Thames Water WRMP19 Resource Options Fine Screening Report Update April 2017 Thames Water Utilities Ltd Thames Water WRMP19 Resource Options 356236 WCD WAM 40 A PiMS/356236/Documents 30 August 2016 Fine Screening Report Update Thames Water WRMP19 Resource Options Fine Screening Report Update April 2017 Thames Water Utilities Ltd Clearwater Court, Vastern Rd, Reading, West Berkshire, RG1 8DB Mott MacDonald, 22 Station Road, Cambridge CB1 2JD, United Kingdom T +44 (0)1223 463500 F +44 (0)1223 461007 W www.mottmac.com Thames Water WRMP19 Resource Options Fine Screening Report Update Issue and revision record Revision Date Originator Checker Approver Description 01 29 September 2016 Ania Bujnowicz Wendy Kilmurray Bill Hume Smith Draft for stakeholder comment Bill Hume Smith 02 21 April 2017 Jamie Radford Wendy Kilmurray Bill Hume Smith Updated draft for stakeholder Ania Bujnowicz Bill Hume Smith comment Robert MacDonald Victoria Price Bill Hume Smith 03 25 April 2017 Jamie Radford Wendy Kilmurray Bill Hume Smith Updated Tables 3.2, 3.3, 5.14 and Figure 3.4 Information class: Secure This report has been prepared solely for use by the party which We accept no responsibility for any error or omission in the commissioned it (the ‘Client’) in connection with the captioned report which is due to an error or omission in data, information project. It should not be used for any other purpose. No person or statements supplied to us by other parties including the other than the Client or any party who has expressly agreed client (‘Data’). We have not independently verified such Data terms of reliance with us (the ‘Recipient(s)’) may rely on the and have assumed it to be accurate, complete, reliable and content, information or any views expressed in the report. We current as of the date of such information. accept no duty of care, responsibility or liability to any other recipient of this document. This report is confidential and Forecasts presented in this document were prepared using contains proprietary intellectual property. Data and the report is dependent or based on Data. Inevitably, some of the assumptions used to develop the No representation, warranty or undertaking, express or implied, forecasts will not be realised and unanticipated events and is made and no responsibility or liability is accepted by us to circumstances may occur. Consequently Mott MacDonald any party other than the Client or any Recipient(s), as to the does not guarantee or warrant the conclusions contained in accuracy or completeness of the information contained in this the report as there are likely to be differences between the report. For the avoidance of doubt this report does not in any forecasts and the actual results and those differences may be way purport to include any legal, insurance or financial advice material. While we consider that the information and opinions or opinion. given in this report are sound all parties must rely on their own skill and judgement when making use of it. We disclaim all and any liability whether arising in tort or contract or otherwise which it might otherwise have to any Under no circumstances may this report or any extract or party other than the Client or the Recipient(s), in respect of this summary thereof be used in connection with any public or report, or any information attributed to it. private securities offering including any related memorandum or prospectus for any securities offering or stock exchange listing or announcement. 356236/WCD/WAM/40/03 25 April 2017 Sharepoint/356236/Documents/BA14 Thames Water WRMP19 Resource Options Fine Screening Report Update Contents Chapter Title Page Executive Summary i 1 Introduction 1 1.1 Background _______________________________________________________________________ 1 1.2 Structure of report___________________________________________________________________ 2 1.3 Stakeholder engagement _____________________________________________________________ 2 2 Statement of need 4 2.1 Requirement for a Water Resources Management Plan _____________________________________ 3 2.2 The TW Water Resource Zones ________________________________________________________ 3 2.3 The supply-demand balance situation ___________________________________________________ 4 2.4 London Water Resources Zone ________________________________________________________ 6 2.5 Requirements for new resource options __________________________________________________ 7 3 Approach to fine screening and option appraisal of water resources 9 3.1 Overview of four-phased approach _____________________________________________________ 9 3.2 Developments in the fine screening approach between Phase 1 and Phase 2 ___________________ 12 3.3 Generic list of options _______________________________________________________________ 12 3.4 Feasibility assessments _____________________________________________________________ 12 3.5 Cross-option studies ________________________________________________________________ 13 3.5.1 Water treatment cross option study ____________________________________________________ 14 3.5.2 Treatment of Water to be Discharged to the Environment ___________________________________ 14 3.5.3 Network reinforcement cross option study _______________________________________________ 15 3.5.4 Raw water system cross option study __________________________________________________ 16 3.5.5 Operational philosophy ______________________________________________________________ 17 3.5.6 System Strategy ___________________________________________________________________ 18 3.6 Fine screening ____________________________________________________________________ 18 3.6.1 Environment & social dimension ______________________________________________________ 19 3.6.2 Cost dimension ____________________________________________________________________ 20 3.6.3 Promotability dimension _____________________________________________________________ 29 3.6.4 Flexibility dimension ________________________________________________________________ 31 3.6.5 Deliverability dimension _____________________________________________________________ 34 3.6.6 Resilience dimension _______________________________________________________________ 35 3.6.7 Screening decisions ________________________________________________________________ 39 3.6.8 Back-checking process ______________________________________________________________ 39 4 Generic screening of water resource management options 40 4.1 Generic option screening ____________________________________________________________ 40 5 London WRZ water resource options 42 5.1 Resource option types ______________________________________________________________ 42 5.2 Feasibility report findings ____________________________________________________________ 42 5.2.1 Water reuse ______________________________________________________________________ 42 5.2.2 New reservoirs ____________________________________________________________________ 45 356236/WCD/WAM/40/03 25 April 2017 Sharepoint/356236/Documents/BA14 Thames Water WRMP19 Resource Options Fine Screening Report Update 5.2.3 Raw water transfers ________________________________________________________________ 50 5.2.4 Desalination ______________________________________________________________________ 53 5.2.5 Direct river abstraction ______________________________________________________________ 54 5.2.6 Aquifer recharge ___________________________________________________________________ 56 5.2.7 Aquifer storage and recovery _________________________________________________________ 57 5.2.8 Groundwater development ___________________________________________________________ 57 5.2.9 Removal of Deployable Output constraints ______________________________________________ 59 5.2.10 Catchment management ____________________________________________________________ 59 5.3 Exclusivities/Interdependencies _______________________________________________________ 61 5.4 Fine screening assessment __________________________________________________________ 61 5.4.1 Scenario analysis __________________________________________________________________ 63 5.4.2 Rejection reasoning ________________________________________________________________ 65 5.5 Next steps for water resource options passing fine screening ________________________________ 68 5.5.1 Deephams reuse __________________________________________________________________ 68 5.5.2 Beckton reuse ____________________________________________________________________ 68 5.5.3 Severn-Thames Transfer ____________________________________________________________ 69 5.5.4 Abingdon reservoir _________________________________________________________________ 69 5.5.5 Teddington direct river abstraction _____________________________________________________ 69 5.5.6 Beckton desalination _______________________________________________________________ 70 5.5.7 Crossness desalination _____________________________________________________________ 70 5.5.8 Groundwater options _______________________________________________________________ 70 5.5.9 Catchment management options ______________________________________________________ 71 6 SWOX WRZ resource options 72 6.1 Resource option types ______________________________________________________________ 72 6.2 Feasibility Report findings ___________________________________________________________ 72 6.2.1 New reservoirs ____________________________________________________________________ 72 6.2.2 Raw water transfers ________________________________________________________________