River Clun SAC Nutrient Management Plan - FINAL Part 1 Evidence Base and Part 2 Options Appraisal
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River Clun SAC Nutrient Management Plan - FINAL Part 1 Evidence Base and Part 2 Options Appraisal Environment Agency and Natural England October 2014 River Clun SAC Nutrient Management Plan Notice This document and its contents have been prepared and are intended solely for the Environment Agency and Natural England’s information and use in relation to the River Clun SAC Nutrient Management Plan. ATKINS assumes no responsibility to any other party in respect of or arising out of or in connection with this document and/or its contents. This document has 269 pages including the cover. Document history Job number: 5120447 Document ref: Revision Purpose description Originated Checked Reviewed Authorised Date Rev 6.0 Final D Gasca C Allaway D Ross B Cox 23/10/14 Client signoff Client Environment Agency and Natural England Project River Clun SAC Nutrient Management Plan Document title River Clun SAC NMP Job no. 5120447 Copy no. 1 Document reference 70\Final report v6 \ River_Clun_NMP_v6 FINAL.docx Signatures Atkins River Clun SAC NMP_Version6.0_October 2014 River Clun SAC Nutrient Management Plan Table of contents Chapter Pages Executive Summary 8 1. Purpose of the Plan 13 Part one – Evidence and Supporting Information 23 2. Freshwater Pearl Mussel 24 3. Catchment Character 27 4. Water quality baseline 46 5. Pressures 62 6. Source apportionment 72 Part two – Options appraisal 93 7. Options appraisal 94 Part three – Conclusions and recommendations 121 8. Conclusions and recommendations 122 9. References 133 Appendix A. Comments 136 A.1. Summary 136 A.2. Severn Trent Water 137 A.3. AONB 138 A.4. Natural England 140 A.5. CLA 148 A.6. Environment Agency 150 A.7. NFU 157 Appendix B. Maps 173 Appendix C. Freshwater Pearl Mussel 174 C.1. Species details 174 C.2. Habitat requirements 174 C.3. Surveys 175 Appendix D. Flow estimation in the Clun catchment 177 D.1. Location of EA water level and spot flow monitoring around Leintwardine 177 D.2. Map showing the catchments of the River Clun (green) and Upper Teme (pink) 178 D.3. Table summarising the areas of different component water bodies of the Clun and Upper Teme catchments 178 D.4. Water level timeseries data 179 D.5. Spot flow data 180 D.6. Composite stage-discharge relationships for the River Clun and Upper Teme at Leintwardine 181 D.7. Test of how adequately spot flows are estimated using the composite stage-discharge relationship 182 D.8. Low flows check 182 D.9. Final flow time series and apportionment of flows in Clun vs Upper Teme based on area weighting (Appendix D3) 183 Appendix E. Land use 184 E.1. Defra agricultural census data 184 E.2. Pie-chart of catchment 185 E.3. Defra agricultural census 2010 data for sub-catchments of the River Clun 186 Atkins River Clun SAC NMP_Version6.0_October 2014 River Clun SAC Nutrient Management Plan E.4. Sub-catchments landcover summary piecharts (from CORINE 2006) 187 E.5. Defra robust farm types in the Clun catchment 188 E.6. Summary of number of land holdings in the Clun catchment by Defra Robust Farm type 189 E.7. Defra robust farm types in Clun sub-catchments 190 Appendix F. Mechanisms to address water pollution 191 F.1. Summary table 191 F.2. Delivery mechanisms 192 Appendix G. Environment Agency water quality sampling in the Clun catchment 197 G.1. Catalogue 198 G.2. Best data records 202 G.3. Complete records for the River Clun SAC at Leintwardine 203 Appendix H. Turbidity data 207 H.1. Picture of a turbidity sonde similar to that used by the EA 207 H.2. Suspended solids and turbidity relationship for the River Frome (Collins, 2008) 208 H.3. Suspended solids and turbidity relationship for sites in the River Teme, including MILL Lane at Leintwardine in the River Clun catchment (WRC, 2010) 208 H.4. SS vs turbidity (Clungunford and Purslow) 209 H.5. Spot samples vs continuous turbidity monitoring 210 Appendix I. Turbidity events 211 I.1. 8th June 2012 211 I.2. 15 June 2012 212 I.3. 7th July 2012 213 I.4. 14th July 2012 214 I.5. 29th August 2012 215 I.6. 24th September 2012 216 I.7. 21st – 27th November 2012 217 I.8. 7th December 2012 218 I.9. 14th December 2012 219 I.10. 20th December 2012 220 I.11. 27th – 31st December 2012 221 I.12. 27th January 2013 222 I.13. 31st January 2013 223 I.14. 10th February 2013 224 I.15. 14th February 2013 225 I.16. 17th March 2013 226 I.17. 