Technical Report Flood Mitigation Strategy

Transcription

1 Technical Report Flood Mitigation Strategy Contract No Document No. Document Approval Rev Date Prepared by Reviewed by Approved by Remarks C_01 19/05/2016 J. Beck (AEH) L. Segundo T.Dias CDR for FD Issue D_00 02/06/2016 J. Beck (AEH) L. Segundo T.Dias FD Issue

2 Table of Contents 1 Executive Summary Introduction Description of the Works Scope of this Report Differences between the Draft and the Final Stages Definitions and Abbreviations Design Criteria and Performance Requirements System Requirements Safety Requirements Safety Requirements Design Life Durability Design Criteria and Loadings Peer Review Standards, Codes and Guidelines Agreed Exceptions Identification of Flood Risk Introduction Temporary Site Access Works Construction Staging Assessment of Flood Risk Parramatta Road Civil Site (C10) Implications of Climate Change Consideration of Waterway Structure Blockage Flood Mitigation Measures Site Specific Flood Mitigation Measures Parramatta Road Civil Site (C10) Emergency Response and Evacuation Scour and Energy Dissipation Drainage System Upgrades Mitigation Measures Identified in Environmental Documents Timing and Maintenance Requirements Timing Maintenance Design Integration Cross Discipline Review Integration with Other Stakeholders Consultation Design Compliance Page 2 of 34

3 7.1 Non-Conformances Approvals and Certifications Internal Verification Process Independent Verification and Assurance Independent Certifier, Company and RMS Outstanding issues Hold Schedule Other Issues Sustainability Targets and Initiatives References Annexure A Comments and Responses Register Annexure B Figures Annexure C Requirements Analysis Allocation and Traceability Matrix (RATM) Annexure D Peer Review Tables Table 1: Design Lots... 6 Table 2: Differences between SDD and FD... 7 Table 3: Definitions used within this Report... 7 Table 4: Abbreviations used within this Report... 7 Table 5: Relationship between ARI and AEP... 9 Table 6: Planning Minister s Conditions of Approval Condition B Table 7: Additional Codes, Standards, Technical Publications and Guidelines Table 8: Agreed Exceptions Table 9: Summary of Construction Sites Table 10: Mitigation Measures referred to in Table 8.1 of Condition A2(c) Table 11: Identified Non-Conformances Table 12: Design Approval and Certification Requirements Page 3 of 34

4 1 Executive Summary This technical report addresses the Planning Minister s Conditions of Approval B14 (Flood Mitigation Strategy). To facilitate the proposed construction program, the Flood Mitigation Strategy Report has been split into five (5) stages, which will be covered under separate technical reports: Flood Mitigation Strategy Report Permanent Works: M4E-AEH-TR Flood Mitigation Strategy Report - HBD Temporary Works: M4E-AEH-TR Flood Mitigation Strategy Report - CR Temporary Works: M4E-AEH-TR Flood Mitigation Strategy Report - WS Temporary Works: M4E-AEH-TR Flood Mitigation Strategy Report - PR Temporary Works: M4E-AEH-TR The content of this report relates specifically to the Zone 50 construction site - Parramatta Road (C10). Details of Condition B14 are listed in Table 6, which also identifies the relevant sections of this report that deal with each individual clause of that Condition. This Flood Mitigation Strategy Report provides a summary of the flood assessments undertaken for the temporary works in Zone 50 as well as a discussion on proposed mitigation measures to meet Condition B14. Details of the development and validation of the hydrologic and hydraulic models that were used to undertake the assessments are discussed in detail in the M4E Hydrology and Flooding Design Report (Document No M4E-AEH-TR ). The flood impact assessment considers both the temporary site access works as well as construction staging. The flood risk assessment is documented in Section 4. Under existing conditions Parramatta Road is affected by local overland flows draining to the low point on Parramatta Road just north of Chandos Street. The existing drainage system on Parramatta Road has limited capacity. Stormwater runoff from the eastern side of Parramatta Road overtops the kerb along the westbound carriageway and heads in a north-westerly direction through private properties towards the Sydney Water trunk drainage network. The remaining runoff heads north along Parramatta Road towards Bland Street and south to Chandos Street. The portion of Parramatta Road Civil Site between Chandos Street and Orpington Street is not flood affected. The flood impact assessment as documented in this report has considered both the temporary site access works as well as Traffic Staging Stage 1. Gaps in the temporary traffic barriers and hoarding along Parramatta Road have been proposed to minimise flood impacts to Parramatta Road and surrounding properties. Flood impacts are confined to Parramatta Road, Chandos Street and Bland Street. No adjoining properties will be adversely affected. Flood impacts of up to 0.1 m are estimated around the site entry and exit on Chandos Street and Bland Street. These are within the temporary works boundary and only affect a small area. These impacts will be reduced once the construction staging commences, in particular the excavation of the cut and cover as the storage effect of the excavation would attenuate flows. A key consideration for flooding during the construction staging for the Parramatta Road site is the management of the overland flow path that crosses the site to the north-west of Chandos Street. Measures to manage that overland flow path will need to be implemented in the first stages and carried through construction. Therefore later construction stages are considered unlikely to change the required flood mitigation measures as documented in this report. Mitigation measures developed for the construction site in Zone 50 are documented in Section 5. Page 4 of 34

5 2 Introduction The WestConnex M4 East is being designed and constructed by the CPB Contractors (ABN ) Samsung (ABN ) John Holland (ABN ) Joint Venture (CSJ JV). The purpose of this report is to document the flood impact assessments and to provide supporting information which has been applied during the development of the design. This report has been prepared by AECOM Hyder Joint Venture (AEH) on behalf of CSJ JV. 2.1 Description of the Works The M4 East will comprise two new, three lane carriageways (Main Carriageway, Eastbound or Eastbound Carriageway and Main Carriageway Westbound or Westbound Carriageway), generally beneath Parramatta Road (together the Main Carriageways ). The Main Carriageways will be constructed between the eastern end of the M4 West Motorway near Homebush Bay Drive and the City West Link and Parramatta Road at Haberfield. 1 The Main Carriageway Eastbound will be provided with: a b c d e f g A connection from the M4 West Motorway eastbound A western tunnel portal between Homebush Bay Drive and Concord Road Access from Homebush Bay Drive A ramp from Concord Road A ramp to the City West Link (Wattle Street / Dobroyd Parade) northbound A ramp to Parramatta Road eastbound with the ramp portal located between Wattle Street and Dalhousie Street Provisions for a future, uninterrupted, three lane connection to the future M4 South, located in the vicinity of Parramatta Road and Wattle Street at Haberfield. 2 The Main Carriageway Westbound will be provided with: a b c d e f g Provisions for a future, uninterrupted, three lane connection from the future M4 South, located in the vicinity of Parramatta Road and Wattle Street at Haberfield A ramp from Parramatta Road westbound with the ramp portal located between Wattle Street and Dalhousie Street A ramp from City West Link (Wattle Street / Dobroyd Parade) southbound A ramp to Concord Road A direct connection to the M4 Motorway westbound near Parramatta Road Access to the Homebush Bay Drive A connection to the M4 West Motorway westbound between Homebush Bay Drive and Concord Road. The project has been split into five geographical zones for delivery purposes. The zones are split as follows and shown below: Zone 00 (General Wide) Zone 10 Tunnels Zone 20 Homebush Bay Drive Interchange Zone 30 Concord Road Interchange Zone 40 Wattle Street Interchange Zone 50 Parramatta Road Interchange Page 5 of 34

