Business plan documents
Business plan 2025-2030
In October 2023 we submitted our business plan for 2025-30 to our regulator, Ofwat, for scrutiny and assessment.
Read a summary of our initial plan and find out how we created it.
The following four documents summarise our initial business plan.
WSX01 - Striking the balance (Executive summary)
WSX02 - An overview of our business plan
WSX03 - Long term delivery strategy
You can read further detail in the supporting documents listed below:
WSX08 - Base cost assessment commentary and analysis
WSX09 - Annexes - Base cost adjustment claims
WSX10 - Maintaining our services commentary and analysis
WSX11 - Annexes - Maintaining our services
WSX12 - Water Resources strategy and investment
WSX14 - Water networks Plus strategy and investment
WSX15 - Annexes - Water networks Plus strategy and investment
WSX16 - Wastewater networks Plus strategy and investment
WSX17 - Annexes - Wastewater networks Plus strategy and investment
WSX18 - Bioresources strategy and investment
WSX19 - Annexes - Bioresources strategy and investment
WSX20 - Residential retail strategy and analysis
WSX21 - Annexes - Residential retail
WSX22 - Developer Services strategy and analysis
WSX25 - Improving biodiversity
WSX26 - Price control deliverables (PCDs)
WSX29 - Transition and delivery
WSX30 - Direct Procurement for Customers assessment
WSX37 - Resilience, risk management and decision frameworksÂ
WSX38 - Annexes - Resilience, risk management and decision frameworks
WSX32 - Annexes - Risk and return
WSX33 - Financial resilience and financeability
WSX34 - Annexes - Financial resilience and financeability
WSX35 - Financial assumptions underpinning the plan
WSX36 - Annexes - Financial assumptions underpinning the plan
WSX39 - Estimating the cost of equity for PR24 - report by KPMG
WSX40 - Inference analysis as a cross-check on allowed returns - report by KPMG
WSX47 - Outcomes - tables commentary
WSX48 - Risk and return - tables commentary
WSX49 - Costs Wholesale Water - tables commentary
WSX50 - Costs Wholesale Waste Water - tables commentary
WSX51 - Water resources - tables commentary
WSX52 - Bioresources - table commentary
WSX53 - Retail - tables commentary
WSX54 - Long Term Strategies - tables commentary
WSX55 - Developer Services - tables commentary
WSX56 - Supplementary - tables commentary
WSX27 - PCD modelling spreadsheet
WSX68 - PR19 Innovation funding reconciliation model
WSX69 - Ofwat financial model - Ofwat view on notional structure and cost of capital
WSX70 - Ofwat financial model - Wessex Water view on notional structure and cost of capital
WSX72 - Revenue reconciliation model
WSX73 - RCV reconciliation model
WSX74 - Revenue forecasting incentive model
WSX75 - Bilateral entry adjustment (BEA) model
WSX76 - 2023-24 ODI performance model for use in the PR24 business plans
WSX77 - 2024-25 ODI performance model for use in the PR24 business plans
WSX78 - Residential retail reconciliation model
WSX79 - PR19 Water trading incentive model
WSX80 - Developer services model
WSX81 - Water industry national environment programme (WINEP) reconciliation model
WSX82 - Cost of new debt reconciliation model
WSX83 - Gearing outperformance sharing mechanism model
WSX84 - Cost reconciliations model
WSX85 - Tax reconciliation model
In July 2024 Ofwat published its provisional assessment of our business plan, known as its draft determination. In light of the assessment, we submitted further information to Ofwat in August 2024, which included some changes to our initial business plan.
WSX-M02 Summary of WSX response to Ofwat's PR24 DD
WSX-M03 Guide to reading representations
WSX-M04 Company representation proforma
WSX-M05 Quality and ambition assessment
WSX-M06 Long-term delivery strategy
WSX-M08 Briefing document for company representation meeting
WSX-A01 Board assurance statement
WSX-C01 Step up in capital maintenance and base costs
WSX-C03 Overall approach to costing
WSX-C04 Retrospective nature of draft determination
WSX-C05 Enhancement costs - water quality improvements
WSX-C06 Enhancement costs - Strategic Resource Options (SROs)
WSX-C07 Enhancement costs - leakage and smart metering
WSX-C08 Enhancement costs - supply schemes
WSX-C09 Enhancement costs - wastewater treatment
WSX-C10 Enhancement costs - Water Recycling Centre (WRC) growth
WSX-C11 Enhancement costs - storm overflows
WSX-C12 Enhancement costs - pollutions
WSX-C13 Enhancement costs - resilience
WSX-C14 Enhancement costs - greenhouse gas emissions
WSX-C15 Enhancement costs - water investigations
WSX-C16 Enhancement costs - wastewater investigations
WSX-C17 Enhancement costs - biodiversity and conservation
WSX-C18 Bioresources and the Industrial Emissions Directive (IED)
WSX-C20 Cost adjustment claims
WSX-C23 Appendix - Business Rates Model
WSX-R03 Ofwat's proposed gearing cap
WSX-R04 Consultation on equity listing mechanism
WSX-R05 Financeability and financial resilience
