Overflow history upstream of Friars Meadow, River Stour
The spot's forecast · For event organisers
This page lists the monitored storm overflows upstream of this spot and how often each spilled in each year. It is not a water test, and it does not say whether the water is fit to swim in. It does not include farm runoff, misconnected drains, treated sewage effluent, wildlife or overflows without a monitor. A year's count depends on how long the monitor worked, shown as monitor uptime.
Each year, all overflows upstream
| Year | Overflows with a return | Spills | Spill hours | Spill hours, weighted by reach |
|---|---|---|---|---|
| 2021 | 12 | 231 | 2,429 | 49 |
| 2022 | 15 | 220 | 880 | 53 |
| 2023 | 15 | 333 | 2,971 | 101 |
| 2024 | 16 | 404 | 4,198 | 140 |
| 2025 | 16 | 113 | 799 | 47 |
Reach is the share of a spill's bacteria SwimSignal's model expects to arrive here, after die-off on the way and dilution by the river. Weighting by it counts an hour of spilling just upstream for far more than one 40 km away. Spills are counted by the Environment Agency's 12/24 method: any discharge in the first 12 hours counts as one spill, then one more for each 24 hours with any discharge. How reach is worked out.
The overflows, by reach
All 16, the one whose spills matter most here first. Hours away is how long sewage takes to arrive at the model's river speed.
| Overflow and id | Company | km upstream | Hours away | Reach | Spills 2023 | Spills 2024 | Spills 2025 | Spill hours 2025 | Monitor uptime 2025 |
|---|---|---|---|---|---|---|---|---|---|
| Sudbury Great Eastern Road pumping station overflow Sudbury Great Eastern Road Terminal Pumping Station · AWS01331 | Anglian Water | 0.2 | under 1 | 99% | 27 | 29 | 20 | 35 | 100% |
| Sudbury The Croft storm overflow Sudbury The Croft CSO · AWS01333 | Anglian Water | 2.0 | 1 | 89% | 25 | 16 | 5 | 1 | 100% |
| Boxted-Cottage (Suffolk) sewage works overflow Boxted-Cottage (Suffolk) STW · AWS01573 | Anglian Water | 16.7 | 9 | 9% | – | 23 | 3 | 40 | 100% |
| Sturmer-Kedington Rd pumping station overflow Sturmer-Kedington RD TPS · AWS01290 | Anglian Water | 30.4 | 17 | 2% | 9 | 16 | 4 | 40 | 100% |
| Sudbury Bailey and Coates storm overflow Sudbury Bailey and Coates Combined Sewer Overflow · AWS01332 | Anglian Water | 0.5 | under 1 | 2% | 15 | 14 | 2 | 0 | 100% |
| Sudbury sewage works overflow Sudbury Water Recycling Centre · AWS01334 | Anglian Water | 1.8 | 1 | 2% | 0 | 1 | 2 | 2 | 98% |
| Haverhill sewage works overflow Haverhill STW · AWS00574 | Anglian Water | 32.5 | 18 | 2% | 8 | 15 | 3 | 29 | 100% |
| Steeple Bumpstead sewage works overflow Steeple Bumpstead Sewage Treatment Works · AWS01291 | Anglian Water | 31.7 | 18 | 1% | 18 | 69 | 20 | 117 | 99% |
| Steeple Bumpstead-Lilley pumping station overflow Steeple Bumpstead-Lilley TPS · AWS01289 | Anglian Water | 32.8 | 18 | 1% | 16 | 21 | 5 | 51 | 100% |
| Glemsford-Skates Hill pumping station overflow Glemsford-Skates Hill SP · AWS01138 | Anglian Water | 11.6 | 6 | 1% | 8 | 6 | 4 | 8 | 100% |
| Steeple Bumpstead-Blois Rd pumping station overflow Steeple Bumpstead-Blois RD TPS · AWS01288 | Anglian Water | 31.8 | 18 | 1% | 8 | 6 | 9 | 38 | 100% |
| Glemsford sewage works overflow Glemsford STW · AWS00469 | Anglian Water | 14.7 | 8 | 1% | 31 | 21 | 4 | 43 | 100% |
| Wickhambrook-Brook Cotts pumping station overflow Wickhambrook-Brook Cotts TPS · AWS01500 | Anglian Water | 29.3 | 16 | 1% | 3 | 0 | 0 | 0 | 100% |
| Hundon/Hundon-Lower Church Rd sewage works overflow Hundon STW / Hundon-Lower Church RD TPS · AWS00628 | Anglian Water | 24.9 | 14 | 1% | 85 | 70 | 20 | 300 | 100% |
| Gt Wratting-the Street pumping station overflow GT Wratting-THE Street SP · AWS00514 | Anglian Water | 35.6 | 20 | 0% | 69 | 80 | 9 | 59 | 100% |
| Little Wratting pumping station overflow Little Wratting SPS · AWS00754 | Anglian Water | 36.7 | 20 | <1% | 11 | 17 | 3 | 35 | 100% |
A dash: no annual return for that overflow in that year.
Sources and credits
Storm overflow annual returns: © Environment Agency copyright and/or database right 2025, Open Government Licence v3.0. Overflow positions: the water companies via the National Storm Overflow Hub, CC BY 4.0. River network: contains OS data © Crown copyright and database right 2026 (OS Open Rivers). Traced and weighted by SwimSignal (swimsignal.co.uk), whose method is at swimsignal.co.uk/methods.html. All credits and licences.