6 Zone 60 (Mechanical and Electrical) Figure 1: Schematic showing M4 East zones 2.2 Scope of this Report This Technical Report has been prepared in accordance with the WestConnex M4 East Design and Construction Deed Clause 13 and SWTC Appendix C.2 Clause 3 and in accordance with CSJ Design Management Plan M4E-LSJ MP _B_00. The scope of works covered by this technical report relates specifically to the Planning Minister s Conditions of Approval B14 (Flood Mitigation Strategy). To facilitate the proposed construction program, the Flood Mitigation Report has been split into five (5) stages, which will be covered under separate technical reports: Flood Mitigation Strategy Report Permanent Works: M4E-AEH-TR Flood Mitigation Strategy Report - HBD Temporary Works: M4E-AEH-TR Flood Mitigation Strategy Report - CR Temporary Works: M4E-AEH-TR Flood Mitigation Strategy Report - WS Temporary Works: M4E-AEH-TR Flood Mitigation Strategy Report - PR Temporary Works: M4E-AEH-TR This technical report describes the assessment of flood risk and development of mitigation measures undertaken for the proposed temporary works in Zone 50 (Parramatta Road Civil Site), and includes the lot numbers listed in Table 1. Table 1: Design Lots Lot Number Description Comment Flood Mitigation Strategy Flood mitigation strategy for Parramatta Road (Zone 50) temporary works Page 6 of 34

7 2.3 Differences between the Draft and the Final Stages Table 2 describes the differences between the SDD and FD Report. Table 2: Differences between SDD and FD Location Difference Reason for the Difference N/A - Not issued at SDD 2.4 Definitions and Abbreviations Table 3: Definitions used within this Report Term The Contractor Company Existing Conditions Design Conditions Afflux Floodplain Temporary Works Description CPB Samsung John Holland Joint Venture WCX M4 Pty Limited Conditions representing the pre-m4 upgrade (also referred to as Base Case) Conditions representing the post-m4 upgrade (also referred to as Design Case) The rise in water level on the upstream side of a constriction in a stream or channel relative to the water level on the downstream side (Austroads Glossary of Terms, 2015) Area of land which is subject to inundation by floods up to and including the probable maximum flood event. Any temporary physical works required for the purpose of the carrying out of the Contractor's Activities, but which does not form part of the Works including any such works specified in Section 3.4A of the SWTC and including, to the extent relevant to such works, Changes directed in accordance with the Deed. Table 4: Abbreviations used within this Report Abbr. AEH AEP AHD ARI BoM CDR CEMP CH CR CSJ JV DxV EB EIS EY Description AECOM Hyder Joint Venture Annual Exceedance Probability Australian Height Datum Average Recurrence Interval Bureau of Meteorology Cross Discipline Review Construction Environment Management Plan Chainage Concord Road CPB Samsung John Holland Joint Venture Depth-Velocity Product Eastbound Environmental Impact Statement Exceedances per Year Page 7 of 34

8 Abbr. FD GIS HBD HHWSS IC IFC LGA LoS CSJ M&E MCoA M4E MGA NB O&M OSD PMF PR PRVF RCBC RCP RMS RTM SB SiD SSI SWTC WB WS Description Final Design Geographic Information Systems Homebush Bay Drive High High Water Solstices Springs Independent Certifier Issued for Construction Local Government Area Level of Service CPB Samsung John Holland Joint Venture Mechanical & Electrical Minister s Conditions of Approval M4 East Map Grid of Australia Northbound Operations & Maintenance On-site Detention Probable Maximum Flood Parramatta Road Parramatta Road Ventilation Facility Reinforced Concrete Box Culvert Reinforced Concrete Pipe Roads and Maritime Services Requirements Traceability Matrix Southbound Safety in Design State Significant Infrastructure Scope of Work and Technical Criteria Westbound Wattle Street It should be noted that this report uses the Average Recurrence Interval (ARI) terminology when discussing design flood events. The latest draft of the new edition of Australian Rainfall and Runoff (AR&R) recommends the use of the Annual Exceedance Probability (AEP) and Exceedances per Year (EY) terminology. However, the term ARI was used for simpler comparison to older flood studies in particular for minor storm events. The two terms are defined as follows: Annual Exceedance Probability (AEP) - the probability of an event occurring or being exceeded within a year. Average Recurrence Interval (ARI) the average period between occurrences equalling or exceeding a given value. The relationship between ARI and AEP is summarised in Table 5. Page 8 of 34

9 Table 5: Relationship between ARI and AEP ARI (years) AEP (%) Page 9 of 34

10 3 Design Criteria and Performance Requirements 3.1 System Requirements There are two types of system requirements that have been identified for managing the design and implementation of this design component. System requirements that can be verified and validated have been categorised as Technical Requirements, while the remaining system requirements achieved through a process are classified as Process Requirements. Contract clauses classified as Information, Advice or Commercial (i.e. they are background details or non-engineering requirements) have not been included in the Technical or Process system requirements outlined above. The Technical Requirements form the design to criteria and the baseline against which CSJ can verify compliance, and provide validation of the implemented systems. The Process Requirements are linked to process documentation such as the relevant management plans, management meeting minutes, Risk Assessments (RA), audits etc, in order to satisfy compliance. During this design stage, these system requirements have been developed and where available, design verification evidence against these requirements is included in Annexure C Requirements Analysis Allocation Traceability Matrix (RTM). 3.2 Safety Requirements In addition to the safety requirements derived from the Deed and SWTC, a number of risk workshops and Safety in Design (SiD) workshops have been carried out on the design to date. The subsequently generated safety requirements have been analysed and addressed through the SiD process and actions identified within this report. Verification and validation of these safety requirements will be incorporated into the Matrix as works progress. 3.3 Safety Requirements In addition to the safety requirements derived from the Deed and SWTC, a number of risk workshops and Safety in Design (SiD) workshops have been carried out on the design to date. The subsequently generated safety requirements have been analysed and addressed through the SiD process and actions arising are identified in the M4E Hydrology and Flooding Report (M4E-AEH-TR ).Verification and validation of these safety requirements will be incorporated into the Matrix as works progress. 3.4 Design Life All assets designed as part of this package are in accordance with the minimum design life specified in SWTC Appendix B.13 and as per the Durability Report (M4E-AEH-RP ). 3.5 Durability Not applicable to this design lot. Page 10 of 34

