South Hampshire: Integrated Water Management Strategy
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South Hampshire: Integrated Water Management Strategy Partnership for Urban South Hampshire (PUSH) December 2008 Client: PUSH South Hampshire Integrated Water Management Strategy Note This document has been produced by ATKINS for PUSH solely for the purpose of the Integrated Water Management Strategy for South Hampshire. It may not be used by any person for any other purpose other than that specified without the express written permission of ATKINS. Any liability arising out of use by a third party of this document for purposes not wholly connected with the above shall be the responsibility of that party who shall indemnify ATKINS against all claims costs damages and losses arising out of such use. Atkins Limited Document History JOB NUMBER: 5056925 DOCUMENT REF: 5056925 / 70 / DG / 23 05 Final for Distribution PS ED HR PS 2/12/08 04 Final PS RH HR PS 4/11/08 03 External Draft for Review HR/JS/PS AB BSP PS 02 Internal draft review HR/JS/PS AB AB PS 01 Draft in progress HR/JS/PS ED BP PS Originated Checked Reviewed Authorised Date Revision Purpose Description Client: PUSH South Hampshire Integrated Water Management Strategy Acknowledgements The Atkins team would like to thank the Steering Committee for its advice and support throughout the project. The technical specialists in the Environment Agency have also been very supportive. We would like to thank Tony Burch from the Environment Agency who has provided detailed comments and recommendations for improved flood risk management which we have included within this document. Susanne Grigsby, David Lowthian and Tim Sykes have also provided important advice which has helped to steer the project with respect to water quality and understanding the methodology and conclusions of the Review of Consents investigations. Representatives of the Water Companies have also provided very helpful assistance on the assessments of water supply and wastewater management. In this regard, particular thanks are due to Mike Dannatt (Portsmouth Water) and Bob Tambling (Southern Water). Client: PUSH South Hampshire Integrated Water Management Strategy Contents Section Page Glossary of Terms 5 Executive Summary 7 1 Introduction 11 1.1 Background to this Report 11 1.2 Objectives of the South Hampshire IWMS 11 1.3 Approach to the IWMS 12 2 Context for the IWMS 16 2.1 Environmental Background 16 2.2 Environmental Context for the IWMS priority issues 17 2.3 Review of relevant environmental policy 22 2.4 Review of relevant planning policy 23 3 Water Supply 26 3.1 Overview 26 3.2 Responsibility for Water Supply 26 3.3 Forecasting the Balance between Supply and Demand 28 3.4 Identification and Appraisal of Resource Options 50 3.5 Reducing Forecast Uncertainty (Target Headroom) 60 3.6 Summary 60 4 Wastewater Management 69 4.1 Overview 69 4.2 Capacity Assessment 76 4.3 Summary 110 5 Flood Risk Management 114 5.1 Overview 114 5.2 Planning Policy & Flood Risk 117 5.3 Strategic Flood Risk Assessment 120 5.4 IWMS review of development and flood risk 124 5.5 Conclusions 132 5.6 Recommendations 134 6 Planning and Water Management 147 6.1 Water Management and the Planning System 147 6.2 Opportunities and Constraints of the Current System 150 6.3 Recommendations 154 ` 1 FINAL Client: PUSH South Hampshire Integrated Water Management Strategy 7 Summary 164 7.1 Scope of Work undertaken 164 7.2 Conclusions 165 7.3 Recommendations 174 8 References 192 9 Appendices 194 Appendix A : Review of Relevant Planning Policy and Guidance 195 Appendix B : Review of relevant environmental policy & Guidance 209 Appendix C : Flood Risk Management 235 List of Tables Table 2.1 South Hampshire housing allocation by location and phasing between 2006 and 2026 distributed and phased as follows as set out under Policy SH12 24 Table 3.1 Portsmouth Water Source Types and Licensed Quantities 28 Table 3.2 Southern Water Source Types and Licensed Quantities 28 Table 3.3 Peak Period SDB in South Hampshire in 2007 31 Table 3.4 Scenario 1 (Baseline) Demand Forecast for the PUSH Area based on no population and household growth to 2026 35 Table 3.5 Scenario 2a Demand Forecast for the PUSH Area based on population and household growth to 2026 41 Table 3.6 Scenario 2b Demand Forecast for the PUSH Area based on population and household growth to 2026 42 Table 3.7 Scenario 4 Demand Forecast for the PUSH Area based on population and household growth to 2026 47 Table 3.8 Scenario 5 Demand Forecast for the PUSH Area based on population and household growth to 2026 48 Table 3.9 Multi-Criteria Analysis of Resource Options 55 Table 3.10 “Short-list” of Preferred Resource Options 59 Table 4.1 Summary of PE growth 77 Table 4.2 DWF comparison between study and Southern Water figures 81 Table 4.3 