Aislaby Road Pumping Station

Storm overflow run by Northumbrian Water, discharging into Tees Estuary.

Storm discharge at pumping station Stockton West constituency
Right now
Not discharging
Last discharge ended on (16 hours ago).
Times are UK time. Company feed updated 4 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
24spills
at least 91 h discharging on 25 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
30spills
155 h · up from 0 in 2024
Rank in Northumbrian Water
#336
of 1,547 overflows by 2025 spills (1 = most)
Monitor in 2025
58.0% working
Long-term average 30.0 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.

2024
0 spills · 0 hmonitor 99.9%
2025
30 spills · 155 hmonitor 58.0%
2026so far
24 spills · at least 91 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.

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
Operational investigation ongoing
Improvement work
Operational improvement ongoing
Monitored since
2025
Water body
Tees from Skerne to Tidal Limit

"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

33 discharge periods since 9 Jan 2026, 2 whose end the feed never gave. Recorded from the live status feed only — Northumbrian Water has not published an event-level log we hold, so this is what the feed has shown us, not a complete record. The official annual count is the figure to quote.

Show 23 earlier
StartedEndedDischarge time
2 h 58 min
1 h 0 min
7 h 10 min
1 h 36 min
10 min
not captured, before not captured
1 h 50 min
2 h 6 min
12 h 8 min
8 min
8 min
6 h 30 min
6 min
6 min
11 h 36 min
14 h 16 min
2 h 42 min
40 min
3 h 30 min
7 h 0 min
14 min
8 min
1 h 2 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 36 raw blocks were merged into 33 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 Morton Palms, 9.6 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
Yarm (River Tees) · 0.3 km
Nearest rain gauge
Council area
Stockton-on-Tees (B)
Site reference
NWL01584 · permit 254/1250
Coordinates
54.51216, -1.35989

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. 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.