Our Local Plan Strategic Flood T Risk Assessment 1 r ._,and � Update September 2015 Revision Schedule Date Details Prepared by Reviewed by Approved by September Draft SFRA update Matthew Marie Surtees Sarah 2015 Chapman Thompson December SFRA update Matthew Marie Surtees Planning Policy 2015 Chapman Committee Planning Policy Tandridge District Council The Council Offices 8 Station Road East Oxted, Surrey RH8 0BT 1 Executive Summary This Tandridge District Council Strategic Flood Risk Assessment (SFRA) 2015 Update report updates the Tandridge District Strategic Flood Risk Assessment 2007. This report has been prepared to update the work that was included in the previous SFRA and provide appropriate supporting evidence for Tandridge District Local Plan. Since the previous SFRA there have been a number of changes to the planning system, including the Localism Act (2011) and the 2012 National Planning Policy Framework (NPPF) with accompanying Planning Practice Guidance (March 2014). In addition, the provisions of the Flood and Water Management Act (2010) have been substantially commenced under a programme that was initiated by Defra in April 2010 and the Flood Risk Regulations came into force in December 2009 (these regulations transposed the EU Floods Directive into UK law). SFRA objectives There are two levels of SFRAs . Level One: where flooding is not a major issue and where development pressures are low. The Assessment should be sufficiently detailed to allow application of the Sequential Test. Level Two: where land outside flood risk areas cannot appropriately accommodate all the necessary development and the NPPF’s Exception Test needs to be applied. The Assessment should consider the detailed nature of the flood characteristics within a flood zone. An SFRA was completed in 2007 that formed part of the evidence base for the examination into the Tandridge District Core Strategy. The report comprised of a level one desk-based study that used existing information to carry out an assessment that was proportionate to the risk and appropriate to the scale, nature and location of development. The objectives of this SFRA is to update and review the 2007 SFRA which covers the whole of the District and if required a more detailed assessment of potential employment and housing allocations emerging through the Local Plan process. SFRA outputs This report is a level one Strategic Flood Risk Assessment and as set out in the Planning Practice Guidance it “should be sufficiently detailed to allow application of the Sequential Test to the location of development and to identify whether development can be allocated outside high and medium flood risk areas, based on all sources of flooding, without application of the Exception Test” (Paragraph: 012 Reference ID: 7-012-20140306). Summary The findings of this updated SFRA have fed into the Housing and Economic Land Availability Assessment and assisted in the development of the strategic policies options within the Regulation 18 consultation paper. If site allocations are necessary at the regulation 19 stage to deliver the amount of housing that is required within the Local Plan, the SFRA, along with the Caterham Bourne Flood Alleviation Project, the Burstow Flood Alleviation Project, and the modelling of the River Eden will provide the necessary information required to undertake the site specific assessments. This will ensure that any allocation of sites will take account of the long term solutions to flooding within the district, particularly if the acquisition of land is required to deliver a flood alleviation scheme. The SFRA presents Flood Zone Maps that outline the Environment Agency flood zones as Flood Zone 1, low probability, Flood Zone 2, medium probability and Flood Zone 3a, high probability. In addition, the map from the Environment Agency showing the risk of flooding from surface water and ground water have played a key role within this SFRA. The application of the Sequential Test (and where appropriate, the Exception Test) in order to steer vulnerable development away from 2 areas of flood risk, remains a fundamental part of the planning process and these maps have been used in the assessment and will be used in the future for the assessment of the site allocations. Recommendations This Level 1 SFRA report has been developed by building heavily upon existing knowledge with respect to flood risk within the district. The report has not been prepared to consider site-specific allocations, instead, it has informed the development of the Strategic Options (Regulation 18) consultation. As mentioned above there are three key pieces of modelling that are being carried out: . Caterham Bourne Flood Alleviation Project; . Burstow Flood Alleviation Project; and . Environment Agency modelling of the flood zones 2 and 3 in the River Eden catchment. Once these projects are completed the SFRA will be updated so that the information contained within them will assist in the flood risk assessment for the site allocations. In summary, the SFRA is a ‘living’ document and will be reviewed regularly in light of emerging policy directives and an improving understanding of flood risk within the district. Proceeding with the SFRA in the production of the Local Plan: . The Council will apply the Sequential Test to the potential development sites and identify those sites they consider will be necessary to apply the Exception Test; . The layout of buildings and access routes should adopt a sequential approach, steering buildings (and hence people) towards areas of lowest risk within the boundaries of the site. This will also ensure that the risk of flooding is not worsened by, for example, blocked flood flow routes. Consultation with Surrey County Council as the Local Lead Flood Authority and the Environment Agency following completion of the Exception Test will be carried out to ensure that they accept the justification for progressing with sites that require the Exception Test; and . The SFRA outputs will be used by the district to assess flood risk to windfall sites which become available for redevelopment. If such sites require the Exception Test a site-specific flood risk assessment will be needed to be considered sound. 3 Contents Executive Summary .............................................................................................................. 2 Introduction ........................................................................................................................... 5 The Planning Framework, Flood Risk Policy and catchment studies ................................... 12 Roles and responsibilities in the management of flood risk ................................................. 16 Overview of Geology and Topography in Tandridge District ................................................ 21 Flood defences ................................................................................................................... 23 Flooding from artificial sources ............................................................................................ 25 Overview of types of flooding .............................................................................................. 27 Historic flood events and sources of flooding by area.......................................................... 31 Overview of all development options ................................................................................... 45 Flood risk management in the Local Plan ............................................................................ 48 Conclusions and recommendations .................................................................................... 51 Appendix 1 Advice Note on contents of a Sustainable Drainage Statement ........................ 52 Appendix 2: Flood event records from the three catchments ............................................... 62 Appendix 3 Topographic map ............................................................................................. 63 Appendix 4 Map showing areas at risk from river flooding ................................................... 64 Appendix 5 Map showing areas at risk from surface water flooding .................................... 65 Appendix 6 Map showing areas at risk of groundwater flooding .......................................... 66 4 Introduction Purpose of the Strategic Flood Risk Assessment This Tandridge District Council Strategic Flood Risk Assessment (SFRA) 2015 Update report updates the Tandridge District Strategic Flood Risk Assessment 2007. This report has been prepared to update the work that was included in the previous SFRA and provide appropriate supporting evidence for Tandridge District Local Plan. Since the previous SFRA there have been a number of changes to the planning system, including the Localism Act (2011) and the 2012 National Planning Policy Framework (NPPF) with accompanying Planning Practice Guidance (March 2014). In addition, the provisions of the Flood and Water Management Act (2010) have been substantially commenced under a programme that was initiated by Defra in April 2010 and the Flood Risk Regulations came into force in December 2009 (these regulations transposed the EU Floods Directive into UK law). The planning practice guidance provides a summary diagram of how flood risk should be taken into account in the preparation of Local plans, this is set out below. 5 Figure 1 Taking flood risk into account in the preparation of a Local Plan Local planning authority undertakes a level 1 strategic