Sewage Map

Cold Hiendley/STW

Storm overflow operated by Yorkshire Water. The source names Cold Hiendley Reservoir as the receiving water.

41
Spills in 2025
328.8
Recorded hours
100%
Monitor operation
3
Years listed

The reported spill count was 22 lower than in 2024. This compares event counts, not discharge volume.

Current status unknown

Checking the latest monitor report…

Open official annual data ↗

How it compares in 2025

Cold Hiendley/STW recorded 41 spills in 2025. That is more than 83% of the 14,239 overflows in England with a reported figure, and ranks 2,313th nationally. Among Yorkshire Water overflows it ranks 443rd of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Owler Beck from Source to River Calder waterbody it ranks 2nd of 13.

GroupRank by spillsMedian spillsMedian hours
This outlet–41328.8
England2,313th of 14,2391122.3
Yorkshire Water443rd of 2,1761637.8
Owler Beck from Source to River Calder2nd of 131231.8

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

792023632024412025
From 2023 to 2025, the reported count went from 79 to 41 spills. The highest count was 79 in 2023 and the lowest was 41 in 2025. The monitor worked for less than 90% of 2023, so that count may be low.Amber bars mark years when the monitor worked for less than 90% of the year.
YearSpillsDurationMonitor operationSource
202541328.8 hours100%Official data
202463433.8 hours99.6%Official data
2023791,219.3 hours52.7%Low coverageOfficial 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 tank at a wastewater treatment works
Permit
431
Activity reference
A2
Grid reference
SE3701014540
Waterbody ID
GB104027062530Official 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 “Storm tank at WwTW”: storm tank at a wastewater treatment works. The overflow comes from storm storage at a treatment works.

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 1.9 km west of the Havercroft and Ryhill 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

Questions about Cold Hiendley/STW

Who operates Cold Hiendley/STW?
Yorkshire Water is the operator named in the annual record. The permit reference is 431.
Where does Cold Hiendley/STW discharge?
The source names Cold Hiendley Reservoir as the receiving water. This does not show how far a discharge travelled.
How many times did Cold Hiendley/STW spill in 2025?
The 2025 return records 41 counted spill events and 328.8 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 100% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
Is Cold Hiendley/STW 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 Cold Hiendley/STW?
The annual return lists the asset type as “Storm tank at WwTW”, which means storm tank at a wastewater treatment works. The overflow comes from storm storage at a treatment works.
How does Cold Hiendley/STW compare with other overflows?
Cold Hiendley/STW recorded 41 spills in 2025. That is more than 83% of the 14,239 overflows in England with a reported figure, and ranks 2,313th nationally. Among Yorkshire Water overflows it ranks 443rd of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Owler Beck from Source to River Calder waterbody it ranks 2nd of 13. 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.