EPRs require the following key elements with respect to surface water management:
◼ SW1 A Surface Water Management Plan during construction - This plan will be in accordance with
relevant publications and guidelines including:
◼ EPA Victoria publications:
◼ 275 Construction techniques for sediment pollution controls
◼ 1834 Civil construction, building and demolition guide
◼ 1698 Liquid storage and handling guideline
◼ 978 Reducing stormwater pollution a guide for industry
◼ 1896 Working within or adjacent to waterways
◼ Managing stormwater to meet objectives outlined in Urban Stormwater Best Practice Environmental
Management Guidelines (CSIRO 1999)
◼ Maximise opportunities for reuse on site to the extent reasonably practicable, in accordance with the
SRL East Integrated Water Management Strategy
◼ SW2 Develop and implement flood emergency management plans – this will address the
management of flood risk for the project in both the construction and operational phases. This would be
developed in consultation with Melbourne Water and Councils as the responsible floodplain and drainage
authorities.
◼ SW3 Minimise risks from changes to flood levels, flows and velocities – This requires a detailed
flood impact assessment of all works during and after construction. These assessments have been
initiated as part of the EES process with concept mitigation measures proposed. Future detailed designs
will need to meet EPR requirements and satisfy the responsible floodplain authority (Melbourne Water).
◼ SW4 Model climate change effects on surface water – The future impacts of climate change on surface
water will be taken into account by following the Melbourne Water "Standards for infrastructure projects
in flood-prone areas” (2019) and the Victorian Climate Projections (VCP) for 2050 and 2090 timeframes.
The assessment will also be in line with the guiding principles of the Victorian Climate Change Act 2017.
◼ SW5 Manage stormwater runoff during operation – This will involve the development and
implementation of a Stormwater Management Plan in consultation with Melbourne Water, Councils and
EPA Victoria. This will have regard to:
◼ EPA Victoria Publication 1739.1 Urban stormwater management guidance
◼ Integrated Water Management Strategy (EPR SW9) and SRL Urban Design Strategy
◼ Healthy Waterways Strategy Stormwater Targets Practitioner’s Note (Melbourne Water 2021)
◼ SW6 Manage wastewater – This covers the disposal of wastewaters to surface water systems if
necessary (where discharge to sewer is not possible). Discharge to surface water systems would be in
accordance with a wastewater discharge management plan prepared in consultation with and to the
requirements of EPA Victoria and other relevant authorities.
◼ SW7 Develop and implement a water quality monitoring program – A water quality monitoring
program to be developed in conjunction with EPA Victoria, Melbourne Water and asset owners (where
applicable). General guidance for sampling of surface water is provided in EPA Victoria Publication
IWRG701: sampling and analysis of waters, wastewaters, soils and wastes and the Australian and New
Zealand Guidelines for Fresh and Marine Water Quality.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 12◼ SW8 Develop and implement a management plan for naturalisation of Gardiners Creek – The EPR
seeks to develop and implement a plan for naturalisation of Gardiners Creek in consultation with
Melbourne Water (as the waterway manager) and Whitehorse Council. There are no specific guidelines
for the design of naturalisation works, other than being to the satisfaction of the waterway manager,
Melbourne Water, which is required.
◼ SW9 Develop and implement an Integrated Water Management Strategy – The requires the
development and implementation of an Integrated Water Management Strategy (IWMS) in consultation
with EPA Victoria, Melbourne Water and relevant local councils. The IWMS is intended to be in general
accordance with the Integrated Water Management Framework for Victoria (DELWP, 2017).
I considered the EPRs to be:
◼ Clear and concise, whilst providing an appropriate level of detail to ensure a suitable outcome is achieved;
and
◼ Appropriately scoped to ensure that the detailed ultimate design meets the performance standards
necessary.
Some submissions suggest changes to the wording of the EPRs. From a technical perspective I am satisfied
that the EPRs as currently drafted will achieve the necessary outcomes to avoid, minimise and mitigate
potential surface water impacts.
