infrastructure · the national record
Water leakage and reliability in England and Wales
How much water leaks away before it reaches the tap, from Ofwat's company performance figures. In 2024 to 2025 the water companies of England and Wales lost about 2,869 million litres a day to leaks, roughly a fifth of all the water they put into supply, and progress on fixing it has stalled. This page shows which companies leak most, who is improving, and where supply is least reliable. It is the companion to the sewage page.
How to read this
These are Ofwat's water company performance figures for the 17 water and wastewater companies of England and Wales. Leakage is the volume of treated water lost from the network each day. Supply interruptions are the average minutes per property each year that homes are without water for more than three hours. Both are measured against targets the companies agreed with the regulator.
Ofwat Water Company Performance Report 2024-25 and long term leakage data. England and Wales, 17 companies. Leakage in million litres per day.
The national picture
A fifth of the water lost, and progress stalled
Water companies in England and Wales lose about 2,869 million litres a day to leaks, around 20 per cent of everything they put into supply. Leakage is down on the long run, but over the last five years the sector cut it by only about 9 per cent against a commitment of around 16 per cent, and only 4 of the 17 companies met their leakage target in 2024 to 2025. The largest leaker by volume is Thames Water.
Who leaks most
The biggest leakers, and who is improving
Thames Water loses the most water of any company, about 569 million litres a day, followed by United Utilities and Severn Trent. On progress the picture splits: Affinity Water has cut leakage most against its baseline, down 19.4 per cent, while Welsh Water has gone the wrong way, up 15.0 per cent.
down 13.2% vs baseline
down 7.3% vs baseline
down 16.8% vs baseline
down 15.1% vs baseline
up 15% vs baseline
down 3.9% vs baseline
down 12% vs baseline
down 19.4% vs baseline
down 9.2% vs baseline
up 8% vs baseline
Daily leakage by company, 2024-25, in million litres per day. The largest companies serve the most properties, so high volume does not by itself mean poor performance. Source: Ofwat.
When the taps run dry
Supply interruptions, getting worse
Reliability has slipped too. Across the sector the typical home lost water for more than three hours for about 10.0 minutes over the year, double the 5.0 minute target, and the gap between companies is stark. Portsmouth Water kept interruptions to 2.0 minutes, while Southern Water and Welsh Water left the average home without water for well over two hours across the year.
Worst
Best
Average minutes per property per year that supply was interrupted for more than three hours, 2024-25. The target is 5 minutes. Source: Ofwat.
Questions this raises
For the water companies
- 1.
About a fifth of treated water leaks away before it reaches a tap, and progress has stalled. Is the investment matching the scale of the problem?
- 2.
Only 4 of 17 companies met their leakage target. What happens when a regulated company misses a target it agreed to?
- 3.
Supply interruptions are worsening and vary enormously between companies. Why can one company keep homes supplied while another cannot?
- 4.
Leakage and sewage spills are two sides of the same ageing network. Is the infrastructure being renewed fast enough for a drier, more crowded future?
Sources & method
Data provenance
- Water company performance report 2024-25 (Ofwat) ↗· Open Government Licence v3.0
Caveats & data notes
- Leakage is the volume of treated water lost from the network each day, about a fifth of the water put into supply. The figure is the company reported number assured by Ofwat.
- Large companies serve more properties and longer networks, so a high leakage volume does not by itself mean poor performance; the change against each company's own baseline is the fairer guide to effort.
- Supply interruptions count the average minutes per property each year that homes were without water for more than three hours. A few long incidents can dominate a company's figure.
- Figures cover the 17 water and wastewater companies of England and Wales for 2024-25. Pollution and sewage are covered on the separate sewage page.
- Source: Ofwat Water Company Performance Report 2024-25 and long term leakage data.
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