As of Ofwat APR 2024-25 / DWI 2024: Essex and Suffolk Water leaks the least water in England and Wales at 64 l/p/d, well below the national average of 109 l/p/d. Dŵr Cymru Welsh Water has the highest leakage at 169 l/p/d. Source: Ofwat Annual Performance Report 2024-25 via DiscoverWater.co.uk (OGL v3.0).
| Rank (lowest leakage first) | Company | Leakage (l/p/d) | vs avg (109) | GWSS |
|---|---|---|---|---|
| #1 | Essex and Suffolk Water | 64 l/p/d | -45 ▼ | 69.4/100 |
| #2 | SES Water | 68 l/p/d | -41 ▼ | 93.2/100 |
| #3 | Bristol Water | 68 l/p/d | -41 ▼ | 89.7/100 |
| #4 | Anglian Water | 80 l/p/d | -29 ▼ | 87.1/100 |
| #5 | Cambridge Water | 80 l/p/d | -29 ▼ | 73.1/100 |
| #6 | Southern Water | 89 l/p/d | -20 ▼ | 50/100 |
| #7 | Portsmouth Water | 90 l/p/d | -19 ▼ | 88.9/100 |
| #8 | Northumbrian Water | 94 l/p/d | -15 ▼ | 58/100 |
| #9 | Affinity Water | 95 l/p/d | -14 ▼ | 84/100 |
| #10 | South East Water | 96 l/p/d | -13 ▼ | 75.8/100 |
| #11 | Severn Trent Water | 98 l/p/d | -11 ▼ | 58.2/100 |
| #12 | South West Water | 102 l/p/d | -7 ▼ | 79.5/100 |
| #13 | South Staffs Water | 103 l/p/d | -6 ▼ | 64.3/100 |
| #14 | Wessex Water | 108 l/p/d | -1 ▼ | 77.9/100 |
| #15 | Yorkshire Water | 111 l/p/d | +2 ▲ | 70.8/100 |
| #16 | United Utilities | 119 l/p/d | +10 ▲ | 48.2/100 |
| #17 | Thames Water | 143 l/p/d | +34 ▲ | 62.7/100 |
| #18 | Hafren Dyfrdwy | 145 l/p/d | +36 ▲ | 64.2/100 |
| #19 | Dŵr Cymru Welsh Water | 169 l/p/d | +60 ▲ | 19.4/100 |
Source: Ofwat Annual Performance Report 2024-25, accessed via DiscoverWater.co.uk (CSV: 2025-leakage-per-property-per-day-UK-Current.csv). Open Government Licence v3.0. GWSS methodology.