Runnymede Water Cycle Study: Phase 1 Scoping Runnymede Borough Council January 2018 Prepared for: Runnymede Borough Council AECOM 1 Runnymede Scoping Water Cycle Study Project reference 60550988 Quality information Prepared by Checked by Approved by Bernadine Maguire Chris Gordon Carl Pelling Principal Flood Risk & Coastal Senior Environmental Engineer Associate Director Consultant Bernadine Maguire Miguel Headley Principal Flood Risk & Coastal Graduate Engineer Consultant Revision History Revision Revision date Details Authorized Name Position 1 15/11/2017 Draft for Client and 16/11/2017 Carl Pelling Associate Director Stakeholder comment 2 19/12/2017 Final for issue 04/01/2018 Carl Pelling Associate Director 3 09/01/2018 Final 10/01/2018 Carl Pelling Associate Director Prepared for: Runnymede Borough Council Prepared by: AECOM Infrastructure & Environment UK Limited Midpoint Alencon Link Basingstoke Hampshire RG21 7PP UK T: +44(0)1256 310200 aecom.com Copyright © 2017 AECOM Infrastructure & Environment UK Limited. 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Prepared for: Runnymede Borough Council AECOM Runnymede Scoping Water Cycle Study Project reference 60550988 Table of Contents List of Acronyms ..................................................................................................................................................... 1 Executive Summary ................................................................................................................................................ 2 Background ................................................................................................................................................. 2 Water Resources Key Findings..................................................................................................................... 2 Water Quality Key Findings .......................................................................................................................... 2 Flood Risk & Water Environment Key Findings ............................................................................................. 3 1 Introduction.................................................................................................................................................. 5 1.1 Background ...................................................................................................................................... 5 1.1 Objectives of the Water Cycle Study .................................................................................................. 5 2 Runnymede Water Cycle Study .................................................................................................................... 6 2.1 The Water Cycle ............................................................................................................................... 6 2.2 Implications for Development ............................................................................................................. 6 2.3 Stages of a Water Cycle Study .......................................................................................................... 7 2.4 Integration with the Planning System ................................................................................................. 9 2.5 National, Regional and Local Drivers and Policies .............................................................................. 9 3 Development in Runnymede ...................................................................................................................... 12 3.1 Runnymede Borough ...................................................................................................................... 12 3.2 Future growth.................................................................................................................................. 12 4 Water Cycle Environment and Infrastructure baseline.................................................................................. 16 4.1 Introduction ..................................................................................................................................... 16 4.2 Water Environment.......................................................................................................................... 16 4.3 Ecology and Biodiversity.................................................................................................................. 22 4.4 Flood Risk....................................................................................................................................... 23 4.5 Water Resources and Supply .......................................................................................................... 25 4.6 Wastewater Treatment and Collection .............................................................................................. 27 5 Findings, Constraints and Recommendations ............................................................................................. 32 5.1 Water Resources ............................................................................................................................ 32 5.2 Water Quality .................................................................................................................................. 33 5.3 Flood Risk & Water Environment ..................................................................................................... 35 6 Recommendations ..................................................................................................................................... 37 Figures Figure 2-1 The Water Cycle Study (Source: Environment Agency)............................................................................ 6 Figure 3-1 Location map of Runnymede Borough .................................................................................................. 12 Figure 3-2 Preferred sites for allocation in the Runnymede Local Plan .................................................................... 13 Figure 4-1: Geology within Runnymede ................................................................................................................. 17 Figure 4-2 Watercourses of Runnymede................................................................................................................ 18 Figure 4-3: Map of nature conservation and designated sites in and adjacent to Runnymede .................................. 22 Figure 4-4 The CAMS areas of the Thames and Thames tributaries22..................................................................... 25 Figure 4-5: Supply/demand balance with the AWS preferred plan implemented showing the water available or use (WAFU) and final demand plus target headroom (THR) ......................................................................................... 26 Prepared for: Runnymede Borough Council AECOM Runnymede Scoping Water Cycle Study Project reference 60550988 Tables Table 2-1 EU Directives & UK Legislation & Guidance on Water ............................................................................... 9 Table 3-1 Preferred housing allocations in the Runnymede 2035 Additional Sites and Options Consultation Document............................................................................................................................................................. 14 Table 3-2 Runnymede Housing Commitments and Allocations ............................................................................... 14 Table 3-3 Indicative employment floorspace figures and assumed water requirements ............................................ 15 Table 4-1 WFD classifications of surface water bodies in Runnymede .................................................................... 20 Table 4-2 Statutory sites in Runnymede with identified wetland flora species .......................................................... 23 Table 4-3 WwTW Permitted DWF limits ................................................................................................................. 27 Table 4-4 DWF consent capacity at Chertsey WwTW in Runnymede serving areas of proposed new developments ....................................................................................................................................................... 29 Prepared for: Runnymede Borough Council AECOM Runnymede Scoping Water Cycle Study Project reference 60550988 List of Acronyms AMP Asset Management Plan AWS Affinity Water Services BAP Biodiversity Action Plan BGS British Geological Society BOD Biochemical Oxygen Demand BREEAM Building Research Establishment Environmental Assessment Method CAMS Catchment Abstraction Management Strategy CBA Cost Benefit Analysis CFMP Catchment Flood Management Plan CIL Community Infrastructure Levy CIRIA Construction Industry Research and Information Association CLG Communities and Local Government CRC Carbon Reduction Commitment DEFRA Department for Environment, Food and Rural Affairs DWF Dry