I have made minor suggested wording changes to EPRs SW7 and SW9. These are not substantive. Some
minor changes to wording may provide clarity or accommodate concerns of submitters, however there is
nothing that has been raised in submissions that I consider substantive to the management of surface water
impacts.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 136 WATER QUALITY MODELLING
The SRL Environmental Performance Requirement SW5 requires stormwater runoff to be managed “with
principles outlined in the Integrated Water Management Strategy (EPR SW9) and SRL Urban Design
Strategy”. As a result of these two EPRs (SW9 and SW5), any SRL projects need to meet water quantity and
quality objectives outlined in ‘Environment Protection Authority Victoria (EPA) Publication 1739.1 (June 2021):
Urban Stormwater Management Guidance’ and other relevant guidelines.
The SRL East Surface Water Impact Assessment included a qualitative assessment of water quality impacts
during the project operation. It concluded that any impact can be mitigated “through harvesting, infiltration,
and/or treatment using Integrated Water Management and Water Sensitive Urban Design” (WSUD). These
measures would aim to reduce the volume of stormwater and improve the quality of stormwater runoff during
operation such that there would be negligible adverse impact on water quality or flow regime in accordance
with Best Practice environmental objectives. Details of these WSUD measures were to be finalised at a later
stage, during detailed design stage and in accordance with the relevant EPRs.
In my peer review report I stated that future water quality modelling using the Model for Urban Stormwater
Improvement Conceptualisation (MUSIC) software would be required at the detailed design stage to inform
the design and evaluation the performance of water sensitive urban design measures to manage stormwater
quality. This approach was considered appropriate and acceptable given the available detail in the reference
design.
Subsequent to the EES exhibition, additional work has been undertaken by AJM (February 2022) to
demonstrate the level of expected treatment performance via quantitative water quality modelling. This
modelling used the industry-accepted Model for Urban Stormwater Improvement Conceptualisation (MUSIC)
software:
◼ MUSIC modelling has been undertaken for the SRL East stations at Cheltenham, Clayton, Monash and
Burwood and the Stabling Facility site, where there would be a net increase in impervious area from
existing (pre-development) to post-development conditions;
◼ There would likely be a net decrease in impervious area from pre to post development conditions at the
other sites (e.g., Box Hill and Glen Waverley), due to inclusion of additional open pervious spaces. These
sites will also incorporate WSUD features, such as rainwater tanks for re-use and bio-retention basins,
however no modelling was considered warranted as the development of these SRL sites would most likely
result in improvements in water quality.
6.1 Potential WSUD Measures
As noted above, there is an increase in fraction impervious area for SRL East stations at Cheltenham, Clayton,
Monash and Burwood and the Stabling Facility site. Water quality modelling was then undertaken for these
five sites, to identify and approximately size potential WSUD treatment measures, consistent with EPA
guidance publication 1739.1.
The following potential measures have been identified as examples of applicable WSUD measures that would
meet water quality targets. I note that alternative or complementary WSUD measures may emerge from the
IWM strategy (EPR SW9). The items listed here are considered preliminary and conceptual.
◼ Smart RWT’s (tanks with automation to empty prior to forecast rainfall to increase storage effect),
◼ Roof and surface runoff to be captured and re-used to meet partial non-potable demands as well as
attenuating runoff events.
◼ Landscape strips and swales.
◼ Rain gardens and wetlands.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 14◼ Site flood attenuation (SFA) tanks, with a primary flood mitigation role.
6.2 Water Quality Modelling
The Model for Urban Stormwater Improvement Conceptualisation (MUSIC) was used to test that the potential
WSUD measures could satisfy the water quality treatment requirements within EPRs SW5 and SW9. The
MUSIC model methodology is considered to be in accordance with current industry guidelines, including
Melbourne Water Guidance (Healthy Waterways Strategy Stormwater Targets Practitioner’s notes).
I note that:
◼ The modelling allowed for some conservatism, by adopting meteorological data from a wetter station (i.e.,
which would result in larger WSUD assets); and
◼ The design principles were shared with Kingston City Council, Monash City Council, Whitehorse City
Council and Melbourne Water and no objections were raised.