11 3.6 Design Criteria and Loadings The design described in this report has been prepared in accordance with the Deed and the SWTC. The Planning Minister s Conditions of Approval (MCoA) include several conditions related to flooding. This report relates specifically to Condition B14, with details as summarised in Table 6. Table 6: Planning Minister s Conditions of Approval Condition B14 Clause Description of requirement Comment B14 B14 (a) B14 (b) B14 (c) B14 (d) B14 (e) B14 (f) The Flood Mitigation Strategy must be designed to ensure that the SSI (State Significant Infrastructure), where feasible and reasonable, does not worsen existing flooding characteristics in the vicinity of the SSI during construction and operation. The Flood Mitigation Strategy must include but not be limited to: the identification of flood risks to the SSI and adjoining areas, including further modelling and the consideration of local drainage catchment assessments, and climate change implications on rainfall and drainage characteristics. This must consider blockages of waterway structures from floating debris in its flood level modelling; the identification of design and mitigation measures that would be implemented to protect proposed operations and not worsen existing flooding characteristics within and in the vicinity of the SSI boundary during construction and operation, including soil erosion and scouring; consideration of limiting flooding characteristics to the following levels: (i) a maximum increase in inundation time of one hour in a 100 year ARI rainfall event; (ii) a maximum increase of 10 mm in inundation at properties where floor levels are currently exceeded in a 100 year ARI rainfall event; (iii) a maximum increase of 50 mm in inundation at properties where floor levels would not be exceeded in a 100 year ARI rainfall event; and (iv) no inundation of floor levels which are currently not inundated in a 100 year ARI rainfall event, or else provide alternative flood mitigation solutions consistent with the intent of these limits; the processes and actions committed to in the mitigation measures referred to in conditions A2(b) and A2(c) the identification of measures to be implemented to minimise scour and dissipate energy at locations where flood velocities are predicted to increase as a result of the SSI and cause localised soil erosion or scour; identification of drainage system upgrades including those upgrades considered as mitigation measures and identified during the process This report Refer to Sections 4.2 for assessment of flood risk. Refer to Section 4.3 for climate change assessment. Refer to Section 4.4 for blockage assessment. Refer to Section 5 Refer to Section 4.2 Refer to Section 5.5 Refer to Section 5.3 Refer to Section 5.4 Page 11 of 34

12 Clause Description of requirement Comment B14 (g) B14 B14 outlined in condition B20 identification of the timing and maintenance requirements responsibility of any necessary works The Flood Mitigation Strategy must be prepared by a suitably qualified and experienced person in consultation with directly affected landowners, Sydney Water, OEH and relevant councils. The Flood Mitigation Strategy must be peer reviewed and confirmed as meeting the requirements of this condition by a suitably qualified and experienced independent hydrological engineer. Conditions A2(b) and A2(c) refer to: Refer to Section 5.6 Refer to Section Refer Section and Annexure C A2(b): M4 East Environmental Impact Statement (EIS) Volumes 1A, 1B, 2A, 2B, 2C, 2D, 2E, 2F, 2G and 2H prepared by AECOM Australia Pty Ltd and GHD Pty Ltd, dated September 2015 A2(c): M4 East Submission Report Volumes 1A, 1B and 2 (WestConnex, 2015) Condition B20 refers to Stormwater Drainage: The Proponent must undertake further hydrological and hydraulic modelling based on the detailed design of the SSI to determine the ability of the receiving drainage systems to effectively convey pavement drainage from the SSI. The modelling must be undertaken in consultation with relevant council(s) and the outcomes documented in a Stormwater Drainage Report. The Stormwater Drainage Report must: (a) confirm the location, size and capacity of all drainage basin structures associated with the operation of the SSI; (b) assess the potential impacts of pavement drainage discharges from the SSI drainage systems on the receiving environment including the hydrology (water quality and quantity) of receiving waterways, riparian vegetation, aquatic ecology and property; (c) identify all feasible and reasonable mitigation measures to be implemented where pavement drainage from the SSI drainage systems is predicted to adversely impact on the receiving environment; (d) where pavement drainage from the SSI flows to a council stormwater drainage system, confirm the location of the cross drainage point and, where available, use drainage information obtained from the relevant council, to - i. confirm the capacity of the council s drainage system and its ability to receive and convey the flows, ii. identify any consequent upstream and downstream impacts on cross drainage infrastructure capacity, iii. assess the impacts on the receiving environment at the final outflow point resulting from any additional flow volume (including, but not limited to, scour, flooding, water quality impacts, and impacts on riparian vegetation, aquatic ecology and property), and iv. identify all feasible and reasonable mitigation measures to be implemented where increased flows through cross drainage systems adversely impact on council drainage infrastructure and the receiving environment; and (e) set out a clear time frame for the implementation of mitigation measures. The Stormwater Drainage Report must be submitted to the Secretary at least four weeks prior to the commencement of any new drainage works, modifications to existing drainage works, or construction of hard Page 12 of 34

13 surfaces that would result in runoff to existing stormwater drainage systems, unless otherwise agreed by the Secretary Peer Review The Planning Minister s Conditions of Approval Condition B14 requires The Flood Mitigation Strategy must be peer reviewed and confirmed as meeting the requirements of this condition by a suitably qualified and experienced independent hydrological engineer. AEH have nominated a suitably qualified and independent hydrological engineer from AECOM who has not been involved in the design development for this to undertake this review which is documented in Annexure C. 3.7 Standards, Codes and Guidelines The Design has as a minimum been designed in accordance with the Codes and Standards referred to in Section 3.16 of the SWTC and in accordance with the order of precedence set out in SWTC Section 2.4. Additional Design Standards and Codes, Technical Publications and Guidelines not referenced as above and relevant to this design package are listed in Table 7. Table 7: Additional Codes, Standards, Technical Publications and Guidelines Reference AR&R BoM GSDM NSW Floodplain Development Manual Title Engineers Australia: Australian Rainfall and Runoff, 3 rd Edition (1987, with 1998 updated Book VI) The Estimation of Probable Maximum Precipitation in Australia: Generalised Short-Duration Method NSW Floodplain Development Manual The Management of Flood Liable Land, Department of Infrastructure, Planning and Natural Resources, April Agreed Exceptions In some cases SWTC requirements have required exception or clarification via RFIs. These have been agreed with the Company and this section of the report identifies those relevant to this design package. For this package there are no agreed exceptions or clarifications at this design stage. A number of exceptions have been agreed during the tender evaluation process and have been included in SWTC Appendix B.1. Agreed exceptions from Appendix B.1 specific to this design lot are listed in Table 8. Table 8: Agreed Exceptions Item SWTC App B.1 Item Reference Agreed Exception 1 11 SWTC Appendix B.7, (Drainage), section 5 (Pavement Surface Drainage) Locations: Wattle Street low points Parramatta Road low points Both within Wattle Street and Parramatta Road large amount of runoff from external source approaches the project work areas inundating the roadway low point during heavy rainfall events. Page 13 of 34

14 Item SWTC App B.1 Item Reference Agreed Exception For this item, amend SWTC Appendix B.7 (Drainage), Section 5 (Pavement Surface Drainage), item (b) as follows: Add the words except within the Wattle Street and Parramatta Road low points after more than 1metre Page 14 of 34

