Wilmington STW SSO Wilmington

Storm overflow operated by South West Water. The source names (S) Umborne Brook as the receiving water.

34
Spills in 2025: 419.4
Recorded hours: 100%
Monitor operation: 5
Years listed

The reported spill count was 30 lower than in 2024. This compares event counts, not discharge volume.

Current status unknown

Checking the latest monitor report…

How it compares in 2025

Wilmington STW SSO Wilmington recorded 34 spills in 2025. That is more than 78% of the 14,239 overflows in England with a reported figure, and ranks 3,010th nationally. Among South West Water overflows it ranks 498th of 1,357; the median South West Water overflow recorded 21 spills. On the Umborne Brook waterbody it ranks 3rd of 4.

Group	Rank by spills	Median spills	Median hours
This outlet	–	34	419.4
England	3,010th of 14,239	11	22.3
South West Water	498th of 1,357	21	39.4
Umborne Brook	3rd of 4	48.5	453.6

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

From 2021 to 2025, the reported count went from 19 to 34 spills. The highest count was 93 in 2022 and the lowest was 19 in 2021. The monitor worked for less than 90% of 2021, so that count may be low.Amber bars mark years when the monitor worked for less than 90% of the year.

Year	Spills	Duration	Monitor operation	Source
2025	34	419.4 hours	100%	Official data
2024	64	667.4 hours	100%	Official data
2023	61	609.6 hours	100%	Official data
2022	93	764.3 hours	100%	Official data
2021	19	189.8 hours	72%Low coverage	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: South West Water
Outlet type: Inlet storm overflow at a wastewater treatment works
Permit: NRA-SW-2877
Activity reference: A2
Grid reference: ST21700010
Waterbody ID: GB108045008880Official waterbody record ↗
Location source: Official annual grid reference
Location precision: About 10 metres
Location note: Unknown

About the name and type

The annual return lists this asset as “Inlet SO at WwTW”: inlet storm overflow at a wastewater treatment works. The overflow is at the inlet of a treatment works, where wastewater enters the 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 2.3 km east of the Offwell reference point in the ONS built-up areas data.

Area and water pages

Umborne Brook waterbody →

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

Offwell STW So Offwell
South West Water · Tributary of Offwell Brook
Current status unknown

Dalwood Spst Pscsoeo Dalwood
South West Water · The Corry Brook (S)
Current status unknown
Waterleat Park SPS Pscsoeo Honiton
South West Water · Tributary of River Otter
Current status unknown
High Street CSO Honiton
South West Water · The Gissage (S)
Current status unknown

Questions about Wilmington STW SSO Wilmington

Who operates Wilmington STW SSO Wilmington?: South West Water is the operator named in the annual record. The permit reference is NRA-SW-2877.
Where does Wilmington STW SSO Wilmington discharge?: The source names (S) Umborne Brook as the receiving water. This does not show how far a discharge travelled.
How many times did Wilmington STW SSO Wilmington spill in 2025?: The 2025 return records 34 counted spill events and 419.4 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 Wilmington STW SSO Wilmington 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 10 metres. It shows the recorded outlet position, not the extent of any discharge.
What kind of outlet is Wilmington STW SSO Wilmington?: The annual return lists the asset type as “Inlet SO at WwTW”, which means inlet storm overflow at a wastewater treatment works. The overflow is at the inlet of a treatment works, where wastewater enters the works.
How does Wilmington STW SSO Wilmington compare with other overflows?: Wilmington STW SSO Wilmington recorded 34 spills in 2025. That is more than 78% of the 14,239 overflows in England with a reported figure, and ranks 3,010th nationally. Among South West Water overflows it ranks 498th of 1,357; the median South West Water overflow recorded 21 spills. On the Umborne Brook waterbody it ranks 3rd of 4. 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.