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Executive overview
Key findings
Over 4.7 million people: served, with an average of 560 megaliters of water supplied a day (joint regulator report, October 2026)
Around £8.9 billion: investment to deliver in 2025-30, the second year of which is now under way (joint regulator report)
1 star: Environment Agency rating for 2025, with 301 pollution incidents, 12 of them serious
Since 10 July 2026: hosepipe ban in Hampshire and the Isle of Wight; a River Test drought order awaits the Secretary of State
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Buyer relevance
Who the report is for
Contractors and engineering consultancies bidding for Southern Water work
Locate the delivery pressure points, from 929 environmental schemes due by March 2030 to Inspectorate deadlines running to 2035, before choosing where to bid.
Infrastructure investors and credit analysts
Read the price control (Competition and Markets Authority revenue of £6,646 million for 2025-30) against operating and environmental performance in one place.
Regional planners and stakeholders in Hampshire and the Isle of Wight
Track where the Hampshire Water Transfer and Water Recycling Project, Havant Thicket Reservoir and the Sandown scheme stand while drought orders remain the fallback.
Policy and regulatory teams
See how Ofwat, the Competition and Markets Authority, the Environment Agency, the Drinking Water Inspectorate, the Secretary of State and the Planning Inspectorate each act on one company.
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Decision scope
Questions answered
How much water does Southern Water supply, and to how many people?
An average of 560 megaliters a day to over 4.7 million people, according to the regulators' October 2026 joint report.
Is demand the cause of Hampshire's restrictions?
Household consumption was 126.6 liters per person per day in FY2025-26, below the industry average of 137.3, and leakage was 76.6 liters per property per day against 104.5.
How did the Competition and Markets Authority change Southern Water's price control?
It set allowed revenue for 2025-30 at £6,646 million, £155 million above Ofwat's updated figure; the company had sought £7,416 million, £949 million above Ofwat's original determination.
How many drinking water improvement items does the Inspectorate list?
42 live items: 5 enforcement orders, 35 notices and 2 undertakings, with completion dates running to 2035.
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Inside the report
Inside the complete report
Executive Overview
1. Water Resource Profile
2. Governance and Institutional Framework
3. Infrastructure and Service Delivery
Strategic Outlook and Opportunities
Source Register
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Public preview
What to watch next
1. Water Resource Profile
The Secretary of State's decision on the River Test and non-essential use ban applications; the timetable set at the start of the Hampshire Water Transfer and Water Recycling Project examination; the Isle of Wight Council decision on Sandown.
2. Governance and Institutional Framework
Further hearings in the Environment Agency's criminal case at Medway Magistrates' Court; sentencing on the Fullerton guilty pleas (14 July 2026); the case due in court in December 2026; receipt of the final £300 million of equity; any change in Ofwat's monitoring category.
3. Infrastructure and Service Delivery
The Environment Agency's 2026 assessment (published in 2027); Inspectorate closure reports on the deadlines due by 30 April 2027: Bush Road Cuxton (31 October 2026), service reservoirs and Thanet supply system (31 January 2027), Yew Hill and West Hill and Patcham works (31 March 2027) and Sandown works (30 April 2027); the internal sewer flooding and customer satisfaction measures in Ofwat's next operational performance report.
Strategic Outlook and Opportunities
Ofwat's cost change final decision (December 2026); the Hampshire Water Transfer and Water Recycling Project examination timetable and the Secretary of State's decision on consent; the River Test drought order decision; receipt of the final £300 million of equity before 31 March 2027; the Competition and Markets Authority bill uplift that applies from April 2027; WINEP year-two delivery against the 929-scheme program.
Strategic Outlook: allowances, allowed revenue, bills, cost change and financial results for 2025-30.
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Included
What you receive
The complete PDF report: 12 pages, 6 sections, 10 tables and a register of 30 sources.
This edition
November 2026, First edition.
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Evidence & method
Evidence and method
The report draws on Ofwat, Competition and Markets Authority, Environment Agency and Drinking Water Inspectorate publications, including the regulators' October 2026 joint performance report and the Environment Agency's 2025 environmental performance report. It also uses Southern Water's audited annual reports, Planning Inspectorate project records and dated company, shareholder and contractor announcements on equity, frameworks and schemes.
Sources
30 sources, listed in the report's source register. Evidence current to 11 November 2026. Principal data periods: FY2025-26 annual report (year ended 31 March 2026); regulators' calendar 2025 and FY2025-26 performance data (published October 2026); price control 2025-30. Drought, project and legal status checked on 11 November 2026. All currency is pounds sterling (£)..
Evidence boundaries
This report uses authoritative source material available at the stated research cutoff. It distinguishes published facts, calculated values and analytical interpretation. No independent modelling is performed. Forward-looking analysis reflects published plans, documented trends and stated uncertainties. It does not constitute legal, financial, investment or engineering advice.
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Lead analyst
Robert C. Brears
Founder, Our Future Water Intelligence
Robert C. Brears is a water-security specialist and author whose work examines utility governance, infrastructure investment, climate resilience and long-term water-system change for executive and policy audiences.
- Decision-focused utility intelligence
- Published water-policy author
- Evidence-grounded system analysis
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Buyer FAQs
Before you purchase
Who can use the report?
Licensed for internal use within one purchasing organization. The PDF and its contents may be shared with colleagues within that organization. External redistribution, resale and public publication are prohibited without permission.
How is the report delivered?
The PDF is available to download immediately after confirmed payment, through our secure delivery system.
Can my organization buy wider access?
Institutional purchasing: For invoice enquiries, multi-organization licensing or broader access requirements, contact Our Future Water Intelligence.
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Water Systems Overview: Southern Water
- Format
- Length
- 12 pages
- Edition
- November 2026, First edition
- Price
- USD 499
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Report details
Publication details
- Publisher
- Our Future Water Intelligence
- Report family
- Water Utility Intelligence Report
- Edition
- November 2026, First edition
- Format
- Length
- 12 pages
- Reference
- OFW_EXT_WATER_SYSTEMS_OVERVIEW_SOUTHERN_WATER_2116b02b1321
- Evidence current to
- 11 November 2026
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