CSO At Tarrington STW

Storm overflow run by Dwr Cymru Welsh Water, discharging into River Frome.

Storm tank at sewage treatment works North Herefordshire constituency
Right now
Not discharging
Times are UK time. Company feed updated just now

"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
0spills
0 h discharging · live feed since 23 Sep, not yet official
2025 official
23spills
233 h · −81% on 2024
Rank in Dwr Cymru Welsh Water
#46
of 119 overflows by 2025 spills (1 = most)
Monitor in 2025
99.9% working
Long-term average 49.9 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 the live feed since 23 September (when we began keeping every discharge it reports) — so it can only be lower than the full year. The official figure is published next spring.

2021
49 spills · 349 hmonitor 99.9%
2022
40 spills · 422 hmonitor 100%
2023
97 spills · 1,426 hmonitor 99.8%
2024
120 spills · 1,405 hmonitor 99.7%
2025
23 spills · 233 hmonitor 99.9%
2026since 23 Sep
0 spills · 0 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.

Downstream of this overflow

The next gauge downstream that the river map places is Mordiford (River Wye), 11.2 km along the river.

Water-sampling points downstream

The nearest Environment Agency sampling points the river map places below Mordiford. Points between this overflow and that gauge cannot be put in order with it on the map, so they are not listed.

A sample is dated: it is not the river now, and its results are on its own page. A sample taken after a discharge does not show that the discharge caused what was measured. Samples: Environment Agency Water Quality Archive, © Environment Agency and/or database right 2026, Open Government Licence v3.0.

A river gauge measures the level of the river; it does not measure this overflow's discharge, and a spill does not by itself explain a change there. Traced on OS Open Rivers (edition 2026-04), which leaves out many small channels.

Contains OS data © Crown copyright and database rights 2026.

What the 2025 return says

From Dwr Cymru Welsh Water's annual return to the Environment Agency for this overflow.

High-spill review
High spill threshold not met
Long-term review
Not Applicable - Ongoing investigation
Investigation
No investigation activity in reporting period
Improvement work
No improvement action in reporting period
Monitored since
2016
Water body
Tarrington Bk - source to conf R Frome

"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

No discharge has been recorded from the live feed for this overflow since we started following it. The official annual figure above is the record to rely on.

What the feed showed

FloodRadar's own record of every change of state Dwr Cymru Welsh Water's live feed has shown for this overflow, kept since : 1 state. 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 1 states
SeenStatusSinceLatest discharge
Not discharging——

Rain nearby last 30 days

Nearest live rain gauge: Rainfall gauge nr Tarrington, 1.2 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
Yarkhill (River Frome (Wye)) · 1.2 km
Nearest rain gauge
Council area
County of Herefordshire
Dwr Cymru Welsh Water's own name for it
Tarrington
Site reference
DCW00036 · permit AN0338901
Coordinates
52.07042, -2.56245

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 North Herefordshire 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: © Dŵr Cymru Welsh Water, from its Storm Overflow Map. Annual spill figures: Environment Agency Event Duration Monitoring return, © Environment Agency copyright and/or database right, Open Government Licence (OGL) v3.0. 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.