WSX-R06 Appendix - Table SUP15
WSX-R07 Appendix - RCV Run-off Rate Model
WSX-O01 Performance and outcomes
WSX-O02 Price control deliverables
WSX-O03 Measures of experience
WSX-O04 Ofwat's reporting and assurance proposals
WSX-D00a August 2024 data tables
WSX-D01 Commentary on data table changes - Outcomes
WSX-D02 Commentary on data table changes - Risk and return
WSX-D03 Commentary on data table changes - Costs wholesale water
WSX-D04 Commentary on data table changes - Costs wholesale wastewater
WSX-D05 Commentary on data table changes - Water resources
WSX-D06 Commentary on data table changes - Bioresources
WSX-D07 Commentary on data table changes - Retail
WSX-D08 Commentary on data table changes - Developer services
WSX-D09 Commentary on data table changes - Long-term strategies
WSX-D10 Commentary on data table changes - Supplementary tables
WSX-D11 Commentary on data table changes - Summary tables
WSX-D12 Commentary on data table changes - Past delivery
WSX-D13 Data tables commentary - Additional tables
WSX-D14 Data tables summary - company response
WSX-T01 Financial model - Draft Determinsation response
WSX-T02 Revenue reconciliation model
WSX-T03 RCV reconciliation model
WSX-T04 Revenue forecasting incentive model
WSX-T05 2023-24 ODI performance model for use in the PR24 business plans
WSX-T06 2024-25 ODI performance model for use in the PR24 business plans
WSX-T07 Residential retail reconciliation model
WSX-T08 Developer services model
WSX-T09 Water industry national environment programme (WINEP) reconciliation model
WSX-T10 Cost of new debt reconciliation model
WSX-T11 Cost reconciliations model
WSX-T12 Tax reconciliation model
WSX-T14 RPI-CPIH Wedge True Up model
WSX-T15 Strategic regional water resources reconciliation model
01.01.C - Young People's Panel
01.01.D - Willingness to pay research 1 - Accent
01.01.E - Willingness to pay research 2 - Accent
01.01.F - Willingness to pay research 3 - Populus
01.01.G - Willingness to pay research 4 Populus PDF
01.01.H - Literature review on perception of local
01.01.I - Cognitive testing - Accent
01.01.J - Cognitive testing - Populus
01.01.O - Acceptability testing
01.01.P - Evaluation of priority services
01.01.Q - Stakeholder survey with advice agencies
01.01.R - Evidence from day to day engagement
01.01.S - Online panel surveys
01.01.T - Image tracking research
01.01.U - Customer magazine and Facebook chatbot surveys
01.01.V - Review of customer participation
01.01.W - Image tracker analysis
01.01.X - Developer services research
01.01.Y - Outcome delivery incentives
01.01.Z - PR14 engagement review
01.01.AA - People in vulnerable circumstances
03.01.A - Performance commitment detail
03.01.B - Bespoke performance commitment methodology (Ofwat pro forma)
03.01.C - Third party report on our PR19 performance commitments
03.02.A - Triangulation analysis spreadsheet
03.02.B - Third party report on triangulation methodology
03.03.A - Third party report on cost benefit analysis
03.04.A - Incentive rate analysis spreadsheet
03.04.B - Third party report on calculation of incentive rates
03.04.C - Sharing success - our proposals for sharing information with other companies
03.05.B - Third party report on analysis of RORE for outcome delivery incentives
05.01.A - Catchment Panel report on ambition and innovation
05.01.B - Meeting WISER and innovation
05.01.C - Atkins - Phosphorus removal - technology review
05.01.D - Chandler KBS - Phosphorus removal - financial review
05.01.E - APEM - Investigations - cost assurance
05.01.F - Alternative approaches to delivery of the WINEP
05.03.A - PR19 Drinking water quality submission to the DWI
05.03.A.01 - PR19 Drinking Water Quality Submission to DWI
05.03.A.02 - Annex 1 and 2 - Nitrate Schemes
05.03.A.03 - PR19 Catchment intervention to control nitrates
05.03.A.04 - WSX-Risk-T33081000 - Fonthill Bishop
05.03.A.05 - WSX-Risk-T33126200 - Sturminster Marshall
05.03.A.06 - WSX-Risk-Z44000101 - WQZ 101 - Shaftesbury
05.03.A.07 - WSX-Risk-Z44000092 - WQZ 92 - Shapwick
05.03.A.08 - Annex 3 - Lead Strategy
05.03.A.09 - Regulation 28 Submission - High risk lead zones
05.03.B - DWI letters of support
05.03.B.01 - Confirmation of DWI support PR19_WSX_Fonthill
05.03.B.02 - Confirmation of DWI support PR19_WSX_Shapwick_Sturminster_Marshall
05.03.B.03 - Confirmation of DWI support PR19 WSX_Lead strategy
05.03.C - Long Term Planning for drinking water quality
05.03.D - DWI statement for the Wessex Water Partnership
05.09.A - Third party report - MWH
05.09.B - Third party report MWH published
05.09.D - Water network plus MEAV methodology
08.01.A - Economic Insight report on input cost and frontier shift assumptions
08.02.A - Wholesale cost models
08.02.B - Further commentary on efficient costs
08.03.A - Economic Insight report on household retail cost assessment for PR19
08.03.B - Peer review of residential retail cost assessment
