St Briavels WwTW
Storm overflow operated by Dŵr Cymru Welsh Water. The source names Wye Estuary as the receiving water.
- 136
- Spills in 2025
- 1,198.5
- Recorded hours
- 99.9%
- Monitor operation
- 5
- Years listed
The reported spill count was 59 lower than 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
St Briavels WwTW recorded 136 spills in 2025. That is more than 99% of the 14,239 overflows in England with a reported figure, and ranks 73rd nationally. Among Dŵr Cymru Welsh Water overflows it ranks 1st of 122; the median Dŵr Cymru Welsh Water overflow recorded 14.5 spills. On the Wye waterbody it ranks 1st of 3.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 136 | 1,198.5 |
| England | 73rd of 14,239 | 11 | 22.3 |
| Dŵr Cymru Welsh Water | 1st of 122 | 14.5 | 29.3 |
| Wye | 1st of 3 | 59 | 332.3 |
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 | 136 | 1,198.5 hours | 99.9% | Official data |
| 2024 | 195 | 1,998.5 hours | 99.4% | Official data |
| 2023 | 149 | 1,278.8 hours | 99.8% | Official data |
| 2022 | 90 | 524.3 hours | 96.9% | Official data |
| 2021 | 61 | 587.3 hours | 99.9% | 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
- Dŵr Cymru Welsh Water
- Outlet type
- Inlet storm overflow at a wastewater treatment works
- Permit
- AS1004501
- Activity reference
- A2
- Grid reference
- SO5374704785
- Waterbody ID
- GB530905415406Official 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 “Inlet SO at WwTW”: inlet storm overflow at a wastewater treatment works. The overflow is at the inlet of a treatment works, where wastewater enters the 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 2.3 km west of the St Briavels 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
- Newland (Nr Coleford)Current status unknown
Dŵr Cymru Welsh Water · Valley Brook
- Newland (Nr Coleford)Current status unknown
Dŵr Cymru Welsh Water · Valley Brook
- Newland (Nr Coleford)Current status unknown
Dŵr Cymru Welsh Water · Valley Brook
- Wyebank Road CSO, ChepstowCurrent status unknown
Dŵr Cymru Welsh Water · River Wye
Questions about St Briavels WwTW
- Who operates St Briavels WwTW?
- Dŵr Cymru Welsh Water is the operator named in the annual record. The permit reference is AS1004501.
- Where does St Briavels WwTW discharge?
- The source names Wye Estuary as the receiving water. This does not show how far a discharge travelled.
- How many times did St Briavels WwTW spill in 2025?
- The 2025 return records 136 counted spill events and 1,198.5 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 99.9% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is St Briavels 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 St Briavels WwTW?
- The annual return lists the asset type as “Inlet SO at WwTW”, which means inlet storm overflow at a wastewater treatment works. The overflow is at the inlet of a treatment works, where wastewater enters the works.
- How does St Briavels WwTW compare with other overflows?
- St Briavels WwTW recorded 136 spills in 2025. That is more than 99% of the 14,239 overflows in England with a reported figure, and ranks 73rd nationally. Among Dŵr Cymru Welsh Water overflows it ranks 1st of 122; the median Dŵr Cymru Welsh Water overflow recorded 14.5 spills. On the Wye waterbody it ranks 1st of 3. 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.