15 4 Identification of Flood Risk 4.1 Introduction The M4 Motorway and connecting roads cross various creeks and their associated floodplains as well as numerous council drainage lines and Sydney Water stormwater trunk mains (refer Figure A.1 in Annexure B for a map of the study area). The flood behaviour in these areas affects the design, particularly around the proposed tunnel portals. Hydrologic and hydraulic models have been developed for those areas of the SSI that are flood affected during both construction and operation of the SSI. The development and validation of the hydrologic and hydraulic models is discussed in detail in the M4E Hydrology and Flooding Design Report (Document No M4E-AEH-TR ). That technical report informs the design development of temporary and permanent works and documents the flood impact assessment associated with the works. This Flood Mitigation Strategy Reports provide a summary of the flood assessments documented in the Hydrology and Flooding Report as well as a discussion on proposed mitigation measures to satisfy Condition B14. There are nominally 10 temporary construction sites (C1 to C10) for this project (refer Table 9), some of which comprise both tunnel and civil sites. Flood impact assessments have been undertaken for each site. This particular Flood Mitigation Strategy Report covers the temporary works within Zone 50 (ie site C10 only) which extends from Bland Street to Dalhousie Street (refer Figure A.2). Table 9: Summary of Construction Sites Site ID Site Name Zone C1 Homebush Bay Drive civil site 20 C2 Pomeroy Street civil site 20 C3 Underwood Road (tunnel ** and civil compound) 20 C4 Powells Creek civil site 30 C5 Concord Road (tunnel ** and civil compound) 30 C6 Cintra Park tunnel site ** 30 C7 Northcote Street tunnel site ** 40 C8 Parramatta Road ventilation facility (PRVF) 40 C9 Wattle Street civil site 40 C10* Parramatta Road civil site 50 *: Subject of this report; **: Part of Zone 10 Tunnels, but included in Zone 20/30/40 design package due to its geographical location Temporary Site Access Works The flood impact assessment covers the temporary site access works, which include features such as site access and haul roads, hardstand areas (eg for laydown and parking), acoustic sheds, noise walls, sediment control basins and drainage infrastructure. These features will be in place for most of the duration of the construction activities (2 to 3 years). Temporary Site Access Design packages have been developed for each construction site. Summaries of the flood impact assessments have been included in those design packages and mitigation measures have been incorporated into the design. Page 15 of 34

16 The design package for the Parramatta Road Temporary Site Access Works (C10) is currently at Substantial Detailed Design (SDD) stage. The flood impact assessment has been based on the SDD designs for that package Construction Staging The construction staging works involve traffic staging along Parramatta Road and staging of permanent works such as the cut and cover. The staging works were still under development at the time of submission of this report, except for Stage 1, which is at SDD stage. However, it was identified that the key consideration for flooding during the construction staging for the Parramatta Road site is the management of the overland flow path that crosses the site to the north-west of Chandos Street. Measures to manage that overland flow path will need to be implemented in the first stages and carried through construction. Therefore later construction stages are considered unlikely to change the required flood mitigation measures. As the staging works are being developed further flood impact assessments will be undertaken to identify flood risks and additional mitigation measures if required. Flood mitigation measures identified for the staging works are being documented in the Construction Staging Temporary Works Design packages. The individual stages will typically be in place for a relatively short duration (less than one year). Therefore the probability of a major flood event occurring during each construction stage is less compared to the longer duration site access works and permanent works. A preliminary assessment of the flood impacts associated with the construction staging is included in this submission of the report, including the Stage 1 works. 4.2 Assessment of Flood Risk The Parramatta Road construction site is located in the Iron Cove Creek catchment but the site is not in the immediate vicinity of the creek and not affected by creek flooding. The catchment draining to Chandos Street from the east is approximately 4.2 ha and the critical storm duration is estimated to be 25 minutes. The Parramatta Road site generally experiences short duration flooding (ie hours, not days), but would also have relatively short flood warning times Parramatta Road Civil Site (C10) Existing Conditions Under existing conditions, Parramatta Road is affected by local overland flow approaching the road from the east, with a relatively large catchment (4.2 ha) draining to the intersection of Chandos Street and Parramatta Road. This flow then drains to the existing low point on Parramatta Road just north of Chandos Street. The existing drainage system on Parramatta Road has limited capacity with only a 600 mm diameter pipe draining the low point. Stormwater runoff from the eastern side of Parramatta Road then overtops the kerb along the westbound carriageways and heads in a north-westerly direction through private properties towards the Sydney Water trunk drainage network (refer to Figure B.1). The remaining runoff heads north along Parramatta Road towards Bland Street and south to Chandos Street Flood Risk Associated with the Proposed Temporary Site Access Works The temporary site access works proposed for the Parramatta Road site that could potentially affect flooding include: Noise walls and hoarding The Parramatta Road site is generally not flood affected except for the overland flow path around Chandos Street (refer Figure B.1). This flow path would be managed through local stormwater measures during construction. Page 16 of 34

17 Hoarding would be put up along Parramatta Road which would potentially block the overland flows. Flaps in the hoarding are therefore proposed along a 25 m section of the hoarding to mitigate flood impacts on Parramatta Road and adjoining properties, in particular the child care centre at the corner of Chandos Street and Parramatta Road (refer Figure C.1). This would allow flows to overtop the kerb and enter the site similar to existing conditions. Temporary noise walls are proposed along the western boundary of the site between the site and adjoining properties. These would block the overland flows that enter the site from Parramatta Road. Flows would then need to be managed within the site. Flows would run along the haul road towards the north of the site during larger flood events. The driveway to the apartment block at 98 Chandos Street will be relocated as part of the early works to enable the haul road to be built. The drainage system along the driveway to 98 Chandos Street will be replaced as part of those early works. The driveway will be constructed at a slightly higher level than the existing road level on Chandos Street to suit the ultimate interchange ramps. The driveway will need to be temporarily tied in to the existing Chandos Street level. This would block the northern kerb of Chandos Street at the driveway and potentially block flows coming down Chandos Street. To minimise flood impacts a small temporary 150 mm diameter drainage pipe is proposed under the driveway access along Chandos Street. Site facilities would be located near the southern end of the site at the intersection of Parramatta Road and Orpington Street. These are remote from any major overland flow paths. The flood assessment shows that there would be flood level impacts of up to 0.03 m outside the project boundary on Chandos Street. No properties would be adversely affected (refer Figure C.1). There would be flood impacts up to 0.1 m on Chandos Street near the new driveway for 98 Chandos Street, but these are very localised within the temporary works boundary and they will not lead to flood impacts on adjoining properties. These impacts would also be reduced as soon as Temporary Traffic Staging Stage 1 is implemented (refer Section ). Minor flood impacts of up to 0.02 m are estimated on Parramatta Road, but these are within the 0.05 m allowable limit. The flood modelling also shows impacts of up to 0.1 m on Bland Street at the construction site exit. This area is already flood affected under existing conditions. The estimated flood impacts are confined to the temporary works boundary and are very localised around a short section (20m) of footpath and road. The impact is less in smaller flood events and would be reduced once the excavation for the cut and cover commences as the storage effect of the excavation would attenuate flows. Inundation times have been checked as the proposed works affect overland flows. In particular the inundation times on Parramatta Road were investigated but the provision of flaps in the hoarding would maintain flow paths similar to existing conditions. This would mean that inundation times in the 100 year ARI would be very similar to existing conditions (refer Figure 2). Page 17 of 34

