Sewage Map

Colerne Storm Tank

Storm overflow operated by Wessex Water. The source names By Brook as the receiving water.

4
Spills in 2025
15.2
Recorded hours
99.9%
Monitor operation
6
Years listed

The reported spill count was 10 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

Colerne Storm Tank 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 Wessex Water overflows it ranks 897th of 1,332; the median Wessex Water overflow recorded 11 spills. On the By Bk - conf Doncombe Bk to conf R Avon (Brist) waterbody it ranks 5th of 5.

GroupRank by spillsMedian spillsMedian hours
This outlet–415.2
England9,334th of 14,2391122.3
Wessex Water897th of 1,3321118.9
By Bk - conf Doncombe Bk to conf R Avon (Brist)5th of 54050.8

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

52020220212202211202314202442025
From 2020 to 2025, the reported count went from 5 to 4 spills. The highest count was 14 in 2024 and the lowest was 2 in 2021.
YearSpillsDurationMonitor operationSource
2025415.2 hours99.9%Official data
20241455.3 hours100%Official data
20231145.5 hours100%Official data
202224 hours100%Official data
202124.8 hours99.2%Official data
202059.8 hours98%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
Wessex Water
Outlet type
Storm tank at a wastewater treatment works
Permit
102713
Activity reference
2-SETTLEMENT TREATMENT ONLY
Grid reference
ST8316669867
Waterbody ID
GB109053027380Official 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 1.4 km west of the Rudloe 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 Colerne Storm Tank

Who operates Colerne Storm Tank?
Wessex Water is the operator named in the annual record. The permit reference is 102713.
Where does Colerne Storm Tank discharge?
The source names By Brook as the receiving water. This does not show how far a discharge travelled.
How many times did Colerne Storm Tank spill in 2025?
The 2025 return records 4 counted spill events and 15.2 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 99.9% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
Is Colerne Storm Tank 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 Colerne Storm Tank?
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 Colerne Storm Tank compare with other overflows?
Colerne Storm Tank 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 Wessex Water overflows it ranks 897th of 1,332; the median Wessex Water overflow recorded 11 spills. On the By Bk - conf Doncombe Bk to conf R Avon (Brist) waterbody it ranks 5th of 5. 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.