River Wensum Restoration Strategy Implementation SSSI Unit 47 Tatterford Common to Fakenham Mill FEASIBILITY & ENVIRONMENTAL SCOPING ASSESSMENT November 2011 Reference number/code We are The Environment Agency. It's our job to look after your environment and make it a better place - for you, and for future generations. Your environment is the air you breathe, the water you drink and the ground you walk on. Working with business, Government and society as a whole, we are making your environment cleaner and healthier. The Environment Agency. Out there, making your environment a better place. Published by: Environment Agency Anglian Region, Eastern Area Dragonfly House 2 Gilders Way Norwich NR Tel: 03708 506 506 Email: [email protected] www.environment-agency.gov.uk © Environment Agency All rights reserved. This document may be reproduced with prior permission of the Environment Agency. River Wensum Restoration Strategy Implementation SSSI Unit 47: Feasibility and Environmental Scoping Report River Wensum Restoration Strategy Implementation SSSI Unit 47 Tatterford Common to Fakenham Mill Feasibility & Environmental Scoping Assessment September 2011 Notice This report was produced by Atkins for the Environment Agency for the specific purpose of assessing the feasibility of restoring favourable condition to the River Wensum SSSI. This report may not be used by any person other than the Environment Agency without Environment Agency express permission. In any event, Atkins accepts no liability for any costs, liabilities or losses arising as a result of the use of or reliance upon the contents of this report by any person other than the Environment Agency. Document History JOB NUMBER: 5078052 DOCUMENT REF: 5078052/60/DG/069 Revision Purpose Description Originated Checked Reviewed Authorised Date v.01 Initial Draft Ian Morrissey Kevin Skinner 20/08/2010 Final Draft Final draft for internal review Ian Morrissey Aurelie Paoli Kevin Skinner Don Ross 14/10/2010 Final Final for issue Ian Morrissey Aurelie Paoli Kevin Skinner Don Ross 8/09/2011 Final For publication Ian Morrissey Ellen Derbyshire Kevin Skinner Don Ross 4/11/2011 Unit 47 Tatterford Common to Fakenham Mill_Final.docx River Wensum Restoration Strategy Implementation SSSI Unit 47: Feasibility and Environmental Scoping Report Contents Section Page Non Technical Summary 1 1. Introduction 3 1.1 Context 3 1.2 River Wensum Restoration Strategy 7 1.3 Feasibility Assessment aims 9 1.4 Methodology 9 2. Tatterford Common to Fakenham Mill Overview 12 2.1 Terminology and site location 12 2.2 Previous works within Unit 47 15 2.3 RWRS restoration vision for Unit 47 15 3. Environmental Baseline 17 3.1 Introduction 17 3.2 Common environment features across all reaches 18 3.3 Environmental baseline for each reach within Unit 47 31 4. Consultation 61 4.1 Introduction 61 4.2 Consultation with key stakeholders 61 4.3 Drop-in session September 2009 63 4.4 Future consultation 63 5. Multi-Criteria Analysis Options Appraisal 65 5.1 Introduction 65 5.2 Constructing the MCA tool 65 5.3 Using the MCA tool 71 6. Developing Conceptual Design 83 6.1 Introduction and approach 83 6.2 Description of River Restoration and Targeted Maintenance options 83 6.3 Reach 26: Fakenham Reach 91 6.4 Reach 27: Hempton Reach 95 6.5 Reach 28: Moor Reach 99 6.6 Reach 29: Shereford Reach 105 6.7 Reach 30: South Mill Reach 110 6.8 Reach 31: Confluence Reach 114 7. Cost Estimate 118 7.1 Previous cost estimates 118 7.2 Present cost estimates 119 7.3 Potential cost savings 120 7.4 Delivery 123 7.5 Summary 125 8. Scoping 128 8.1 Introduction 128 8.2 Method of assessment 130 8.3 Results of scoping 131 Unit 47 Tatterford Common to Fakenham Mill_Final.docx River Wensum Restoration Strategy Implementation SSSI Unit 47: Feasibility and Environmental Scoping Report 9. Consents 139 10. Project Risks 141 11. Conclusions and Recommendations 143 11.1 Conclusions 143 11.2 Recommendations 144 12. References 145 Appendices 147 Appendix A – Multi-Criteria Analysis technical note Appendix B – Costings Appendix C – Ecology tables Appendix D – Terrestrial SSSI unit links to River Wensum SSSI units List of Figures Figure 1.1- Unit 47 River Wensum location plan 4 Figure 1.2 – Environmental and restoration related investigations and events, showing how this assessment fits within the process of realising restoration on the River Wensum 6 Figure 1.3 - The approach adopted during feasibility assessment for determining the recommended restoration option on individual reaches and the overall river unit 10 Figure 2.1 - Location of Reaches 26 to 31 within Unit 47 14 Figure 3.1 - Environmental constraints on Unit 47 27 Figure 3.2 - Environmental baseline for Reach 26 (Fakenham Reach) 34 Figure 3.3 - Environmental baseline for Reach 