GRIDLINK INTERCONNECTOR Scoping Report for a Marine Environmental Appraisal
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GRIDLINK INTERCONNECTOR Scoping Report for a Marine Environmental Appraisal P2114_R4493_Rev2 | 16 August 2018 Intertek Energy & Water Consultancy Services Exchange House, Station Road, Liphook, Hampshire GU30 7DW, United Kingdom GridLink Interconnector Scoping Report for a Marine Environmental Appraisal DOCUMENT RELEASE FORM GridLink Interconnector P2114_R4493_Rev2 Scoping Report for a Marine Environmental Appraisal Author/s Jill Hobbs Project Manager Authoriser Anna Farley Anna Farley Rev No Date Reason Author Checker Authoriser Rev 0 24/05/2018 Draft JH AF AF Rev 1 29/06/2018 Addressing client comments JH AF AF Rev 2 16/08/2018 Final for issue JH AF AF Intertek Energy & Water Consultancy Services is the trading name of Metoc Ltd, a member of the Intertek group of companies. I P2114_R4493_Rev2 | 16 August 2018 GridLink Interconnector Scoping Report for a Marine Environmental Appraisal CONTENTS DOCUMENT RELEASE FORM I 1. INTRODUCTION 1 1.1 Background 1 1.2 Scoping Opinion 1 2. THE PROPOSED DEVELOPMENT 3 2.1 Background 3 2.2 French Components of GridLink 3 2.3 Overview of the Proposed Development 3 2.4 Subsea HVDC Cables 8 2.5 Shore Crossing 14 2.6 Converter Station 15 2.7 Onshore HVAC Cables to NGET Kingsnorth Sub-station 17 2.8 Environmental Management of Construction of the Proposed Development 18 2.9 Operation and Maintenance of the Proposed Development 19 2.10 Decommissioning 20 3. REGULATORY CONTEXT 21 3.1 Introduction 21 3.2 Need for EIA in the UK 21 3.3 Need for EIA in France 21 4. SCOPING METHODOLOGY 22 4.1 Introduction 22 4.2 Scoping Methodology 22 4.3 Consultation 24 5. SEABED SEDIMENTS AND PHYSICAL PROCESSES 26 5.1 Introduction 26 5.2 Baseline Conditions 26 5.3 Mitigation Measures 28 5.4 Potential Effects to be Excluded from the EA 28 II P2114_R4493_Rev2 | 16 August 2018 GridLink Interconnector Scoping Report for a Marine Environmental Appraisal 5.5 Potential Effects to be Included in the EA 29 5.6 Additional Baseline Information and Collection Methods 30 5.7 Appraisal of Potential Effects 30 6. PROTECTED SITES FOR NATURE CONSERVATION 31 6.1 Introduction 31 6.2 Protected Sites for Nature Conservation 31 6.3 Preliminary Consultations with Natural England and Joint Nature Conservation Committee 43 6.4 Appraisal of Potential Effects 43 6.5 Habitats Regulation Appraisal 44 6.6 Marine and Conservation Zone Assessment 44 7. BENTHIC ECOLOGY 46 7.1 Introduction 46 7.2 Baseline Conditions 46 7.3 Mitigation Measures 47 7.4 Potential Effects to be Excluded from the EA 47 7.5 Potential Effects to be Included in the EA 48 7.6 Additional Baseline Information and Collection Methods 49 7.7 Appraisal of Potential Effects 50 8. MARINE AND COASTAL BIRDS 51 8.1 Introduction 51 8.2 Baseline Conditions 51 8.3 Mitigation Measures 52 8.4 Potential Effects to be Excluded from the EA 52 8.5 Potential Effects to be Included in the EA 53 8.6 Additional Baseline Information and Collection Methods 53 8.7 Appraisal of Potential Effects 54 9. MARINE MAMMALS 55 9.1 Introduction 55 9.2 Baseline Conditions 55 9.3 Mitigation Measures 57 9.4 Potential Effects to be Excluded from the EA 57 III P2114_R4493_Rev2 | 16 August 2018 GridLink Interconnector Scoping Report for a Marine Environmental Appraisal 9.5 Potential Effects to be Included in the EA 58 9.6 Additional Baseline Information and Collection Methods 58 9.7 Appraisal of Potential Effects 59 10. FISHERIES 60 10.1 Introduction 60 10.2 Baseline Conditions 60 10.3 Mitigation Measures 66 10.4 Potential Effects to be Excluded from the EA 67 10.5 Potential Effects to be Included in the EA 68 10.6 Additional Baseline Information and Collection Methods 69 10.7 Appraisal of Potential Effects 70 11. HISTORIC ENVIRONMENT 71 11.1 Introduction 71 11.2 Baseline Conditions 71 11.3 Mitigation Measures 83 11.4 Potential Effects to be Excluded from the EA 84 11.5 Potential Effects to be Included in the EA 84 11.6 Additional Baseline Information and Collection Methods 84 11.7 Appraisal of Potential Effects 85 12. OTHER ENVIRONMENT ISSUES 86 12.1 Introduction 86 12.2 Water Quality 86 12.3 Shipping and Navigation 87 12.4 Third Party Infrastructure 88 12.5 Other Marine Users 88 12.6 Air Quality 88 13. SUMMARY 89 13.1 Scoping of Potential Effects of the Proposed Development 89 13.2 EA Structure 89 13.3 Impact Assessment Methodology 90 13.4 Cumulative Effects Assessment 95 IV P2114_R4493_Rev2 | 16 August 2018 GridLink Interconnector Scoping Report for a Marine Environmental Appraisal LIST OF TABLES AND FIGURES Tables Table 4-1 Pressure Description 23 Table 4-2 Consultations Undertaken to Date 24 Table 5-1 Effects on Seabed Sediments and Physical Processes to be Excluded from the EA 29 Table 5-2 Effects on Seabed Sediments and Physical Processes to be Included in the EA 29 Table 6-1 