Upton Cross CSO Rilla Mill

Storm overflow operated by South West Water. The source names Tributary of River Lyner as the receiving water.

0
Spills in 2025: 0
Recorded hours: 95.1%
Monitor operation: 5
Years listed

The reported spill count was the same as in 2024. This compares event counts, not discharge volume.

Current status unknown

Checking the latest monitor report…

How it compares in 2025

Upton Cross CSO Rilla Mill 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 Lynher	9th of 9	33	452.6

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 0 to 0 spills. Every listed year has the same count. The monitor worked for less than 90% of 2021, 2022, 2023, so those counts may be low.Amber bars mark years when the monitor worked for less than 90% of the year.

Year	Monitor operation	Source
2025	95.1%	Official data
2024	97.9%	Official data
2023	65%Low coverage	Official data
2022	45%Low coverage	Official data
2021	78%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: Storm overflow on the sewer network
Permit: 301891
Activity reference: A1
Grid reference: SX28617266
Waterbody ID: GB108047007670Official 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 3.1 km north of the Pensilva reference point in the ONS built-up areas data.

Area and water pages

Lower River Lynher 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

Rilla Mill STW So Rilla Mill
South West Water · (S) River Lynher
Current status unknown

Bathpool STW So Bathpool
South West Water · River Lyner (S)
Current status unknown
Minions CSO Minions
South West Water · East Looe River (S)
Current status unknown
Minions STW So Minions
South West Water · Tributary of River Seaton (S)
Current status unknown

Questions about Upton Cross CSO Rilla Mill

Who operates Upton Cross CSO Rilla Mill?: South West Water is the operator named in the annual record. The permit reference is 301891.
Where does Upton Cross CSO Rilla Mill discharge?: The source names Tributary of River Lyner as the receiving water. This does not show how far a discharge travelled.
How many times did Upton Cross CSO Rilla Mill 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 95.1% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
Is Upton Cross CSO Rilla Mill 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 Upton Cross CSO Rilla Mill?: 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 Upton Cross CSO Rilla Mill compare with other overflows?: Upton Cross CSO Rilla Mill 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.