Royal Borough of Windsor & Maidenhead Local Flood Risk Management Strategy Published in December 2014 RBWM Local Flood Risk Management Strategy December 2014 2 RBWM Local Flood Risk Management Strategy December 2014 TABLE OF CONTENTS PART A: GENERAL INFORMATION .............................................................................................8 1 Introduction ......................................................................................................................8 1.1 The Purpose of the Strategy ...........................................................................................8 1.2 Overview of the Royal Borough of Windsor and Maidenhead ................................................9 1.3 Types of flooding ....................................................................................................... 11 1.4 Who is this Strategy aimed at? .....................................................................................12 1.5 The period covered by the Strategy ...............................................................................12 1.6 The Objectives of the Strategy ......................................................................................12 1.7 Scrutiny and Review ...................................................................................................13 2 Legislative Context ..........................................................................................................14 2.1 The Pitt Review .........................................................................................................14 2.2 EU Floods Directive & Flood Risk Regulations (2009) ........................................................14 2.3 Flood and Water Management Act 2010 .........................................................................14 2.4 The National Flood and Coastal Erosion Risk Management Strategy ....................................15 2.5 The Localism Act 2011 ................................................................................................15 2.6 Water Resources Act 1991 ...........................................................................................16 2.7 Highways Act 1980 .....................................................................................................16 2.8 Making Space for Water 2004 .......................................................................................16 2.9 Civil Contingencies Act 2004 ........................................................................................16 2.10 Reservoirs Act 1975 ...................................................................................................17 2.11 The Conservation of Habitats and Species Regulations (2010) ............................................17 2.12 Water Environment Regulations (2003) ..........................................................................17 2.13 River Basin Management Plans (RBMP) .........................................................................17 2.14 The Land Drainage Act 1991 ........................................................................................18 2.15 Thames Catchment Flood Management Plan (CFMP) 2009 ................................................18 The Lower Thames ....................................................................................................18 The Addlestone Bourne, Emm Brook, The Cut .................................................................19 Windsor & Maidenhead ...............................................................................................19 2.16 Planning Policy ..........................................................................................................19 3 RBWM Local Flood Risk Management Strategy December 2014 3 Roles and Responsibilities ...............................................................................................21 3.1 Why define roles and responsibilities? ............................................................................21 3.2 Key Agencies involved in the management of flood risk within the Royal Borough of Windsor and Maidenhead ................................................................................. 21 3.3 Risk Management Authorities in the Royal Borough of Windsor and Maidenhead ....................22 The Royal Borough of Windsor and Maidenhead Council as the Lead Local Flood Authority ......22 The Royal Borough of Windsor and Maidenhead Council as the Highway Authority .................23 The Environment Agency .............................................................................................23 National Strategic Role ...............................................................................................23 Local Operational Role ................................................................................................24 Emergency Planning ..................................................................................................24 Planning Process .......................................................................................................24 Main Rivers ..............................................................................................................24 Consenting Works to Main Rivers ..................................................................................26 Reservoirs ................................................................................................................26 Thames Water Utilities ................................................................................................26 The DG5 Register ......................................................................................................27 Tackling sewer flooding ...............................................................................................27 3.4 Other Groups and Stakeholders ....................................................................................27 The Royal Borough of Windsor and Maidenhead Council as Planning Authority ......................27 Riparian Owners ........................................................................................................27 Residents and Businesses ...........................................................................................28 Town and Parish Councils ............................................................................................28 Highways Agency ......................................................................................................28 The Thames Regional Flood and Coastal Committee (RFCC) .............................................29 Thames Valley Local Resilience Forum ..........................................................................29 Royal Borough Flood Forum ........................................................................................29 The Parish Flood Group ..............................................................................................29 Residents Associations ...............................................................................................29 Developers ...............................................................................................................29 3.5 Risk Management Authority Cooperation ........................................................................30 Berkshire Five Strategic and Technical Groups.................................................................30 4 RBWM Local Flood Risk Management Strategy December 2014 PART B: SPECIFIC INFORMATION ............................................................................................31 4 Understanding Flood Risk within the Royal Borough of Windsor and Maidenhead ..................31 4.1 Overview of flood risk in the Royal Borough of Windsor and Maidenhead ..............................31 Rivers and Waterbodies ..............................................................................................31 Geology ...................................................................................................................31 Topography ..............................................................................................................34 Environmentally Sensitive Sites ....................................................................................34 4.2 Existing Information on Flood Risk .................................................................................37 Surface Water Flooding ...............................................................................................38 Updated Flood Map for Surface Water............................................................................38 Groundwater Flooding ................................................................................................40 Main River and Ordinary Watercourse Flooding ................................................................42 Sewer Flooding .........................................................................................................42 Highway Flooding ......................................................................................................42 Reservoir Flooding .....................................................................................................42 Combined flooding .....................................................................................................44 4.3 Changes to current and future Flood Risk .......................................................................44 Assessment