The MUSIC modelling demonstrates that the example water quality “treatment train1” achieves or exceeds
best practice stormwater management targets and water quantity objectives at each site (i.e., Cheltenham,
Clayton, Monash, Burwood and Stabling Facility). Based on this quantitative assessment, I am confident that
any surface water quality impacts of the SRL East project can be addressed through the design of appropriate
WSUD features. These are to be finalised through the detailed design process in conjunction with the
preparation of an Integrated Water Management Plan for each site, as required by EPRs SW5 and SW9.
1A treatment train is a series of water quality measures within a catchment that combine to produce an
overall water quality treatment outcome. An example may be a gross-pollutant trap, followed by a sediment
basin and then a wetland.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 157 SUBMISSIONS I have responded to issues raised by submissions related to Suburban Rail Loop East and its EES, as relevant to my expertise, in Table 7-1. Please note that I have grouped similar flooding and drainage issues together, where appropriate. Expert witness statement of Warwick Bishop | 12 February 2022 Suburban Rail Loop East Page 16
Table 7-1 Summary of Matters Raised in Submissions
Item Submission Concerns Raised Comments
Number
1 225 (Bayside Lack of Integrated Water The work to date addresses the potential impacts of the SRL East and mitigation of those impacts. The
City Council) Management/Strategy to identify development and implementation of an Integrated Water Management Strategy is explicitly specified
opportunities. The scope should be within EPR SW9 to address the works related to the SRL East project.
expanded include stormwater Opportunities exist for additional integrated water management (IWM) outcomes associated with future
management from future development in the vicinity of each site. However, these are not possible to quantify at this stage, are not
developments in the station expected to impact the environmental performance of the core infrastructure, and to my understanding
precinct are outside the scope of the EES.
I also understand that matters related to IWM and urban design for the broader precincts will be the
subject of Precinct Structure Plans that will be assessed in a separate process.
2 251 (Deakin) Improvements to Gardiners Creek This submission supports the proposed naturalisation of Gardiners Creek. It is suggested that
should be continued south to improvements to Gardiners Creek should be continued south to Highbury Road. This is not a technical
Highbury Road issue related to the project impacts from a surface water perspective.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 17Item Submission Concerns Raised Comments
Number
3 260 (Monash The very highest standard and See response to submission 225 (item 1).
City Council) leadership in innovation in Water The areas around each station will, in most cases, provide an opportunity for urban renewal and the ability
Sensitive Urban Design (WSUD) and to embed best practice integrated water management as part of this process. However, in terms of surface
Integrated Water Management water management and impacts compared to existing conditions, IWM plans are not crucial to mitigating
(IWM) is warranted. surface water impacts of the proposed Rail Loop for the EES assessments.
The EES does not properly explain Complementary IWM benefits could be realised between the surface water designs for the SRL East
the WSUD measures proposed by project and broader urban development in the vicinity. These can be explored through the Precinct
the Project. …the WSUD design Structure Planning process that will come after the EES.
response remains unknown I note the development and implementation of an Integrated Water Management Strategy (for the
because the management of runoff project) is explicitly specified within EPR SW9 and will be subject to a future assessment process.
from the broader precincts was not Subsequent to the EES exhibition, WSUD measures identified in the EES have been tested in a technical
within the scope. memorandum (refer to section 6). Potential WSUD measures are supported by a quantitative assessment,
using the Model for Urban Stormwater Improvement Conceptualisation (MUSIC) software, for the SRL
stations at Cheltenham, Clayton, Monash and Burwood and the Stabling Facility site. There is a reduction
in fraction impervious area for the other sites, thus projected water quality improvement, even when
ignoring any benefits from WSUD measures. The detailed selection, location and sizing of WSUD measures
will be determined through the course of detailed design in accordance with EPRs SW5 and SW9.
