Suffolk Coastal and Waveney District Strategic Flood Risk Assessment Appendix B – Suffolk Coastal District Council
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Suffolk Coastal and Waveney District Councils Suffolk Coastal and Waveney District Strategic Flood Risk Assessment Appendix B – Suffolk Coastal District Council Report January 2009 Prepared for: Suffolk Coastal …where quality of life counts Suffolk Coastal and Waveney District Councils Strategic Flood Risk Assessment – Appendix B – Suffolk Coastal District Revision Schedule Strategic Flood Risk Assessment – Appendix B Suffolk Coastal January 2009 Rev Date Details Prepared by Reviewed by Approved by 01 1/06/07 Draft Elizabeth Williams Elizabeth Williams Damon O’Brien Senior Consultant Senior Consultant Associate Director Eleanor Cole Graduate Hydrologist 02 16/07/2007 Draft Elizabeth Williams Senior Consultant Eleanor Cole Graduate Hydrologist 03 06/2008 Final Eleanor Cole Elizabeth Williams Assistant Hydrologist Principal Consultant 04 11/2008 Final – EA Eleanor Cole Elizabeth Williams comments Assistant Hydrologist Principal Consultant 05 01/2009 Final – EA final Eleanor Cole Elizabeth Williams comments Assistant Hydrologist Principal Consultant This document has been prepared in accordance with the scope of Scott Scott Wilson Wilson's appointment with its client and is subject to the terms of that 8 Greencoat Place appointment. It is addressed to and for the sole use and reliance of Scott Wilson's client. Scott Wilson accepts no liability for any use of this document London other than by its client and only for the purposes, stated in the document, for SW1P 1PL which it was prepared and provided. No person other than the client may copy (in whole or in part) use or rely on the contents of this document, without the prior written permission of the Company Secretary of Scott Tel 0207 7985000 Wilson Ltd. Any advice, opinions, or recommendations within this document should be read and relied upon only in the context of the document as a Fax 0207 7985001 whole. The contents of this document are not to be construed as providing legal, business or tax advice or opinion. www.scottwilson.com © Scott Wilson Group PLC 2006 Addendum The 1 in 1000 year event modelling for Woodbridge, in the SFRA document, uses 4.38 metres AOD (Above Ordnance Datum), which has been taken from the extreme water levels report. However, advice from the Environment Agency has stated that the water level which should now be used for this scenario event is 4.61 metres AOD taken from the estuaries studies. Please note that Flood Risk Assessments and flooding consideration in the Woodbridge area should be aware of these levels and may be asked to use the higher 4.61 metres AOD in any modelling. For further information please contact the local Environment Agency office. Suffolk Coastal and Waveney District Councils Strategic Flood Risk Assessment – Appendix B – Suffolk Coastal District Table of Contents 1 Non-Technical Summary.................................................................... 5 1.1 SFRA Background............................................................................................................ 5 1.2 SFRA Planning Objectives ............................................................................................... 5 1.3 SFRA Report Layout ........................................................................................................ 5 1.4 Suffolk Coastal District Council Considerations ............................................................... 6 1.5 Way Forward .................................................................................................................... 8 1.6 A Living Document ........................................................................................................... 8 2 Introduction and Background.............................................................. 9 2.1 Introduction....................................................................................................................... 9 2.2 Scope and Objectives ...................................................................................................... 9 2.3 Suffolk Coastal District Area........................................................................................... 10 3 Sources of Flooding in Suffolk Coastal............................................. 14 3.1 Introduction..................................................................................................................... 14 3.2 Fluvial ............................................................................................................................. 14 3.3 Tidal................................................................................................................................ 