Sewage Map

Itchen Bank STW (SSTO)

Storm overflow operated by Severn Trent Water. The source names River Itchen as the receiving water.

53
Spills in 2025
560.8
Recorded hours
100%
Monitor operation
6
Years listed

The reported spill count was 68 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

Itchen Bank STW (SSTO) recorded 53 spills in 2025. That is more than 89% of the 14,239 overflows in England with a reported figure, and ranks 1,451st nationally. Among Severn Trent Water overflows it ranks 118th of 2,431; the median Severn Trent Water overflow recorded 8 spills. On the Itchen - conf R Stowe to conf R Leam waterbody it ranks 1st of 3.

GroupRank by spillsMedian spillsMedian hours
This outlet–53560.8
England1,451st of 14,2391122.3
Severn Trent Water118th of 2,431816.2
Itchen - conf R Stowe to conf R Leam1st of 312163.8

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

51202045202148202210720231212024532025
From 2020 to 2025, the reported count went from 51 to 53 spills. The highest count was 121 in 2024 and the lowest was 45 in 2021. The monitor worked for less than 90% of 2021, 2022, so those counts may be low.Amber bars mark years when the monitor worked for less than 90% of the year.
YearSpillsDurationMonitor operationSource
202553560.8 hours100%Official data
20241211,834.2 hours97%Official data
20231071,239.9 hours99.8%Official data
202248524 hours82.1%Low coverageOfficial data
202145593 hours65.1%Low coverageOfficial data
202051487.2 hours100%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
Severn Trent Water
Outlet type
Storm tank at a wastewater treatment works
Permit
S/12/26557/R
Activity reference
A2
Grid reference
SP4067462821
Waterbody ID
GB109054044110Official 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 1.5 km north-west of the Southam (Stratford-on-Avon) 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 Itchen Bank STW (SSTO)

Who operates Itchen Bank STW (SSTO)?
Severn Trent Water is the operator named in the annual record. The permit reference is S/12/26557/R.
Where does Itchen Bank STW (SSTO) discharge?
The source names River Itchen as the receiving water. This does not show how far a discharge travelled.
How many times did Itchen Bank STW (SSTO) spill in 2025?
The 2025 return records 53 counted spill events and 560.8 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 Itchen Bank STW (SSTO) 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 Itchen Bank STW (SSTO)?
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 Itchen Bank STW (SSTO) compare with other overflows?
Itchen Bank STW (SSTO) recorded 53 spills in 2025. That is more than 89% of the 14,239 overflows in England with a reported figure, and ranks 1,451st nationally. Among Severn Trent Water overflows it ranks 118th of 2,431; the median Severn Trent Water overflow recorded 8 spills. On the Itchen - conf R Stowe to conf R Leam waterbody it ranks 1st of 3. 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.