Mh At Junction Of Black Tor Road

Storm overflow run by Severn Trent Water, discharging into River Derwent.

Storm overflow on the sewer network Derbyshire Dales constituency
Right now
Not discharging
Last discharge ended on (6 days 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
19spills
9.1 h discharging on 19 days · live feed, before 28 Feb via Top of the Poops, not yet official
2025 official
22spills
33 h · −27% on 2024
Rank in Severn Trent Water
#585
of 2,418 overflows by 2025 spills (1 = most)
Monitor in 2025
93.3% working
Long-term average 28.2 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.

2021
29 spills · 153 hmonitor 97.1%
2022
33 spills · 126 hmonitor 97.2%
2023
27 spills · 197 hmonitor 98.9%
2024
30 spills · 68 hmonitor 93.6%
2025
22 spills · 33 hmonitor 93.3%
2026so far
19 spills · 9.1 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 River Derwent. They share the sewer and the storm, so one outlet's figures are only part of what reaches the water.

283m Bonsall Dale Mh At JunctionSVT00305Bonsall - Yeoman Street (CSO) 3spills in 2025

This overflow (Bonsall - Clatterway/Black Tor Rd (CSO)): 22 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
Performance - SW Infiltration
Investigation
UWWTR investigation completed, Operational investigation completed
Improvement work
Operational improvement ongoing
Monitored since
2021
Water body
Derwent from Wye to Amber

"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

125 discharge periods since 1 Jan 2024. 93 of them come from Severn Trent Water's own event-duration-monitoring records (published on Stream, Jan 2024 – Dec 2025); the live feed adds anything after that. The official annual count is the figure to quote.

Show 30 earlier (of 125)
StartedEndedDischarge time
13 min
2 min
6 min
13 min
41 min
21 min
27 min
7 min
4 min
26 min
11 min
5 min
2 min
9 min
4 min
28 min
39 min
1 h 34 min
14 min
9 min
1 h 38 min
7 min
56 min
8 min
9 min
1 min
24 min
22 min
22 min
1 h 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 127 raw blocks were merged into 125 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 : 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 Brassington CP, 5.7 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
Matlock (River Derwent) · 1.8 km
Nearest rain gauge
Council area
Derbyshire Dales District
Severn Trent Water's own name for it
Bonsall - Clatterway/Black Tor Rd (CSO)
Site reference
SVT01548 · permit DT/2187
Coordinates
53.11573, -1.58162

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 Derbyshire Dales 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.