Baseline situation in 2006/07 84 Table 4.4 Summary of scenario growth forecasts 85 Table 4.5 Predicted quality consents on the basis of Scenario 1 2025/26 flows 92 Table 4.6 Predicted quality consents on the basis of Scenario 1 2025/26 flows (assuming no change in existing DWF consent) 94 Table 4.7 Predicted quality consents on the basis of Scenario 1 2025/26 flows 96 Table 4.8 Predicted quality consents on the basis of Scenario 1 2025/26 flows 98 Table 4.9 Predicted quality consents on the basis of 2025/26 flows and loads 100 Table 4.10 Peel Common predicted interim N consents – Scenario 1 101 Table 4.11 Predicted quality consents on the basis of Scenario 1 2025/26 flows 104 Table 4.12 Predicted quality consents on the basis of Scenario 1 2025/26 flows 106 Table 4.13 Predicted quality consents on the basis of Scenario 1 2025/26 flows 109 ` 2 FINAL Client: PUSH South Hampshire Integrated Water Management Strategy Table 5.1 Descriptions of the Flood Zones 119 Table 9.1 South Hampshire housing allocation by location and phasing between 2006 and 2026 distributed and phased as follows as set out under Policy SH12 203 Table 9.2 Substances monitored under the Shellfish Waters Directive 211 Table 9.3 Significant Water Management Issues identified through the RBMP process. 219 Table 9.4 Summary description and licensing strategy for WRMUs. 224 Table 9.5 SMP Policies from the Western Solent and Southampton Water SMP 1998 and the Eastern Solent and Harbours SMP 1997. 237 Table 9.6 Policy units and selected policies 241 List of Figures Figure 2.1 Environmental Designations in South Hampshire 19 Figure 3.1 Areas of PUSH supplied by Portsmouth Water and Southern Water 27 Figure 3.2 Schematic of the Supply Demand Balance (SDB) 30 Figure 3.3 Scenario 1 (Baseline – No Growth) Forecast Peak Period Supply Demand Balance for Southern Water’s Hampshire South WRZ 38 Figure 3.4 Scenario 1 (Baseline – No Growth) Forecast Peak Period Supply Demand Balance for Portsmouth Water’s WRZs 38 Figure 3.5 Scenario 2 (a&b) Peak Period Forecast Supply Demand Balance for Southern Water’s Hampshire South WRZ 39 Figure 3.6 Scenario 2 (a&b) Peak Period Forecast Supply Demand Balance for Portsmouth Water’s WRZs 40 Figure 3.7 Scenario 3 Peak Period Forecast Supply Demand Balance for Southern Water’s Hampshire South WRZ 44 Figure 3.8 Scenario 3 Peak Period Forecast Supply Demand Balance for Portsmouth Water’s WRZs 44 Figure 3.9 Summary of Scenarios 1-5 for the Peak Period Demand Forecast for Southern Water’s Hampshire South WRZ 49 Figure 3.10 Summary of Scenarios 1-5 for the Peak Period Demand Forecast for Portsmouth Water’s WRZs 49 Figure 4.1 Location and outline catchments for wastewater treatment works in the PUSH region 71 Figure 4.2 Forecast flow growth and quality consents at Ashlett Creek Fawley 89 Figure 4.3 Forecast flow growth and quality consents at Bishops Waltham 90 Figure 4.4 Forecast flow growth and quality consents at Budds Farm Havant 91 Figure 4.5 Forecast flow growth at Bursledon 93 Figure 4.6 Forecast growth at Chickenhall Eastleigh 95 Figure 4.7 Forecast flow growth at Millbrook 97 Figure 4.8 Forecast flow growth at Peel Common (including Woolston) 99 Figure 4.9 Forecast flow growth at Portswood 102 Figure 4.10 Forecast flow growth at Romsey 103 Figure 4.11 Forecast flow growth at Slowhill Copse Marchwood 105 Figure 4.12 Forecast flow growth at Southwick 107 Figure 4.13 Forecast flow growth at Thornham 108 ` 3 FINAL Client: PUSH South Hampshire Integrated Water Management Strategy Figure 4.14 Forecast flow growth at Wickham 109 Figure 5.1 Source-Pathway-Receptor Model 114 Figure 5.2 Extract from the PUSH SFRA website, showing the variation in flood hazard across Portsmouth. 122 Figure 5.3 PUSH Site Allocations 141 Figure 5.4 Flood Zones (2007) 142 Figure 5.5 Flood Zones (2115) 143 Figure 5.6 Impact of Land Use Change on Surface Water Runoff 144 Figure 5.7 Groundwater Flooding 145 Figure 5.8 Surface Water Sewer Flooding 146 ` 4 FINAL Client: PUSH South Hampshire Integrated Water Management Strategy Glossary of Terms Term Meaning / Definition PWS Public Water Supply WRMU Water Resource Management Unit RSS Regional Spatial Strategy SRSS Sub region spatial strategy RoC Review of Consents (Stage 4 Review of Consents for the Hampshire Natura 2000 sites) LDF Local Development Framework EA Environment Agency PUSH Partners for Urban South Hampshire IWMS Integrated Water Management Strategy SFRA Strategic Flood Risk Assessment SEP South East Plan SEEDA South East England Development Agency DCLG Department for Communities and Local Government WWTW Waste water treatment works EiP Examination in Public Defra Department for Environment, Food and Rural Affairs LPA Local Planning Authority PPS Planning Policy Statement GOSE Government Office for the South East OFWAT Water Services Regulation Authority DWI