#n/A

Storm overflow run by South West Water, discharging into River Meavy.

Inlet storm overflow at sewage treatment works South West Devon constituency
Right now
Status unknown
The live feed has not updated for 26 d 10 h.
Times are UK time. Company feed updated 26 days 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
7spills
at least 2.9 h discharging on 6 days · live feed, before 28 Feb via Top of the Poops, not yet official · 2 discharges whose end the feed did not report (counted, no hours)
2025 official
15spills
49 h · −82% on 2024
Rank in South West Water
#773
of 1,357 overflows by 2025 spills (1 = most)
Monitor in 2025
100% working
Long-term average 49.5 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: our own log of it begins on 28 February, and the discharges before that are Top of the Poops' record of the same 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.

2024
84 spills · 245 hmonitor 99.9%
2025
15 spills · 49 hmonitor 100%
2026so far
7 spills · at least 2.9 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.

Twin outlet

South West Water runs another overflow within 300 m that also discharges into River Meavy. They share the sewer and the storm, so one outlet's figures are only part of what reaches the water.

0m Gratton Wastewater Treatment WorksdischargingSBB00515GRATTON STW_SSO_YELVERTON 143spills in 2025

This overflow (GRATTON STW_SO_YELVERTON): 15 spills in 2025. Distances are between the published outlet points. The names in brackets are South West Water's own, from its return.

Downstream of this overflow

Its water reaches 2 gauges next on the river map, on different channels: CARNWOOD, 7.9 km along the river; Carnwood (River Plym), 7.9 km along the river.

Water-sampling points downstream

The nearest Environment Agency sampling points the river map places below the gauges above. 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 South West Water's annual return to the Environment Agency for this overflow.

High-spill review
High spill threshold not met
Long-term review
Performance - SW Infiltration
Investigation
UWWTR investigation completed
Improvement work
No improvement action in reporting period
Monitored since
2023
Water body
Meavy

"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

261 discharge periods since 1 Jan 2024, 2 whose end the feed never gave. 238 of them come from South West Water's own event-duration-monitoring records (published on Stream, Jan 2024 – Nov 2025); the live feed adds anything after that. The official annual count is the figure to quote.

Show 30 earlier (of 261)
StartedEndedDischarge time
4 min
not captured, before not captured
not captured, before not captured
3 min
2 min
5 min
3 min
6 min
1 min
1 min
2 min
1 min
6 min
13 min
12 min
2 h 5 min
25 min
1 h 6 min
13 min
32 min
1 h 5 min
16 min
14 min
10 min
22 min
10 min
16 min
20 min
55 min
12 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 327 raw blocks were merged into 261 continuous discharge periods (gaps under 15 min joined).

Rain nearby last 30 days

Nearest live rain gauge: Rainfall gauge nr Dousland, 2.7 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
Horrabridge (River Walkham) · 3.4 km
Nearest rain gauge
Council area
West Devon District (B)
South West Water's own name for it
GRATTON STW_SO_YELVERTON
Site reference
SBB01433 · permit Unpermitted
Coordinates
50.48140, -4.08267

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 South West Devon 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: © South West 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 "EA start/stop data": Environment Agency Event Duration Monitoring storm overflow start/stop detailed data, © Environment Agency copyright and/or database right 2026, Open Government Licence v3.0; the companies' monitor records as the EA received them, not verified by the EA. Discharges marked "via Top of the Poops", and this year's figures before 28 February, 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.