Level 1 Strategic Flood Risk Assessment Update
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Final Report Submitted to Submitted by Breckland District Council AECOM Midpoint Alençon Link Basingstoke Hampshire RG21 7PP United Kingdom Breckland District Council Level 1 Strategic Flood Risk Assessment Update January 2017 AECOM Project No. 60472852 AECOM Level 1 Strategic Flood Risk Assessment Update Page i Prepared by: Sarah Littlewood Checked by: Christopher Gordon Flood Risk Consultant Senior Engineer Sarah Betts Graduate Water Consultant Approved by: Carl Pelling Associate Director Rev No Comments Checked by Approved by Date 1 Draft report for client and stakeholder comment GH EC 07/12/15 2 Final report following client and stakeholder review CP CP 13/05/16 3 Final report – final planning changes CG CP 13/01/17 Midpoint, Alençon Link, Basingstoke, Hampshire, RG21 7PP, United Kingdom Telephone: 01256 310 200 Website: http://www.aecom.com Job No 60472852 Final Report January 2017 Project Number: 60472852 January 2017 AECOM Level 1 Strategic Flood Risk Assessment Update Page ii Limitations AECOM Infrastructure & Environment UK Limited (“AECOM”) has prepared this Report for the sole use of Breckland District Council (“Client”) in accordance with the Agreement under which our services were performed (AECOM Breckland WCS & SFRA Tender.pdf, April 2015). No other warranty, expressed or implied, is made as to the professional advice included in this Report or any other services provided by AECOM. This Report is confidential and may not be disclosed by the Client nor relied upon by any other party without the prior and express written agreement of AECOM. The conclusions and recommendations contained in this Report are based upon information provided by others and upon the assumption that all relevant information has been provided by those parties from whom it has been requested and that such information is accurate. Information obtained by AECOM has not been independently verified by AECOM, unless otherwise stated in the Report. The methodology adopted and the sources of information used by AECOM in providing its services are outlined in this Report. The work described in this Report was undertaken between May 2015 and Jan 2017 and is based on the conditions encountered and the information available during the said period of time. The scope of this Report and the services are accordingly factually limited by these circumstances. Where assessments of works or costs identified in this Report are made, such assessments are based upon the information available at the time and where appropriate are subject to further investigations or information which may become available. AECOM disclaim any undertaking or obligation to advise any person of any change in any matter affecting the Report, which may come or be brought to AECOM’s attention after the date of the Report. Certain statements made in the Report that are not historical facts may constitute estimates, projections or other forward-looking statements and even though they are based on reasonable assumptions as of the date of the Report, such forward-looking statements by their nature involve risks and uncertainties that could cause actual results to differ materially from the results predicted. AECOM specifically does not guarantee or warrant any estimate or projections contained in this Report. Copyright © This Report is the copyright of Breckland District Council. Any unauthorised reproduction or usage by any person other than the addressee is strictly prohibited. Project Number: 60472852 January 2017 AECOM Level 1 Strategic Flood Risk Assessment Update Page iii Contents 1 Introduction ................................................................................................................................................................. 1 .............................................................................................................................................. 1 1.1 Terms of Reference .............................................................................................................................................. 1 1.2 Project Background .................................................................................................................. 2 1.3 Approach to Flood Risk Management ........................................................................................................................................... 2 1.4 Partner Organisations ........................................................................................................................................ 3 1.5 Level 1 SFRA Approach .............................................................................................. 3 1.5.1 Gathering data and analysing it for suitability ............................................ 3 1.5.2 Producing strategic flood risk maps, GIS deliverables and a technical report ......................................................................................................................... 4 1.5.3 Providing suitable guidance 2 Legislative and Planning Policy Context .................................................................................................................... 5 .......................................................................................................................................................... 5 2.1 Introduction ....................................................................................................................... 5 2.2 Flood and Water Management Act ........................................................... 5 2.2.1 National Strategy for Flood and Coastal Erosion Risk Management ...................................................................................................... 6 2.2.2 Local Flood Risk Management Strategy ................................................................................................................ 6 2.2.3 Surface Water Management Plan ......................................................................................................................................... 6 2.3 Flood Risk Regulations ............................................................................................................. 7 2.3.1 Preliminary Flood Risk Assessment ........................................................................... 7 2.4 Anglian River Basin District draft Flood Risk Management Plan .................................................................................................................... 9 2.5 National Planning Policy Framework .................................................................................................. 10 2.5.1 NPPF Guidance SuDS Policy (April 2015) .......................................................................................................................................... 10 2.6 Local Planning Policy ............................................................................................................................................................ 10 2.7 IDB Policy ............................................................................................................................................................. 11 2.8 Summary 3 Assessing Flood Risk ................................................................................................................................................. 12 ........................................................................................................................................................ 12 3.1 Introduction .......................................................................................................................................................... 12 3.2 Study Area .................................................................................................................................................. 12 3.2.1 Landscape ................................................................................................................................................ 12 3.2.2 Topography ............................................................................................................................................. 12 3.2.3 Hydrogeology ..................................................................................................................................................... 12 3.3 Tidal Flooding ........................................................................................................................................... 13 3.4 Flooding from Rivers ............................................................................................................................... 13 3.4.1 Detailed River Network ............................................................................................................ 14 3.4.2 Historic Records of River Flooding ...................................................................................................................................... 15 3.4.3 NPPF Flood Zones .......................................................................................................................................... 17 3.4.4 Flood defences .................................................................................................................................. 18 3.4.5 Flood Warning Areas ........................................................................................................................... 18 3.4.6 Emergency Rest Centres ............................................................................................................................