Reading Borough Council Strategic Flood Risk Assessment On behalf of: Project Ref: 27560/4001 | Rev: FIRST ISSUE | Date: June 2017 Office Address: Caversham Bridge House, Waterman Place, Reading, Berkshire RG1 8DN T: +44 (0)118 950 0761 +44 (0)118 959 7498 E: [email protected] Reading Borough Council Strategic Flood Risk Assessment Contents Glossary ................................................................................................................................................. 6 1 Introduction ................................................................................................................................. 9 1.1 Borough Setting ............................................................................................................. 9 1.2 SFRA Scope and Structure ........................................................................................... 9 1.3 Outputs of the SFRA ................................................................................................... 10 1.4 A Proactive Approach – Reduction in Flood Risk ....................................................... 10 1.5 A Living Document ...................................................................................................... 10 1.6 Disclaimer .................................................................................................................... 10 2 Study Area ................................................................................................................................. 12 2.1 Geographical Location ................................................................................................ 12 2.2 Topography ................................................................................................................. 13 2.3 Watercourses and Catchments ................................................................................... 14 2.4 Geology ....................................................................................................................... 14 2.5 Growth of Reading Borough ........................................................................................ 15 2.6 Future Development Implications ................................................................................ 16 3 Approach and Methodology ..................................................................................................... 18 3.1 Objectives of SFRA ..................................................................................................... 18 3.2 Data Collection ............................................................................................................ 18 3.3 Integration of Flood Risk Documentation .................................................................... 23 4 National Planning Policy .......................................................................................................... 25 4.1 Overview of National Planning Policy.......................................................................... 25 4.2 National Planning Policy (NPPF), 2012 ...................................................................... 25 4.3 NPPF Planning Practice Guidance, updated April 2015 ............................................. 25 4.4 Flood Risk Regulations, 2009 ..................................................................................... 25 4.5 Flood and Water Management Act, 2010 ................................................................... 26 4.6 Water Framework Directive, 2000 ............................................................................... 26 4.7 River Basin Management Plan –Thames River Basin District, updated 2015 ............ 27 4.8 Thames Catchment Flood Management Plan, 2009 ................................................... 28 4.9 Flood Risk Assessments: Climate Change Allowances, 2016 .................................... 28 5 Local Planning Policy ............................................................................................................... 30 5.1 Reading Core Strategy ................................................................................................ 30 5.2 Reading Central Area Action Plan (RCAAP) ............................................................... 31 5.3 Sites and Detailed Policies Document (January 2015) ............................................... 31 J:\27560 RBC LLFA support\4002 - Reading 1 SFRA\wp\Report\27560_4001_Reading SFRA_rmf_June17.docx Reading Borough Council Strategic Flood Risk Assessment 5.4 Revised Sustainable Design and Construction SPG (July 2011) ............................... 31 5.5 Reading’s Climate Change Strategy 2013-2020 (Sept 2013) ..................................... 32 6 Sources of Flood Risk .............................................................................................................. 33 6.1 Sources of Flooding..................................................................................................... 33 6.2 Fluvial (River) Flooding ............................................................................................... 34 6.3 Surface Water Flooding ............................................................................................... 42 6.4 Flooding from Impounded Bodies of Water (Reservoirs and Canals) ......................... 43 6.5 Groundwater Flooding ................................................................................................. 47 6.6 Sewer Flooding ............................................................................................................ 48 7 Flood Defences .......................................................................................................................... 50 7.1 Types of Flood Defences ............................................................................................ 50 7.2 Green Park Flood Management Strategy (GPFMS) ................................................... 50 7.3 RBC Asset Register..................................................................................................... 52 8 Historic Fluvial Flooding Records ........................................................................................... 53 8.1 Historic Fluvial Flood Events ....................................................................................... 53 8.2 Thames and Kennet Lock Records ............................................................................. 54 9 Overview of Flood Risk across Borough ................................................................................ 58 9.1 RBC Character Areas .................................................................................................. 58 9.2 Reading North – Caversham, Hemdean Bottom and Emmer Green .......................... 58 9.3 Central Reading ........................................................................................................... 60 9.4 Reading South/East – The Mount, Earley, Whitley and Whitley Wood ....................... 61 9.5 Reading West – Tilehurst and Southcote .................................................................... 63 10 Planning and New Development Considerations .................................................................. 65 10.1 Definition of NPPF Flood Zones .................................................................................. 65 10.2 Consideration of Climate Change ............................................................................... 66 10.3 Residual Risk of Flooding ............................................................................................ 69 10.4 Site Specific FRA Requirements ................................................................................. 70 10.5 EA Engagement .......................................................................................................... 71 11 Flood Risk Management - Planning ........................................................................................ 73 11.1 Sequential Approach to Locating Development .......................................................... 73 11.2 Flood Risk Vulnerability and Compatibility .................................................................. 73 11.3 Application of the Sequential Test ............................................................................... 75 11.4 Undertaking the Exception Test .................................................................................. 76 J:\27560 RBC LLFA support\4002 - Reading 2 SFRA\wp\Report\27560_4001_Reading SFRA_rmf_June17.docx Reading Borough Council Strategic Flood Risk Assessment 12 Flood Risk Management - Design ............................................................................................ 77 12.1 Reducing Flood Risk through Design .......................................................................... 77 12.2 Sequential Approach ................................................................................................... 77 12.3 Ground Floor Levels .................................................................................................... 77 12.4 Building Design ............................................................................................................ 78 12.5 Floodplain Storage Capacity ....................................................................................... 79 12.6 Conservation of Flow Routes ...................................................................................... 80 12.7 Safe Access Arrangements