Overflow history upstream of River Avon at Fordingbridge
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 | 19 | 1,015 | 11,819 | 831 |
| 2022 | 21 | 725 | 7,020 | 437 |
| 2023 | 23 | 1,675 | 23,460 | 2,494 |
| 2024 | 23 | 2,044 | 31,262 | 2,314 |
| 2025 | 25 | 898 | 12,521 | 438 |
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 26, 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 |
|---|---|---|---|---|---|---|---|---|---|
| Fordingbridge Salisbury Street WXW00437 | Wessex Water | 0.3 | under 1 | 99% | 82 | 92 | 31 | 26 | 100% |
| Downton Moot Lane storm tank overflow Downton Moot Lane Storm Tank · WXW00379 | Wessex Water | 12.2 | 7 | 54% | 106 | 99 | 31 | 309 | 100% |
| Salisbury Petersfinger Southampton Road storm tank overflow Salisbury Petersfinger Southampton Road Storm Tank · WXW00949 | Wessex Water | 23.6 | 13 | 6% | 102 | 123 | 51 | 840 | 100% |
| Wishford Wilton Road storm tank overflow Wishford Wilton Road Storm Tank · WXW00481 | Wessex Water | 34.9 | 19 | 4% | 122 | 109 | 10 | 190 | 100% |
| WSX10053 WSX10053 | Wessex Water | 29.5 | 16 | 4% | – | – | – | – | – |
| Barford St Martin Burcombe storm tank overflow Barford ST Martin Burcombe Storm Tank · WXW00104 | Wessex Water | 37.4 | 21 | 4% | 122 | 185 | 81 | 1,551 | 100% |
| Barford ST Martin WXW00103 | Wessex Water | 37.8 | 21 | 3% | 11 | 23 | 4 | 42 | 100% |
| Hurdcott storm tank overflow Hurdcott Storm Tank · WXW00571 | Wessex Water | 30.9 | 17 | 3% | 253 | 310 | 167 | 3,119 | 100% |
| Hurdcott WXW00570 | Wessex Water | 31.1 | 17 | 3% | 19 | 26 | 1 | 1 | 100% |
| Hanging Langford WXW00498 | Wessex Water | 42.7 | 24 | 2% | 170 | 191 | 84 | 242 | 100% |
| Idmiston WXW00574 | Wessex Water | 37.3 | 21 | 1% | 1 | 2 | 1 | 0 | 100% |
| Allington OLD INN WXW00075 | Wessex Water | 40.7 | 23 | 1% | 49 | 126 | 85 | 1,978 | 100% |
| Alderbury, Home Farm pumping station overflow Alderbury - Home Farm SPS · WXW00560 | Wessex Water | 19.5 | 11 | 1% | – | – | 0 | 0 | 100% |
| Salisbury Endless Lane/Scots Lane WXW00028 | Wessex Water | 24.8 | 14 | 0% | 33 | 42 | 22 | 9 | 100% |
| Salisbury Bridge Street/High Street WXW00533 | Wessex Water | 24.8 | 14 | 0% | 22 | 30 | 7 | 10 | 100% |
| Tisbury Nadder Close Playing Fields WXW01139 | Wessex Water | 54.5 | 30 | 0% | 52 | 56 | 36 | 71 | 100% |
| Salisbury, THE Close storm overflow Salisbury - THE Close - Combined Sewer Overflow · WXW01348 | Wessex Water | 24.8 | 14 | 0% | – | – | 0 | 0 | 100% |
| Salisbury Churchill Gardens Near College WXW00293 | Wessex Water | 24.8 | 14 | 0% | 0 | 0 | 0 | 0 | 100% |
| Salisbury College Street NO 28 WXW00310 | Wessex Water | 24.8 | 14 | 0% | 0 | 3 | 4 | 0 | 100% |
| Amesbury Off Church Street storm tank overflow Amesbury OFF Church Street Storm Tank · WXW00081 | Wessex Water | 44.3 | 25 | <1% | 3 | 2 | 1 | 2 | 100% |
| Shrewton storm tank overflow Shrewton Storm Tank · WXW00993 | Wessex Water | 48.7 | 27 | <1% | 262 | 235 | 116 | 2,679 | 100% |
| Fovant storm tank overflow Fovant Storm Tank · WXW00443 | Wessex Water | 46.7 | 26 | <1% | 139 | 193 | 81 | 1,252 | 100% |
| Chilmark WXW00273 | Wessex Water | 51.3 | 28 | <1% | 0 | 27 | 7 | 101 | 100% |
| Amesbury Flower Lane WXW00434 | Wessex Water | 45.6 | 25 | <1% | 0 | 0 | 0 | 0 | 100% |
| Hindon Inlet WXW00545 | Wessex Water | 58.5 | 32 | <1% | 113 | 129 | 74 | 97 | 100% |
| Hindon THE Dene WXW00544 | Wessex Water | 58.5 | 32 | <1% | 14 | 41 | 4 | 2 | 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.