Live Updates arrow
Account Login
search-icon
Close

Business Plan 2025–30

This is our largest and most ambitious plan yet, double the size of our current delivery plan.

background

Our plan

We submitted an ambitious business plan for 2025-30 to our regulator Ofwat in 2023, outlining our proposals to approximately double our annual investment in water and waste services for our customers.

Our plan was challenging and showed how we will improve the health and wellbeing of our communities, protect and improve the environment and help sustain the local economy.

We will work differently, using innovative technology and nature-based solutions to go further and faster to tackle the challenges of water scarcity, river water quality, pollutions and flooding, delivering a step change in our environmental performance.

We will build new assets and secure reliable high-quality water supplies for the future.

Our response to Ofwat’s Draft Determination on our business plan

Ofwat responded to our business plan in July 2024 with a Draft Determination and held a public consultation on its response. It's due to make a final decision on our plan in December 2024.

Maintaining and improving

Our response has focused on areas customers have told us are a priority:

  • A reliable supply of water.
  • Healthy rivers and seas.
  • Trusted and easy customer service.
An establishing shot of weir wood reservoir

Our response

In our response we:

  • stress the need for a plan which has achievable targets and balanced incentives and penalties
  • stress the need for financial controls which will give confidence to investors to support delivery of the plan
  • seek Ofwat’s approval for our multi-tiered approach to provide support for our customers who will struggle to pay their bills
    express our support to deliver more of the investment through third parties, with oversight from Ofwat
  • underline our ability to deliver our plan and assure it.

New investment

Following further investigations and guidance from regulators our response includes new investment which will deliver:

  • more environmental improvements in a shorter timescale, such as tackling storm overflows. We had requested extra time to introduce nature-based options first and give them time to deliver, rather than building storage and concrete options. However, we have now shortened the programme to meet Environment Agency deadlines
  • the new water resources we need to keep taps flowing, increase our resilience to drought and protect our sensitive environments, following an update to our long-term draft Water Resources Management Plan. This now includes the upgrade of another water treatment works, bringing the total to five
  • increased investment in cyber security.
An aerial view of a water treatment facility

Read the business plan documents submitted to our regulator below:

Our DD Response Document 

SRN PR24 DD Response Document

Guide to Southern Water's DD Response to Documents 

Southern Water DD Guide to Documents

Annexes and Appendices

SRN-DDR-012: Risk Appendix
SRN-DDR-021: Sustainable Botex Technical Annex
SRN-DDR-026: Real Price Effect and Frontier Shift Methodology
SRN-DDR-051: Delivery Action Plan 
SRN-DDR-052: Price Control Deliverables
SRN-DDR-053: Financial Resilience Plan
SRN-DDR-056: Past Performance 
SRN-DDR-057: Ofwat's Quality and Ambition Assessment


