Water Durham County Council March 2012 County Durham Outline Water Cycle Study Final Report Water Durham County Council March 2012 Prepared by: Christian Lomax Checked by: Alex Perryman Associate Director Consultant Approved by: Roy Lobley Associate Director County Durham Outline Water Cycle Study Rev No Comments Checked by Approved Date by 0 Draft for comment CL VH Feb 2011 1 Update based on new data AP RL Feb 2012 2 Final Report incorporating feedback AP RL March 2012 5th Floor, 2 City Walk, Leeds, LS11 9AR Telephone: 0113 391 6800 Website: http://www.aecom.com Job No: 60155102.M012 Reference: Outline WCS Date Created: March 2012 This document is confidential and the copyright of AECOM Limited. Any unauthorised reproduction or usage by any person other than the addressee is strictly prohibited. f:\projects\water resources - durham swmpwcs\04_reports\wcs\wcs outline report\durham wcs outline report final.doc Table of Contents Abbreviations .......................................................................................................................................................................... 1 Glossary .................................................................................................................................................................................. 3 1 Introduction................................................................................................................................................................ 7 1.1 Background .................................................................................................................................................... 7 1.2 The Water Cycle ............................................................................................................................................. 7 1.3 What is a Water Cycle Study? ......................................................................................................................... 7 1.4 Partnership ..................................................................................................................................................... 8 1.5 Links with Other Studies .................................................................................................................................. 9 2 Future Housing Development .................................................................................................................................. 12 2.1 Introduction ................................................................................................................................................... 12 2.2 Planning Policy Context within County Durham .............................................................................................. 12 2.3 Housing Development in County Durham: 2011/12 – 2030/31 ........................................................................ 12 3 Water Resources and Water Supply ........................................................................................................................ 17 3.1 Introduction ................................................................................................................................................... 17 3.2 Water Resources & the Environment Agency ................................................................................................. 17 3.3 Water Resources & Northumbrian Water ....................................................................................................... 19 3.4 Water Supply & Northumbrian Water ............................................................................................................. 20 3.5 Conclusions .................................................................................................................................................. 20 4 Sewerage and Sewage Treatment ........................................................................................................................... 22 4.1 Introduction ................................................................................................................................................... 22 4.2 Sewerage ..................................................................................................................................................... 22 4.3 Sewage Treatment ........................................................................................................................................ 24 4.4 Conclusions .................................................................................................................................................. 31 5 Water Quality and Other Environmental Considerations ........................................................................................ 33 5.1 Introduction ................................................................................................................................................... 33 5.2 The Strategic Water Environment in County Durham ...................................................................................... 33 5.3 Water Framework Directive Classification ...................................................................................................... 34 5.4 Geology ........................................................................................................................................................ 40 5.5 Nature Conservation Areas and Protected Areas............................................................................................ 43 5.6 Conclusions .................................................................................................................................................. 46 6 Flood Risk ................................................................................................................................................................ 48 6.1 Introduction ................................................................................................................................................... 48 6.2 Catchment Flood Management Plans ............................................................................................................ 48 6.3 Strategic Flood Risk Assessment ................................................................................................................... 50 6.4 Preliminary Flood Risk Assessment ............................................................................................................... 51 6.5 Surface Water Management Plan .................................................................................................................. 52 6.6 Northumbrian Water Flood Data .................................................................................................................... 55 6.7 Conclusions .................................................................................................................................................. 56 7 Conclusions ............................................................................................................................................................. 58 7.1 Introduction ................................................................................................................................................... 58 7.2 Water Resources & Supply ............................................................................................................................ 58 7.3 Sewerage and Sewage Treatment ................................................................................................................. 58 7.4 Water Quality and Environmental Considerations ........................................................................................... 58 7.5 Flood Risk Management ................................................................................................................................ 59 7.6 Summary ...................................................................................................................................................... 59 8 Guidance for Developers - SuDS ............................................................................................................................. 61 8.1 Introduction ................................................................................................................................................... 61 8.2 What are SuDS? ........................................................................................................................................... 61 8.3 Selection of Appropriate SuDS ...................................................................................................................... 62 8.4 Different Types of SuDS ................................................................................................................................ 63 8.5 Summary ...................................................................................................................................................... 66 LIST OF APPENDICES Appendix A: Water Quality Legislation Review ......................................................................................................................... 69 Appendix B: Relevant Programme of Measures from the Northumberland RBMP ..................................................................... 71 Appendix C: SHLAA Sites Potentially at Risk of Surface Water ................................................................................................