18 Figure 2: Inundation times at Parramatta Road for temporary site access works 100 year ARI Flood Risk Associated with the Proposed Temporary Traffic Staging The initial traffic staging works along Parramatta Road were at SDD stage at the time of submission of this report and the flood impact assessment associated with those works are discussed below. In addition to the temporary site access works, the construction works proposed for the Parramatta Road site during Temporary Traffic Staging - Stage 1 that could potentially affect flooding include: Temporary traffic barriers Temporary median Following the site establishment, temporary concrete traffic barriers will be placed on Parramatta Road reducing the road to two lanes each way instead of the existing three lanes. This will enable the start of the excavation for the cut and cover to the south of Parramatta Road. A 25 m gap in the concrete barriers is proposed to coincide with the flaps in the hoarding (refer Section above). Thrie-beam barriers or similar will be placed along that gap for traffic safety. Between the barriers and the hoarding a shallow drain is proposed to prevent the overland flows from ponding between the barriers and the hoarding and direct flows to existing/temporary drainage pits along Parramatta Road. Temporary traffic barriers will also be placed across Chandos Street. These also require gaps to maintain the overland flow path along Chandos Street until some of the permanent drainage along Parramatta Road can be constructed. The existing narrow concrete median along Parramatta Road will also be shifted north to facilitate the changed traffic conditions. The height of the temporary median will be set at 130 mm so that the median is no higher than the existing median. This will maintain similar overtopping levels along Parramatta Road. Page 18 of 34

19 The existing drainage system along the westbound carriageway (consisting of a single 225 mm diameter pipe connecting to the 600 mm diameter pipe running down Chandos Street) will be relocated during Stage 1. A new 225 mm diameter pipe will be provided which will run underneath the new drain located behind the traffic barrier. During storm events up to the 1 year ARI, flows do not overtop the kerb at Parramatta Road under existing conditions and there would only be minor ponding on Parramatta Road at the low point near Chandos Street. Flows start overtopping the kerb between the 1 and 2 year ARI. A similar flow regime would be maintained during construction by providing openings in the traffic barriers and hoarding. The Parramatta Road site would therefore only receive overland flows in events greater than a 1 year ARI. The flood impact assessment has shown that impacts would be similar to those under the temporary site access conditions, but there would be no flood level impacts outside the project boundary (refer Figure C.2). The proposed temporary barriers on Chandos Street would hold back some of the overland flows. Minor flood impacts of up to 0.04 m are estimated on Parramatta Road, but these are within the 0.05 m allowable limit. Similar flood impacts are estimated at Bland Street to those already discussed in Section Inundation times have been checked as the proposed works affect overland flows. The inundation times were found to be very similar to those estimated under the temporary site access works (see Figure 3). Construction Staging following Temporary Traffic Staging - Stage 1 Once the excavation for the cut and cover commences, some of the overland flows would drain into the excavation. The stormwater will then need to be pumped out and treated before discharge to the local drainage system. The excavation would provide some attenuation to flows by providing temporary storage. The overland flows through the site at Chandos Street will need to be maintained until some of the new permanent drainage systems along Parramatta Road are built. The new drainage system would not be built before the new permanent OSD basin at Chandos Street is constructed. The new OSD minimises flood impacts to properties along Chandos Street associated with the diversion of flows from Parramatta Road. It is therefore likely that flood impacts following the commencement of the excavation and construction of new drainage system on Parramatta road would be no worse than those assessed for Temporary Traffic Staging - Stage 1. Page 19 of 34

20 Figure 3: Inundation times at Parramatta Road Stage 1 temporary traffic staging 100 year ARI 4.3 Implications of Climate Change Condition B14 requires an assessment of the risk of climate change to the project. The assessment of two climate change scenarios has been prescribed in the SWTC. Considering the short-term nature of the temporary works (duration of construction up to 3 years) and the planning horizon for climate change (greater than 10 years), a climate change impact assessment for temporary works is not deemed applicable. Climate change assessments for permanent works are documented in the Flood Mitigation Strategy Report for the permanent works (M4E-AEH-TR ). 4.4 Consideration of Waterway Structure Blockage Condition B14 requires the consideration of blockage of waterway structures from floating debris. There are no open channels in the vicinity of the Parramatta Road site. As such blockage of waterway structures from floating debris is not considered relevant to this site. Page 20 of 34

21 5 Flood Mitigation Measures Possible flood mitigation measures for the temporary work sites have been identified based on the flood model results for the temporary works sites in Zone 50. These are discussed in more detail below. The design measures listed in Section 5.1 have been included in the design package drawings associated with each site. Management measures such as clearing of waterways or storage material outside of flood zones will be implemented in the Contractor s Construction Environmental Management Plan (CEMP) and Incident Response Plan (refer Section 5.2). 5.1 Site Specific Flood Mitigation Measures Parramatta Road Civil Site (C10) The proposed mitigation measures to manage potential impacts and the risk of flooding at the Parramatta Road site for the temporary access works and Stage 1 temporary traffic staging include: The proposed site facilities will be located at the southern end of the site at the intersection of Parramatta Road and Orpington Street. These are remote from any major overland flow paths. A minimum 25 m section without solid concrete safety barriers is required along the westbound carriageway of Parramatta Road near Chandos Street to maintain overland flow paths. Thrie-beam barriers or similar will be provided for traffic safety. Flaps along a minimum 25 m section in the temporary hoarding along Parramatta Road near Chandos Street would need to be provided. A minimum 1 m gap is required between the kerb and edge of barrier on Chandos Street to maintain overland flow paths. The top level of the temporary median would be set at 130 mm so match the existing median height to maintain overtopping levels. A 150 mm drainage pipe will be provided across the temporary connection of the driveway to Chandos Street for the apartment block on 98 Chandos Street to maintain the flow path along Chandos Street. Construction Staging following Temporary Traffic Staging - Stage 1 Overland flows draining into the cut and cover excavation will then need to be pumped out and treated before discharge to the local drainage system. New permanent drainage systems at the intersection of Parramatta Road and Chandos Street will need to be built in conjunction with the new permanent OSD at Chandos Street to minimise flood level impacts along Chandos Street. 5.2 Emergency Response and Evacuation Weather conditions in the vicinity of site C10 will need to be monitored with sufficient warning of impending flood producing rain or severe weather warnings disseminated to all construction personnel on site so they can implement precautionary measures and relocate any mobile equipment stored on site outside the overland flow paths where possible. A flood emergency response procedure is being developed based on the five Flood Mitigation Strategy reports to remove construction materials, such as mobile equipment where required/possible when severe weather warnings are issued for the area and to provide staff evacuation plans. This will be documented in the Contractor s Incident Response Plan (M4E-LSJ MP ). Flood warning times would likely be short as the catchment response is fast (the critical storm duration is estimated to be 25 minutes for the site). This would limit how much equipment could be moved out of the floodplain during an event and could have implications for safety of construction staff and the public in the vicinity of the works. While the catchment response may be short, the Bureau of Meteorology (BoM) Severe Page 21 of 34

