Flood Emergency Response Plan
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FLOOD EMERGENCY RESPONSE PLAN for Service Station, Restaurant and Motel Facilities at 61-79 Aberdeen Street, Scone Job No: NL171259 Revision: 1 Date: 24/01/2019 BY DATE Prepared LG 22/01/2019 Checked GB 22/01/2019 Admin LB 24/01/2019 Report Details Project: Service Station, Restaurant and Motel Facilities 61-79 Aberdeen Street, Scone Project Ref: NL171259_E02_[1] File Location: Y:\YEAR 2017 Jobs\NL171259\E - Reports\NL171259_E02(1)_LG.docx Revision History Revision Report Status Prepared Reviewed Issue Date 1 For Information L Gitzel A Brien 24/01/2019 Limitation Statement Northrop Consulting Engineers Pty Ltd (Northrop) has been retained to prepare this report based on specific instructions, scope of work and purpose pursuant to a contract with its client. It has been prepared in accordance with the usual care and thoroughness of the consulting profession for the use by Stevens Group. The report is based on generally accepted practices and standards applicable to the scope of work at the time it was prepared. No other warranty, express or implied, is made as to the professional advice included in this report. Except where expressly permitted in writing or required by law, no third party may use or rely on this report unless otherwise agreed in writing by Northrop. Where this report indicates that information has been provided to Northrop by third parties, Northrop has made no independent verification of this information except as expressly stated in the report. Northrop is not liable for any inaccuracies in or omissions to that information. The report was prepared on the dates shown and is based on the conditions and information received at the time of preparation. It makes no comment or assertions on the structures or their ability to withstand flooding or flood forces. This report should be read in full, with reference made to all sources. No responsibility is accepted for use of any part of this report in any other context or for any other purpose. Northrop does not purport to give legal advice or financial advice. Appropriate specialist advice should be obtained where required. To the extent permitted by law, Northrop expressly excludes any liability for any loss, damage, cost or expenses suffered by any third party relating to or resulting from the use of, or reliance on, any information contained in this report. \\ncl-fp\job_files1\YEAR 2017 Jobs\NL171259\E - Reports\NL171259_E02(1)_LG.docx 2 of 23 Table of Contents 1 INTRODUCTION 5 1.1 Site Locality 5 1.2 Proposed Development 6 2 METHODOLOGY AND AVAILABLE DATA 8 3 FLOOD BEHAVIOUR 9 3.1 Flood Source and Behaviour 9 3.2 Peak Flood Levels and Velocities 9 3.3 Flood Behaviour and Hazard Category 11 4 FLOOD AND EVACUATION WARNINGS 13 4.1 Warning Types 13 4.1.1 Severe Weather Warning 13 4.1.2 Severe Thunderstorm Warning 13 4.1.3 Flood Alert/Watch/Advice 13 4.1.4 Detailed Flood Warning 13 4.1.5 Minor/Moderate/Severe Flood Warning 13 4.2 SES Flood Bulletins 14 4.3 Evacuation Warning 14 4.4 Evacuation Order 14 4.5 On-site Emergency Tone 14 4.6 Early Warning Network Automated Text and Email Service 14 5 FLOOD RESPONSE PERSONNEL 15 5.1 Responsibilities 15 5.2 Anticipated Allocation of Responsibilities 16 6 ASSEMBLY POINT AND EVACUATION ROUTES 17 6.1 Emergency Assembly Point 17 6.2 Trigger for Evacuation 17 6.3 Evacuation Centres 19 \\ncl-fp\job_files1\YEAR 2017 Jobs\NL171259\E - Reports\NL171259_E02(1)_LG.docx 3 of 23 6.4 Evacuation Routes 19 7 FLOOR LEVELS AND ON-SITE REFUGE 21 7.1 Floor Levels 21 7.2 On-site Refuge 21 8 EMERGENCY CONTACT 22 9 FLOOD RESPONSE PREPARATION 23 9.1 Evacuation Drills and Lessons 23 9.2 Flood Emergency Kit 23 9.3 Monitoring of Weather Situation 24 10 FLOOD RESPONSE ACTIONS 25 10.1 Evacuation 25 10.2 Refuge On-Site 26 10.3 Emergency Services Attending Site 27 10.4 After a Flood 27 11 REVISION OF THE FLOOD EMERGENCY RESPONSE PLAN 28 12 CONCLUSION 29 13 REFERENCES 30 \\ncl-fp\job_files1\YEAR 2017 Jobs\NL171259\E - Reports\NL171259_E02(1)_LG.docx 4 of 23 1 Introduction Northrop Consulting Engineers have been engaged by Stevens Group to prepare a Flood Emergency Response Plan for the proposed commercial development at 61-79 Aberdeen Street, Scone (the subject site). This Flood Emergency Response Plan (FERP) has been developed to: • Promote a satisfactory awareness of the expected flood behaviour and flood risks associated with the subject site; • Identify measures to monitor weather forecasts and to become flood prepared; and • Provide a recommended course of action during and after flood events; This assessment has given consideration to the following documents; • New England Highway Bypass of Scone – Hydrological and Hydraulic Assessment completed by GHD in December 2015 (Ref #22/17554), included in Appendix B and referenced as the “Scone Bypass Flood Impact Study (GHD, 2015)” in this report; • Scone