Finally, EPR SW5 requires stormwater runoff to be managed “with principles outlined in the Integrated
Water Management Strategy (EPR SW9) and SRL Urban Design Strategy”. As a result of EPRs SW5 and
SW9, any SRLA projects will need to meet water quantity and quality objectives outlined in ‘Environment
Protection Authority Victoria (EPA) Publication 1739.1 (June 2021): Urban Stormwater Management
Guidance’ and other relevant guidelines such as the Healthy Waterways Strategy Stormwater Targets
Practitioner’s Note (Melbourne Water 2021). Through the design process, in accordance with the EPRs, the
management of stormwater runoff will be integrated with the principles, objectives and outcomes of the
project's Integrated Water Management Strategy and the Urban Design Strategy.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 18Item Submission Concerns Raised Comments
Number
4 260 (Monash Council is concerned there may be The SRL East project may temporarily impact on Damper Creek flows due to groundwater drawdown
City Council) impacts to baseflow in Damper during the construction phase. It is anticipated that this would be for a period of less than 4 months. I note
Creek and the drawdown will EPA is seeking more information to clarify the existing groundwater characteristics and surface water –
compound the impact of groundwater interactions in the area where Damper Creek crosses the SRL alignment. This is outside of my
impervious surfaces which greatly area of expertise. I would expect a groundwater specialist and ecology specialist should be able to
reduce rainwater infiltration, determine whether further monitoring and/or investigations of Damper Creek are warranted.
groundwater recharge and stream
baseflow contributions in urban
environments.
5 260 (Monash Council advocates for the See response to 251(item 2)
City Council) naturalisation of Gardiners Creek
between Warrigal and Highbury
Roads, as an extension of the
naturalisation of the creek planned
alongside Burwood Station.
6 260 (Monash The solutions presented to date do See responses to 225(item 1) and 260(item 3).
City Council) not place a strong enough emphasis I note that EPR SW5 references EPA Publication 1739.1 Urban stormwater management guidance (June
on infiltration-based solutions. This 2021), which is the most recent document to inform the stormwater industry in meeting the requirements
is a priority within Melbourne of the Melbourne Water Healthy Waterways Strategy. EPA Publication 1739.1 incorporates performance
Water’s Healthy Waterways objectives for both stormwater harvesting/evapotranspiration as well as infiltration of stormwater.
Strategy, EPA Publication 1739.1 To date the outputs of the IWM Catchment Plans are not publicly available in final form. I note however
and consistent with Targets in the that these documents are part of the overall process outlined in the Integrated Water Management
Catchment IWM Plans. Framework for Victoria (DELWP, 2017) and hence would be expected to be considered in the development
of the IWMS as required by EPR SW9.
7 260 (Monash Council considers more information See responses to 225(item 1) and 260(item 3).
City Council) is necessary to understand how
stormwater runoff and sediment
from the broad precinct (beyond
the station boxes) will be managed.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 19Item Submission Concerns Raised Comments
Number
8 262 (Monash EES indicates an increase in flow There is a small area of minor residual flood impact, post mitigation, indicated on afflux plots for the
University) depths on University Land at the Monash University student accommodation precinct south of Normanby Road. This is primarily in a
on-campus student accommodation carpark area and can be managed through the detailed design process to eliminate any residual flood risk.
precinct to the south of Normanby
Road.
9 262 (Monash Concerning that future increases of See response 262(item 8) above. Any cumulative impact due to further development to the north will need
University) impervious area will cumulatively to be managed through a separate planning process as development occurs. Melbourne Water and
increase the runoff destined for the Council, as the responsible floodplain and drainage authorities will oversee any future development to
University campus ensure it is managed appropriately for flood risk and impacts.
10 262 (Monash The EES proposes no mitigation Safety access is a standard requirement associated with development, which is covered by EPRs SW3 and
University) measures to maintain accessibility SW5.
during storm events, risking
pedestrian safety.
11 267 The proposed works along See response to 251(item 2).
(Whitehorse Gardiners Creek are inadequate and
City Council) should be continued south to
Highbury Road to provide for a
complete section of improvements
rather than just in the immediate
vicinity of the station box.
12 267 Council remains concerned with the The surface water EPRs, SW1-5 will address matters related to stormwater performance. Further,
(Whitehorse capacity of the drain/culvert Melbourne Water and/or Council will be involved with signoff of designs. This will include the Burwood
City Council) underneath Burwood Highway, Highway culvert. SW3 requires that designs meet Melbourne Water’s standards.
particularly whether the possibility
of blockage and the resultant
impacts.