Enhancement Cost Evidence Cases

SRN-DDR-011: KPMG Industry Risk Analysis
SRN-DDR-018: Economic Insight Frontier Shift Report
SNR-DDR-019: Economic Insight Issues with Ofwat's Approach with Base Cost Assessment 
SRN-DDR-020: Economic Insight Customers Not Paying Twice Report
SRN-DDR-022: Business Rates Cost Evidence Case
SRN-DDR-024: Environment Agency Changes to Charge Proposal for Water Discharges
SRN-DDR-025: Energy Cost Evidence Case
SRN-DDR-027: Supply Resilience Enhancement Programme Cost Evidence Case
SRN-DDR-028: Appendix A 
SRN-DDR-028: Appendix B
SRN-DDR-028: Appendix C
SRN-DDR-028: Water Resources - Supply Enhancement Cost Evidence Case
SRN-DDR-029: Water Resources - Demand Leakage Enhancement Cost Evidence Case
SRN-DDR-030: Water Resources - Demand Water Efficiency Enhancement Cost Evidence Case
SRN-DDR-031: Water Resources - Smart Metering Enhancement Cost Evidence Case
SRN-DDR-032: Water Resources - Strategic Resource Option Enhancement Cost Evidence Case
SRN-DDR-033: Raw Water Deterioration Enhancement Cost Evidence Case
SRN-DDR-034: Lead Enhancement Cost Evidence Case
SRN-DDR-035: Appendix A - Weir Wood Reservoir Auxiliary Spillway Optioneering Report
SRN-DDR-035: Reservoir Safety Enhancement Cost Evidence Case
SRN-DDR-036: Appendix A - WSW AMP 8 Costs Forsharing
SRN-DDR-036: WINEP Supporting Water Abstraction Enhancement Cost Evidence Case
SRN-DDR-037: Water Network Resilience and Disinfection Enhancement Cost Evidence Case
SRN-DDR-038: Network and Information Systems Enhancement Cost Evidence Case
SRN-DDR-039: Market Based Delivery
SRN-DDR-039: Market Based Delivery Appendices
SRN-DDR-040: Appendix A - Southern Water PR24 SEMD Summary Report v1.0
SRN-DDR-040: Appendix B - Southern Water PR24 SEMD Benchmarking Review v1.0
SRN-DDR-040: Security and Emergency Measure Direction Enhancement Cost Evidence Case
SRN-DDR-041: Climate Resilience Enhancement Cost Evidence Case
SRN-DDR-042: Industrial Emissions Directive Enhancement Cost Evidence Case
SRN-DDR-043: WINEP - Nutrients Phosphorus and Nitrogen Schemes Enhancement Cost Evidence Case
SRN-DDR-044: WINEP - Storm Overflows Enhancement Cost Evidence Case
SRN-DDR-045: WINEP - Monitoring Enhancement Cost Evidence Case
SRN-DDR-046: WINEP - Wastewater Investigations Enhancement Cost Evidence Case
SRN-DDR-047: WINEP - Bioresources Additional Cake Storage Enhancement Cost Evidence Case
SRN-DDR-048: Wastewater Treatment Growth Enhancement Cost Evidence Case
SRN-DDR-049: Resilience - Coastal Enhancement Cost Evidence Case
SRN-DDR-050: Resilience - Infiltration Enhancement Cost Evidence Case
SRN-DDR-054: Estimating the Cost of Equity for PR24
SRN-DDR-055: Economic Insight - Gearing and Capital Structures Report 
SRN-DDR-058: Cost of Embedded Debt
SRN-DDR-059: Estimating the Cost of New Debt

Cost Adjustment Claims

SRN-DDR-013: Regional Wages - Cost Adjustment Claim
SRN-DDR-014: Water Treatment Economies of Scale  - Cost Adjustment Claim
SRN-DDR-015: Coastal Population  - Cost Adjustment Claim
SRN-DDR-016: Bioresources AAD  - C ost Adjustment Claim
SRN-DDR-017: Wastewater Growth Network Reinforcement  - Cost Adjustment Claim

 

Data Tables and Commentaries

PR24 Draft Determination Commentary 2024 v1.0 OUT TABLES
PR24 Draft Determination Commentary 2024 v1.0 SUP TABLES
PR24 Draft Determination Commentary 2024 v1.0 SUM TABLES
PR24 Draft Determination Commentary 2024 v1.0 PD TABLES
PR24 Draft Determination Commentary 2024 v1.0 ADD TABLES
PR24 Draft Determination Commentary 2024 v1.0 RR TABLES
PR24 Draft Determination Commentary 2024 v1.0 CW TABLES
PR24 Draft Determination Commentary 2024 v1.0 CWW TABLES
PR24 Draft Determination Commentary 2024 v1.0 RES TABLES
PR24 Draft Determination Commentary 2024 v1.0 BIO TABLES
PR24 Draft Determination Commentary 2024 v1.0 RET TABLES
PR24 Draft Determination Commentary 2024 v1.0 DS TABLES

SRN DD Business Plan Table Summary
SRN PR24 DD Submission Data Tables
SRN PR24 DD Submission Data Tables ADD 1-21
SRN PR24 DD Submission Data Tables ADD 24-25

Financial Model

SRN PR24 DD Financial Model 

 

PR24 DD Response Proforma

SRN PR24 Draft Determinations Representation Proforma

 

PR19 Reconciliation Models 

PR24 DD ODI Peformance Model 2023-24 SRN 
PR24 DD ODI Peformance Model 2024-25 Southern Waer aligned to EP24 
SRN PR24 RCV Adjustments Feeder Model v2.0 
SRN 2023-24 PR19IPD04 In-Period Adjustments Model 
SRN Cost Sharing Total Costs Reconciliation v4.0
SRN Bioresources Revenue Reconciliation Model Dec 2020 v2.3
SRN Developer Services Reconciliation Model 
SRN PR24 Revenue Adjustments Feeder Model v2.0
SRN Residential Retail Reconciliation Model Dec 2020 v2.0
SRN RFI Model Apr 2023 v1.0 2024.25 charges
SRN RPI CPIH Wedge True Up Model Dec 2020 v5.0