17 3.4 Overland Flow ................................................................................................................ 19 4 Level 1 Assessment ......................................................................... 20 4.1 Level 1 SFRA – Study Area, Flood Source Review and Data Review........................... 20 4.2 Level 1 Mapping Methodology ....................................................................................... 22 5 Level 2 Assessment ......................................................................... 25 5.1 Level 2 SFRA – Further Detailed Assessment............................................................... 25 5.2 Fluvial ............................................................................................................................. 25 5.3 Overland Flow ................................................................................................................ 26 5.4 Tidal Flood Defence Breach Analysis ............................................................................ 26 5.5 Results ........................................................................................................................... 28 6 Policy Review ................................................................................... 32 6.2 Flood Risk ......................................................................................................................32 6.3 Sustainable Drainage Systems ...................................................................................... 33 6.4 Flood Mitigation .............................................................................................................. 33 6.5 Water Environment......................................................................................................... 34 7 Summary .......................................................................................... 36 Suffolk Coastal and Waveney District Councils Strategic Flood Risk Assessment – Appendix B – Suffolk Coastal District 8 Annex 1: Flood Records Database................................................... 37 8.1 Suffolk Flood Records Database.................................................................................... 37 8.2 Examples of Tables From Access Database.................................................................. 40 Suffolk Coastal Figures Appendix ............................................................... 43 Suffolk Coastal and Waveney District Councils Strategic Flood Risk Assessment – Appendix B – Suffolk Coastal District List of Figures B I SUFFOLK COASTAL SOILD GEOLOGY B II SUFFOLK COASTAL DRIFT GEOLOGY B III SUFFOLK COASTAL NFCDD B 1 MAIN SETTLEMENTS/SOURCES OF FLOODING B 2 TOPOGRAPHIC RELIEF MAP/FLOOD CELL + BREACH LOCATIONS NORTHEAST SUFFOLK B 3 TOPOGRAPHIC RELIEF MAP/FLOOD CELL + BREACH LOCATIONS NORTHWEST SUFFOLK B 4 TOPOGRAPHIC RELIEF MAP/FLOOD CELL + BREACH LOCATIONS SOUTHEAST SUFFOLK B 5 TOPOGRAPHIC RELIEF MAP/FLOOD CELL + BREACH LOCATIONS SOUTHWEST SUFFOLK B 6 ENVIRONMENT AGENCY FLOOD ZONES OF WAVENEY (A1) B 7 PPS25 FLOOD ZONES 2007 - ALDERTON B 8 PPS25 FLOOD ZONES 2007 - BRAMFIELD B 9 PPS25 FLOOD ZONES 2007 - EARL SOHAM B 10 PPS25 FLOOD ZONES 2107 - EARL SOHAM B 11 PPS25 FLOOD ZONES 2007 - FOXHALL B 12 PPS25 FLOOD ZONES 2007 - FRAMLINGHAM B 13 PPS25 FLOOD ZONES 2007 - GRUNDISBURGH B 14 PPS25 FLOOD ZONES 2007 - HOLLESLEY B 15 PPS25 FLOOD ZONES 2007 - IPSWICH EASTERN FRINGE WARREN HEATH B 16 PPS25 FLOOD ZONES 2007 - KNODISHALL B 17 PPS25 FLOOD ZONES 2107 - KNODISHALL B 18 PPS25 FLOOD ZONES 2007 - MARTLESHAM HEATH B 19 PPS25 FLOOD ZONES 2007 - MELTON LEVEL 1 B 20 PPS25 FLOOD ZONES 2107 - MELTON B 21 PPS25 FLOOD ZONES 2007 - ORFORD B 22 PPS25 FLOOD ZONES 2007 - PEASENHALL B 23 PPS25 FLOOD ZONES 2107 - PEASENHALL B 24 PPS25 FLOOD ZONES 2007 - RUSHMERE B 25 PPS25 FLOOD ZONES 2007 - SAXMUNDHAM B 26 PPS25 FLOOD ZONES 2007 - SNAPE B 27 PPS25 FLOOD ZONES 2007 - WICKHAM MARKET B 28 PPS25 FLOOD ZONES 2107 - WICKHAM MARKET B 29 PPS25 FLOOD ZONES 2007 - WITNESHAM B 30 PPS25 FLOOD ZONES 2007 - YOXFORD B 31 PPS25 FLOOD ZONES 2107 - YOXFORD Suffolk Coastal and Waveney District Councils SFRA January 2009 1 Suffolk Coastal and Waveney District Councils Strategic Flood Risk Assessment – Appendix B – Suffolk Coastal District B 32 PPS25 FLOOD ZONES 2007 - LEISTON/SIZEWELL B 33 PPS25 FLOOD ZONES 2107 - LEISTON/SIZEWELL B 34 DEPTH MAP OF C1 (1 IN 200 YEAR PLUS CLIMATE CHANGE) B 35 DEPTH MAP OF C1 (1 IN 1000 YEAR PLUS CLIMATE CHANGE) B 36 HAZARD MAP OF C1 (1 IN 200 YEAR PLUS CLIMATE CHANGE) LEISTON/ SIZEWELL B 37 HAZARD MAP OF C1 (1 IN 1000 YEAR PLUS CLIMATE CHANGE) B 38 LEVEL 2 ASSESSMENT OF LEISTON/SIZEWELL B 39 PPS25 FLOOD ZONES 2007 - ALDEBURGH B 40 PPS25 FLOOD ZONES 2107 - ALDEBURGH B 41 DEPTH MAP OF D1 (1 IN 200 YEAR PLUS CLIMATE CHANGE) B 42 DEPTH MAP OF D1 (1 IN 1000 YEAR PLUS CLIMATE CHANGE) B 43 HAZARD MAP OF D1