Natura 2000 sites crossed or within 10 km of the Proposed Development 32 Table 6-2 NATURA 2000 sites crossed or within 10 km of the Proposed Development 40 Table 7-1 Effects on Benthic Ecology to be Excluded from the EA 48 Table 7-2 Effects on Benthic Ecology to be Included in the EA 48 Table 8-1 Effects on Marine and Coastal Birds to be Excluded from the EA 52 Table 8-2 Effects on Marine and Coastal Birds to be Included in the EA 53 Table 9-1 Effects on Marine Mammals to be Excluded from the EA 57 Table 9-2 Effects on Marine Mammals to be Included from the EA 58 Table 10-1 Fish Species with Spawning and/or Nursery Grounds within the cable route 61 Table 10-2 Landing Values by Generic Species Types for ICES Rectangle 31F0 66 Table 10-3 Landing values by Generic Species Types for ICES Rectangle 31F1 66 Table 10-4 Effects on Fisheries to be Excluded from the EA 67 Table 10-5 Effects on Fisheries to be Included from the EA 68 Table 11-1 The details of the wrecks which are of particular interest (two of which are designated wrecks under the Protection of Wrecks Act) in the UKHO records are presented in Figures 11-7 to Figure 11-9.Known and Potential Marine Archaeological Receptors within 2 km of the Cable Route 73 Table 11-2 Known and Potential Marine Archaeological Receptors by Area 73 Table 11-3 Effects on Fisheries to be Excluded from the EA 84 Table 13-1 Summary of the Pressures to be Included Within the EA 89 Table 13-2 Criteria for characterising the magnitude of the impact 92 Table 13-3 Criteria for characterising the sensitivity of the receptor (receptor value) 93 Table 13-4 Significance matrix 94 Table 13-5 Definitions of significance levels 94 Figures Schematic of the GridLink project 3 V P2114_R4493_Rev2 | 16 August 2018 GridLink Interconnector Scoping Report for a Marine Environmental Appraisal Overview of the GridLink project 5 Alternative subsea cables routes in outer Thames Estuary 7 Cross-sections of subsea HVDC cable and bundled cable configuration 8 Schematic sectional view of the trench of the submarine cable 9 Schematic sectional view of rock placement over the submarine cable where seabed trenching is not feasible 10 Schematic sectional view of placement of concrete mattresses at crossing of third party infrastructure with protection by rock placement 10 Typical cable-lay vessel used to lay the subsea electricity cables 13 Typical cable-lay barge used to lay the subsea electricity cables 13 Profile of HDD shore crossing at Kingsnorth 14 Profile of HDD shore crossing at Kingsnorth 15 Illustration of HDD process 15 Converter station site within the Kingsnorth industrial area 16 Example of converter station design 16 Figure 2-15 Location of GridLink converter station and National Grid Kingsnorth 400 kV sub-station 17 Figure 2-16 Schematic of alternative configurations of underground double-circuit HVAC cable 18 Schematic Sediment Transport Pathways5 28 Medway Bass Nursery Area 62 Spawning and Nursery Grounds 63 Shellfish waters 65 Archaeological and Cultural Heritage Receptors Identified in the Intertidal Zone 72 Archaeological and Cultural Heritage Receptors Identified in the Medway Estuary 74 Archaeological and Cultural Heritage Receptors Identified in the Outer Thames Estuary Section 1 75 Archaeological and Cultural Heritage Receptors Identified in the Outer Thames Estuary Section 2 76 Archaeological and Cultural Heritage Receptors Identified in the Outer Thames Estuary Section 3 77 Archaeological and Cultural Heritage Receptors Identified in the southern North Sea 78 Potentially Important Wrecks and Aircraft Crashes in the Medway Estuary and Outer Thames Estuary 79 Potentially Important Wrecks and Aircraft Crashes in the Outer Thames Estuary 80 Potentially Important Wrecks and Aircraft Crashes in the southern North Sea 81 VI P2114_R4493_Rev2 | 16 August 2018 GridLink Interconnector Scoping Report for a Marine Environmental Appraisal 1. INTRODUCTION 1.1 Background GridLink Interconnector Limited (herein referred to as the “Applicant”) is intending to submit an application for a Marine Licence for the construction, operation and maintenance of a new electricity interconnector (herein referred to as “GridLink”) under the Marine and Coastal Access Act 2009, which will connect the UK and French electricity networks at Kingsnorth in Kent and Dunkerque in Nord region of France respectively. GridLink will be a high voltage direct current (HVDC) electricity interconnector with an approximate capacity of 1,400 megawatts (MW). HVDC is the most effective technology for the import or export of electricity over significant distances, with the system experiencing lower losses than an alternating current (AC) system. It requires a converter station at each end on the interconnector to convert the HVDC power to high voltage alternating current (HVAC) power for use within the UK and French national electricity networks.