Overflow history upstream of River Frome, Tellisford Weir
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 | 23 | 454 | 1,724 | 206 |
| 2022 | 27 | 565 | 3,024 | 1,407 |
| 2023 | 37 | 1,369 | 10,227 | 1,974 |
| 2024 | 37 | 1,317 | 10,483 | 2,037 |
| 2025 | 37 | 803 | 5,576 | 764 |
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 38, 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 |
|---|---|---|---|---|---|---|---|---|---|
| Rode storm tank overflow Rode Storm Tank · WXW00936 | Wessex Water | 1.0 | under 1 | 93% | 102 | 82 | 39 | 522 | 100% |
| Rode Barrow Farm Tank WXW00935 | Wessex Water | 1.4 | under 1 | 92% | 4 | 5 | 3 | 7 | 97% |
| Beckington storm tank overflow Beckington Storm Tank · WXW00120 | Wessex Water | 4.7 | 3 | 76% | 31 | 55 | 11 | 132 | 100% |
| Frome Farrant Road Near Youth Centre WXW01297 | Wessex Water | 10.1 | 6 | 29% | 47 | 40 | 21 | 7 | 97% |
| Frome Welshmill Lane storm tank overflow Frome Welshmill Lane Storm Tanks Storm Tank · WXW00454 | Wessex Water | 10.4 | 6 | 28% | 33 | 43 | 22 | 60 | 100% |
| Frome Whatcombe Road NO 20 WXW01245 | Wessex Water | 10.3 | 6 | 28% | 42 | 45 | 31 | 10 | 100% |
| Frome Welshmill Lane Inlet 2 WXW01335 | Wessex Water | 10.4 | 6 | 28% | – | – | 0 | 0 | 100% |
| Frome Welshmill Lane Inlet WXW00453 | Wessex Water | 10.4 | 6 | 28% | 20 | 2 | 0 | 0 | 100% |
| Frome Westway Precinct CAR Park R/O WXW01242 | Wessex Water | 11.2 | 6 | 27% | 5 | 2 | 3 | 0 | 100% |
| Frome Singers Cattle Market WXW00051 | Wessex Water | 11.3 | 6 | 27% | 16 | 9 | 6 | 1 | 100% |
| Frome Court House King Street WXW00333 | Wessex Water | 11.4 | 6 | 27% | 29 | 35 | 19 | 6 | 100% |
| Frome Merchants Barton WXW00711 | Wessex Water | 11.4 | 6 | 27% | 24 | 35 | 17 | 4 | 100% |
| Frome Rodden Road WXW00934 | Wessex Water | 11.9 | 7 | 27% | 6 | 5 | 2 | 2 | 100% |
| Frome North OF Carpet Factory Near Railway Junction WXW00805 | Wessex Water | 12.4 | 7 | 26% | 7 | 5 | 4 | 1 | 100% |
| Frome Wallbridge WXW01185 | Wessex Water | 12.6 | 7 | 26% | 4 | 6 | 3 | 11 | 100% |
| Frome Portway / Locks Hill WXW00880 | Wessex Water | 12.6 | 7 | 26% | 15 | 19 | 17 | 2 | 100% |
| Frome Adderwell Close WXW00062 | Wessex Water | 13.5 | 8 | 18% | 69 | 72 | 58 | 107 | 100% |
| Frome Lower Keyford WXW00654 | Wessex Water | 13.6 | 8 | 18% | 74 | 69 | 58 | 81 | 100% |
| Frome Feltham Drive Near Footbridge WXW00420 | Wessex Water | 13.6 | 8 | 18% | 16 | 5 | 13 | 1 | 100% |
| Mells WXW00709 | Wessex Water | 15.2 | 8 | 8% | 3 | 4 | 0 | 0 | 100% |
| Coleford Kings Head WXW00596 | Wessex Water | 20.2 | 11 | 4% | 52 | 55 | 26 | 77 | 83% |
| Nunney storm tank overflow Nunney Storm Tank · WXW00816 | Wessex Water | 15.7 | 9 | 4% | 104 | 81 | 77 | 1,383 | 100% |
| Nunney Market Place South END WXW00815 | Wessex Water | 16.6 | 9 | 4% | 6 | 0 | – | – | 100% |
| Witham Friary WXW01272 | Wessex Water | 24.8 | 14 | 3% | 36 | 37 | 17 | 163 | 100% |
| Edford storm tank overflow Edford Storm Tank · WXW00402 | Wessex Water | 22.4 | 12 | 3% | 97 | 61 | 46 | 366 | 100% |
| Edford Inlet WXW00401 | Wessex Water | 22.4 | 12 | 3% | 77 | 68 | 46 | 219 | 100% |
| Stoke ST Michael Stoke Hill WXW01068 | Wessex Water | 24.1 | 13 | 2% | 1 | 11 | 1 | 7 | 99% |
| Chapmanslade Divers Bridge WXW00369 | Wessex Water | 17.9 | 10 | 2% | 1 | 16 | 2 | 15 | 100% |
| Frome Courts Barton Marston Lane WXW00693 | Wessex Water | 14.6 | 8 | 2% | 0 | 0 | 0 | 0 | 100% |
| Mells storm tank overflow Mells Storm Tank · WXW00710 | Wessex Water | 14.7 | 8 | 2% | 25 | 2 | 0 | 0 | 100% |
| Oakhill storm tank overflow Oakhill Storm Tank · WXW00818 | Wessex Water | 25.3 | 14 | 1% | 21 | 23 | 5 | 30 | 100% |
| Coleford storm tank overflow Coleford Storm Tank · WXW00308 | Wessex Water | 19.6 | 11 | 1% | 119 | 98 | 73 | 780 | 100% |
| Coleford Inlet WXW00307 | Wessex Water | 19.6 | 11 | 1% | 28 | 59 | 42 | 162 | 100% |
| Trudoxhill WXW01156 | Wessex Water | 21.5 | 12 | 1% | 65 | 81 | 53 | 584 | 100% |
| Cranmore Inlet WXW00340 | Wessex Water | 21.5 | 12 | 1% | 84 | 60 | 37 | 422 | 100% |
| Leigh on Mendip storm tank overflow Leigh ON Mendip Storm Tank · WXW00627 | Wessex Water | 19.2 | 11 | 1% | 38 | 35 | 16 | 195 | 100% |
| Wanstrow WXW01187 | Wessex Water | 22.6 | 13 | 1% | 29 | 27 | 16 | 123 | 100% |
| Gurney Slade WXW00490 | Wessex Water | 27.8 | 15 | 1% | 39 | 65 | 19 | 95 | 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.