13 267 The proposed modelling does not The EPRs, along with Melbourne Water approval process, will allow for a robust assessment of flood risk.
(Whitehorse adequately establish that the risk of
City Council) unreasonable stormwater discharge
through buildings and structures
will be mitigated
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 20Item Submission Concerns Raised Comments
Number
14 267 Mitigated flood mapping shows This issue is addressed in the EES documentation and discussed in Section 5.2.2.1 of this statement.
(Whitehorse afflux through some properties
City Council) within the vicinity of Burwood
Highway and McComas Grove,
which the EES does not adequately
consider.
15 269 (EPA) Potential impact on Damper Creek See response to 260(item 4).
due to surface water/groundwater
interaction
16 272 (Yarra SW1 – SW9 Call for more Suggestions are related to consultation with the authority. From a technical point of view, this does not
Valley Water) consultation. influence the EES impact and mitigation assessments or outcomes. I note that SW9 does not contain an
explicit reference to consultation with water authorities (such as Yarra Valley Water or South East Water),
however this is implied within the Integrated Water Management Framework for Victoria (DELWP, 2017)
that is referenced in the EPR.
17 291 (City of Absence of detailed Integrated See response to 260(item 3).
Kingston) Water Management Strategy
(Cheltenham Station). Amended or
additional EPR’s as appropriate.
Refer to alternative option which
integrates water features
18 291 (City of The Stabling Yards report lacks See response to 260(item 3).
Kingston) conceptual & strategic information At the planning stage of the project the details of each station area and the stabling yard must be, to some
on the functionality of the extent, conceptual. In accordance with EPRs SW5 and SW9 detailed design of water management assets
proposed wetland and retarding will occur in conjunction with the ultimate design of the surface elements of the project.
basin. The EES and further modelling has demonstrated that mitigation measures are able to meet the water
quality treatment requirements of EPA Victoria and flood requirements of Melbourne Water. The
functionality of the proposed or potential stormwater management measures is appropriate to assess
impacts for the EES process.
Broader beneficial outcomes from an IWM approach are desirable and to be considered as part of the
required IWMS. The EES overview states that Precinct Structure Plans will follow the EES process and
address broader landuse and urban planning aspects.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 21Item Submission Concerns Raised Comments
Number
19 291 (City of Stormwater management does not See responses to 225(item 1) and 260(item 3).
Kingston) consider future development sites
20 291 (City of Flooding mitigation in areas The flood impacts of the proposed Stabling Yard area have been assessed through detailed hydrologic and
Kingston) surrounding Stabling Yard. hydraulic modelling. In the EES and further work undertaken by AJM at my request, this assessment has
The Stabling Facility has the considered both the 1% AEP and 5% AEP design storms. The results from these assessments show that,
potential to cause the displacement once mitigation measures were included, no significant off-site flood impacts are predicted. Further
of flood waters that could lead to assessment of future detailed designs will be subject to Melbourne Water requirements and review in
adverse flood impacts to accordance with ERPs SW3 and SW4..
surrounding property, key
infrastructure and the environment.
21 291 (City of Impacts on underground drainage Design floods for the 1% AEP and 5% AEP storms have been simulated for existing and mitigated
Kingston) system neglected. The Cheltenham conditions at both sites. The hydraulic models have included the best available pipe network data
Station and Stabling Yards report representing Melbourne Water and Council drainage systems. The EES technical reports (Q.1 and Q.2)
considers above ground flooding acknowledge that these datasets are not without errors and were corrected where possible. Imperfect
during major storm events, pipe data is common for urban flood studies and the approach taken in the EES is considered appropriate.
however it doesn’t review the The results of the modelling show no significant offsite flood impacts.
potential impacts on the capacity of
the underground drainage system.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 227.1 Melbourne Water (Submission 229)
Melbourne Water (MW), as a statutory floodplain and waterway authority, has provided in-principle support for
the draft EES as exhibited. As noted in its submission, Melbourne Water is a key referral authority in respect
to surface water management and should be consulted as the project progresses. This would be a continuation
of the consultation between SLRA and Melbourne Water, which has been occurring to-date.
