Calverton STW (SSTO)
Storm overflow operated by Severn Trent Water. The source names Grimesmoor Dyke as the receiving water.
- 20
- Spills in 2025
- 159.3
- Recorded hours
- 99.7%
- Monitor operation
- 6
- Years listed
The reported spill count was 3 lower than in 2024. This compares event counts, not discharge volume.
Checking the latest monitor report…
How it compares in 2025
Calverton STW (SSTO) recorded 20 spills in 2025. That is more than 63% of the 14,239 overflows in England with a reported figure, and ranks 5,045th nationally. Among Severn Trent Water overflows it ranks 642nd of 2,431; the median Severn Trent Water overflow recorded 8 spills. On the Dover Beck Catchment (trib of Trent) waterbody it ranks 1st of 3.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 20 | 159.3 |
| England | 5,045th of 14,239 | 11 | 22.3 |
| Severn Trent Water | 642nd of 2,431 | 8 | 16.2 |
| Dover Beck Catchment (trib of Trent) | 1st of 3 | 9 | 64.5 |
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
| Year | Spills | Duration | Monitor operation | Source |
|---|---|---|---|---|
| 2025 | 20 | 159.3 hours | 99.7% | Official data |
| 2024 | 23 | 70.6 hours | 99.9% | Official data |
| 2023 | 19 | 65.3 hours | 54.5%Low coverage | Official data |
| 2022 | 37 | 36.8 hours | 99.9% | Official data |
| 2021 | 37 | 25.1 hours | 83.1%Low coverage | Official data |
| 2020 | 63 | 830.4 hours | 100% | 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
- T/64/45588/R
- Activity reference
- A2
- Grid reference
- SK6292649052
- Waterbody ID
- GB104028053370Official 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 1.3 km north of the Woodborough (Gedling) 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
- Woodborough - Shelt Hill (CSO)Current status unknown
Severn Trent Water · Unnamed Tributary of the Dover Beck
- Oxton - Southwell Road (SSO)Current status unknown
Severn Trent Water · Oxton Dumble
- Blidworth - Dale Lane/Baulker Lane (CSO)Current status unknown
Severn Trent Water · GW via Infiltration System
- Blidworth - Dale Lane/Lyndhurst Ave (CSO)Current status unknown
Severn Trent Water · Groundwater via Infiltration
Questions about Calverton STW (SSTO)
- Who operates Calverton STW (SSTO)?
- Severn Trent Water is the operator named in the annual record. The permit reference is T/64/45588/R.
- Where does Calverton STW (SSTO) discharge?
- The source names Grimesmoor Dyke as the receiving water. This does not show how far a discharge travelled.
- How many times did Calverton STW (SSTO) spill in 2025?
- The 2025 return records 20 counted spill events and 159.3 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 99.7% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is Calverton 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 Calverton 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 Calverton STW (SSTO) compare with other overflows?
- Calverton STW (SSTO) recorded 20 spills in 2025. That is more than 63% of the 14,239 overflows in England with a reported figure, and ranks 5,045th nationally. Among Severn Trent Water overflows it ranks 642nd of 2,431; the median Severn Trent Water overflow recorded 8 spills. On the Dover Beck Catchment (trib of Trent) 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.