22 Weather Warnings are generally issued at least a day in advance, which would allow precautionary action to be taken. Therefore emphasis should be on implementing some precautionary actions based on the Severe Weather Warnings rather than responding during the actual events. Monitoring weather conditions is covered in the Construction Environmental Management Plan (CEMP) Soil and Water Management Plan (M4E-ES-PLN-PWD-00242). 5.3 Scour and Energy Dissipation Clause (e) of Condition B14 requires the identification of mitigation measures to reduce scour where flood velocities are estimated to be increased as a result of the SSI. This assessment is detailed in the sections below. Temporary sediment and erosion controls on construction sites to manage site runoff do not form part of this assessment. These are documented in the CEMP and Temporary Site Access Works packages. Overland flow velocities for Zone 50 are generally less than 0.5 m/s in the 100 year ARI, but at the low point on Parramatta Road the overtopping velocities are as high as 1.5 m/s under existing conditions. These velocities together with flood depths of up to 0.5 m create a significant flood hazard on Parramatta Road under existing conditions. Overland flow velocities would generally only be changed through the construction site as a result of changes to overland flow paths and potential erosion within the construction site will be managed through the temporary sediment and erosion controls. No additional scour measures are considered necessary or proposed. 5.4 Drainage System Upgrades Condition B20 requires the assessment of potential impacts where the proposed pavement drainage systems would connect to council s existing drainage system. Assessments for Condition B20 will be documented as part of the Temporary Site Access Works packages for construction works and Drainage Design Reports for permanent works. For the temporary access site works and temporary traffic staging in Zone 50 there would be adjustments to the local drainage system required along Parramatta Road and Chandos Street, including new driveway drainage for the apartment block at 98 Chandos Street. The proposed temporary drainage system has been designed to generally convey flows to the existing drainage system at the intersection of Parramatta Road and Chandos Street. Under existing conditions some overland flows drain towards Chandos Street and by continuing the majority of overland flows through the site, the existing drainage patterns are mostly being maintained. No drainage system upgrades are required for flood mitigation due to temporary works. 5.5 Mitigation Measures Identified in Environmental Documents Condition B14 Clause (d) requires the consideration of the processes and actions documented in Condition A2(b) and A2(c), which refer to the M4 East Environmental Impact Statement (EIS) and the M4 East Submission Report. These documents outline flood mitigation measures for permanent and temporary works. Condition A2(c) is the most recent document and provides the revised environmental management measures for the in Chapter 8 of that report. The relevant flood related management measures have been extracted from the M4E Submissions Report and are summarised in Table 10 together with mitigation measures developed as part of the M4E detailed design process. The mitigation measures that have been developed for the Zone 50 construction works are generally in line with mitigation measures identified in Condition A2(c). Page 22 of 34

23 Table 10: Mitigation Measures referred to in Table 8.1 of Condition A2(c) Ref * Location Possible Mitigation Measures Identified in Condition A2(c) FD01 FD04 Management of flood and stormwater General Impacts of future climate change on flooding behaviour A flood management strategy (FMS) will be prepared to manage flooding and stormwater related issues and will include: (i) The layout of construction ancillary facilities (ii) Location of amenities buildings and equipment outside high flood hazard areas (iii) Controlled diversion of overland flow either through or around work areas (iv) Staging construction to limit the extent and duration of temporary works on the floodplain (v) Monitoring weather conditions (vi) Ensuring construction equipment and materials are removed from floodplain areas at the completion of each work activity, or upon issuing of a weather warning of impending flood producing rain (vii) Provision of temporary flood protection for properties identified as being at risk of adverse flood impacts during any stage of construction of the project (viii) Development of flood emergency response procedures to remove temporary works during periods of heavy rainfall and staff evacuation plans (ix) For site facilities located within the floodplain, the FMS will identify how risks to personal safety and damage to construction facilities will be managed. The project will be designed to manage the potential impacts due to climate change in accordance with the Practical Considerations of Climate Change Floodplain Risk Management Guideline (DECC Proposed Mitigation Measures Developed as Part of the Detailed Design Process The Flood Mitigation Strategy deals with flooding issues only. Stormwater issues are documented in the individual Temporary Site Access Works design packages for temporary works and Drainage Design packages for permanent works. (i) Provided in figures in Annexure B (ii) Stationary equipment not included. Site amenities will be located outside flood affected areas (refer Section ) (iii) Refer Section , (iv) Not applicable. This site is not located within a floodplain area, it is only affected by local overland flows. (v) Refer to Section 5.2 (vi) Construction equipment and materials will be removed as soon as practical after completion of works in an area. Refer also Section 5.2 (vii) Refer Section 5.1 (viii) Refer Section 5.2 (ix) Refer Section 5.2 Refer Section 4.3 Page 23 of 34

24 Ref * Location Possible Mitigation Measures Identified in Condition A2(c) 2007). Proposed Mitigation Measures Developed as Part of the Detailed Design Process FD18 Scour prevention Measures will be implemented and maintained to intercept concentrated flow and divert it in a controlled manner to prevent scour of disturbed surfaces and transportation of sediment and construction materials. This is covered in the individual Temporary Site Access Works packages for each construction site *: As per Table 8.1 of the M4E Submissions Report 5.6 Timing and Maintenance Requirements Timing The mitigation measures identified in this report for the Zone 50 construction site will be implemented during the establishment of the temporary site access works Maintenance Whilst the temporary construction sites are operational it is recommended that a visual inspection of the temporary stormwater system is undertaken regularly. It is paramount that the drainage systems are maintained, especially before and after a storm event, to allow them to function efficiently. Maintenance activities would include: Removing any debris from pit grates Keeping swale and catch drains free from vegetation and debris Removing any debris that will stop the flaps functioning at the bottom of noise walls Assessing any structural damage to pits during construction Keeping open channels free from vegetation and debris Inspections and clean up after storms Clearing slots in barriers. Page 24 of 34

25 6 Design Integration 6.1 Cross Discipline Review A cross discipline review (CDR) has been undertaken on this design package by design and construction team discipline leaders to verify appropriate integration of other disciplines design components prior to submission to IC and the Company. 6.2 Integration with Other Stakeholders Design integration will be documented in the individual design packages Consultation Consultation with councils and agencies commenced in late February A meeting with Council of the Municipality of Ashfield to discuss staging of the Flood Mitigation Strategy Reports and requests for council flood study information was held on 16 March The draft report will be provided for comment to: Council of the Municipality of Ashfield Sydney Water Office of Environment and Heritage (OEH) Roads and Maritime Services At the time of submission of this report there are no properties identified that would experience flood impacts greater than the allowable maximum criteria. As further assessments are being carried out on the construction staging works any affected landowners will be consulted where required. Page 25 of 34

