Back Wharf Street/CSO
Storm overflow operated by Yorkshire Water. The source names River Calder as the receiving water.
- 33
- Spills in 2025
- 43.2
- Recorded hours
- 86.9%
- Monitor operation
- 6
- Years listed
Checking the latest monitor report…
How it compares in 2025
Back Wharf Street/CSO recorded 33 spills in 2025. That is more than 77% of the 14,239 overflows in England with a reported figure, and ranks 3,116th nationally. Among Yorkshire Water overflows it ranks 608th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Calder from Ryburn Confluence to River Colne waterbody it ranks 14th of 39.
The monitor worked for 86.9% of 2025, so this count may be low and its rank may understate activity.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 33 | 43.2 |
| England | 3,116th of 14,239 | 11 | 22.3 |
| Yorkshire Water | 608th of 2,176 | 16 | 37.8 |
| Calder from Ryburn Confluence to River Colne | 14th of 39 | 21 | 27.5 |
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 | 33 | 43.2 hours | 86.9%Low coverage | Official data |
| 2024 | 28 | 7.7 hours | 61.5%Low coverage | Official data |
| 2023 | 55 | 65.7 hours | 65.2%Low coverage | Official data |
| 2022 | 27 | 3 hours | 100% | Official data |
| 2021 | 27 | 6 hours | 99.8% | Official data |
| 2020 | 31 | 26.5 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
- WRA9230
- Activity reference
- A1
- Grid reference
- SE0622523620
- Waterbody ID
- GB104027062642Official 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 1.4 km east of the Sowerby Bridge reference point in the ONS built-up areas data.
Area and water pages
- Brighouse area →
- Norwood Green area →
- Elland area →
- Queensbury area →
- Shelf and Northowram area →
- Holywell Green and Stainland area →
- Thornton (Bradford) area →
- Outlane area →
- Scapegoat Hill area →
- Bolster Moor area →
- Linthwaite and Slaithwaite area →
- Halifax area →
- Calder from Ryburn Confluence to River Colne waterbody →
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
- Rochdale Canal/CSOCurrent status unknown
Yorkshire Water · River Calder
- Wharfe House/CSOCurrent status unknown
Yorkshire Water · River Calder
- Town Hall Street/CSOCurrent status unknown
Yorkshire Water · River Calder
- New Inn West Street/CSOCurrent status unknown
Yorkshire Water · River Ryburn
Questions about Back Wharf Street/CSO
- Who operates Back Wharf Street/CSO?
- Yorkshire Water is the operator named in the annual record. The permit reference is WRA9230.
- Where does Back Wharf Street/CSO discharge?
- The source names River Calder as the receiving water. This does not show how far a discharge travelled.
- How many times did Back Wharf Street/CSO spill in 2025?
- The 2025 return records 33 counted spill events and 43.2 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 86.9% of the reporting period. Below 90%, some events can be missed, so the count and hours may understate activity.
- Is Back Wharf Street/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 Back Wharf Street/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 Back Wharf Street/CSO compare with other overflows?
- Back Wharf Street/CSO recorded 33 spills in 2025. That is more than 77% of the 14,239 overflows in England with a reported figure, and ranks 3,116th nationally. Among Yorkshire Water overflows it ranks 608th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Calder from Ryburn Confluence to River Colne waterbody it ranks 14th of 39. 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.