Asselby/STW/6Xdwf Overflow
Storm overflow operated by Yorkshire Water. The source names Unnamed Tributary of River Ouse as the receiving water.
- 48
- Spills in 2025
- 252.3
- Recorded hours
- 100%
- Monitor operation
- 6
- Years listed
The reported spill count was 10 higher than in 2024. This compares event counts, not discharge volume.
Checking the latest monitor report…
How it compares in 2025
Asselby/STW/6Xdwf Overflow recorded 48 spills in 2025. That is more than 87% of the 14,239 overflows in England with a reported figure, and ranks 1,775th nationally. Among Yorkshire Water overflows it ranks 331st of 2,176; the median Yorkshire Water overflow recorded 16 spills.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 48 | 252.3 |
| England | 1,775th of 14,239 | 11 | 22.3 |
| Yorkshire Water | 331st of 2,176 | 16 | 37.8 |
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 | 48 | 252.3 hours | 100% | Official data |
| 2024 | 38 | 111.7 hours | 99.7% | Official data |
| 2023 | 40 | 91.4 hours | 99.9% | Official data |
| 2022 | 35 | 161.8 hours | 99.3% | Official data |
| 2021 | 37 | 72.4 hours | 98.9% | Official data |
| 2020 | 35 | 48.3 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
- Yorkshire Water
- Outlet type
- Inlet storm overflow at a wastewater treatment works
- Permit
- 27/24/0403
- Activity reference
- A1
- Grid reference
- SE7194028230
- Waterbody ID
- Unknown
- 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.
Where it is
The recorded position is about 2.1 km north-west of the Booth reference point in the ONS built-up areas data.
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
- Airmyn Crossing/CSOCurrent status unknown
Yorkshire Water · River Aire
- Howden Broad Ln/CSOCurrent status unknown
Yorkshire Water · Howden Dike Drain
- Howden/STWCurrent status unknown
Yorkshire Water · River Ouse (Tidal)
- Goole Carr Lane/SPS/6Xdwf OverflowCurrent status unknown
Yorkshire Water · River Ouse
Questions about Asselby/STW/6Xdwf Overflow
- Who operates Asselby/STW/6Xdwf Overflow?
- Yorkshire Water is the operator named in the annual record. The permit reference is 27/24/0403.
- Where does Asselby/STW/6Xdwf Overflow discharge?
- The source names Unnamed Tributary of River Ouse as the receiving water. This does not show how far a discharge travelled.
- How many times did Asselby/STW/6Xdwf Overflow spill in 2025?
- The 2025 return records 48 counted spill events and 252.3 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 100% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is Asselby/STW/6Xdwf Overflow 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 Asselby/STW/6Xdwf Overflow?
- 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 Asselby/STW/6Xdwf Overflow compare with other overflows?
- Asselby/STW/6Xdwf Overflow recorded 48 spills in 2025. That is more than 87% of the 14,239 overflows in England with a reported figure, and ranks 1,775th nationally. Among Yorkshire Water overflows it ranks 331st of 2,176; the median Yorkshire Water overflow recorded 16 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.