27 (Hempton Reach) 38 Figure 3.4 - Environmental baseline for Reach 28 (Moor Reach) 42 Figure 3.5 - Environmental baseline for Reach 29 (Shereford Reach) 46 Figure 3.6 - Environmental baseline for Reach 30 (South Mill Reach) 49 Figure 3.7 - Environmental baseline for Reach 31 (Confluence Reach) 52 Figure 6.1 - Conceptual restoration plan for Reach 26 (Fakenham Reach) 94 Figure 6.2 - Conceptual restoration plan for Reach 27 (Hempton Reach) 98 Figure 6.3 - Conceptual restoration plan for Reach 28 (Moor Reach) 104 Figure 6.4 - Conceptual restoration plan for Reach 29 (Shereford Reach) 109 Figure 6.5 - Conceptual restoration plan for Reach 30 (South Mill Reach) 113 Figure 6.6 - Conceptual restoration plan for Reach 31 (Confluence Reach) 117 Figure 8.1 - Environmental Scoping within the EIA process 129 List of Tables Table 1.1 - Chapters constituting this report 7 Table 2.1- Summary of previous restoration works consented on Unit 47 (JBA, 2007) 15 Table 2.2 - Recommended restoration measures for each reach in Unit 47 as provided in the RWRS (JBA, 2007) 16 Table 3.1 - Mill details in Unit 47 (Environment Agency, 2007) 24 Table 3.2 - Water quality (Environment Agency, 2010) 25 Table 3.3 - Condition summary of Unit 47 attributes (Natural England, 2010) 26 Table 3.4 - Baseline information common to Unit 47 28 Table 3.5 - Baseline information specific to Reach 26 (Fakenham Reach) 31 Table 3.6 - Baseline information specific to Reach 27 (Hempton Reach) 35 Table 3.7 - Baseline information specific to Reach 28 (Moor Reach) 39 Table 3.8 - Baseline information specific to Reach 29 (Shereford Reach) 43 Unit 47 Tatterford Common to Fakenham Mill_Final.docx River Wensum Restoration Strategy Implementation SSSI Unit 47: Feasibility and Environmental Scoping Report Table 3.9 - Baseline information specific to Reach 30 (South Mill Reach) 47 Table 3.10 - Baseline information specific to Reach 31 (Confluence Reach) 50 Table 4.1 - Consultation undertaken to date (August 2010) 61 Table 5.1 - Overview of the process by which the MCA was constructed and applied 65 Table 5.2 - Restoration measures recommended in previous studies 66 Table 5.3 - Options identified for restoration on the River Wensum 67 Table 5.4 - Description of river restoration measures as defined under option G5 68 Table 5.5 - Criteria defined for the MCA 70 Table 5.6 - Scoring system defined for the Multi-Criteria Analysis 71 Table 5.7 - Results of MCA for Reach 26 (Fakenham Reach) 73 Table 5.8 - Results of MCA for Reach 27 (Hempton Reach) 74 Table 5.9 - Results of MCA for Reach 28 (Moor Reach) 75 Table 5.10 - Results of MCA for Reach 29 (Shereford Reach) 76 Table 5.11 - Results of MCA for Reach 30 (South Mill Reach) 77 Table 5.12 - Results of MCA for Reach 31 (Confluence Reach) 78 Table 5.13 - Summary of favourable options and measures for Unit 47 81 Table 6.1 - Different management classes of restoration activity 84 Table 6.2 - Active and passive river restoration measures 84 Table 6.3 - River restoration measures and their potential ecological benefits 87 Table 6.4 - The effect of river restoration measures according to flow condition 89 Table 6.5 - Significant features and possible measures observed for Reach 26 during site visit 91 Table 6.6 - Review of strategy objectives and recommendations for Reach 26 92 Table 6.7 - Recommended restoration options for Reach 26 93 Table 6.8 - Significant features and possible measures observed for Reach 27 during site visit 95 Table 6.9 - Review of strategy objectives and recommendations for Reach 27 96 Table 6.10 - Recommended restoration options for Reach 27 97 Table 6.11 - Significant features and possible measures observed for Reach 28 during site visit 99 Table 6.12 - Review of strategy objectives and recommendations for Reach 28 101 Table 6.13 - Recommended restoration options for Reach 28 102 Table 6.14 - Significant features and possible measures observed for Reach 29 during site visit 105 Table 6.15 - Review of strategy objectives and recommendations for Reach 29 106 Table 6.16 - Recommended restoration options for Reach 29 107 Table 6.17 - Significant features and possible measures observed for Reach 30 during site visit 110 Table 6.18 - Review of strategy objectives and recommendations 111 Table 6.19 - Recommended restoration options for Reach 30 112 Table 6.20 - Significant features and possible measures observed for Reach 31 during site visit 114 Table 6.21 - Review of strategy objectives and recommendations 115 Table 6.22 - Recommended restoration options for Reach 31 115 Table 7.1 - RWRS Unit 47 cost estimate (JBA, 2007) 118 Table 7.2 - Halcrow PSA Unit 47 cost estimate 119 Table 7.3 - Comparison of cost estimates between JBA and Halcrow reports for Unit 47 119 Table 7.4 - Unit 47 cost estimates for various