Colchester Borough Council Level 1 SFRA Update Page I
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Final Report Submitted to Submitted by Colchester Borough Council AECOM Scott House Alençon Link Basingstoke Hampshire RG21 7PP United Kingdom Colchester Borough Council Level 1 Strategic Flood Risk Assessment Update August 2016 Project Number: 60473444 AECOM Colchester Borough Council Level 1 SFRA Update Page i Prepared by: Sarah Betts Checked by: Elizabeth Gent Graduate Water Consultant Associate Director Sarah Littlewood Gemma Hoad Flood Risk Consultant Senior Water Consultant Approved by: Sarah Kelly Associate Director Rev No Comments Checked by Approved by Date 1 Draft for client and stakeholder comment EG SK June 2016 2 Final Report GH SK August 2016 Scott House, Alençon Link, Basingstoke, Hampshire, RG21 7PP, United Kingdom Telephone: 01256 310 200 Website: http://www.aecom.com Job No Reference Date Created 60473444 August 2016 \\ba-wip-003\4700 - water\water\projects & jobs\4707\47075262 - colchester bc sfra update\draft l1 report\colchester sfra level 1 report draft v1 eg sl.docx 60473444 Final Report August 2016 AECOM Colchester Borough Council Level 1 SFRA Update Page ii Limitations AECOM Infrastructure & Environment UK Limited (“AECOM”) has prepared this Report for the sole use of Colchester Borough Council (“Client”) in accordance with the Agreement under which our services were performed (AECOM_ Colchester SFRA_Proposal_v1.docx 10th June 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 July 2015 and August 2016 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. 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Any unauthorised reproduction or usage by any person other than the addressee is strictly prohibited. 60473444 Final Report August 2016 AECOM Colchester Borough Council Level 1 SFRA Update Page iii Contents Executive Summary ............................................................................................................................................................. 1 1 Introduction and Background ..................................................................................................................................... 3 1.1 Terms of Reference .............................................................................................................................................. 3 1.2 Project Background .............................................................................................................................................. 3 1.3 Approach to Flood Risk Management .................................................................................................................. 4 1.4 Level 1 SFRA Deliverables .................................................................................................................................... 4 1.5 Partner Organisations ........................................................................................................................................... 6 1.6 Study Area ............................................................................................................................................................ 7 1.6.1 Location ....................................................................................................................................................... 7 1.6.2 Human Geography ....................................................................................................................................... 7 1.6.3 Physical Geography ..................................................................................................................................... 7 2 Legislative and Planning Policy Context .................................................................................................................... 8 2.1 Introduction .......................................................................................................................................................... 8 2.2 Flood and Water Management Act ....................................................................................................................... 8 2.2.1 National Strategy for Flood and Coastal Erosion Risk Management ........................................................... 8 2.2.2 Local Flood Risk Management Strategy ...................................................................................................... 9 2.2.3 Surface Water Management Plan ................................................................................................................ 9 2.3 Flood Risk Regulations ....................................................................................................................................... 10 2.3.1 Preliminary Flood Risk Assessment ........................................................................................................... 10 2.4 Anglian River Basin District Flood Risk Management Plan ................................................................................. 10 2.5 National Planning Policy Framework .................................................................................................................. 12 2.5.1 NPPF Guidance SuDS Policy (April 2015) .................................................................................................. 12 2.6 Local Planning Policy .......................................................................................................................................... 13 2.7 Summary ............................................................................................................................................................. 13 3 Level 1 SFRA Methodology ....................................................................................................................................... 14 3.1.1 Establishing relationships and understand the planning context .............................................................. 14 3.1.2 Gathering data and analysing it for suitability ............................................................................................ 14 3.1.3 Producing strategic flood risk maps, GIS deliverables and a technical report .......................................... 14 3.1.4 Site Assessment Database ........................................................................................................................ 14 4 Level 1 Strategic Assessment of Flood Risk ........................................................................................................... 15 4.1 Introduction ........................................................................................................................................................ 15 4.2 Tidal Flooding ..................................................................................................................................................... 16 4.2.1 Sources ...................................................................................................................................................... 16 4.2.2 Flood Zones ................................................................................................................................................ 16 4.2.1 Flood Defences .......................................................................................................................................... 16 4.2.2 Historic Records ......................................................................................................................................... 16 4.2.3 Residual Risk – Failure of Colne Barrier .....................................................................................................