Opportunity Peterborough and Peterborough City Council Peterborough Strategic Flood Risk Assessment Level 2 Hyder Consulting (UK) Limited 2212959 Aston Cross Business Village 50 Rocky Lane Aston Birmingham B6 5RQ United Kingdom Tel: +44 (0)121 333 4466 Fax: +44 (0)121 333 4275 www.hyderconsulting.com Opportunity Peterborough and Peterborough City Council Peterborough Strategic Flood Risk Assessment Level 2 FINAL DRAFT* *This report has not yet received sign-off from key stakeholders Author J Chatterton, R Gunasekara, R Tufnell, C Wilson Checker O Davies, R Gunasekara Approver P Harker Report No 5004-BM01234-BMR-01 Date Original October 2009 Amended February 2010. This report has been prepared for Opportunity Peterborough and Peterborough City Council in accordance with the terms and conditions of appointment for Level 2 SFRA dated November 2008. Hyder Consulting (UK) Limited (2212959) cannot accept any responsibility for any use of or reliance on the contents of this report by any third party. Peterborough Strategic Flood Risk Assessment—Level 2 Hyder Consulting (UK) Limited-2212959 Page i x:\lwhoecr\restricted\urc\files\08 environment (s)\s.5 - water cycle study\sfra\(d) deliverables\(ii) reports\sfra level 2 final draft\peterborough sfra l2 final draft.doc CONTENTS i. EXECUTIVE SUMMARY ......................................................................7 PART 1 INTRODUCTION ........................................................................9 1 Background and Scope of Works .......................................................10 2 Report Structure..................................................................................12 3 Study Area ..........................................................................................14 4 Planning Policy and Guidance............................................................16 4.1 National Planning Policy .....................................................................16 4.2 Regional Planning Policy ....................................................................17 4.3 Local Planning Policy..........................................................................19 5 Other Policy and Guidance.................................................................23 5.1 Integrated Growth Study .....................................................................23 5.2 Catchment Flood Management Plans.................................................23 5.3 Padholme Flood Protection Strategy...................................................23 5.4 Regional Flood Risk Appraisal ............................................................24 5.5 Water Cycle Study ..............................................................................24 5.6 Emergency Planning and the Civil Contingencies Act.........................24 PART 2 HISTORICAL APPROACH TO SITE SELECTION ..................27 6 Peterborough: Development Needs ...................................................28 6.1 Introduction .........................................................................................28 6.2 Retail and Services .............................................................................29 6.3 Housing...............................................................................................29 6.4 Employment Opportunities..................................................................29 7 Peterborough Integrated Growth Study (IGS): Development Opportunities and Constraints ............................................................31 7.1 Introduction .........................................................................................31 7.2 Development of Conceptual Options...................................................33 7.3 Development of the Spatial Options....................................................37 7.4 Final Evaluation ..................................................................................48 7.5 Consultants Recommended Option ....................................................48 8 Addressing Flooding Issues in Peterborough Site Selection..............51 8.1 Overview.............................................................................................51 8.2 Defining The Evidence Base...............................................................52 9 Level 1 Application of the Sequential Test: Flood Zone 1 Sites .........56 9.1 Introduction .........................................................................................56 9.2 Overview of All Potential Strategic Sites in Flood Zone 1 ...................56 9.3 Other Site Specific Development Constraints for Urban Extensions...61 Peterborough Strategic Flood Risk Assessment—Level 2 Page ii Hyder Consulting (UK) Limited-2212959 x:\lwhoecr\restricted\urc\files\08 environment (s)\s.5 - water cycle study\sfra\(d) deliverables\(ii) reports\sfra level 2 final draft\peterborough sfra l2 final draft.doc 9.4 Quantum of Growth Summary............................................................ 66 10 Level 1 Application of the Sequential Test: Sites Outside Flood Zone 1.................................................................................................68 10.1 Initial Assessment............................................................................... 68 10.2 Predominantly Employment Urban Extensions .................................. 70 10.3 Key City Centre Sites ......................................................................... 74 10.4 Summary ............................................................................................ 94 11 IGS Recommended Option & Part 2 Conclusions..............................95 11.1 Summary of Final Growth Quantum by Flood Zone ........................... 96 PART 3 LEVEL 2 STRATEGIC FLOOD RISK ASSESSMENT .............97 12 Update on Planning and Site Information Received Subsequently to Part 2...................................................................................................98 12.1 The Local Development Framework................................................... 98 12.2 City Centre Area Action Plan: Consultants Recommended Option .... 99 12.3 Updates to site information................................................................. 99 13 Level 2 SFRA Methodology ..............................................................100 13.1 Consultation and Data Collection ..................................................... 100 13.2 Key Strategic Development Sites ..................................................... 100 13.3 Model Build and Extent..................................................................... 100 13.4 Model Parameters ............................................................................ 101 13.5 Flood Hazard Analysis...................................................................... 103 13.6 Assessment of Surface Water Flood Risk ........................................ 104 13.7 Assumptions and Limitations............................................................ 105 14 Outputs .............................................................................................107 14.1 Flood Defence Condition Appraisal .................................................. 107 14.2 Flood Risk Management Measures.................................................. 109 14.3 Flood Hazard Mapping ..................................................................... 109 14.4 Critical Drainage Areas..................................................................... 110 14.5 Application of Outputs ...................................................................... 111 15 Summary of Level 2 Findings and Assessments..............................112 PART 4 UPDATED SEQUENTIAL AND EXCEPTION TESTS ...........113 16 Updates to Sites’ Flood Risk Status .................................................114 16.1 Potential Sites that were Wholly or Predominantly in Flood Zone 1 . 114 16.2 Sites That Were Partially or Predominantly in Flood Zones 2 and 3 115 16.3 Sites That Were Partially or Predominantly in Flood Zones 2 and 3 116 16.4 Sequential Tests for Key City Centre Sites....................................... 123 17 Exception Test Process ....................................................................141 17.1 Introduction to the Exception Test .................................................... 141 17.2 Exception Test for South Bank: Fletton Quays................................. 143 18 Sequential Test Conclusions ............................................................155 18.1 Site Outcomes.................................................................................. 155 18.2 Growth Quantum .............................................................................. 156 PART 5 WIDER FLOOD RISK AND SURFACE WATER MANAGEMENT ................................................................................159 19 Wider Catchment and Key Risks to Peterborough ...........................160 19.1 Catchment Context........................................................................... 160 19.2 Key Risks ......................................................................................... 162 Peterborough Strategic Flood Risk Assessment—Level 2 Hyder Consulting (UK) Limited-2212959 Page iii x:\lwhoecr\restricted\urc\files\08 environment (s)\s.5 - water cycle study\sfra\(d) deliverables\(ii) reports\sfra level 2 final draft\peterborough sfra l2 final draft.doc 20 Core Spatial Strategy and CCAAP Inputs ........................................164 20.1 Overtopping and Breach Hazard