Appendices Appendix 9A: Flood Risk Assessment
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Preliminary Environmental Information Report Volume III - Appendices Appendix 9A: Flood Risk Assessment The Infrastructure Planning (Environmental Impact Assessment) Regulations 2017 (as amended) Prepared for: Net Zero Teesside Power Ltd. & Net Zero North Sea Storage Ltd. Appendix 9A Flood Risk Assessment Table of Contents 9A. Flood Risk Assessment ................................................................................ 9-1 9.1 Introduction ................................................................................................... 9-1 9.2 Purpose and Scope of the Assessment ........................................................ 9-1 9.3 Data Sources ................................................................................................ 9-2 9.4 Site Information ............................................................................................ 9-4 9.5 The Proposed Development ....................................................................... 9-19 9.6 Planning Policy ........................................................................................... 9-23 9.7 Flood Risk Sources .................................................................................... 9-39 9.8 Management of Surface Water from the Site .............................................. 9-51 9.9 Mitigation of Residual Flood Risks and Off-Site Impacts ............................ 9-55 9.10 Summary and Conclusions ......................................................................... 9-62 9.11 References ................................................................................................. 9-64 Annex 9A- Consultation Responses ...................................................................... 9-67 Tables Table 9A-1: Sources of Data .................................................................................. 9-3 Table 9A-2: Surface Waterbodies ........................................................................... 9-6 Table 9A-3: Geology ............................................................................................. 9-16 Table 9A-4: Hydrogeology ..................................................................................... 9-17 Table 9A-5: Flood Zone Definitions ...................................................................... 9-26 Table 9A-6: Flood Risk Vulnerability and Flood Zone Compatibility ..................... 9-28 Table 9A-7: Sea level allowance for each epoch in millimetres (mm) per year with total sea level rise for each epoch in brackets (use 1981 to 2000 baseline) ......... 9-29 Table 9A-8: Climate Change Allowances to apply based upon the Flood Zone and Development Lane Use Vulnerability .................................................................... 9-29 Table 9A-9: EA Peak River Flow Climate Change Allowances for the Northumbria River Basin District ................................................................................................ 9-30 Table 9A-10: EA Peak Rainfall Intensity Climate Change Allowances across England .............................................................................................................................. 9-30 Table 9A-11: Relevant RCBC Local Planning Policies ......................................... 9-34 Table 9A-12: Relevant STBC Local Planning Policies .......................................... 9-35 Table 9A-13: Records of Historical Flooding ........................................................ 9-40 Table 9A-14: Modelled water levels for the Tidal River Tees ................................ 9-43 Table 9A-15: Summary of Key Flood Risks to the Proposed Development .......... 9-50 Table 9A-16: Relevant Defra SuDS Non-Statutory Technical Standards .............. 9-53 Table 9A-17: SuDS Components.......................................................................... 9-54 Net Zero Teesside Power Ltd. & Net Zero North sea Storage Ltd. Appendix 9A Flood Risk Assessment 9A. Flood Risk Assessment 9.1 Introduction 9.1.1 This Flood Risk Assessment (FRA) has been prepared on behalf of Net Zero Teesside Power Limited (NZT Power) and Net Zero North Sea Storage Limited (NZNS Storage) for the Net Zero Teesside (NZT) Carbon Capture, Utilisation and Storage (CCUS) project on land at Redcar and Stockton-on-Tees on Teesside. 9.1.2 The Site boundary is shown on Figure 3-1: Site Boundary Plan (Preliminary Environmental Information (PEI) Report, Volume II). The area within this boundary is defined as the “Site”. This boundary is provisional and for the purposes of the PEI Report only. The final Site boundary for the purposes of the DCO application, including land for the connection corridors and temporary land required during construction of the Proposed Development, will be refined through on-going studies and taking into account the responses to the statutory consultation. 