08.03.C - Response to Ofwat cost assessment consultation May 2018
08.03.D - Economic Insight report on retail household IPP analysis and evidence
08.03.E - Economic Insight report on household retail margins at PR19
08.05.A - Claim WSX01 - North Bristol sewerage strategy
08.06.A - Claim WSX02 - Sewage treatment works capacity programme
08.07.A - Claim WSX03 - Number of non-infrastructure water supply assets
08.08.A - Claim WSX04 - Reducing leakage by a further 15%
08.09.A - Claim WSX05 - Flooding programme
08.10.A - Claim WSX06 - Pollution reduction strategy
08.11.A - Chandler KBS report on P removal programme cost
08.11.B - Chandler KBS report on non-construction cost benchmarks
Appendix 1 - Completed action template
Appendix 2 - Commentary on data tables that have changed
Appendix 3 - Updated Performance Commitment detail document (update from business plan)
Appendix 4 - Protecting and enhancing the environment - Response to IAP
Appendix 5 - Using water efficiently - Response to IAP
Appendix 6 - Providing excellent drinking water quality - Response to IAP
Appendix 7 - Minimising sewer flooding - Response to IAP
Appendix 8 - Bioresources - Response to IAP
Appendix 9 - Maintaining our services - Response to IAP
Appendix 10 - Accommodating growth and new development - Response to IAP
Appendix 11 - Water resources bid assessment framework - Response to IAP
Appendix 12 - Securing long-term resilience - Response to IAP
Appendix 13 - Enhancement opex - Report from Reckon LLP
Appendix 14 - The link between leakage and bursts
Appendix 15 - Mott MacDonald assurance report
Appendix 17 - Board assurance statement (tracked changes)
Appendix 18 - Additional support for kilometres of river improved (non-WINEP)
Appendix 19 - The link between customer research and performance commitment targets
Appendix 20 - Ensuring consistency in key PR19 parameters - Report from Economic Insight
Appendix 21 - Customer research on ERI - Report from Blue Marble
Appendix 22 - Customer research on ODI range - Report from Turquoise
Representation C1 Cost adjustment claim for Bristol STW
Representation C3 WINEP - Phosphorus removal
Representation C4 WINEP - Sanitary parameters
Representation C5 WINEP - Flow to full treatment (FFT) increase
Representation C6 WINEP - Investigations
Representation C7 WINEP - Event duration monitoring
Representation C8 WINEP - In-the-round 8.6% efficiency challenge
Representation C9 Partnership working
<Representation C10 Sewer flooding
<Representation C11 Pollution reduction strategy
Representation C12 Enhanced supply interruptions
Representation C13 Enhanced leakage reduction
Representation C14 Strategic regional water resource solutions
Representation C15 (Redacted)
Representation C16 (Redacted)
Representation C17 Raw water deterioration
Representation C18 The move to base+ modelling
Representation C19 Retail costs
Representation C20 Using 2018-19 data in the models
Representation C21 Frontier shift and RPEs
Representation C22 Business rates
Representation C23 Totex sharing rate (Redacted)
Representation M1 Bioresources energy adjustment
Representation O1 Event risk index (WW)
Representation O2 Mains repairs
Representation O3 Internal sewer flooding
Representation O4 Water quality customer contacts
Representation O6 Sewer collapses
Representation O7 Unplanned outage
Representation O8 Volume of water saved by water efficiency engagement
Representation O9 Lead communication pipes replaced
Representation O10 Population at risk of flooding in a storm
Representation O11 (Redacted)
Representation R1 PAYG ratios Representation
R2 Removal of cost sharing cash flow benefit
Representation R3 Cost of capital
Representation R4 Capital allowances
Representation R5 PDRC on one side of the AICR calculation
Representation R6 Bill profile and incidence effects
WSX - Commentary on business plan data tables that have changed
WSX - Commentary to DD Representations data template
WSX - Commentary to developer services data request
WSX DD Response - Summary representations (redacted)
WSX PR19 - DD Representations Data Template Final
WSX PR19-draft-determinations-company-representation-pro-forma
WSX PR19 draft determinations Developer services data request new post DD
WSX Representation Appendix C11.1 Third party report - Reckon
WSX Representation Appendix C14.1 Strategic water resources
WSX Representation Appendix C15.1 (Redacted)
WSX Representation Appendix C18.1 Reckon growth
WSX Representation Appendix C21.1 EI parameter consistency
WSX Representation Appendix C21.2 EI RPEs
WSX Representation Appendix P1.1 SIM calcs
WSX Representation Appendix R1.1 PAYG ratio calcs
WSX Representation Appendix R31 Frontier Economics WACC PDF
WSX Representation Appendix R3.2 EI skewness WACC
WSX Representation Appendix R4.1 App29 DD allowances
WSX Representation Appendix R4.2 App29 corrected DD allowances
03 WSX DD Response - response to Ofwat's draft determination actions