Distribution input per person
238 l/person/day
Put into the network per person served, before losses or billing.
Water utility
Thames Water
The largest water and sewerage company in the UK by population served, covering London and the Thames Valley. It operates the oldest and most heavily loaded network in the country, and has the highest absolute leakage of any UK company — largely a consequence of the age and length of that network.
How this company performs
Reported to the Environment Agency for the 2023-24 and 2024-25 regulatory years, alongside the England figure for the same year.
Leakage per person
53.6 l/person/day
Lost from the network, expressed per person served.
Leakage as a share of distribution input
22.5%
The same losses as a share of everything put into distribution.
Leakage per property
136 l/property/day
The same losses normalised by connected property instead.
Household water use per person
138 l/person/day
Used in the home per person per day, excluding leakage.
Household metering
59.1%
Households billed on a measured tariff.
Non-household metering
83.5%
Business customers on a measured tariff, excluding empty properties.
The company
- Ownership
- Private, held through a group structure with substantial external debt
- Population served
- 16 million
- Services
- Water and wastewater
- Regulated by
- Ofwat (economic), DWI (quality), Environment Agency (environment)
Service area: Thames Water service area.
What Hydrionis does not hold for this company
These profiles cover water resources performance only. Hydrionis holds no treatment works, reservoir or network asset records for Thames Water, no pollution incidents or enforcement history, no capital investment programme, and no wastewater or storm overflow performance — none of which is published in the return these figures come from.
The longer leakage record exists: Ofwat holds company leakage back to 1992. It is not held here because ofwat.gov.uk refuses automated requests, and Hydrionis publishes what it can retrieve through its governed ingestion runner rather than what it can retype.
Also held for this company: leakage.
Where these figures come from
ReportedHigh confidence2024
Source: EA water resources — Analysis of the water industry’s annual water resources performance. Licence: Open — attribution required (attribution required).
Method: As published by the Environment Agency: total water put into distribution divided by population served, for the April-to-March regulatory year.
Retrieved 25 August 2026.