Waterside 47/CSO
Storm overflow operated by Yorkshire Water. The source names Mill Stream as the receiving water.
- 28
- Spills in 2025
- 59.8
- Recorded hours
- 92.1%
- Monitor operation
- 6
- Years listed
The reported spill count was 5 higher than in 2024. This compares event counts, not discharge volume.
Checking the latest monitor report…
How it compares in 2025
Waterside 47/CSO recorded 28 spills in 2025. That is more than 72% of the 14,239 overflows in England with a reported figure, and ranks 3,771st nationally. Among Yorkshire Water overflows it ranks 729th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Nidd from Oak Beck to Low Bridge on Briggate (Knaresborough) waterbody it ranks 1st of 6.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 28 | 59.8 |
| England | 3,771st of 14,239 | 11 | 22.3 |
| Yorkshire Water | 729th of 2,176 | 16 | 37.8 |
| Nidd from Oak Beck to Low Bridge on Briggate (Knaresborough) | 1st of 6 | 21 | 39.6 |
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
| Year | Spills | Duration | Monitor operation | Source |
|---|---|---|---|---|
| 2025 | 28 | 59.8 hours | 92.1% | Official data |
| 2024 | 23 | 46.3 hours | 99.7% | Official data |
| 2023 | 24 | 35.3 hours | 100% | Official data |
| 2022 | 17 | 38.3 hours | 99.8% | Official data |
| 2021 | 19 | 16.3 hours | 85.1%Low coverage | Official data |
| 2020 | 17 | 30.7 hours | 93.5% | 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
- Yorkshire Water
- Outlet type
- Storm overflow on the sewer network
- Permit
- 27/21/0259
- Activity reference
- A1
- Grid reference
- SE3474156787
- Waterbody ID
- GB104027068297Official 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 0.4 km south-west of the Knaresborough 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
- Waterside 48/CSOCurrent status unknown
Yorkshire Water · Mill Stream
- Waterside 49/CSOCurrent status unknown
Yorkshire Water · River Nidd
- Abbey Road/No 2 CSOCurrent status unknown
Yorkshire Water · River Nidd
- Boroughbridge Road/CSOCurrent status unknown
Yorkshire Water · Frogmire Dyke
Questions about Waterside 47/CSO
- Who operates Waterside 47/CSO?
- Yorkshire Water is the operator named in the annual record. The permit reference is 27/21/0259.
- Where does Waterside 47/CSO discharge?
- The source names Mill Stream as the receiving water. This does not show how far a discharge travelled.
- How many times did Waterside 47/CSO spill in 2025?
- The 2025 return records 28 counted spill events and 59.8 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 92.1% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is Waterside 47/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 Waterside 47/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 Waterside 47/CSO compare with other overflows?
- Waterside 47/CSO recorded 28 spills in 2025. That is more than 72% of the 14,239 overflows in England with a reported figure, and ranks 3,771st nationally. Among Yorkshire Water overflows it ranks 729th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Nidd from Oak Beck to Low Bridge on Briggate (Knaresborough) waterbody it ranks 1st of 6. 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.