Coventry City Council Strategic Flood Risk Assessment for Local Development Framework Level 1 Volume 1 - FINAL January 2008 Halcrow Group Limited Strategic Flood Risk Assessment Coventry City Council Strategic Flood Risk Assessment Coventry City Council Coventry City Council Strategic Flood Risk Assessment for Local Development Framework Level 1 Volume 1 Contents Amendment Record This report has been issued and amended as follows: Issue Revision Description Date Signed 1 Draft Report 23/11/07 RD 2 Final Report 22/01/08 RD Strategic Flood Risk Assessment Coventry City Council This page is left intentionally blank Strategic Flood Risk Assessment Coventry City Council Contents Contents.................................................................................................................................................1 Executive Summary ..............................................................................................................................3 1 Introduction...................................................................................................................................4 1.1 Terms of Reference ...................................................................................................................4 1.2 Project Aims ...............................................................................................................................4 1.3 Project Objectives ......................................................................................................................4 1.4 Project Deliverables ...................................................................................................................5 1.5 Outcomes of the SFRA Process ................................................................................................5 1.6 SFRA Context ............................................................................................................................9 1.7 The Study Area ........................................................................................................................10 2 Planning Context........................................................................................................................13 2.1 Introduction ..............................................................................................................................13 2.2 Planning Policy Framework .....................................................................................................13 2.3 National Planning Policy ..........................................................................................................13 2.4 Regional Planning Policy .........................................................................................................15 2.5 Local Planning Policy...............................................................................................................17 3 Study Methodology ....................................................................................................................18 3.1 Level 1 SFRA Methodology .....................................................................................................18 3.2 Need for a Level 2 SFRA .........................................................................................................18 3.3 Technical Background..............................................................................................................19 3.4 Environment Agency Flood Zone Maps...................................................................................20 4 Flood Risk in the Study Area ....................................................................................................21 4.1 Approach to Data Gathering ....................................................................................................21 4.2 Historical Flooding....................................................................................................................21 4.3 Fluvial Flood Risk in Coventry City Council as defined by the Flood Zone Maps ...................22 4.4 Flooding from Other Sources...................................................................................................23 5 Strategic Flood Risk Mapping...................................................................................................28 5.1 Strategic Flood Risk Maps .......................................................................................................28 5.2 Climate Change Maps..............................................................................................................29 6 Flood Warning Systems and Flood Risk Management Measures.........................................31 6.1 Flood Management ..................................................................................................................31 6.2 Flood Defences........................................................................................................................32 1 Strategic Flood Risk Assessment Coventry City Council 6.3 Residual Risk ...........................................................................................................................33 6.4 Storage Areas ..........................................................................................................................34 6.5 Existing Flood Warning System ...............................................................................................34 6.6 Flood Response Plan...............................................................................................................36 7 Flood Risk Management Policy Considerations .....................................................................39 7.1 Overview ..................................................................................................................................39 7.2 Policy Considerations...............................................................................................................39 7.3 Development Control Policies..................................................................................................41 7.4 Council Specific Policy Issues .................................................................................................43 7.5 Sensitive Development Locations............................................................................................43 8 Guidance on the Application of the Sequential Test..............................................................45 8.1 Step One: Strategic Overview of flood risk across all potential development areas ...............45 8.2 Step Two: Flood Risk Issues in Zone 1 ...................................................................................45 8.3 Step Three: Sequential Test in Zones 2 and 3 ........................................................................46 9 Guidance for Developers...........................................................................................................47 9.2 Raised Floor Levels and Basements (Freeboard) ...................................................................50 9.3 Developer Contributions...........................................................................................................51 10 Guidance for the Application of Sustainable Drainage Systems ..........................................52 10.1 Introduction ..........................................................................................................................52 10.2 Types of SUDS Systems .....................................................................................................52 10.3 Application of SUDS for Coventry City Council ...................................................................53 11 Recommendations .....................................................................................................................55 11.1 Site Allocation Process ........................................................................................................55 11.2 Council Policy ......................................................................................................................55 11.3 Emergency Planning............................................................................................................55 11.4 Future Updates to the SFRA ...............................................................................................56 11.5 Level 2 SFRA.......................................................................................................................57 12 References/Glossary..................................................................................................................59 APPENDIX A ........................................................................................................................................62 APPENDIX B ........................................................................................................................................63 APPENDIX C ........................................................................................................................................64 2 Strategic Flood Risk Assessment Coventry City Council Executive Summary In August 2007 a group comprising Coventry City Council, Solihull Metropolitan Borough Council and the County, Districts and Boroughs of Warwickshire commissioned Halcrow to produce a Level 1 Strategic Flood Risk Assessment (SFRA) in accordance with Planning Policy Statement 25 (PPS