CSO Yarm Road Dl18

Storm overflow run by Northumbrian Water, discharging into River Skerne.

Storm overflow on the sewer network Darlington constituency
Right now
Not discharging
Last discharge ended on (54 days ago).
Times are UK time. Company feed updated 1 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
2spills
0.2 h discharging on 2 days · live feed, before 28 Feb via Top of the Poops, not yet official
2025 official
4spills
0.8 h · up from 0 in 2024
Rank in Northumbrian Water
#1,010
of 1,547 overflows by 2025 spills (1 = most)
Monitor in 2025
93.1% working
Long-term average 1.4 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
no data
2022
0 spills · 0 hmonitor 16.7%
2023
2 spills · 0.5 hmonitor 100%
2024
0 spills · 0 hmonitor 93.4%
2025
4 spills · 0.8 hmonitor 93.1%
2026so far
2 spills · 0.2 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.

Other outlets here

Northumbrian Water runs 6 other overflows within 300 m that also discharge into River Skerne. They share the sewer and the storm, so one outlet's figures are only part of what reaches the water.

0m Yarm Road CSO (Y2)NWL01563Yarm Road CSO (Y2) 6spills in 2025
0m Yarm Road CSO (Y3)NWL01564Yarm Road CSO (Y3) 3spills in 2025
0m Yarm Road CSO (Y6)NWL01565Yarm Road CSO (Y6) 1spill in 2025
0m Neasham Road (Y4) CSONWL00919Neasham Road (Y4) CSO 3spills in 2025
0m Neasham Road CSO (Y5)NWL00920Neasham Road CSO (Y5) 29spills in 2025
94m Victoria Road SPSNWL01429Victoria Road SPS 2spills in 2025

This overflow: 4 spills in 2025. Distances are between the published outlet points.

Downstream of this overflow

The next gauge downstream that the river map places is South Park (River Skerne), 1.6 km along the river.

Water-sampling points downstream

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

High-spill review
High spill threshold not met
Investigation
Env Act (SODRP) investigation ongoing, Operational investigation ongoing
Improvement work
Operational improvement ongoing
Monitored since
2015
Water body
Skerne from Demons Beck to Tees

"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

5 discharge periods since 15 Jul 2023. 2 of them come from Northumbrian Water's own event-duration-monitoring records (published on Stream, Jul 2023 – Sep 2023); the live feed adds anything after that. The official annual count is the figure to quote.

The year figures above use the EA's 12/24-hour counting method, so they are comparable with the official figures.

What the feed showed

FloodRadar's own record of every change of state Northumbrian 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 Morton Palms, 2.9 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
John St Darlington (River Skerne) · 1.2 km
Nearest rain gauge
Council area
Darlington (B)
Site reference
NWL00408 · permit 25/03/1214
Coordinates
54.52256, -1.55153

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 Darlington 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: © Northumbrian 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 "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.