Overflow history upstream of River Tone at French Weir Park
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 | 13 | 323 | 3,755 | 256 |
| 2022 | 21 | 402 | 2,805 | 410 |
| 2023 | 27 | 1,031 | 10,164 | 1,084 |
| 2024 | 27 | 1,046 | 10,688 | 905 |
| 2025 | 27 | 553 | 4,574 | 426 |
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 |
|---|---|---|---|---|---|---|---|---|---|
| Taunton Mountway Bishops Hull WXW00761 | Wessex Water | 1.5 | under 1 | 93% | 9 | 15 | 11 | 20 | 100% |
| Bishops Hull Shutemead WXW00014 | Wessex Water | 2.2 | 1 | 63% | 6 | 2 | 1 | 2 | 100% |
| Bradford ON Tone Inlet WXW00164 | Wessex Water | 6.6 | 4 | 33% | 154 | 105 | 53 | 619 | 100% |
| Bradford ON Tone Tone Green WXW01144 | Wessex Water | 7.4 | 4 | 32% | 18 | 17 | 12 | 196 | 97% |
| WSX10115 WSX10115 | Wessex Water | 11.1 | 6 | 22% | – | – | – | – | – |
| Wellington Tone storm tank overflow Wellington Tone Storm Tank · WXW01204 | Wessex Water | 13.6 | 8 | 19% | 48 | 43 | 31 | 223 | 100% |
| Wellington Relyon Factory Entrance WXW01054 | Wessex Water | 13.6 | 8 | 19% | 2 | 2 | 2 | 0 | 100% |
| WSX10070 WSX10070 | Wessex Water | 14.0 | 8 | 19% | – | – | – | – | – |
| WSX10122 WSX10122 | Wessex Water | 3.8 | 2 | 13% | – | – | – | – | – |
| WSX10048 WSX10048 | Wessex Water | 7.2 | 4 | 13% | – | – | – | – | – |
| Norton Fitzwarren Langford Lane WXW00615 | Wessex Water | 4.4 | 2 | 6% | 67 | 62 | 23 | 318 | 100% |
| Milverton storm tank overflow Milverton Storm Tank · WXW00742 | Wessex Water | 11.5 | 6 | 6% | 109 | 97 | 35 | 444 | 90% |
| Milverton Houndsmoor Lane WXW00564 | Wessex Water | 12.5 | 7 | 6% | 20 | 10 | 6 | 1 | 100% |
| Bishops Lydeard storm tank overflow Bishops Lydeard Storm Tank · WXW00137 | Wessex Water | 7.6 | 4 | 6% | 23 | 17 | 13 | 167 | 100% |
| WSX10156 WSX10156 | Wessex Water | 7.6 | 4 | 6% | – | – | – | – | – |
| Halse Inlet WXW00493 | Wessex Water | 10.3 | 6 | 5% | 14 | 24 | 15 | 9 | 100% |
| WSX10111 WSX10111 | Wessex Water | 9.2 | 5 | 5% | – | – | – | – | – |
| Hillcommon Hill Common WXW00539 | Wessex Water | 9.4 | 5 | 5% | 7 | 9 | 5 | 8 | 100% |
| Bradford ON Tone Hockholler A38 WXW00550 | Wessex Water | 9.5 | 5 | 4% | 91 | 102 | 63 | 244 | 99% |
| West Buckland WXW01220 | Wessex Water | 9.7 | 5 | 3% | 7 | 18 | 9 | 44 | 100% |
| Combe Florey storm tank overflow Combe Florey Storm Tank · WXW00313 | Wessex Water | 12.2 | 7 | 3% | 10 | 60 | 3 | 16 | 100% |
| Rumwell WXW00943 | Wessex Water | 6.6 | 4 | 3% | 0 | 0 | – | – | 100% |
| Wellington Corams Lane WXW01115 | Wessex Water | 15.3 | 8 | 2% | 0 | 0 | 0 | 0 | 100% |
| Wellington Westford WXW01236 | Wessex Water | 15.9 | 9 | 2% | 13 | 3 | 3 | 18 | 100% |
| Nailsbourne WXW00778 | Wessex Water | 6.0 | 3 | 2% | 21 | 18 | 6 | 64 | 100% |
| WSX10000 WSX10000 | Wessex Water | 3.8 | 2 | 2% | – | – | – | – | – |
| WSX10095 WSX10095 | Wessex Water | 17.1 | 10 | 2% | – | – | – | – | – |
| Sandhill Park storm tank overflow Sandhill Park Storm Tank · WXW00960 | Wessex Water | 9.4 | 5 | 1% | 43 | 51 | 27 | 366 | 100% |
| Bishops Lydeard Church Street WXW00288 | Wessex Water | 9.2 | 5 | 1% | 3 | 3 | 0 | 0 | 100% |
| Wellington Mitchells Pool WXW00746 | Wessex Water | 10.8 | 6 | 1% | 33 | 30 | 16 | 105 | 100% |
| Trull, Taunton Deane Motorway Services, S105A pumping station overflow Trull - Taunton Deane Motorway Services - S105A Sewage Pumping Station · WXW01353 | Wessex Water | 12.2 | 7 | 1% | – | – | 0 | 0 | 99% |
| West Bagborough Inlet WXW01215 | Wessex Water | 14.3 | 8 | 1% | 62 | 122 | 64 | 737 | 100% |
| WSX10026 WSX10026 | Wessex Water | 17.2 | 10 | 1% | – | – | – | – | – |
| WSX10035 WSX10035 | Wessex Water | 17.2 | 10 | 1% | – | – | – | – | – |
| Wiveliscombe Hillsmoor Inlet WXW00541 | Wessex Water | 17.2 | 10 | 1% | 8 | 8 | 9 | 2 | 100% |
| Wiveliscombe Hillsmoor storm tank overflow Wiveliscombe Hillsmoor Storm Tank · WXW00542 | Wessex Water | 17.2 | 10 | 1% | 38 | 34 | 21 | 87 | 100% |
| Wiveliscombe Styles storm tank overflow Wiveliscombe Styles Storm Tank · WXW01274 | Wessex Water | 18.9 | 10 | 1% | 145 | 132 | 75 | 811 | 84% |
| Wiveliscombe Styles Inlet WXW01273 | Wessex Water | 18.9 | 10 | 1% | 80 | 62 | 50 | 72 | 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.