Mistley, School Lane CSO
Storm overflow operated by Anglian Water. The source names River Stour as the receiving water.
- 7
- Spills in 2025
- 1.1
- Recorded hours
- 78.3%
- Monitor operation
- 2
- Years listed
Checking the latest monitor report…
How it compares in 2025
Mistley, School Lane CSO recorded 7 spills in 2025. That is more than 40% of the 14,239 overflows in England with a reported figure, and ranks 8,130th nationally. Among Anglian Water overflows it ranks 619th of 1,438; the median Anglian Water overflow recorded 6 spills. On the Stour (Essex) waterbody it ranks 2nd of 9.
The monitor worked for 78.3% of 2025, so this count may be low and its rank may understate activity.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 7 | 1.1 |
| England | 8,130th of 14,239 | 11 | 22.3 |
| Anglian Water | 619th of 1,438 | 6 | 13.5 |
| Stour (Essex) | 2nd of 9 | 4 | 2.5 |
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 | 7 | 1.1 hours | 78.3%Low coverage | Official data |
| 2024 | 19 | 369.7 hours | 71.9%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
- Anglian Water
- Outlet type
- Storm overflow on the sewer network
- Permit
- Permit Applied For
- Activity reference
- A1
- Grid reference
- TM1178531868
- Waterbody ID
- GB520503613602Official 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 “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 0.6 km north-west of the Mistley reference point in the ONS built-up areas data.
Designated bathing waters within 3 km in a straight line:
Distance does not show that water from this outlet reaches a bathing water. Check the official bathing-water profile for its classification and advice.
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
- Brantham School Lane SpCurrent status unknown
Anglian Water · Trib River Stour
- Brantham Factory Lane OVCurrent status unknown
Anglian Water · Trib River Stour
- Manningtree STWCurrent status unknown
Anglian Water · Wignall Brook Stour Estuary
- Lawford-Wignall St SpCurrent status unknown
Anglian Water · Trib Wignall Brook
Questions about Mistley, School Lane CSO
- Who operates Mistley, School Lane CSO?
- Anglian Water is the operator named in the annual record. The permit reference is Permit Applied For.
- Where does Mistley, School Lane CSO discharge?
- The source names River Stour as the receiving water. This does not show how far a discharge travelled.
- How many times did Mistley, School Lane CSO spill in 2025?
- The 2025 return records 7 counted spill events and 1.1 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 78.3% of the reporting period. Below 90%, some events can be missed, so the count and hours may understate activity.
- Is Mistley, School Lane CSO 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 Mistley, School Lane CSO?
- 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 Mistley, School Lane CSO compare with other overflows?
- Mistley, School Lane CSO recorded 7 spills in 2025. That is more than 40% of the 14,239 overflows in England with a reported figure, and ranks 8,130th nationally. Among Anglian Water overflows it ranks 619th of 1,438; the median Anglian Water overflow recorded 6 spills. On the Stour (Essex) waterbody it ranks 2nd of 9. 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.