Official records compared
Permitted overflows not found on the hub
The Environment Agency's public register lists every permit held by a water company to discharge storm sewage in England. The National Storm Overflow Hub lists the overflows the companies report on. We compare the two.
Active storm sewage permits
10,935
No hub overflow within 500 m
1,297
Share
11.9%
What this does and does not show
The data shows a permitted storm sewage discharge point on the EA register with no overflow published on the hub within 500 m. It does not show that an overflow is unmonitored or that anything is wrong. Common reasons for a gap:
- the permit's grid reference is approximate or marks the works, not the outfall;
- one permit covers an overflow the hub lists under a different location;
- the overflow is not published on the hub.
35 active permits have no usable grid reference on the register and are left out. Each row links to the EA register so it can be checked. England only: Welsh permits are held by Natural Resources Wales. Company names are as recorded on the register. Register last read 2026-09-20.
By company
| Permit holder | Permits | Within 100 m | 100 to 500 m | Over 500 m |
|---|---|---|---|---|
| Severn Trent Water Limited | 1,989 | 977 | 626 | 386 |
| Wessex Water Services Limited | 874 | 442 | 262 | 170 |
| Northumbrian Water Limited | 1,330 | 817 | 373 | 140 |
| United Utilities Water Limited | 2,083 | 1,834 | 119 | 130 |
| Yorkshire Water Services Limited | 1,697 | 1,367 | 215 | 115 |
| Southern Water Services Limited | 708 | 470 | 124 | 114 |
| Anglian Water Services Limited | 995 | 683 | 208 | 104 |
| South West Water Limited | 904 | 544 | 265 | 95 |
| Thames Water Utilities Limited | 254 | 170 | 56 | 28 |
| Dŵr Cymru Cyfyngedig | 95 | 61 | 22 | 12 |
| Ancala Water Services (Estates) Limited | 3 | 0 | 1 | 2 |
| Yorkshire Water Services Limited|Northumbrian Water Limited | 1 | 0 | 0 | 1 |
| Severn Trent Water Limited|Environmental Permits Severn Trent Water | 1 | 1 | 0 | 0 |
| Severn Trent Water Limited|Yorkshire Water Services Limited | 1 | 0 | 1 | 0 |
Dŵr Cymru Cyfyngedig: 12 permits with no hub overflow within 500 m
| Site (register name) | Area | Grid ref | Nearest hub overflow | Permit |
|---|---|---|---|---|
| CSO ADJACENT A548 ROAD BRIDGE | Shropshire | SJ3195037760 | 2.1 km | MI/CG0324302/003 |
| STORMWATER TANK ADJACENT TO HALLS F | Shropshire | SJ3186037650 | 1.7 km | MI/CG0324301/002 |
| RUARDEAN SEWAGE TREATMENT WORKS | Forest of Dean | SO6180817884 | 1.6 km | MI/AS1003902/002 |
| SHOBDON STW | Herefordshire, County of | SO3951061140 | 1.3 km | MI/AN0272501/002 |
| WEST OF WEALSTONE LANE CSO | Cheshire West and Chester | SJ4118468616 | 1.1 km | NW/CM0116401/004 |
| LOWER KINNERTON PS EMERGENCY OVERFL | Cheshire West and Chester | SJ3455061970 | 1.0 km | NW/CG0327201/001 |
| CHESTER KINGS MEADOW WREXHAM RD SPS | Cheshire West and Chester | SJ3930062950 | 0.9 km | NW/CM0150301/001 |
| EARLE DRIVE - PARKGATE ROAD CSO | Cheshire West and Chester | SJ2848577853 | 0.7 km | NW/CM0169901/003 |
| SANDY LANE CSO PS SANDY LANE CAR PA | Cheshire West and Chester | SJ4197065990 | 0.7 km | NW/CG0371201/001 |
| ST.MARTIN'S COMBINED SEWER OVERFLOW | Shropshire | SJ3172336168 | 0.6 km | MI/CM0081201/006 |
| MANHOLE 9 CSO | Herefordshire, County of | SO3996651968 | 0.6 km | MI/AN0125901/003 |
| SEATON AVENUE CSO | Herefordshire, County of | SO5304040290 | 0.5 km | MI/AN0078101/004 |
Sources: Environment Agency public register, Discharges to Water and Groundwater (Environment Agency Conditional Licence); National Storm Overflow Hub. The register is read weekly and every download is archived with a SHA-256 fingerprint (see how we keep the record).