C5B Technical Annex 02 Trunk Mains and Pipe Bridges Investment Case: Technical Approach and Business Case NTPBP-INV-TRU-0526 Trunk Mains and Pipe Bridges: Technical Approach and Business Case Contents 1 FOREWORD....................................................................................................................................................... 1 2 EXECUTIVE SUMMARY .................................................................................................................................... 2 3 BACKGROUND TO OUR INVESTMENT CASE ............................................................................................... 5 3.1 CONTEXT ...................................................................................................................................................... 5 3.2 STRATEGY .................................................................................................................................................... 8 3.3 CUSTOMER PRIORITIES ................................................................................................................................10 3.4 ASSET HEALTH PERFORMANCE COMMITMENTS , AMP7 PERFORMANCE COMMITMENTS & OUTCOME DELIVERY INCENTIVES ............................................................................................................................................................12 3.5 COMPLIANCE OBLIGATIONS .........................................................................................................................13 3.6 AMP6 INVESTMENT AND PERFORMANCE ......................................................................................................13 4 DEVELOPING OUR INVESTMENT PLAN ......................................................................................................16 4.1 INVESTMENT CASE DEVELOPMENT PROCESS ...............................................................................................16 4.1.1 Data & Data Assurance ........................................................................................................................17 4.1.2 Risk Identification, Verification & Needs Assessment Methodology ....................................................19 4.1.3 Optioneering and Intervention Development Methodology ..................................................................20 4.1.4 Intervention Costing Methodology ........................................................................................................20 4.1.5 Benefits Quantification Methodology ....................................................................................................20 4.1.6 Investment optimisation & Intervention Selection .................................................................................22 4.2 APPLYING THE INVESTMENT PROCESS TO TRUNK MAINS ...............................................................................23 4.2.1 Risk Identification, Verification & Needs Assessment ..........................................................................23 4.2.2 Optioneering & Intervention Development ............................................................................................24 4.2.3 Intervention Costing ..............................................................................................................................26 4.2.4 Benefits Quantification ..........................................................................................................................27 5 OUTCOME........................................................................................................................................................29 5.1 INNOVATION ................................................................................................................................................29 5.1.1 Reverse Trace Analysis ........................................................................................................................29 5.1.2 Leakage Monitors .................................................................................................................................30 5.2 SELECTED INTERVENTIONS ..........................................................................................................................30 5.3 CONTRIBUTION TO PERFORMANCE IMPROVEMENT ........................................................................................36 5.3.1 Asset Health ..........................................................................................................................................37 5.3.2 Water quality compliance ......................................................................................................................37 5.4 NON -SELECTED INTERVENTIONS ..................................................................................................................37 5.5 ASSUMPTIONS ............................................................................................................................................37 5.6 AMP8 ........................................................................................................................................................38 5.7 BASE MAINTENANCE ...................................................................................................................................38 5.8 HISTORICAL & AMP7 INVESTMENT COMPARISON .........................................................................................39 6 CONCLUSIONS ...............................................................................................................................................40 7 APPENDICES ..................................................................................................................................................41 7.1 APPENDIX A: LINE OF SIGHT DIAGRAM .........................................................................................................42 7.2 APPENDIX B: DATASETS ..............................................................................................................................44 7.3 APPENDIX C.1: SELECTED RISKS .................................................................................................................50 7.4 APPENDIX C.2: NON -SELECTED RISKS .........................................................................................................55 7.5 APPENDIX D: OPTIONS CONSIDERED ...........................................................................................................60 7.6 APPENDIX E: INTERVENTIONS DEVELOPED ...................................................................................................78 NTPBP-INV-TRU-0526 Trunk Mains Investment Case bristolwater.co.uk i Trunk Mains and Pipe Bridges: Technical Approach and Business Case 7.7 APPENDIX F: NON -SELECTED INTERVENTIONS ..............................................................................................87 Tables Table 1: Performance Commitments Targets and Percentage Contribution ........................................... 4 Table 2: Associated Performance Commitments ................................................................................. 12 Table 3: AMP6 capital investment ........................................................................................................ 13 Table 4: Historic AMP6 Performance Related to Trunk Mains .............................................................. 14 Table 5: Example of Unselected Risk ................................................................................................... 23 Table 6: Example of Options Selection for SRR622 ............................................................................ 25 Table 7: Selected Interventions, Costs, and % Performance Contribution ............................................ 31 Table 8: Water Service and Business Unit Allocation ........................................................................... 36 Table 9: Contribution to Performance Commitments Targets from Selected Interventions ................... 36 Table 10: Example Non-Selected Intervention and Residual Risk ........................................................ 37 Table 11: Contribution to Minimum Infrastructure Base Maintenance Investment ............................... 38 Table 12: Historical & AMP7 capital investment ................................................................................... 39 Figures Figure 1: Approach to meeting Customer Priorities and Mitigating Risks: .............................................. 3 Figure 2: Historic Supply Interruptions ................................................................................................... 6 Figure 3: Historic Supply Interruptions with Outliers Removed ............................................................... 6 Figure 4: Number of Customer Contacts Regarding Appearance per 10,000 Population ....................... 7 Figure 5: Historical and future pipe replacement lengths for distribution and trunk mains....................... 9 Figure 6: The Three Potential Scenarios for our Safe and Reliable Supply Outcome .......................... 11 Figure 7: Investment case process overview - Level 1 diagram ........................................................... 17 Figure 8: Percentage of Data Types by Ofwat Confidence Grade and Risk Grade............................... 18 NTPBP-INV-TRU-0526 Trunk Mains Investment Case bristolwater.co.uk ii Trunk Mains and Pipe Bridges: Technical Approach and Business