7.1.1 Minor and Major Drainage (Flooding)
MW also acknowledged that the agency was consulted and provided comprehensive input into the preparation
of the surface water EES chapter. Melbourne Water had oversight of the development and auditing of models
(as discussed in section 5) in accordance with their organisational responsibility under the Water Act.
Melbourne Water also provided “In-principle Non Objection” for the flood analysis for each of the sites. Each
of the responses contain some comments or conditions that may require further resolution during the design
process. Melbourne Water considers these to be “generally minor and technical in nature mostly relating to
approaches to modelling and some instances where afflux is identified but is expected to be addressed through
further mitigation efforts”.
Residual concerns include:
◼ Proposed works and SRL should not result in unacceptable afflux within private properties
◼ The proposed naturalisation at Gardiners Creek (Burwood Station) should not result in detrimental flood
impacts.
◼ Potential for increasing flows to the Burton Avenue Drain Clayton.
Melbourne Water recommended further refinement of models and design, to ensure compliant designs and no
land parcels adversely impacted by afflux as required under EPR SW3 and the relevant Melbourne Water’s
Standards for Infrastructure in Flood Prone Areas (2019). Additionally, Melbourne Water considers the project
(and multiple stations) provide opportunities to create “multipurpose assets including flood mitigation and water
storage points enabling ‘3rd pipe’ networks”.
I consider each of the above matters will be appropriately addressed through EPRs SW3 and SW4.
7.1.2 Water Quality Management
Melbourne Water commended the relevant section of the EES. Melbourne Water also “endorses and strongly
supports the initiative of developing the EPR - SW9 Develop and implement an Integrated Water Management
Strategy”.
7.1.3 Waterway Management
Melbourne Water noted that whilst the SRL alignment intersects with numerous streams and waterways, the
SRL tunnel will be sufficiently separated vertically (due to the depths of the rail tunnel) not to create interface
concerns. Some monitoring may be required but these can be addressed at a later stage.
Additionally, Melbourne Water endorses the proposal for naturalising Gardiners Creek, and has been in
dialogue with both SRLA and Whitehorse City Council to ensure an appropriate design outcome.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 237.2 EPRs
A number of submissions suggested changes to the Environmental Performance Requirements (EPRs). These
are discussed in the following sections. Other submitters (e.g., Department of Education) have already
indicated they plan to provide comments on the EPRs to the Suburban Rail Loop East Inquiry and Advisory
Committee.
7.2.1 Kingston City Council (Submission 291)
Kingston City Council raised concerns that the EES did not provide sufficient details in respect of the Integrated
Water Strategy (IWMS), for Cheltenham Station and the Stabling Yard Facility. Council considered that the
IWMS should be integrated with the Urban Design Strategy, to help identify holistic solutions. They provided
alternative development solutions for these two sites, both incorporating WSUD measures. They also
recommended certain EPRs be amended, where appropriate, or additional EPRs added.
My responses to Kingston City Council submissions relevant to my area of expertise are contained in Table 7-1
above.
Kingston City Council raised concerns regarding flood management and potential impact on drainage
infrastructure. They therefore requested:
◼ Amended or additional EPR’s as appropriate; and
◼ Additional hydraulic modelling to assess the impacts on the performance of the existing drainage network,
based on 10% AEP flood modelling, and design the drainage system to the satisfaction of the responsible
drainage authority.
In my view, the suggested changes to the EPRs are not warranted on a technical basis. That is, they are not
necessary to achieve an acceptable outcome with respect to surface water impacts in the EES. I consider
them to be related to broader planning and strategic goals.
With respect to stormwater, EPR SW5 already references EPA Publication 1739.1 Urban stormwater
management guidance (June 2021), which is the most recent document to inform the stormwater industry in
meeting the requirements of the Melbourne Water Healthy Waterways Strategy. As such I consider this EPR
sufficiently addresses the requirements of stormwater management.
