Sewage Map

Thornhills Beck Lane/CSO

Storm overflow operated by Yorkshire Water. The source names River Calder as the receiving water.

120
Spills in 2025
737
Recorded hours
100%
Monitor operation
3
Years listed

The reported spill count was 29 lower than in 2024. This compares event counts, not discharge volume.

Current status unknown

Checking the latest monitor report…

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How it compares in 2025

Thornhills Beck Lane/CSO recorded 120 spills in 2025. That is more than 99% of the 14,239 overflows in England with a reported figure, and ranks 122nd nationally. Among Yorkshire Water overflows it ranks 6th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Calder from Ryburn Confluence to River Colne waterbody it ranks 1st of 39.

GroupRank by spillsMedian spillsMedian hours
This outlet–120737
England122nd of 14,2391122.3
Yorkshire Water6th of 2,1761637.8
Calder from Ryburn Confluence to River Colne1st of 392127.5

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

163202314920241202025
From 2023 to 2025, the reported count went from 163 to 120 spills. The highest count was 163 in 2023 and the lowest was 120 in 2025.
YearSpillsDurationMonitor operationSource
2025120737 hours100%Official data
20241491,067 hours100%Official data
20231631,820.8 hours95.2%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
WRA8439
Activity reference
A1
Grid reference
SE1509022520
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 1.1 km south-east of the Brighouse 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.

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Other outlet records nearby

Questions about Thornhills Beck Lane/CSO

Who operates Thornhills Beck Lane/CSO?
Yorkshire Water is the operator named in the annual record. The permit reference is WRA8439.
Where does Thornhills Beck Lane/CSO discharge?
The source names River Calder as the receiving water. This does not show how far a discharge travelled.
How many times did Thornhills Beck Lane/CSO spill in 2025?
The 2025 return records 120 counted spill events and 737 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 Thornhills Beck 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 Thornhills Beck 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 Thornhills Beck Lane/CSO compare with other overflows?
Thornhills Beck Lane/CSO recorded 120 spills in 2025. That is more than 99% of the 14,239 overflows in England with a reported figure, and ranks 122nd nationally. Among Yorkshire Water overflows it ranks 6th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Calder from Ryburn Confluence to River Colne waterbody it ranks 1st 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.