01
About the Utility
United Utilities Water Limited is the regulated water and wastewater company for North West England, a region that includes Cumbria, Cheshire, Greater Manchester, Lancashire and Merseyside. It belongs to the group that describes itself as the UK’s largest listed water company, and Moody’s lists United Utilities PLC as its parent. Ofwat, its economic regulator, set the price control for 2025 to 2030 in its PR24 final determination. The Drinking Water Inspectorate recorded a supplied population of 7,319,000 in 2020, and the Environment Agency rates the company’s environmental performance. The group also describes itself as England’s largest corporate landowner.
02
Water System
United Utilities Water plans supply across four water resource zones, a structure its 2024 Water Resources Management Plan keeps for the horizon to 2050. In 2020 the Drinking Water Inspectorate recorded 93 treatment works. Around 47 per cent of households have a meter, and all new homes are metered automatically. Rainfall is becoming less predictable: annual averages have not changed significantly, but year-to-year variability has increased. Service performance weakened at the end of AMP7, when the company missed its commitments in 2024/25 on supply interruptions and the Compliance Risk Index and fell short of its year-five leakage target.
03
Wastewater System
United Utilities also collects and treats the region’s wastewater through 569 treatment works, and its bioresources facilities treat around 200,000 dry tonnes of sewage sludge each year. Pollution is the weakest part of its environmental record. Environment Agency data show sewerage pollution incidents rising to 347 in 2024, a red-rated result in an assessment that placed the company at two stars, requiring improvement. Storm overflows moved the other way: monitoring returns for that wet year showed spills down 20% and spill duration down 31%.
Sewerage pollution incidents
Total category 1–3 incidents per 10,000 km of sewer, calendar years 2016–2024, Environment Agency assessment
All values are Environment Agency actuals on one measure and basis, published as whole numbers; 2016–2020 come from the 2023 assessment and 2021–2024 from the 2024 assessment.
Sources: Environment Agency, United Utilities EPA data reports 2023 and 2024.04
Investment & Priorities
Ofwat’s PR24 final determination sets the allowances for AMP8, for which United Utilities describes a £13 billion five-year investment plan. In 2025/26 the regulated company incurred £2,444 million of totex, below the £2,624 million assumed in the determination. The settlement also ties revenue to outcomes, and the group reported a net penalty from outcome delivery incentives in FY26. Additional debt capital extends liquidity into the second half of FY28, while the board keeps gearing within its target range as the regulated asset base grows.
05
Sustainability & Resilience
Resilience investment centres on long-lived supply assets: planning permissions for the Haweswater Aqueduct Resilience Programme are now confirmed, and the company made the case to Ofwat for Vyrnwy re-lining in AMP8. United Utilities follows a science-based approach to net zero by 2050, and its PR24 settlement includes a commitment to cut embodied emissions from its planned wastewater treatment programme by 5%. A 2026 industry methodology update raised reported process emissions, an accounting change rather than a change in performance.
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Key Challenges
- Reducing sewerage pollution incidents after a red Environment Agency rating for 2024.
- Restoring supply-interruption and water-quality compliance performance after missed commitments.
- Delivering the AMP8 investment programme within Ofwat’s PR24 cost allowances.
- Securing long-term supply resilience through the Haweswater aqueduct and Vyrnwy schemes.
- Financing a growing asset base while holding gearing within the 55–65% target range.