Tockenham STW

Storm overflow run by Wessex Water, discharging into Cowage Brook,ditch Trib Of.

Inlet storm overflow at sewage treatment works Chippenham constituency
Right now
Not discharging
Last discharge ended on (10 hours ago).
Times are UK time. Company feed updated 2 min ago

"Not discharging" means the company's monitor reports no discharge right now — not that the water is clean. The feed publishes status only; no discharge volume is measured.

2026 so far
12spills
at least 5.7 h discharging on 11 days · counted by us, not yet official · 4 discharges whose end the feed did not report (counted, no hours)
2025 official
17spills
54 h · −67% on 2024
Rank in Wessex Water
#508
of 1,285 overflows by 2025 spills (1 = most)
Monitor in 2025
99.7% working
Long-term average 48.7 spills a year

Year by year

The Environment Agency's official annual returns, counted the EA's way (12/24-hour spills). 2026 is our own running count, the same way, from Wessex Water's monitor log and the live feed. The feed reports only each overflow's latest discharge, so a discharge it moved past before we saw it end is counted as one spill with no hours: the hours are a floor. The official figure is published next spring.

2022
30 spills · 32 hmonitor 99.4%
2023
77 spills · 446 hmonitor 98.7%
2024
52 spills · 210 hmonitor 99.9%
2025
17 spills · 54 hmonitor 99.7%
2026so far
12 spills · at least 5.7 h

A spill is the EA's 12/24-hour count: the first 12 hours of a discharge count as one, each further 24 hours with discharge as one more. "Monitor" is the share of that year the monitor was working, so a 0 beside a working monitor is a real zero; "no data" means the monitor produced no usable data that year — not zero. Years before 2024 are matched to this site by name and location, because the EA's site IDs changed that year; a monitor figure beside one of them means the outlet's permit confirms the match.

What the 2025 return says

From Wessex Water's annual return to the Environment Agency for this overflow.

High-spill review
High spill threshold not met
Long-term review
Data collection - Confirmed exceptional weather
Investigation
No investigation activity in reporting period
Improvement work
No improvement action in reporting period
Monitored since
2023
Water body
Cowage Bk - source to conf unnamed trib

"High spill threshold not met" means this overflow did not spill often enough to trigger the EA's formal high-spill review for that year. It is not a statement that the spills were harmless.

Discharges we have recorded

560 discharge periods since 16 May 2022, 4 whose end the feed never gave. 544 of them come from Wessex Water's own event-duration-monitoring records (published on Stream, May 2022 – Aug 2026); the live feed adds anything after that. The official annual count is the figure to quote.

Show 30 earlier (of 560)
StartedEndedDischarge time
14 min
not captured, before not captured
14 min
2 min
2 min
2 min
6 min
14 min
6 min
28 min
10 min
2 min
2 min
2 min
6 min
2 min
2 min
2 min
4 min
8 min
2 min
6 min
2 min
2 min
2 min
4 min
4 min
2 min
2 min
8 min

The year figures above use the EA's 12/24-hour counting method, so they are comparable with the official figures; the monitor log's 1,102 raw blocks were merged into 560 continuous discharge periods (gaps under 15 min joined).

What the feed showed

FloodRadar's own record of every change of state Wessex Water's live feed has shown for this overflow, kept since : 31 states. The feed publishes its status now and its latest discharge, nothing older; the discharges above are read from this. It is here so the figures can be checked.

Show the last 31 states
SeenStatusSinceLatest discharge
Not discharging →
Not discharging →
Discharging → no end yet
Not discharging →
Discharging → no end yet
Not discharging →
Not discharging →
Discharging → no end yet
Discharging → no end yet
Discharging → no end yet
Not discharging →
Not discharging →
Not discharging →
Discharging → no end yet
Discharging → no end yet
Not discharging →
Discharging → no end yet
Not discharging →
Discharging → no end yet
Not discharging →
Discharging → no end yet
Not discharging →
Not discharging →
Not discharging →
Discharging → no end yet
Monitor offline— →
Not discharging →
Discharging → no end yet
Discharging → no end yet
Monitor offline— →
Not discharging →

Rain nearby last 30 days

Nearest live rain gauge: Rainfall gauge nr Royal Wootton Bassett, 3.8 km away. Brown shading = when this overflow was discharging; ▼ = a discharge start.

Overflow shading is a timing match, not proof of cause — heavy rain and spills share a trigger. Times come from the water company’s event-duration monitor (site status only; no discharge volume is published).

Where it is

Nearest river gauge
Brinkworth Brook (Brinkworth Brook) · 4.0 km
Nearest rain gauge
Council area
Wiltshire
Wessex Water's own name for it
Tockenham Inlet
Site reference
WXW01141 · permit 010238
Coordinates
51.51031, -1.94194

Tell me when this overflow discharges

One message when the company's monitor reports a new discharge here. At most one every 6 hours.

Setting this alert needs JavaScript. The alerts you already have are on your alerts page.

The alert repeats the monitor's status: whether the overflow is discharging, not how much or why. It can only tell you about a discharge that starts after you turn it on.

Concerned about this overflow?

Report pollution you can see or smell to the regulator straight away; the company handles complaints about the overflow itself.

Write to the MP

The Environment Agency's return places this overflow in the Chippenham constituency. An MP can ask the company and the regulator questions on a constituent's behalf. These words carry the official figures; change them as you like.

The link opens Parliament's own "Find your MP", which gives the MP's name and how to write to them. FloodRadar sends nothing and keeps nothing you write. Check the constituency against your own address: an MP acts only for people who live in it.

Live status: © Wessex Water storm overflow activity data, licensed under CC BY 4.0. Annual spill figures: Environment Agency Event Duration Monitoring return, © Environment Agency copyright and/or database right, Open Government Licence (OGL) v3.0. Storm-overflow spill events: © the respective water company, published on Stream (data.streamwaterdata.co.uk) under CC BY 4.0. Discharges marked "via Top of the Poops", come from Top of the Poops' record of the same company feed, used under CC BY-SA 4.0: the feed's own start and end times as its pages print them, not their derived hours. Times are shown in UK local time. FloodRadar republishes the monitor's status and the EA's figures; it does not measure discharges itself. Constituency and council area from the EA's return: contains OS data © Crown copyright and database right 2026.