Ramsden Mill/CSO
Storm overflow operated by Yorkshire Water. The source names River Colne as the receiving water.
- 4
- Spills in 2025
- 8.8
- Recorded hours
- 99.6%
- Monitor operation
- 6
- Years listed
The reported spill count was 4 lower than in 2024. This compares event counts, not discharge volume.
Checking the latest monitor report…
How it compares in 2025
Ramsden Mill/CSO recorded 4 spills in 2025. That is more than 30% of the 14,239 overflows in England with a reported figure, and ranks 9,334th nationally. Among Yorkshire Water overflows it ranks 1,573rd of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the River Colne from Wessenden Brook to R Holme waterbody it ranks 24th of 35.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 4 | 8.8 |
| England | 9,334th of 14,239 | 11 | 22.3 |
| Yorkshire Water | 1,573rd of 2,176 | 16 | 37.8 |
| River Colne from Wessenden Brook to R Holme | 24th of 35 | 14 | 20.3 |
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 | 4 | 8.8 hours | 99.6% | Official data |
| 2024 | 8 | 2.8 hours | 98.2% | Official data |
| 2023 | 61 | 272.3 hours | 96.3% | Official data |
| 2022 | 38 | 128 hours | 99.7% | Official data |
| 2021 | 51 | 297.5 hours | 99.9% | Official data |
| 2020 | 64 | 385.5 hours | 90.3% | 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 overflow on the sewer network
- Permit
- WRA7463
- Activity reference
- A1
- Grid reference
- SE1036215442
- Waterbody ID
- GB104027063330Official 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 “SO on sewer network”: storm overflow on the sewer network. The return places this overflow on the sewer network.
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 1.6 km east of the Bolster Moor 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
- Fernlea Grove/CSOCurrent status unknown
Yorkshire Water · River Colne
- Titanic Mills/CSOCurrent status unknown
Yorkshire Water · River Colne
- Gordon Terrace/CSOCurrent status unknown
Yorkshire Water · River Colne
- Golcar Brook Lane/CSOCurrent status unknown
Yorkshire Water · Unnamed Tributary of River Colne
Questions about Ramsden Mill/CSO
- Who operates Ramsden Mill/CSO?
- Yorkshire Water is the operator named in the annual record. The permit reference is WRA7463.
- Where does Ramsden Mill/CSO discharge?
- The source names River Colne as the receiving water. This does not show how far a discharge travelled.
- How many times did Ramsden Mill/CSO spill in 2025?
- The 2025 return records 4 counted spill events and 8.8 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 99.6% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is Ramsden Mill/CSO 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 Ramsden Mill/CSO?
- The annual return lists the asset type as “SO on sewer network”, which means storm overflow on the sewer network. The return places this overflow on the sewer network.
- How does Ramsden Mill/CSO compare with other overflows?
- Ramsden Mill/CSO recorded 4 spills in 2025. That is more than 30% of the 14,239 overflows in England with a reported figure, and ranks 9,334th nationally. Among Yorkshire Water overflows it ranks 1,573rd of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the River Colne from Wessenden Brook to R Holme waterbody it ranks 24th of 35. 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.