Forest Heath District Council Water Cycle Study Stage 2: Full Strategy
Total Page：16
File Type：pdf, Size：1020Kb
Forest Heath District Council Water Cycle Study Stage 2: Full Strategy Hyder Consulting (UK) Limited 2212959 Aston Cross Business Village 50 Rocky Lane Aston Birmingham B6 5RQ United Kingdom Tel: +44 (0)121 333 4466 Fax: +44 (0)121 333 4275 www.hyderconsulting.com Forest Heath District Council Water Cycle Study Stage 2: Full Strategy Author D Vogtlin Checker L Foster Approver R Gunasekara Report No 5001-UA000034-BMR-06-Forest Heath Detailed WCS Date 31 October 2011 This report has been prepared for Forest Heath District Council in accordance with the terms and conditions of appointment for SFRA and WCS dated June 2008. Hyder Consulting (UK) Limited (2212959) cannot accept any responsibility for any use of or reliance on the contents of this report by any third party. Water Cycle Study—Stage 2: Full Strategy Hyder Consulting (UK) Limited-2212959 \\hc-ukr-bm-fs-01\bm_projects\bm01397 - forest heath wcs & sfra\f- reports\stage 2\fh wcs\5001-ua000034-bmr-06 forest heath detailed wcs.doc CONTENTS 1 Summary .......................................................................................... 1 2 Introduction ....................................................................................... 4 3 Policy Context ................................................................................... 5 3.1 National - Planning Policy Statements................................................ 5 3.2 Local – Core Strategy........................................................................ 5 4 Development Programme.................................................................. 6 4.1 Core Strategy.................................................................................... 6 4.2 Residential Development ................................................................... 7 4.3 Employment Development................................................................. 8 5 Infrastructure Provision ................................................................... 10 5.1 Current Funding Mechanism............................................................ 10 6 Water Resources ............................................................................ 12 6.1 Defra/ EA Strategy .......................................................................... 12 6.2 AWS Strategy ................................................................................. 12 6.3 Ely Ouse to Essex Transfer Scheme ................................................ 14 6.4 National, Regional and Local Policy ................................................. 14 6.5 Potable Water Demand Projections ................................................. 15 6.6 Future Risks ................................................................................... 19 7 Potable Water Supply Infrastructure ................................................ 21 7.1 Existing Infrastructure...................................................................... 21 7.2 Development Impact ....................................................................... 22 7.3 Conclusions and Recommendations ................................................ 22 8 Wastewater Treatment .................................................................... 23 8.1 Cordon Sanitaire ............................................................................. 23 8.2 Wastewater Projections ................................................................... 24 8.3 Wastewater Treatment Constraints .................................................. 26 8.4 Treated Effluent Discharge Options ................................................. 34 9 Environmental Capacity (Water Quality) .......................................... 39 9.1 Water Framework Directive ............................................................. 39 9.2 Methodology ................................................................................... 41 9.3 New discharges .............................................................................. 42 9.4 Future Risks ................................................................................... 47 10 Sewerage Network .......................................................................... 48 10.1 Foul Sewer Capacity ....................................................................... 48 Water Cycle Study—Stage 2: Full Strategy Hyder Consulting (UK) Limited-2212959 Page i \\hc-ukr-bm-fs-01\bm_projects\bm01397 - forest heath wcs & sfra\f- reports\stage 2\fh wcs\5001-ua000034-bmr-06 forest heath detailed wcs.doc 11 Flood Risk Mitigation ....................................................................... 59 11.1 Flood and Water Management Act 2010 .......................................... 59 11.2 Flood Risk from WwTW Discharges ................................................. 60 11.3 Surface Water Management ............................................................ 67 11.4 Sustainable Drainage Systems (SuDS) ............................................ 67 12 Conclusions .................................................................................... 77 12.1 Water Resources Conclusions ......................................................... 78 12.2 Water Supply Infrastructure Conclusions.......................................... 78 12.3 Wastewater Treatment/ Environmental Capacity Conclusions ........... 79 12.4 Fluvial Flood Risk Conclusions ........................................................ 81 12.5 Sewerage Network Conclusions ...................................................... 82 12.6 Surface Water Management Conclusions ........................................ 84 13 Recommendations and Risks .......................................................... 85 14 Timeframe for Review ..................................................................... 91 References Glossary of Terms Technical Glossary Appendix A: Incoming Data Appendix B: Planning Policy Context Appendix C: Development Locations Appendix D: Water Framework Directive Appendix E: Sewerage Network Constraints and Solutions Appendix F: Flood Risk from WwTW Discharges Appendix G: SuDS Policy Unit Figures Water Cycle Study—Stage 2: Full Strategy Page ii Hyder Consulting (UK) Limited-2212959 \\hc-ukr-bm-fs-01\bm_projects\bm01397 - forest heath wcs & sfra\f- reports\stage 2\fh wcs\5001-ua000034-bmr-06 forest heath detailed wcs.doc 1 Summary This Stage 2 Water Cycle Study (WCS) builds on the conclusions and recommendations from the 2009 Outline WCS for Forest Heath District Council (FHDC) and St. Edmundsbury Borough Council. This study aligns with the adopted FHDC Core Strategy (2010), and analyses the impact of the proposed growth in the District on the existing water and wastewater infrastructure, and the water environment, in light of the changes in policy and stakeholder data since 2009. Consultation has been undertaken with Anglian Water Services (AWS); the Environment Agency (EA); Natural England (NE); and the Ely Group of Internal Drainage Boards (IDB); to gather the latest data on infrastructure and environmental capacity, and stakeholder policies and aspirations. Additional water and wastewater infrastructure capacity required, to accommodate the proposed growth whilst protecting the water environment and responding to climate change, has been identified. Recommendations have been made to stakeholders (and developer) regarding the responsibilities, opportunities, constraints and risks associated with the provision of the required infrastructure. Individual proposed sites which may be particularly constrained by infrastructure requirements (in terms of location, size or phasing) have been identified to assist FHDC with the Site Specific Allocations (SSA) process, and encourage developers to begin investigation in partnership with AWS and the EA. The study concludes that the long term AWS plan for water resources in the study area (including local demand management, and resource development in the wider area) will allow the provision of adequate potable water for the proposed growth, and the existing population, whilst allowing sufficient resilience against climatic change risks. The FHDC policy regarding water efficiency in new dwellings (if supported long term by homeowners) will assist AWS to meet the challenges of balancing public health and environmental obligations in the future, and increase the resilience of the area to climate change. FHDC policy imposes that land will not be released for development unless adequate infrastructure is in place, or can be provided as part of the development. The existing potable water strategic supply network in and around the study area is well placed to serve the proposed growth locations, and will be enhanced by AWS as required; funded through their typical business cycle. More locally, any required upgrades to the distribution network will be funded by developers. Developer Forums, facilitated by FHDC, are recommended as a means to promote the efficient design and implementation of upgrades once sites are confirmed. In areas of particularly intensive proposed growth, such as to the west of Red Lodge, this approach would be particularly beneficial. The provision of sewerage infrastructure presents more of a constraint to a number of sites, due to their position in relation to the existing networks serving the urban areas. In some locations, the connection of sites will require extensive upgrades to sewers through the urban area, or the provision of considerable lengths of new pumped bypass sewers. These risks have been identified to FHDC to assist with