CSO East St/Avon Rd Littlehampton

Storm overflow run by Southern Water, discharging into Tidal River Arun.

Storm overflow on the sewer network Bathing water Bognor Regis and Littlehampton constituency

Linked bathing water: Littlehampton, classified Good for 2025. Named in the company’s return to the Environment Agency. A name opens that bathing water’s official profile, with any pollution warning in the season. The classification is the Environment Agency’s for that bathing season, from all its samples there: it is not a reading of the water today, and it does not say what part this overflow played.

Right now
Not discharging
Last discharge ended on (1 day 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
22spills
41 h discharging on 24 days · counted by us, not yet official
2025 official
39spills
118 h · −41% on 2024
Rank in Southern Water
#126
of 970 overflows by 2025 spills (1 = most)
Monitor in 2025
100% working
Long-term average 36.3 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 Southern Water's monitor log and the live feed. The official figure is published next spring.

2021
no data
2022
no data
2023
4 spills · 9.8 hmonitor 99.8%
2024
66 spills · 142 hmonitor 99.9%
2025
39 spills · 118 hmonitor 100%
2026so far
22 spills · 41 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 Southern Water's annual return to the Environment Agency for this overflow.

High-spill review
Not asset maintenance - Hydraulic capacity
Investigation
UWWTR investigation ongoing
Improvement work
No improvement action in reporting period
Monitored since
2023
Water body
ARUN

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

202 discharge periods since 19 Dec 2023. 202 of them come from Southern Water's own event-duration-monitoring records (from its Rivers and Seas Watch service, Dec 2023 – Sep 2026); the live feed adds anything after that. The official annual count is the figure to quote.

Show 30 earlier (of 202)
StartedEndedDischarge time
27 min
13 min
36 min
43 min
17 min
31 min
10 h 3 min
22 min
18 min
32 min
31 min
51 min
40 min
21 min
2 h 45 min
51 min
31 min
40 min
23 min
1 h 35 min
1 h 19 min
44 min
5 h 38 min
31 min
3 h 45 min
35 min
51 min
33 min
1 h 31 min
9 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 249 raw blocks were merged into 202 continuous discharge periods (gaps under 15 min joined).

What the feed showed

FloodRadar's own record of every change of state Southern 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 Angmering, 7.5 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
Littlehampton (River Arun) · 0.3 km
Nearest rain gauge
Council area
Arun District
Southern Water's own name for it
East Street Littlehampton CSO - 108004
Site reference
SWS00234 · permit A00858
Coordinates
50.80425, -0.54291

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 Bognor Regis and Littlehampton 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: © Southern 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. Spill-event history: Southern Water's Rivers and Seas Watch release history (riversandseaswatch.southernwater.co.uk), © Southern Water. Shown by FloodRadar: only releases Southern Water marks Genuine and that have ended; those it marks Not Genuine or still has under review are left out. Discharges marked "via Top of the Poops", 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.