Strategic Flood Risk Assessment - July 2016 WYRE BOROUGH COUNCIL STRATEGIC FLOOD RISK ASSESSMENT July 2016 Strategic Flood Risk Assessment - July 2016 CONTENTS 1.0 INTRODUCTION ........................................................................................... 4 What is a Strategic Flood Risk Assessment? ................................................ 4 Wyre Strategic Flood Risk Assessment ......................................................... 5 Purpose of the Strategic Flood Risk Assessment .......................................... 6 2.0 STUDY AREA ............................................................................................... 8 3.0 POLICY CONTEXT ..................................................................................... 12 Flood Risk Regulations (2009) .................................................................... 12 Flood and Water Management Act (2010) ................................................... 12 National Planning Policy Framework ........................................................... 13 National Planning Practice Guidance .......................................................... 14 4.0 SEQUENTIAL AND EXCEPTION TESTS ................................................... 16 Sequential Test ............................................................................................ 16 Exception Test ............................................................................................. 18 5.0 OVERVIEW OF KEY ROLES AND RESPONSIBILITIES ........................... 22 6.0 RELEVANT STUDIES ................................................................................. 24 7.0 HISTORIC FLOODING ............................................................................... 34 8.0 TOPOGRAPHY, HYDROLOGY AND GEOLOGY AND SOILS .................. 37 Topography ................................................................................................. 37 Hydrology .................................................................................................... 37 Geology and Soils ....................................................................................... 37 9.0 EXISTING FLOOD RISK ............................................................................. 40 River and Sea Flooding ............................................................................... 40 Surface Water Flooding ............................................................................... 42 Groundwater Flooding ................................................................................. 44 Sewer Flooding ............................................................................................ 46 Flooding from Artificial Sources ................................................................... 49 10.0 FUNCTIONAL FLOODPLAIN ..................................................................... 51 11.0 FLOOD DEFENCES ................................................................................... 53 12.0 CLIMATE CHANGE .................................................................................... 54 13.0 SCOPING STUDY OF THE BOROUGH ..................................................... 56 14.0 CONCLUSIONS .......................................................................................... 58 Page 2 of 58 Strategic Flood Risk Assessment - July 2016 ABBREVIATIONS Abbreviation Definition AAP Area Action Plan AMP Asset Management Plan AONB Area of Outstanding Natural Beauty CFMP Catchment Flood Management Plan Defra Department for Environment, Food and Rural Affairs EA Environment Agency FRA Flood Risk Assessment FRMP Flood Risk Management Plan FWMA Flood and Water Management Act (2010) IDB Internal Drainage Board LCC Lancashire County Council LFRMS Local Flood Risk Management Strategy LLFA Lead Local Flood Authority LPA Local Planning Authority NFCDD National Flood and Coastal Defence Database NPPF National Planning Policy Framework NPPG National Planning Practice Guidance PFRA Preliminary Flood Risk Assessment PPG Planning Policy Guidance PPS Planning Policy Statement SAB SuDS Approval Body SFRA Strategic Flood Risk Assessment SMP Shoreline Management Plan SuDS Sustainable Drainage Systems Page 3 of 58 Strategic Flood Risk Assessment - July 2016 1.0 INTRODUCTION 1.1 Wyre Borough Council is in the process of producing a new Local Plan. This plan will set out the vision and planning and development strategy for the borough to 2031 and will comprise of a series of policies, site allocations and land designations. The Local Plan will be adopted in 2017. Once adopted, it will form the statutory Development Plan for Wyre and will replace the “saved” policies in the Local Plan 1999 and the Fleetwood-Thornton Area Action Plan (AAP). 1.2 Previously, the intention was to prepare a two-part Local Plan. This was to comprise of a Part 1 document (originally called the Core Strategy) setting out the strategic direction for the Local Plan, which was to be followed by a Part 2 document (originally called the Allocations Plan) that would identify the sites to help deliver the agreed strategy. As a consequence of the publication of the National Planning Policy Framework (NPPF) in March 2012 and the National Planning Policy Guidance (NPPG) in March 2014, and the updating of key evidence base documents, the Council has decided to prepare a single Local Plan (rather than two separate planning documents). This single Local Plan will both set out the strategic direction for the Borough and identify sites to deliver this strategy. What is a Strategic Flood Risk Assessment? 1.3 Although flooding is a natural process that cannot be wholly prevented, good planning and management of the risk and consequence of flooding can help avoid and reduce the threat posed to people and property. 1.4 All forms of flooding and their impact on the natural and built environment are material planning considerations. Local planning authorities (LPAs) are therefore required to take flood risk into account at all stages of the planning process in order to avoid inappropriate development in areas at risk of flooding. Where new development is exceptionally necessary in such areas, appropriate action and mitigation should be taken to make it safe without increasing the risk elsewhere and, where possible, reducing overall risk. 1.5 A Strategic Flood Risk Assessment (SFRA) is a study carried out by one or more LPAs to assess the risk to an area from flooding from all sources, now and in the future, taking account of the impacts of climate change, and to assess the impact that land use changes and development in the area will have on flood risk. Page 4 of 58 Strategic Flood Risk Assessment - July 2016 1.6 The NPPF states that Local Plans should be supported by a SFRA and their findings should be used to inform strategic land use planning. The NPPG advocates a tiered approach to risk assessment and identifies the following two levels of SFRA: • Level 1 – which is carried out in local authority areas where flooding is not a major issue and where development pressures are low. • Level 2 – which is carried out where a Level 1 Assessment shows that land outside of flood risk areas cannot appropriately accommodate all the necessary development. Wyre Strategic Flood Risk Assessment 1.7 As part of the evidence base to inform the preparation of the Local Plan Part 1 document (Core Strategy), a SFRA was produced in 2007. This SFRA identified flood zones for the Borough, established potential sources and pathways of flooding, considered the likely effects of climate change on flood risk and examined future development proposals, residual flood risks and appropriate mitigation measures. The SFRA highlighted that flood risk is a significant issue for the borough and, in particular, identified that over fifty percent of the current housing stock lies within an area that is at a high probability of flooding from tidal or fluvial sources. 1.8 The threat of flooding and the minimisation of flood risk is therefore a key priority and the Council takes its responsibilities with respect to the maintenance and improvement of flood protection assets and the promoting sustainable development very seriously The SFRA will therefore form a key part of the evidence base for the new Wyre Local Plan, ensuring that future development takes full account of flood risk and sustainability at the outset. 1.9 To provide appropriate supporting evidence to inform the preparation of the Local Plan there is a recognised need for the previous SFRA to be replaced. In particular, the existing SFRA will require updating to take into account changes to policy, legislation and guidance. There have also been updates to some of the data sets used to inform the SFRA. In addition, as the single Local Plan will allocate sites for development, an updated SFRA is required to provide a more detailed analysis of the level of flood risk at potential site allocations identified through the local plan process. 1.10 Although the SFRA will consider the risk of flooding from all sources, the Flood Map for Planning prepared by the Environment Agency (EA) provides a key input for the study. This map defines the following Flood Zones which Page 5 of 58 Strategic Flood Risk Assessment - July 2016 refer to the probability of river and sea flooding, ignoring the presence of defences. Figure 1-1: Flood Zones Flood Zone Definition Zone 1 – Low Probability Land having a less than 1 in 1,000 annual probability of river or sea flooding. Zone 2 – Medium Land having between