Watson Mill Lane/CSO
Storm overflow operated by Yorkshire Water. The source names River Ryburn as the receiving water.
- 7
- Spills in 2025
- 17.9
- Recorded hours
- 27%
- Monitor operation
- 6
- Years listed
Checking the latest monitor report…
How it compares in 2025
Watson Mill Lane/CSO recorded 7 spills in 2025. That is more than 40% of the 14,239 overflows in England with a reported figure, and ranks 8,130th nationally. Among Yorkshire Water overflows it ranks 1,412th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the River Ryburn from Booth Dean Clough to R Calder waterbody it ranks 5th of 8.
The monitor worked for 27% of 2025, so this count may be low and its rank may understate activity.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 7 | 17.9 |
| England | 8,130th of 14,239 | 11 | 22.3 |
| Yorkshire Water | 1,412th of 2,176 | 16 | 37.8 |
| River Ryburn from Booth Dean Clough to R Calder | 5th of 8 | 7.5 | 23.7 |
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 | 7 | 17.9 hours | 27%Low coverage | Official data |
| 2024 | 8 | 8.1 hours | 10.6%Low coverage | Official data |
| 2023 | Unknown | Unknown | 0%Low coverage | Official data |
| 2022 | Unknown | Unknown | 0%Low coverage | Official data |
| 2021 | Unknown | Unknown | 0%Low coverage | Official data |
| 2020 | 69 | 104.6 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
- Storm overflow on the sewer network
- Permit
- WRA8413
- Activity reference
- A1
- Grid reference
- SE0558422995
- Waterbody ID
- GB104027062580Official 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 0.6 km east of the Sowerby Bridge 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
- Sowerby Croft Lane/2 CSOCurrent status unknown
Yorkshire Water · Tributary of the River Ryburn
- West Street/CSOCurrent status unknown
Yorkshire Water · River Ryburn
- New Inn West Street/CSOCurrent status unknown
Yorkshire Water · River Ryburn
- Town Hall Street/CSOCurrent status unknown
Yorkshire Water · River Calder
Questions about Watson Mill Lane/CSO
- Who operates Watson Mill Lane/CSO?
- Yorkshire Water is the operator named in the annual record. The permit reference is WRA8413.
- Where does Watson Mill Lane/CSO discharge?
- The source names River Ryburn as the receiving water. This does not show how far a discharge travelled.
- How many times did Watson Mill Lane/CSO spill in 2025?
- The 2025 return records 7 counted spill events and 17.9 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 27% of the reporting period. Below 90%, some events can be missed, so the count and hours may understate activity.
- Is Watson Mill Lane/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 Watson Mill Lane/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 Watson Mill Lane/CSO compare with other overflows?
- Watson Mill Lane/CSO recorded 7 spills in 2025. That is more than 40% of the 14,239 overflows in England with a reported figure, and ranks 8,130th nationally. Among Yorkshire Water overflows it ranks 1,412th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the River Ryburn from Booth Dean Clough to R Calder waterbody it ranks 5th of 8. 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.