Technical documents
These documents give more detail on the solutions we are exploring. They include our technical investigations, feasibility studies and submissions to our regulators.
Overview of RAPID and the gateway process
The major infrastructure projects we’re exploring – desalination, water recycling and new bulk supplies – are being overseen by the new Regulators’ Alliance for Progressing Infrastructure Development (RAPID). RAPID is an advisory board that makes recommendations to Ofwat.
It comprises Ofwat, the Environment Agency and the Drinking Water Inspectorate – and is being advised by Natural England.
The group is overseeing more than a dozen strategic water resources projects for several water companies to identify optimal regional and inter-regional solutions that could be started in 2025-2030.
For more information on RAPID, see ofwat.gov.uk/regulated-companies/rapid.
Gate 2
Our Gate 2 submissions to RAPID
You can view copies of our submissions to RAPID below. Please note, some company-sensitive information has been redacted.
RAPID Gate 2 Submission: Response to draft decision
Southern Water – Letter to the Environment Agency and RAPID
RAPID Submission: Southern Water Accelerated Gate 2 Submission Summary
RAPID Submission: Water Recycling – Gate 2 Detailed Feasibility & Concept Design Report ii
RAPID Submission: Havant Thicket – Gate 2 Detailed Feasibility & Concept Design Report iii
Annex 2: Water Recycling – Gate 2 Supporting Technical Report
Annex 3: Havant Thicket – Gate 2 Supporting Technical Report
Annex 4: Water Resources – Gate 2 Supporting Technical Report
Annex 5: Options Appraisal Process – Gate 2 Supporting Technical Report
Annex 6: Efficiency of Expenditure – Gate 2 Supporting Technical Report
Annex 7: Assurance Process – Gate 2 Supporting Technical Report
Annex 8: Legal and Regulatory Annex – Gate 2 Supporting Technical Report
Annex 9: Stakeholder and Customer Methodology – Gate 2 Supporting Technical Report
Annex 10: Proposed Gate 3 Outcomes and Activities – Gate 2 Supporting Technical Report
Annex 12: Outline Option Evolution Plan – Gate 2 Supporting Technical Report
Annex 13: Detailed Option Evolution Statement – Gate 2 Supporting Technical Report
Gate 2 – Query responses
Below you can see our responses to RAPID’s queries about our Gate 2 submission. Again, some company-sensitive information has been redacted.
HAV001 CAPEX Updated – B2-B4-B5-D2-Ceramic
HAV002 SDE001 SWR001 Response (Tables 11 12 and 13)
HAV006 Jacobs – New Gate 2 Final Assurance Statement
SRN001 WfLH Memorandum – WfLH Water Recycling Plant Wastewater Discharges
SRN001 WfLH Tech Rp 1 – Watercourses
SRN001 WfLH Tech Rp 2 – Appendix A1 All Figures
SRN001 WfLH Tech Rp 2 – BNG Report
SRN001 WfLH Tech Rp 2 BNG – Appendix A2 Summary BNG Assessment
SRN001 WfLH Tech Rp 2 BNG – Appendix A3 Configuration Summary BNG Assessment
SRN001 WfLH Tech Rp 4 – HRA WRP Marine Consenting
SRN001 WfLH Tech Rp 5 – AQ Site Selection
SRN001 WfLH Tech Rp 6 – Ornithology and Noise
SRN003 RAPID Gate 2 Response (Final Complete Response)
SWR002, SDE002, HAV004 RAPID Gate 2 Consolidated Response
SWR002, SDE002, HAV004 Updated Tables 11,12 and 13
SWR003 (HAV001) CAPEX Updated – B2-B4-B5-D2-Ceramic
SRN001 BNG A2iii Budds Farm to WRP Route 1
SRN001 BNG A2iv Construction Compound Example
SRN001 BNG A2ix Fawley to Testwood Route 3
SRN001 BNG A2v Desal Ashlett Creek Habitat
SRN001 BNG A2vi Desal Meon DS5 Habitat
SRN001 BNG A2vii Fawley to Testwood Route 1
SRN001 BNG A2viii Fawley to Testwood Route 2
SRN001 BNG A2x Fawley to Testwood Route 4
SRN001 BNG A2xi Fawley to Testwood Route SIA
SRN001 BNG A2xiii Fawley to Abstraction and Discharge Route 2
SRN001 BNG A2xiv Fawley to Abstraction and Discharge Route 3
SRN001 BNG A2xix Havant Thicket to Otterbourne Route 4
SRN001 BNG A2xv Fawley to Abstraction and Discharge Route 4
SRN001 BNG A4ix SWS G2 Natural Capital Workbook – BPT and WBS
SRN001 BNG A4v SWS G2 Natural Capital Workbook – Desal
SRN001 BNG A4vi SWS G2 Natural Capital Workbook – WRP
SRN001 BNG A4vii NCA A1 A2 Pipeline 1
SRN001 BNG A4vii NCA A1 A2 Pipeline 2
SRN001 BNG A4xi NCA B2 Route 2
SRN001 BNG A4xii NCA B4 Recycled Water from Budds Farm WTW Route 1
SRN001 BNG A4xiv NCA B4 Recycled Water from Budds Farm WTW Route 2
SRN001 BNG A4xix NCA B4 Water from Budds Farm WTW Route 3
SRN001 BNG A4xl NCA B5 Route 1
SRN001 BNG A4xli NCA B5 Route 2
SRN001 BNG A4xlii NCA D2 61Mld Alternative Bulk Supply Route 4
SRN001 BNG A4xliv NCA D2 61Mld Alternative Supply Route 3
Our Interim Update submission to RAPID
You can view copies of our submissions to RAPID below. Please note, some company-sensitive information has been redacted.
Interim Update – Solution Summary
Interim Update – Regulator and Other Statutory Bodies Engagement Plan
Interim Update – Customer and Stakeholder Engagement
Interim Update – Efficiency of Expenditure
Interim Update – Activity Plan to Gate 2
Interim Update – Options Appraisal Process
Interim Update – Conceptual and Detailed Feasibility – Desalination
Interim Update – Conceptual Design Report – Annex 1 Desalination
Gate 1
RAPID's Gate 1 recommendations
RAPID has published its recommendations on our Gate 1 submission.
Our Gate 1 submissions to RAPID
You can view copies of our submissions to RAPID below. Please note, some company-sensitive information has been redacted.
Southern Water Accelerated Gate 1 Submission Summary
Desalination Accelerated Gate 1 Preliminary Feasibility Assessment
Water Recycling Accelerated Gate 1 Preliminary Feasibility Assessment
West Country Sources North Accelerated Gate 1 Preliminary Feasibility Assessment
Additional Solution Accelerated Gate 1 Preliminary Feasibility Assessment
Southern Water Accelerated Gate 1 Navigation and Glossary
Southern Water Accelerated Gate 1 Priority Actions Submission
Section 20 Operating Agreement
View the legal agreement we signed with the Environment Agency (EA) in 2018: