Thorne/STW
Storm overflow operated by Yorkshire Water. The source names River Don (Tidal) as the receiving water.
- 31
- Spills in 2025
- 204.3
- Recorded hours
- 92.4%
- Monitor operation
- 4
- Years listed
The reported spill count was the same as in 2024. This compares event counts, not discharge volume.
Checking the latest monitor report…
How it compares in 2025
Thorne/STW recorded 31 spills in 2025. That is more than 75% of the 14,239 overflows in England with a reported figure, and ranks 3,344th nationally. Among Yorkshire Water overflows it ranks 649th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Don from Mill Dyke to River Ouse waterbody it ranks 5th of 14.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 31 | 204.3 |
| England | 3,344th of 14,239 | 11 | 22.3 |
| Yorkshire Water | 649th of 2,176 | 16 | 37.8 |
| Don from Mill Dyke to River Ouse | 5th of 14 | 26.5 | 44.3 |
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 | 31 | 204.3 hours | 92.4% | Official data |
| 2024 | 31 | 192.3 hours | 91.8% | Official data |
| 2023 | 44 | 347.5 hours | 99.5% | Official data |
| 2022 | 32 | 268 hours | 52.6%Low coverage | 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
- Yorkshire Water
- Outlet type
- Storm tank at a wastewater treatment works
- Permit
- 3332
- Activity reference
- A2
- Grid reference
- SE6746014680
- Waterbody ID
- GB104027064243Official 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 1.7 km north-west of the Thorne 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
- Wilkinson Avenue/CSOCurrent status unknown
Yorkshire Water · Leonards Drain
- Moor Lane Moorends/CSOCurrent status unknown
Yorkshire Water · Tributary North Soak Drain
- Thorne West Street/CSOCurrent status unknown
Yorkshire Water · Permit applied for
- Ellison Street/CSOCurrent status unknown
Yorkshire Water · Boating Dike
Questions about Thorne/STW
- Who operates Thorne/STW?
- Yorkshire Water is the operator named in the annual record. The permit reference is 3332.
- Where does Thorne/STW discharge?
- The source names River Don (Tidal) as the receiving water. This does not show how far a discharge travelled.
- How many times did Thorne/STW spill in 2025?
- The 2025 return records 31 counted spill events and 204.3 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 92.4% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is Thorne/STW discharging right now?
- This record is linked to a company live feed. The panel above shows the latest report we hold, with its date. That report can be old, and the monitor can be offline, so check the date before relying on it. A report that no discharge is taking place is not a water-quality result.
- 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 Thorne/STW?
- 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 Thorne/STW compare with other overflows?
- Thorne/STW recorded 31 spills in 2025. That is more than 75% of the 14,239 overflows in England with a reported figure, and ranks 3,344th nationally. Among Yorkshire Water overflows it ranks 649th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Don from Mill Dyke to River Ouse waterbody it ranks 5th of 14. 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.