Rossendale WwTW

Storm overflow run by United Utilities, discharging into River Irwell.

Storm tank at sewage treatment works Rossendale and Darwen constituency
Right now
Discharging now
Since on · 3 h 27 min so far.
Times are UK time. Company feed updated 6 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
32spills
at least 306 h discharging on 35 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
84spills
1,205 h · −16% on 2024
Rank in United Utilities
#127
of 2,242 overflows by 2025 spills (1 = most)
Monitor in 2025
100% working
Long-term average 115.8 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 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.

2021
no data
2022
120 spills · 1,318 hmonitor 100%
2023
118 spills · 1,901 hmonitor 61.7%
2024
100 spills · 1,403 hmonitor 100%
2025
84 spills · 1,205 hmonitor 100%
2026so far
32 spills · at least 306 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 Irwell Vale (River Irwell), 760 m along the river.

Water-sampling points downstream

The nearest Environment Agency sampling points the river map places below Irwell Vale. 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 United Utilities's annual return to the Environment Agency for this overflow.

High-spill review
Not asset maintenance - Hydraulic capacity
Investigation
No investigation activity in reporting period
Improvement work
No improvement action in reporting period
Monitored since
2019
Water body
Irwell (Cowpe Bk to Rossendale STW)

This overflow spilled often enough to trigger the EA's high-spill review; the review line is the company's own stated reason.

Discharges we have recorded

199 discharge periods since 1 Jan 2023, 1 still open, 2 whose end the feed never gave. 167 of them come from United Utilities's own event-duration-monitoring records (published on Stream, Jan 2023 – Dec 2025); the live feed adds anything after that. The official annual count is the figure to quote.

Show 30 earlier (of 199)
StartedEndedDischarge time
2 h 17 min
11 h 36 min
6 h 18 min
1 d 1 h
6 h 55 min
3 h 13 min
55 min
2 h 56 min
1 d 2 h
1 h 39 min
5 h 37 min
21 h 23 min
9 h 28 min
8 h 16 min
5 h 48 min
1 d 8 h
19 h 48 min
5 h 52 min
4 h 6 min
3 min
6 h 8 min
2 d 11 h
2 d 17 h
1 d 22 h
5 d 9 h
16 h 0 min
2 d 16 h
16 h 27 min
1 d 17 h
7 h 41 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 209 raw blocks were merged into 199 continuous discharge periods (gaps under 15 min joined).

What the feed showed

FloodRadar's own record of every change of state United Utilities's live feed has shown for this overflow, kept since : 2 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 2 states
SeenStatusSinceLatest discharge
Discharging → no end yet
Not discharging →

Rain nearby last 30 days

Nearest live rain gauge: Rainfall gauge nr Haslingden, 3.4 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
Irwell Vale (River Irwell) · 0.6 km
Nearest rain gauge
Council area
Rossendale District (B)
Site reference
UUP01689 · permit 016950042
Coordinates
53.68155, -2.31079

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 Rossendale and Darwen 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: © United Utilities 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", 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.