Trelander Highway CSO Truro
Storm overflow operated by South West Water. The source names River Allen(ESTUARINE) via SWS as the receiving water.
- 46
- Spills in 2025
- 32
- Recorded hours
- 100%
- Monitor operation
- 5
- Years listed
The reported spill count was 15 higher than in 2024. This compares event counts, not discharge volume.
Checking the latest monitor report…
How it compares in 2025
Trelander Highway CSO Truro recorded 46 spills in 2025. That is more than 86% of the 14,239 overflows in England with a reported figure, and ranks 1,911th nationally. Among South West Water overflows it ranks 373rd of 1,357; the median South West Water overflow recorded 21 spills.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 46 | 32 |
| England | 1,911th of 14,239 | 11 | 22.3 |
| South West Water | 373rd of 1,357 | 21 | 39.4 |
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 | 46 | 32 hours | 100% | Official data |
| 2024 | 31 | 16.2 hours | 100% | Official data |
| 2023 | 34 | 19.5 hours | 100% | Official data |
| 2022 | 29 | 12.4 hours | 100% | Official data |
| 2021 | 28 | 15.1 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
- South West Water
- Outlet type
- Storm overflow on the sewer network
- Permit
- 302681
- Activity reference
- A1
- Grid reference
- SW82924479
- Waterbody ID
- Unknown
- 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 “SO on sewer network”: storm overflow on the sewer network. The return places this overflow on the sewer network.
Where it is
The recorded position is about 0.4 km east of the Truro reference point in the ONS built-up areas data.
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
- St Clements Hill CSO TruroCurrent status unknown
South West Water · River Allen via Sws(ESTUARINE)
- Fairmantle St Car Park CSO TruroCurrent status unknown
South West Water · River Kenwyn(E)
- Old Bridge St Car Park CSO TruroCurrent status unknown
South West Water · River Allen
- Tabernacle St CSO TruroCurrent status unknown
South West Water · River Kenwyn via SWS
Questions about Trelander Highway CSO Truro
- Who operates Trelander Highway CSO Truro?
- South West Water is the operator named in the annual record. The permit reference is 302681.
- Where does Trelander Highway CSO Truro discharge?
- The source names River Allen(ESTUARINE) via SWS as the receiving water. This does not show how far a discharge travelled.
- How many times did Trelander Highway CSO Truro spill in 2025?
- The 2025 return records 46 counted spill events and 32 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 Trelander Highway CSO Truro 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 Trelander Highway CSO Truro?
- 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 Trelander Highway CSO Truro compare with other overflows?
- Trelander Highway CSO Truro recorded 46 spills in 2025. That is more than 86% of the 14,239 overflows in England with a reported figure, and ranks 1,911th nationally. Among South West Water overflows it ranks 373rd of 1,357; the median South West Water overflow recorded 21 spills. 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.