Grays Road CSO

Storm overflow run by Northumbrian Water, discharging into Lustrum Beck.

Storm overflow on the sewer network Stockton West constituency
Right now
Not discharging
Last discharge ended on (6 hours ago).
Times are UK time. Company feed updated 2 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
40spills
at least 266 h discharging on 40 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
37spills
369 h · −46% on 2024
Rank in Northumbrian Water
#246
of 1,547 overflows by 2025 spills (1 = most)
Monitor in 2025
92.2% working
Long-term average 68.6 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
64 spills · 690 hmonitor 100%
2022
66 spills · 507 hmonitor 95.6%
2023
114 spills · 1,457 hmonitor 96.9%
2024
68 spills · 645 hmonitor 95.2%
2025
37 spills · 369 hmonitor 92.2%
2026so far
40 spills · at least 266 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 2 other overflows within 300 m that also discharge into Lustrum Beck. They share the sewer and the storm, so one outlet's figures are only part of what reaches the water.

93m Grays Road CSONWL00611Grays Road CSO 10spills in 2025
180m Grangefield Road SSONWL00604Grangefield Road SSO 31spills in 2025

This overflow: 37 spills in 2025. Distances are between the published outlet points.

Downstream of this overflow

The next gauge downstream that the river map places is Stockton Primrose Hill (Lustrum Beck), 1.2 km along the river.

Water-sampling points downstream

The nearest Environment Agency sampling points the river map places below Stockton Primrose Hill. 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
Not asset maintenance - Hydraulic capacity
Investigation
Env Act (SODRP) investigation ongoing
Improvement work
Operational improvement completed
Monitored since
2018
Water body
Lustrum Beck Catchment (trib of Tees)

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

340 discharge periods since 9 Jan 2020, 2 whose end the feed never gave. 303 of them come from Northumbrian Water's own event-duration-monitoring records (published on Stream, Jan 2020 – Dec 2024); the live feed adds anything after that. The official annual count is the figure to quote.

Show 30 earlier (of 340)
StartedEndedDischarge time
56 min
18 min
6 h 10 min
8 h 20 min
1 h 58 min
1 h 42 min
1 h 42 min
38 min
1 h 34 min
not captured, before not captured
5 min
4 min
15 min
3 h 12 min
2 min
21 h 2 min
1 h 54 min
1 h 56 min
3 d 20 h
4 h 26 min
1 d 20 h
1 h 36 min
17 h 40 min
24 min
1 h 48 min
1 d 10 h
1 h 24 min
2 h 0 min
1 d 20 h
30 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 367 raw blocks were merged into 340 continuous discharge periods (gaps under 15 min joined).

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 : 5 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 5 states
SeenStatusSinceLatest discharge
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 Middlesbrough, 8.6 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
Stockton Primrose Hill (Lustrum Beck) · 1.1 km
Nearest rain gauge
Council area
Stockton-on-Tees (B)
Site reference
NWL00610 · permit 25/04/1628
Coordinates
54.56762, -1.32898

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 Stockton West 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.