Mill Hill Lane SSO

Storm overflow run by Yorkshire Water, discharging into Trib Of River Wiske.

Storm discharge at pumping station Richmond and Northallerton constituency
Right now
No live feed
Yorkshire Water does not publish a live status for this overflow; only the annual figures below are available.

"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.

2025 official
1spill
0.8 h · up from 0 in 2024
Rank in Yorkshire Water
#1,768
of 2,161 overflows by 2025 spills (1 = most)
Monitor in 2025
100% working
Long-term average 1.2 spills a year

Year by year

The Environment Agency's official annual returns, counted the EA's way (12/24-hour spills).

2021
1 spill · 0.5 hmonitor 100%
2022
0 spills · 0 hmonitor 100%
2023
3 spills · 3.0 hmonitor 100%
2024
0 spills · 0 hmonitor 100%
2025
1 spill · 0.8 hmonitor 100%

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 Yorkshire Water's annual return to the Environment Agency for this overflow.

High-spill review
High spill threshold not met
Investigation
No investigation activity in reporting period
Improvement work
No improvement action in reporting period
Monitored since
2020
Water body
Otterington Beck catchment (trib of Wiske)

"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

1 discharge period since 21 Sep 2025. Recorded from the live status feed only — Yorkshire 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.

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

Rain nearby last 30 days

Nearest live rain gauge: Rainfall gauge nr Romanby, 1.9 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
Northallerton (Willow Beck) · 1.2 km
Nearest rain gauge
Council area
North Yorkshire
Yorkshire Water's own name for it
Mill Hill Lane/CSO
Site reference
YWS01151 · permit WADC1137
Coordinates
54.33194, -1.42774

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 Richmond and Northallerton 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.

Annual spill figures: Environment Agency Event Duration Monitoring return, © Environment Agency copyright and/or database right, Open Government Licence (OGL) v3.0. 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.