26 7 Design Compliance 7.1 Non-Conformances The design has been developed to comply with the SWTC; however in some instances the design may not satisfy all design criteria. Design Non-Conformances are summarised in Table 11 below to identify the details of design departures from the SWTC, the reason for the departure or proposed action to mitigate these departures and the current status of approval. The design departures are to be reviewed and discussed with the Company and Independent Certifier during the detailed design with the objective of gaining acceptance prior to seeking formal approval to amend the SWTC prior to issue of the final design. Table 11: Identified Non-Conformances Details of Non-conformance Reason for Non-conformance Proposed action Status (open/closed) Nil at this stage Page 26 of 34

27 8 Approvals and Certifications The following design approval(s) and certification(s) have been identified for this package (refer Table 12). Table 12: Design Approval and Certification Requirements Design stage Required party to approve Design Approval Required Status of Approval Nil at this stage 8.1 Internal Verification Process All design outputs are subject to informal internal verification that may take the form of general overview, spot checking, compliance with the brief, or a detailed check. The form of verification is relevant to the risk presented by the design activity, and the degree to which risk can be effectively mitigated by the form of verification. 8.2 Independent Verification and Assurance The design has been internally verified by independent design team members. We have addressed the verification comments where possible prior to this submission. Any outstanding comments will be addressed during the next design stage. 8.3 Independent Certifier, Company and RMS Comments made by the IC, PC and RMS and evidence of closure from previous design package submissions are included in Annexure A Comments and Responses Register. Page 27 of 34

28 9 Outstanding issues 9.1 Hold Schedule There are no areas of the design package that are currently on Hold. 9.2 Other Issues At the time of this report submission there are no additional stakeholder issues that are still to be addressed before the design can progress to the next stage. Page 28 of 34

29 10 Sustainability Targets and Initiatives Details of the sustainability targets and initiatives as set out in the SWTC Appendix D.5 Sustainability Requirements are being addressed in the individual design packages. Page 29 of 34

30 11 References AECOM Australia Pty Ltd and GHD Pty Ltd (2015). M4 East Environment Impact Statement - Volumes 1A, 1B, 2A, 2B, 2C, 2D, 2E, 2F, 2G and 2H.September 2015 Bureau of Meteorology (2003). The Estimation of Probable Maximum Precipitation in Australia: Generalised Short-Duration Method Department of Infrastructure, Planning and Natural Resources (2005). NSW Floodplain Development Manual The Management of Flood Liable Land Engineers Australia (1987, with 1998 updated Book VI). Australian Rainfall and Runoff, 3rd Edition Engineers Australia (2015). AR&R Revision 11: Blockage of Hydraulic Structures Blockage Guidelines, February 2015 WestConnex (2015). M4 East Submissions Report Volumes 1A, 1B and 2 Page 30 of 34

31 Annexure A Comments and Responses Register Not applicable at this stage. Page 31 of 34

32 Annexure B Figures Figure Number Figure A.1 Figure A.2 Figure B.1 Figure C.1 Figure C.2 Figure Title Location Map Construction Sites Parramatta Road - Existing Conditions Flood Extents Parramatta Road (C10) Temporary Site Access 100 Year ARI Relative Flood Impacts Parramatta Road (C10) Temporary Traffic Staging Stage Year ARI Relative Flood Impacts Page 32 of 34

33 Foster St Boundary Homebush Bay Drive Interchange Centenary Roberts Rd Dr Arthur St Creek Creek Saleyards Homebush Bay Dr Underwood Rd Powells Creek George St Pomeroy St Western Mtwy (M4 Mtwy) Western Rail Line Broughton Rd STRATHFIELD MUNICIPAL COUNCIL Northern Rail Line Concord Rd Beresford Rd The Boulevarde Alexandra St CITY OF CANADA BAY COUNCIL Concord Road Interchange Park Rd Gipps St BURWOOD COUNCIL Broughton St Burwood Rd Cintra Park St Lukes Park Canal Cheltenham Rd Paisley Rd Exile Bay Lyons Thomas Canada Bay Rd W Queens Rd St Iron Cove Creek Frederick St Northern Rail Line Great North Rd Bland St Elizabeth St Ramsay Rd Parramatta Road Interchange Wattle St THE COUNCIL OF THE MUNICIPALITY OF ASHFIELD St Alt Ramsay St Dobroyd Wattle Street Interchange Dalhousie St Pde Lyons Rd Hawthorne Canal Tebbutt St Bayswater St City Iron Cove West Marion St Link Darley Rd Rd Parramatta Rd MARRICKVILLE COUNCIL Victoria Rd LEICHHARDT MUNICIPAL COUNCIL GIS Printed:Date: 27/04/2016 Z:\AEH\M4 East \5. Engineering\00 - Wide\ HY\A - Calcs \GIS \Outgoing\Figures for Zone 20 Temporary W orks\figure A.1-Location_V01.mxd Legend Creeks Railway Local Government Boundary Concord Road Catchment (Exile Bay) Cintra Park Catchment Powells Creek Catchment Iron Cove Creek Catchment!«N # m Disclaimer Spatial data used under licence from Land and Property Management Authority, NSW SCALE 1:30,000 TITLE FIGURE A.1 - Location Map PROJECT CLIENT WESTCONNEX DELIVERY AUTHORITY COO RDINATE SYST EM GDA 1994 MGA Zone 56 WestConnex Stage 1b - M4 East (M4E) SIZ E A3 AEH makes no representations or warranties of any ki nd, about the accuracy, reli ability, compl eteness, suitabili ty or fitness for purpose in rel ation to the m ap content. DRAWN CHE CK KV DAT E MAP # REV 27/04/2016 DAT E JB 27/04/2016 A

34 ` Bland St Denman Av Bland St Parramatta Rd Chandos St Tinana St Curt St Parramatta Road Civil Site (C10) Chandos St Cecil St Loftus St Orpington St Rogers Av GIS Prin te d: Da te : 2 6/ 05 / Z: \AEH\ M 4 E ast Pr oje ct\ 5. En gin ee ri ng \0 0 - Pr oj ect Wid e \ H Y\A - Ca lcs \G IS\O ut go in g\f ig ur e s fo r Z on e 50 Te m po r ar y W or ks\ Fig u re A.2 -C on str u ctio n Site s.m xd Legend Temporary Site Acess Layout Temporary Site Boundary!«N # m Disclaimer Spati al data used under licence from Land and Property Management A uthority, NS W SC AL E 1:2,500 TIT LE FIGURE A.2 - Construction Sites PR OJECT CLIENT WESTCONNEX DELIVERY AUTHORITY SIZ E A4 COOR DINATE SYST EM MGA56 WestConnex Stage 1b - M4 East (M4E) AEH makes no representations or warranties of any kind, about the accuracy, reliability, completeness, suitability or fitness for purpose in relation to the map content. DRAWN CHECK KV DATE MAP # REV 26/05/2016 DAT E JB 26/05/2016 A.2 01 Pr oje ct

