The Monument CSO Helston
Storm overflow operated by South West Water. The source names River Cober via SWS as the receiving water.
- 0
- Spills in 2025
- 0
- Recorded hours
- 100%
- Monitor operation
- 5
- Years listed
The reported spill count was the same as in 2024. This compares event counts, not discharge volume.
Checking the latest monitor report…
How it compares in 2025
The Monument CSO Helston recorded no spills in 2025. It is one of 2,231 overflows in England with a reported count of zero, out of 14,239 with a count.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 0 | 0 |
| England | 12,009th of 14,239 | 11 | 22.3 |
| South West Water | 1,180th of 1,357 | 21 | 39.4 |
| Lower River Cober | 5th of 5 | 3 | 1.3 |
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 | 0 | 0 hours | 100% | Official data |
| 2024 | 0 | 0 hours | 100% | Official data |
| 2023 | 3 | 1.6 hours | 100% | Official data |
| 2022 | 0 | 0 hours | 100% | Official data |
| 2021 | 2 | 7.3 hours | 97% | 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
- 033996/CS/01
- Activity reference
- A1
- Grid reference
- SW65532731
- Waterbody ID
- GB108048001172Official 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 “SO on sewer network”: storm overflow on the sewer network. The return places this overflow on the sewer network.
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 0.8 km west of the Helston 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
- Coinagehall St CSO HelstonCurrent status unknown
South West Water · River Cober via SWS
- Grange Rd S.A. Tank CSO HelstonCurrent status unknown
South West Water · River Cober (via SWS)
- Helston Market Spst Pscsoeo HelstonCurrent status unknown
South West Water · River Cober
- Helston STW SSO HelstonCurrent status unknown
South West Water · River Cober
Questions about The Monument CSO Helston
- Who operates The Monument CSO Helston?
- South West Water is the operator named in the annual record. The permit reference is 033996/CS/01.
- Where does The Monument CSO Helston discharge?
- The source names River Cober via SWS as the receiving water. This does not show how far a discharge travelled.
- How many times did The Monument CSO Helston spill in 2025?
- The 2025 return records 0 counted spill events and 0 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 The Monument CSO Helston 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 The Monument CSO Helston?
- 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 The Monument CSO Helston compare with other overflows?
- The Monument CSO Helston recorded no spills in 2025. It is one of 2,231 overflows in England with a reported count of zero, out of 14,239 with a count. 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.