Sewage Map

Flanshaw Lane/CSO

Storm overflow operated by Yorkshire Water. The source names Alverthorpe Beck as the receiving water.

4
Spills in 2025
1
Recorded hours
100%
Monitor operation
6
Years listed

The reported spill count was 4 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

Flanshaw Lane/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 Chald from Source to River Calder waterbody it ranks 8th of 14.

GroupRank by spillsMedian spillsMedian hours
This outlet–41
England9,334th of 14,2391122.3
Yorkshire Water1,573rd of 2,1761637.8
River Chald from Source to River Calder8th of 1464.3

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

7202011202112022920238202442025
From 2020 to 2025, the reported count went from 7 to 4 spills. The highest count was 11 in 2021 and the lowest was 1 in 2022. The monitor worked for less than 90% of 2022, 2023, so those counts may be low.Amber bars mark years when the monitor worked for less than 90% of the year.
YearSpillsDurationMonitor operationSource
202541 hours100%Official data
202484.3 hours100%Official data
202394.8 hours69.9%Low coverageOfficial data
202210.3 hours61.2%Low coverageOfficial data
2021115.3 hours100%Official data
2020745.7 hours99.9%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
WRA9203
Activity reference
1
Grid reference
SE3100021350
Waterbody ID
GB104027062620Official 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 1.8 km south-east of the Kirkhamgate 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 Flanshaw Lane/CSO

Who operates Flanshaw Lane/CSO?
Yorkshire Water is the operator named in the annual record. The permit reference is WRA9203.
Where does Flanshaw Lane/CSO discharge?
The source names Alverthorpe Beck as the receiving water. This does not show how far a discharge travelled.
How many times did Flanshaw Lane/CSO spill in 2025?
The 2025 return records 4 counted spill events and 1 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 Flanshaw 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 Flanshaw 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 Flanshaw Lane/CSO compare with other overflows?
Flanshaw Lane/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 Chald from Source to River Calder waterbody it ranks 8th of 14. 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.