Marehay Sewage Treatment Works

Storm overflow run by Severn Trent Water, discharging into Tributary Of Bottle Brook.

Storm tank at sewage treatment works Amber Valley constituency
Right now
Not discharging
Last discharge ended on (14 hours ago).
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
4spills
11 h discharging on 4 days · live feed, before 28 Feb via Top of the Poops, not yet official
2025 official
30spills
429 h · −63% on 2024
Rank in Severn Trent Water
#379
of 2,418 overflows by 2025 spills (1 = most)
Monitor in 2025
99.2% working
Long-term average 63.8 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 official figure is published next spring.

2024
81 spills · 1,094 hmonitor 96.6%
2025
30 spills · 429 hmonitor 99.2%
2026so far
4 spills · 11 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

Severn Trent Water runs another overflow within 300 m that also discharges into Tributary Of Bottle Brook. They share the sewer and the storm, so one outlet's figures are only part of what reaches the water.

0m Marehay Sewage Treatment WorksSVT01495Marehay STW (6dwf) 8spills in 2025

This overflow (Marehay STW (SSTO)): 30 spills in 2025. Distances are between the published outlet points. The names in brackets are Severn Trent Water's own, from its return.

What the 2025 return says

From Severn Trent 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
Env Act (SODRP) investigation ongoing, UWWTR investigation completed, Operational investigation completed
Improvement work
UWWTR improvement completed
Monitored since
2021
Water body
Bottle Brook Catchment (trib of Derwent)

"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

147 discharge periods since 21 Jan 2024. 142 of them come from Severn Trent Water's own event-duration-monitoring records (published on Stream, Jan 2024 – May 2025); the live feed adds anything after that. The official annual count is the figure to quote.

Show 30 earlier (of 147)
StartedEndedDischarge time
3 h 49 min
14 h 8 min
17 h 55 min
23 h 40 min
7 h 8 min
25 min
18 h 10 min
25 min
25 min
14 h 10 min
25 min
25 min
25 min
6 h 10 min
14 h 55 min
2 h 25 min
3 d 3 h
7 h 11 min
2 h 55 min
25 min
10 min
10 min
10 min
1 h 55 min
10 min
4 h 55 min
10 min
4 h 55 min
40 min
1 h 10 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 149 raw blocks were merged into 147 continuous discharge periods (gaps under 15 min joined).

What the feed showed

FloodRadar's own record of every change of state Severn Trent Water's live feed has shown for this overflow, kept since : 7 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 7 states
SeenStatusSinceLatest discharge
Not discharging →
Discharging → no end yet
Not discharging →
Discharging → no end yet
Not discharging →
Discharging → no end yet
Not discharging →

Rain nearby last 30 days

Nearest live rain gauge: Rainfall gauge nr Denby CP, 1.1 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
Smithy Houses (Bottle Brook) · 1.6 km
Nearest rain gauge
Council area
Amber Valley District (B)
Severn Trent Water's own name for it
Marehay STW (SSTO)
Site reference
SVT01494 · permit T/45/45471/R
Coordinates
53.02959, -1.40786

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 Amber Valley 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: © Severn Trent 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.