The 10% AEP design storm assessment will be covered by EPR SW3 and is a requirement of the MW
“Standards for infrastructure projects in flood prone areas” (2019).
7.2.2 Monash City Council
Monash City Council raised concerns that the EES did not provide sufficient details regarding the Integrated
Water Management Strategy (IWMS). Additionally, Council considered that:
◼ The very highest standard and leadership in innovation in Water Sensitive Urban Design (WSUD) and
Integrated Water Management (IWM) is warranted, given the scale of the project.
◼ WSUD measures are not consistent with the EPA Publication 1739.1 Urban Stormwater management
guidance (2021), nor Council’s own policies relating to IWM (Environmental Sustainability Strategy
2016/2026 and Water Saving Feasibility Study 2019).
◼ I note that EPR SW5 references EPA Publication 1739.1 Urban stormwater management guidance
(June 2021) and requires compliance with it. This is the most recent document to inform the
stormwater industry in meeting the requirements of the Melbourne Water Healthy Waterways
Strategy.
Expert witness statement of Warwick Bishop | 12 February 2022
Suburban Rail Loop East Page 24My responses to Monash City Council submissions relevant to my area of expertise are contained in Table 7-1
above.
Monash recommended the EPRs to be amended as follows:
◼ EPR SW1 to be amended to provide further detailed requirements on how EPA Victoria Publications 275
Construction techniques for sediment pollution controls and 1834 Civil construction, building and
demolition guide will be applied to manage sediment and runoff from sites.
◼ EPRs SW1, SW3, SW5 and SW9 be amended to ensure integration with the Monash Planning Scheme
and ensure IWM is considered in stormwater management plans throughout construction and operation.
◼ EPR SW5 to be amended to:
◼ Address how stormwater runoff from the broad precinct will be managed, including station
approaches, carparks, access roads and other hard surfaces.
◼ Be integrated with EPR AR3 (Develop and implement a Tree Canopy Replacement Plan) to enable
runoff to be used to support healthy tree growth and enhance urban cooling.
◼ Be integrated with SW9 to make use of stormwater runoff for fit-for-purpose uses.
◼ EPR GW5 and SW7 to be amended to require SRLA to communicate with Council regarding any
significant observations or detections of changed surface water or groundwater quality, or significant
unexpected changes in surface water flows or groundwater drawdown, for waters within the City of
Monash.
◼ EPR SW8 to be amended to include the naturalisation of Gardiners Creek between Warrigal and Highbury
Roads, to connect to the naturalisation of the creek alongside the Burwood Station (EPR EC5).
◼ EPR SW9 to be amended to:
◼ Require the Project to use innovative and best practice WSUD technologies and IWM approaches,
consistent with EPA Publication 1739.1 and the EPA’s General Environmental Duty.
◼ Require the IWM Strategy to cover the entire precinct, not just the station boxes, and be continuously
reviewed and updated as necessary.
◼ Require the IWM Strategy to refer to the Victorian Government’s IWM Catchment Plans and outline
how the Project will contribute towards the Targets.
◼ Be integrated with EPR AR3 and require the IWM Strategy to consider the mitigation of the urban
heat island effect and added impacts from the loss trees and how WSUD can be incorporated to
provide a water source for replanted vegetation.
◼ Require the IWM Strategy to outline how WSUD and IWM will be integrated into design solutions for
amenity, passive irrigation of garden beds and plantings, cooling of the pedestrian and vehicle
approaches, carparks, places to rest, waiting areas, and the façade or roof of station buildings.
These suggested changes to the EPRs are not warranted, on a technical basis, to achieve a more acceptable
outcome with respect to surface water impacts in the EES. I consider them to be related to broader planning
and strategic goals. Alignment with Council strategies is a desirable outcome in a broad sense.
With respect to stormwater management, EPA Victoria Publications 275, 1834 and 1739.1 are all currently
referenced in the surface water EPRs and will be applied in the design and implementation of the project.
Further enhancements to EPRs are suggested to address issues such as potential urban heat impacts for
development in areas that are currently not intensely developed; Sir William Fry Reserve for example.
Expert witness statement of Warwick Bishop | 12 February 2022
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