Clapham WwTW
Storm overflow operated by United Utilities. The source names River Wenning as the receiving water.
- 3
- Spills in 2025
- 15.2
- Recorded hours
- 100%
- Monitor operation
- 2
- Years listed
The reported spill count was the same as in 2024. This compares event counts, not discharge volume.
We do not have a live report for this outlet. Its annual spill records are shown below.
How it compares in 2025
Clapham WwTW recorded 3 spills in 2025. That is more than 26% of the 14,239 overflows in England with a reported figure, and ranks 9,843rd nationally. Among United Utilities overflows it ranks 1,655th of 2,270; the median United Utilities overflow recorded 15 spills.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 3 | 15.2 |
| England | 9,843rd of 14,239 | 11 | 22.3 |
| United Utilities | 1,655th of 2,270 | 15 | 29.1 |
Rank 1 has the most spills. Equal counts share a rank. Only overflows with a reported count are ranked. Counts do not measure volume, so a higher rank does not mean more sewage.
Annual spill history
| Year | Spills | Duration | Monitor operation | Source |
|---|---|---|---|---|
| 2025 | 3 | 15.2 hours | 100% | Official data |
| 2024 | 3 | 83.5 hours | 100% | Official data |
A missing figure means the source did not provide a usable value. A zero is shown as zero. Monitor operation below 90% can make comparison less reliable.
Outlet details
- Water company
- United Utilities
- Outlet type
- Storm tank at a wastewater treatment works
- Permit
- EPREP3526XK
- Activity reference
- A2
- Grid reference
- SD7372967616
- Waterbody ID
- GB112072071840Official waterbody record ↗
- Location source
- Official annual grid reference
- Location precision
- About 1 metres
- Location note
- Unknown
About the name and type
The annual return lists this asset as “Storm tank at WwTW”: storm tank at a wastewater treatment works. The overflow comes from storm storage at a treatment works.
The waterbody link opens the Environment Agency record for the exact ID in the return. It is a source lookup; we do not import its classification.
Where it is
The recorded position is about 3.1 km west of the Austwick reference point in the ONS built-up areas data.
Area and water pages
Check the official record
Public access to this outlet is unknown. Do not enter restricted land or use this page as a route guide.
Open official source ↗Other outlet records nearby
- INGLETON WwTWCurrent status unknown
United Utilities · River Greta
- HIGH BENTHAM WwTWCurrent status unknown
United Utilities · River Wenning
- HIGH BENTHAM WwTWCurrent status unknown
United Utilities · River Wenning
- BURTON-IN-LONSDALE WwTWCurrent status unknown
United Utilities · River Greta
Questions about Clapham WwTW
- Who operates Clapham WwTW?
- United Utilities is the operator named in the annual record. The permit reference is EPREP3526XK.
- Where does Clapham WwTW discharge?
- The source names River Wenning as the receiving water. This does not show how far a discharge travelled.
- How many times did Clapham WwTW spill in 2025?
- The 2025 return records 3 counted spill events and 15.2 hours of recorded discharge. Spills are counted with the 12/24-hour method, so this is not a count of every start signal.
- Can I trust the 2025 figures for this outlet?
- The monitor worked for 100% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is Clapham WwTW discharging right now?
- This record is not matched to a company live feed, so we cannot show a current report. Only the annual figures are available for this outlet.
- How accurate is the map marker?
- The marker comes from the grid reference in the official annual return, which is accurate to about 1 metres. It shows the recorded outlet position, not the extent of any discharge.
- What kind of outlet is Clapham WwTW?
- The annual return lists the asset type as “Storm tank at WwTW”, which means storm tank at a wastewater treatment works. The overflow comes from storm storage at a treatment works.
- How does Clapham WwTW compare with other overflows?
- Clapham WwTW recorded 3 spills in 2025. That is more than 26% of the 14,239 overflows in England with a reported figure, and ranks 9,843rd nationally. Among United Utilities overflows it ranks 1,655th of 2,270; the median United Utilities overflow recorded 15 spills. Ranks compare counted spill events only. They do not compare volume or harm.
- Does zero spills mean the water was safe?
- No. A zero means the annual return recorded zero counted spill events for this outlet and year. It is not a water-quality test, and pollution can come from other sources.