9.1.3 For the purposes of this report the terms used to identify the various parts of the Site are outlined below and are consistent with the terms used elsewhere in the PEI Report. 9.1.4 The Site is divided into the following areas (described in more detail in Chapter 4: Proposed Development (PEI Report, Volume I) and shown on the Figures below which are presented in PEI Report, Volume II: · The Power, Capture and Compressor site (PCC) (Figure 3-1); · Onshore CO2 Export Corridor (Figure 3-2A); · Electrical Connection Corridor (Figure 3-2C); · Water Connection Corridors (Figure 3-2D); · Natural Gas Connection Corridor (Figure 3-2B); and · CO2 Gathering Network Corridor (Figure 3-2E). 9.2 Purpose and Scope of the Assessment 9.2.1 The Environment Agency’s (EA) Flood Map for Planning (Rivers and Sea) (Environment Agency, n.d.a) indicates that the entire PCC is located within Flood Zone 1. Areas located within Flood Zone 1 are defined as having a ‘low risk’ of flooding from fluvial or tidal sources. The definition of flood zones, in accordance with the Planning Policy Guidance (PPG) (Department for Communities and Local Government, 2014) are summarised in Table 9A-3. 9.2.2 As shown on the EA’s ‘Flood Map for Planning’ (see Figure 9-4: Environment Agency Fluvial Flood Zones in PEI Report, Vol II) the connection corridors (the electrical grid connection, water abstraction and discharge, the onshore element of the CO2 Export Pipeline, connections to the National Gas Grid Prepared for: Net Zero Teesside Power Ltd. & Net Zero North sea Storage Ltd 9-1 Appendix 9A Flood Risk Assessment (NGG) and the CO2 Gathering Network) are located predominantly in Flood Zone 1, however some sections of these connection corridors are located in Flood Zone 2 (medium risk of flooding from fluvial or tidal sources) and Flood Zone 3 (high risk of flooding from fluvial or tidal sources ), for example, where the connection corridor crosses a watercourse. 9.2.3 The NPPF and the PPG specify that applications for development proposals greater than 1 ha in area, or located in Flood Zone 2 or 3, should be accompanied by an FRA that identifies and assesses all forms of flooding to and from the development. A FRA should demonstrate how these flood risks will be managed so that the development remains safe throughout its lifetime, taking into account the vulnerability of the proposed development and the potential impact of climate change on risk. 9.2.4 The aim of this study is to undertake a FRA that is appropriate to the nature and scale of the Proposed Development, which determines existing flood risk at the Site and arising from the Proposed Development, and, where required, recommends suitable mitigation measures. 9.2.5 The objectives of this report are to: · Collect and review existing information relating to the flood risk posed to the Proposed Development from all sources (e.g. fluvial, tidal, surface water, artificial, groundwater, drain and sewer flooding); · Consult with the EA and Lead Local Flood Authority (LLFA) in relation to flood risk and their requirements for management of any risk; · Assess the flood risk to the Proposed Development under existing and post-development conditions (taking into account climate change); and · Outline any mitigating measures needed to ensure the Proposed Development and its occupants will be safe for the lifetime of the development and to meet the requirements of the NPPF. 9.3 Data Sources 9.3.1 The baseline conditions for the Site have been established through a desk study including a review of publicly available information and supporting modelling and hydrology study reports (where available), and via consultation with the associated LLFAs and the EA. Relevant consultation responses are provided in Annex A1. This information has been utilised to inform the assessment made within the FRA. Data collected during the course of this assessment is described in Table 9A-1. 1 Not all data received has been included within Annex A due to file format and size of data files. This can be reviewed on request. Prepared for: Net Zero Teesside Power Ltd. & Net Zero North sea Storage Ltd 9-2 Appendix 9A Flood Risk Assessment Table 9A-1: Sources of Data Purpose Data Source Comment Identification of Hydrological 1: 25,000 Ordnance Survey Identifies the position of the site Features (OS) mapping and local hydrological features. Identification of Ground Levels 1: 25,000 Ordnance Survey Provides existing Site levels. (OS) mapping Identification of Existing Flood EA Indicative Flood Zone Map Identifies fluvial/ tidal inundation Risk extents and historical flooding. EA Long-term Flood Information Provides information on the risk Mapping