Report Rawreth Lane, Rayleigh Essex 2019-12-04
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Land Off Rawreth Lane, Rayleigh, Essex Flood Risk Assessment Project number: 60469673 September 2020 Land Off Rawreth Lane, Rayleigh Essex Project number: 60469673 Quality information Prepared by Checked by Verified by Approved by Helen Judd Sarah Littlewood Peter Mansell Dan Scurlock Principal Water & Flood Principal Water & Flood Technical Director Associate Director Risk Consultant Risk Consultant Revision History Revision Revision date Details Authorized Name Position 1 July 2020 Draft for Client Dan Scurlock Associate Director Comment 2 August 2020 Draft for Legal Dan Scurlock Associate Director Review 3 2nd Sep 2020 Draft following Dan Scurlock Associate Director Legal Review 4 14th September Final for planning Dan Scurlock Associate Director submission Distribution List # Hard Copies PDF Required Association / Company Name - 1 Countryside Properties (UK) Limited Prepared for: Countryside Properties (UK) Limited Prepared by: AECOM Limited Midpoint, Alencon Link Basingstoke Hampshire RG21 7PP United Kingdom T: +44(0)1256 310200 aecom.com © 2020 AECOM Limited. All Rights Reserved. This document has been prepared by AECOM Limited (“AECOM”) for sole use of our client (the “Client”) in accordance with generally accepted consultancy principles, the budget for fees and the terms of reference agreed between AECOM and the Client. Any information provided by third parties and referred to herein has not been checked or verified by AECOM, unless otherwise expressly stated in the document. No third party may rely upon this document without the prior and express written agreement of AECOM. AECOM Land Off Rawreth Lane, Rayleigh Essex Project number: 60469673 Table of Contents 1. Introduction ........................................................................................................... 5 1.1 Terms of Reference ..........................................................................................................................................5 1.2 Background.......................................................................................................................................................5 1.3 Aims and objectives .........................................................................................................................................5 1.4 Methodology .....................................................................................................................................................6 2. Site Description..................................................................................................... 7 2.1 Location ............................................................................................................................................................7 2.2 Local Water Features .......................................................................................................................................7 2.3 Flood Zone........................................................................................................................................................8 2.4 Topography .......................................................................................................................................................9 2.5 Geology, Soils and Hydrogeology ...................................................................................................................9 3. Development Proposals ..................................................................................... 10 3.1 Proposed Development .................................................................................................................................10 3.2 Development Lifetime ....................................................................................................................................10 3.3 Development Vulnerability Classification ......................................................................................................10 4. Flood Risk to the Proposed Development......................................................... 12 4.1 Overview .........................................................................................................................................................12 4.2 Fluvial Flood Risk ...........................................................................................................................................12 4.3 Tidal Flood Risk ..............................................................................................................................................14 4.4 Surface Water Flood Risk and Overland Flow ..............................................................................................16 4.5 Groundwater Flood Risk ................................................................................................................................17 4.6 Sewer Flood Risk ...........................................................................................................................................18 4.7 Artificial Sources.............................................................................................................................................18 4.8 Summary of Flood Risk to the Proposed Development ...............................................................................18 5. Flood Risk from the Proposed Development .................................................... 20 5.1 Overview .........................................................................................................................................................20 5.2 Tidal Flood Risk ..............................................................................................................................................20 5.3 Fluvial Flood Risk ...........................................................................................................................................20 5.4 Surface Water Flood Risk and Overland Flow ..............................................................................................21 5.5 Groundwater Flood Risk ................................................................................................................................21 5.6 Sewer Flood Risk ...........................................................................................................................................21 5.7 Artificial Sources.............................................................................................................................................22 5.8 Summary of Flood Risk from the Proposed Development ...........................................................................22 6. Mitigation Measures ........................................................................................... 23 6.1 Overview .........................................................................................................................................................23 6.2 Mitigation of Groundwater Flood Risk ...........................................................................................................23 7. Planning Policy ................................................................................................... 24 7.1 National Planning Policy Framework: ...........................................................................................................24 7.2 Local Planning Policy: Rochford District Council Local Development Framework Core Strategy .............25 7.3 Rochford District Council Local Development Framework Allocations Plan ...............................................26 8. Residual Flood Risk............................................................................................ 27 8.1 Overview .........................................................................................................................................................27 8.2 Blockages at structures along Rawreth Brook ..............................................................................................27 8.3 Failure or Exceedance of Sewer Network.....................................................................................................27 9. Summary ............................................................................................................. 29 9.1 Overview .........................................................................................................................................................29 9.2 Flood Risk – To the Proposed Development ................................................................................................29 9.3 Flood Risk – From the Proposed Development............................................................................................29 AECOM Land Off Rawreth Lane, Rayleigh Essex Project number: 60469673 9.4 Planning Policy ...............................................................................................................................................29 9.5 Recommended Mitigation ..............................................................................................................................29 Appendix A Redline Boundary....................................................................................... 30 Appendix B Topographic Survey ................................................................................... 31 Appendix C Proposed Development Plans .................................................................. 32 Appendix D Outline Drainage