Charlton to Bexley Riverside Integrated Water Management Strategy Greater London Authority Project Number: 60506626 April 2017 Charlton to Bexley Riverside Intergrated Water Managment Strategy Quality information Prepared by Checked by Approved by Melinda Davies Michael Henderson Carl Pelling Joanna Bolding James Rose Travis Kelly Revision History Revision Revision date Details Authorized Name Position 0 Nov 2016 Draft Report 11/11/2016 Galo Pinto Regional Director 1 Apr 2017 Final Report 19/04/2017 Carl Pelling Associate Director Prepared for: Greater London Authority Prepared by: AECOM Infrastructure & Environment UK Limited Midpoint Alencon Link Basingstoke Hampshire RG21 7PP UK T: +44(0)1256 310200 aecom.com © 2017 AECOM Infrastructure & Environment UK Limited. All Rights Reserved. This document has been prepared by AECOM Infrastructure & Environment UK 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. Prepared for: Greater London Authority AECOM Charlton to Bexley Riverside Intergrated Water Managment Strategy Table of Contents List of Acronyms ...................................................................................................................................................... 1 1. Introduction .................................................................................................................................................. 2 1.1 Background ...................................................................................................................................... 2 1.2 Key Drivers ....................................................................................................................................... 2 1.3 Strategy Governance and Stakeholder Engagement ....................................................................... 3 1.4 Strategy aims and objectives ............................................................................................................ 3 1.5 Legislative and Policy Considerations .............................................................................................. 4 2. Proposed Development ............................................................................................................................... 9 2.1 Introduction ....................................................................................................................................... 9 2.2 Planning Context .............................................................................................................................. 9 2.3 Growth Scenarios for Testing .......................................................................................................... 10 2.4 Spatial distribution of growth ........................................................................................................... 10 3. IWMS Approach and Method ..................................................................................................................... 12 3.1 Stages of the IWMS ........................................................................................................................ 12 3.2 Step 1: Defining the baseline conditions ......................................................................................... 12 3.3 Stage 2: The Water Balance ........................................................................................................... 13 3.4 Step 3: Options Appraisal and Strategy Development .................................................................... 13 3.5 Step 4: Strategy Delivery ................................................................................................................ 15 4. Study Area Constraints and Opportunities ................................................................................................. 16 4.1 Topography, Land Use and Infrastructure ....................................................................................... 16 4.2 Geology and Groundwater .............................................................................................................. 17 4.3 Watercourses .................................................................................................................................. 17 4.4 Drainage and Wastewater Network ................................................................................................ 18 4.5 Water Resources and Water Supply ............................................................................................... 20 4.6 Contaminated Land and Environmental Designations .................................................................... 20 4.7 Flood Risk ....................................................................................................................................... 21 5. Opportunity Area Water Cycle .................................................................................................................... 23 5.1 Annual Water Balance .................................................................................................................... 23 5.2 Temporal Variation and Peak Instantaneous Water Flows .............................................................. 28 6. Water Management Measures ................................................................................................................... 31 6.1 Demand Management .................................................................................................................... 31 6.2 Blue and Green Roofs .................................................................................................................... 31 6.3 Roof Water Recycling ..................................................................................................................... 32 6.4 Grey Water Recycling ..................................................................................................................... 32 6.5 Green Source Control Measures .................................................................................................... 33 6.6 Below Ground Storage ................................................................................................................... 33 6.7 Strategic SuDS Networks ............................................................................................................... 34 6.8 Groundwater Recharge .................................................................................................................. 34 6.9 Tidal and Fluvial Discharge............................................................................................................. 35 6.10 Downstream Stormwater Retention Ponds or Wetlands ................................................................. 35 6.11 Stormwater Recycling ..................................................................................................................... 36 6.12 Wastewater Recycling .................................................................................................................... 36 7. Charlton Riverside – Option Appraisal and Strategy Development ............................................................ 37 7.1 Post-Development Conditions ........................................................................................................ 37 7.2 Summary of key local constraints and opportunities ....................................................................... 38 7.3 Preferred Water Management Strategy .......................................................................................... 39 7.4 Key Recommendations and Next Steps ......................................................................................... 41 8. Woolwich Town Centre - Option Appraisal and Strategy Development ...................................................... 42 8.1 Post-Development Conditions ........................................................................................................ 42 8.2 Summary of Local Constraints and Opportunities .......................................................................... 43 Prepared for: Greater London Authority AECOM Charlton to Bexley Riverside Intergrated Water Managment Strategy 8.3 Preferred Water Management Strategy .......................................................................................... 43 8.4 Key Recommendations and Next Steps ......................................................................................... 46 9. Thamesmead and Abbey Wood – Option Appraisal and Strategy Development ....................................... 47 9.1 Post-Development Conditions ........................................................................................................ 47 9.2 Summary of Local Constraints and Opportunities .......................................................................... 48 9.3 Preferred Water Management Strategy .......................................................................................... 49 9.4 Key Recommendations and Next Steps ......................................................................................... 51