35 Alt St Yasmar Av Denman Av Bland St Chandos St Curt St Legend Peak Flood Extent 20 Year ARI F lood Extent 100 Year ARI Flood Extent Cecil St Chandos St Temporary Site Boundary Cadas tre Existing Drainage System Loftus St Parramatta Rd Parramatta Road Civil Site (C10) Orpington St!«N# m Disclaimer Spati al data used under licence from Land and Property Management A uthority, NS W AEH makes no representations or warranties of any kind, about the accuracy, reliability, completeness, suitability or fitness for purpose in relation to the map content. Flood m odel resul ts presented on these maps have been specifically pepared for the WestConnex M 4E and shoul d not be used for any other purposes. SC AL E SH EET Tinana St 1:2,500 TIT LE Rogers Av CLIENT WESTCONNEX DELIVERY AUTHORITY DRAWN CHECK COOR DINATE SYST EM GDA 1994 MGA Zone 56 FIGURE B.1 - Parramatta Road Existing Conditions Flood Extent PR OJECT WestConnex Stage 1b - M4 East (M4E) KV DATE MAP # REV 26/05/2016 DAT E JB 26/05/2016 B.1 01 Pr oje ct SIZ E A GIS Prin te d: Da te : 2 6/ 05 / Z: \AEH\ M 4 E ast Pr oje ct\ 5. En gin ee ri ng \0 0 - Pr oj ect Wid e \ H Y\A - Ca lcs \G IS\O ut go in g\f ig ur e s fo r Z on e 50 Te m po r ar y W or ks\ Fig u re B.1 -Pa rr am a tta Ro a d - Ex istin g Co nd itio ns flo o d e xt en ts. mx d

36 Haul Road Bland St Minimum 25m gap in hoarding required Childcare Centre Tinana St Parramatta Rd Curt St Legend Relative Flood Impact (m) Cecil St Chandos St 98 Chandos Street Apartment Block Driveway Loftus St Parramatta Road Civil Site (C10) SC AL E SH EET Site Facilities 1:2,00 0 Orpington St Rogers Av SIZ E A4 COOR DINATE SYST EM GDA 1994 MGA Zone 56 GIS Prin te d: Da te : 2 /0 6/ Z :\AE H\M 4 Ea st P ro jec t\5. En g ine er in g\0 0 - Pro je ct W ide \ HY\ A - Calc s\g IS\ Ou tg oin g \F igu re s for Z o ne 5 0 T em p or a ry Wo rks \F igu r e C.1 -Par ra m at ta Ro ad _T SA Yea r Fl oo d Im pa cts.m xd < to to to to to to 0.1 > 0.1 Was w et, now dry Was dry, now w et Drainage System Cadastre Temporary Site Boundary Temp Noise Walls/Hoarding!«N# Disclaimer Spati al data used under licence from Land and Property Management A uthority, NS W AEH makes no representations or warranties of any kind, about the accuracy, reliability, completeness, suitability or fitness for purpose in relation to the map content. Flood m odel resul ts presented on these maps have been specifically pepared for the WestConnex M 4E and shoul d not be used for any other purposes. m TIT LE FI GUR E C. 1 - Parram atta R oa d (C1 0) Temporary Site Access 100 Ye ar ARI Relative Flo od Im pact PR OJECT WestConnex Stage 1b - M4 East (M4E) CLIENT WESTCONNEX DELIVERY AUTHORITY DRAWN CHECK KV DATE MAP # REV 2/0 6/2 016 DAT E JB 2/0 6/2 016 C.1 02 Pr oje ct

37 Haul Road Bland St Minimum 25m gap in traffic barrier and hoarding required Childcare Centre Tinana St Parramatta Rd Curt St Legend Relative Flood Impact (m) Cecil St 98 Chandos Street Apartment Block Driveway Chandos St Loftus St Minimum 1m gap between kerb and edge of barriers to be provided Parramatta Road Civil Site (C10) SC AL E SH EET Site Facilities 1:2,00 0 Orpington St Rogers Av SIZ E A4 COOR DINATE SYST EM GDA 1994 MGA Zone 56 GIS Prin te d: Da te : 2 /0 6/ Z :\AE H\M 4 Ea st P ro jec t\5. En g ine er in g\0 0 - Pro je ct W ide \ HY\ A - Calc s\g IS\ Ou tg oin g \F igu re s for Z o ne 5 0 T em p or a ry Wo rks \F igu r e C.2 -Par ra m at ta Ro ad _S TG 1 _ Ye ar F lo od Im p ac ts. mx d < to to to to to to 0.1 > 0.1 Was w et, now dry Was dry, now w et Drainage System Temp Traffic Barriers Temp M edian Cadastre Temporary Site Boundary Temp Noise Walls/Hoarding!«N# m Disclaimer Spati al data used under licence from Land and Property Management A uthority, NS W AEH makes no representations or warranties of any kind, about the accuracy, reliability, completeness, suitability or fitness for purpose in relation to the map content. Flood m odel resul ts presented on these maps have been specifically pepared for the WestConnex M 4E and shoul d not be used for any other purposes. TIT LE FI GUR E C. 2 - Parram atta R oa d (C1 0) Temporary Traffic Staging Stage Ye ar ARI Relative Flo od Im pact PR OJECT WestConnex Stage 1b - M4 East (M4E) CLIENT WESTCONNEX DELIVERY AUTHORITY DRAWN CHECK KV DATE MAP # REV 2/0 6/2 016 DAT E JB 2/0 6/2 016 C.1 02 Pr oje ct

38 Annexure C Requirements Analysis Allocation and Traceability Matrix (RATM) Not applicable to this design lot. Page 33 of 34

39 Annexure D Peer Review Page 34 of 34

40 AECOM Australia Pty Ltd ABN PO Box Q410, QVB Post Office NSW 1230 Tel Fax Hyder Consulting Pty Ltd ABN Locked Bag 6503, North Sydney NSW 2060 Tel Fax May 2016 CPB Samsung John Holland Joint Venture Level 3 85 Harrington Street THE ROCKS NSW 2000 Attention: Don Johnson Your Ref: Our Ref: WestConnex M4 East Flood Mitigation Strategy - Zone 50 Temporary Works Peer Review Dear Don, We refer to NSW Government Planning & Environment Approval for the WestConnex M4 East. Under Condition B14 this approval requires the Flood Mitigation Strategy to be peer reviewed and confirmed as meeting the requirements of Condition B14. AEH confirm that this review has been undertaken by a suitably qualified and experienced independent hydrological engineer, Bruce Withnall, who has not been involved in the design development for this. We confirm that the Flood Mitigation Strategy for Zone 50 Temporary Works meets the requirements of Condition B14 subject to the flood impact assessments for the construction staging being included in the final version of the Flood Mitigation Strategy for Zone 50 Temporary Works. Yours sincerely Bruce Withnall Industry Director D M Office: Level 3, 85 Harrington Street, The Rocks NSW 2000, Australia c:\users\withnallb\appdata\local\microsoft\windows\temporary internet files\content.outlook\pcgjocj0\m4e-aeh-lt _a_01 flood mitigation strategy zone 50 temp works peer review.docx