Bypass Service Centre Proposal – Flood Assessment completed by GHD in December 2017 (Ref #2219273-171212), included in Appendix B and referenced as the “Scone Service Centre Flood Impact Study (GHD, 2017)” in this report; • Expert Peer Review: Flood Study, Proposed Service Centre Development, 61-79 Aberdeen Street Scone, NSW completed by Grantley Smith from the University of New South Wales in October 2018 (Ref #WRL2018068), also included in Appendix B and referenced as the “Expert Peer Review (UNSW, 2018)” in this report; • Concept Stormwater Management Strategy for the proposed Service Centre Development at 61-79 Aberdeen Street, Scone, NSW report [Rev B] completed by Northrop Consulting Engineers in 2018 and referenced as the “Civil Design Report (Northrop, 2018)” in this report; • Proposed Service Station, Restaurant and Motel 61-79 Aberdeen Street Scone, NSW – Concept Stormwater Management Civil Drawings [Rev B] completed by Northrop Consulting Engineers in 2018 and referenced as the “Civil Design Drawings (Northrop, 2018)” in this report; and • The Upper Hunter Shire Flood Emergency Sub Plan developed by the State Emergency Service (SES) in consultation with Upper Hunter Shire Council, completed in 2013 and referenced as the “SES EMPLAN (SES, 2013)” in this report. Contained herein is a description of the subject site, the study methodology, a summary of the likely flood behaviour, recommendations for flood preparation and response actions prior to a flood event. 1.1 Site Locality The subject site is located on the western fringe of the Scone town centre, adjacent to the Scone bypass which is currently under construction. The subject site is bounded to the north by St Aubins Street, Aberdeen Street to the east, Liverpool Street to the south and vacant land to the west. The site is currently occupied by a residential dwelling located in the north eastern corner and two dwellings in the south-eastern corner of the subject site. The remainder of the subject site is predominately vacant land consisting of pasture grass and sparse trees. The Parson Gully watercourse, a tributary to the Kingdon Ponds watercourse, is located to the west of the subject site as shown in the below Figure 1 which presents the locality of the subject site and surrounds. \\ncl-fp\job_files1\YEAR 2017 Jobs\NL171259\E - Reports\NL171259_E02(1)_LG.docx 5 of 23 Although it is not shown in the below Figure 1, the Scone bypass is currently under construction and is located adjacent to the western boundary of the subject site. Figure 1 - Locality Plan 1.2 Proposed Development The development proposes the construction of a service station, food premises, restaurant, motel and associated carparking, landscaping and stormwater infrastructure. The proposed development is shown in Figure 2 overleaf. \\ncl-fp\job_files1\YEAR 2017 Jobs\NL171259\E - Reports\NL171259_E02(1)_LG.docx 6 of 23 Figure 2 - Proposed Development Masterplan \\ncl-fp\job_files1\YEAR 2017 Jobs\NL171259\E - Reports\NL171259_E02(1)_LG.docx 7 of 23 2 Methodology and Available Data This Flood Emergency Response Plan has been prepared using the following methodology: • Desktop review of the available flood information for the subject site including a summary of the likely flood behaviour across and within the general vicinity of the subject site; • Investigation and presentation of the local flood evacuation procedures and summary of how and where flood warnings can be assessed; • Nomination of the persons responsible for site specific roles such as the preparation and maintenance of the onsite flood emergency kit and identification of the responsible guides for safe evacuation and/or refuge for the subject site; and • Identification of potential on-site refuge points and off-site evacuation assembly points. \\ncl-fp\job_files1\YEAR 2017 Jobs\NL171259\E - Reports\NL171259_E02(1)_LG.docx 8 of 23 3 Flood Behaviour 3.1 Flood Source and Behaviour Flooding of the subject site is expected to occur from the regional catchment including Kingdon Ponds, Middle Brook and Parsons Gully catchments. The upstream catchment extends approximately 22km north of Scone to Tims Range and Towarri National Park. The catchment areas are approximately 214 km2, 71km2 and 25km2 for Kingdon Ponds, Middle Brook and Parsons Gully catchments respectively. The Scone Bypass Flood Impact Study (GHD, 2015) suggests the Parsons Gully floodplain is generally lower than the Kingdon Ponds and Middlebrook catchments and therefore receives surcharging flow from the two larger catchments. The floodplain of all three catchments connects and disconnects a number of times before reaching Scone and therefore there is a high potential for variability of flows across the subject site. There is also the potential for localised flooding as a result of quick short bursts of rainfall that have the potential to exceed the capacity of the local street drainage network.