23rd March 2013 227 Appendix J. Pressures tables 228 J.1. Consented discharges 228 J.2. Septic tanks 229 J.3. Estimated growth in the Clun catchment to 2027 and additional population and flows 230 J.4. Estimated employment growth in the Clun catchment to 2027 and additional population and flows 231 J.5. Poultry information 232 Appendix K. SAGIS model technical note 233 K.1. Introduction 233 K.2. Model performance and refinement 233 Appendix L. Estimation of river bank erosion loads 242 Appendix M. FARMSCOPER optimiser summaries 243 M.1. Upland grazing farm 244 M.2. Lowland arable farm 245 Appendix N. FARMSCOPER technical note 246 Atkins River Clun SAC NMP_Version6.0_October 2014 River Clun SAC Nutrient Management Plan Appendix O. NFU and CLA comments on second draft 259 O1. NFU comments on second draft 260 O2. CLA comments on second draft 264 Figures Figure 1-1 Clun catchment initiatives and linkages to the Nutrient Management Plan ................................ 14 Figure 1-2: Iterative process adopted .............................................................................................................. 15 Figure 1-3: Overview of the approach taken on the Clun NMP ....................................................................... 16 Figure 1-4: Key stakeholders and delivery partners for the Clun NMP ........................................................... 21 Figure 2-1 Estimated population of freshwater pearl mussel in the River Clun SAC 1995 to 2013. ............ 25 Figure 2-2 Freshwater pearl mussel photographed in 2013......................................................................... 25 Figure 3-2 Summary of flow data for the River Clun catchment. The data have been synthetically derived through the development of a stage-discharge relationship described in Appendix D. .............. 33 Figure 3-3 Defra land use 2010 .................................................................................................................... 36 Figure 3-4 Sub-catchment data .................................................................................................................... 37 Figure 3-5 May 2013 Catchment Sensitive Farming activity levels in the River Clun catchment ................ 45 Figure 4-1 Average annual orthophosphate concentrations in the River Clun SAC at Leintwardine between 1995 and 2012. ........................................................................................................................... 49 Figure 4-2 Changes in STW effluent phosphate concentrations between 1994 and 2012. There are no data for any works without a phosphate consent post-2008. Source of data: Environment Agency and Severn Trent Water. .................................................................................................................... 49 Figure 4-3 Seasonal phosphate variations in the River Clun SAC at Leintwardine between 2007 and 2012. Source of data: Environment Agency. ........................................................................................ 51 Figure 4-4 Seasonal phosphate variations in the tributaries of the River Clun. Source of data: Environment Agency. ....................................................................................................................................... 51 Figure 4-5 Average annual nitrogen levels (TON) in the River Clun SAC at Leintwardine from 1995 to 2012 .................................................................................................................................................... 53 Figure 4-6 Seasonal nitrogen (TON) variations in the River Clun SAC at Leintwardine .............................. 54 Figure 4-7 Suspended solids variations in the River Clun SAC at Leintwardine.......................................... 57 Figure 4-8 Estimated SS levels in the River Clun SAC at Leintwardine based on Environment Agency sondes. ........................................................................................................................................ 58 Figure 4-9 Seasonal variations in suspended solids in the River Clun SAC at Leintwardine 1999-2009. The blue line is the favourable condition target. Source of data: Environment Agency. .................... 60 Figure 4-10 Mean monthly turbidity in the Clun catchment. Based on turbidity data measured at Environment Agency sondes between May 2012 and April 2013. ............................................. 60 Figure 5-1 Comparison between loads of nitrate, phosphate and sediment generated by a ‘typical’ arable, livestock and poultry farm according to FARMSCOPER ............................................................ 68 Figure 5-2 Photographs illustrating one of the main pathways of sediment movement from arable fields to the River Clun.............................................................................................................................. 68 Figure 6-1 SAGIS predicted in-river phosphate concentration for the River Clun from its source to its confluence with the River Teme at Leintwardine. ....................................................................... 73 Figure 6-2 Summary source apportionment for the River Clun SAC at Leintwardine under current conditions