It's a Dirty Business

Watch Channel 4's documentary about the state of the water industry, then sign the petition to bring water back to public ownership.

Chippenham - 2025 Sewage

Polluted by sewage 3,814 hours in 2025 , monitoring offline 8,289 hours , potential overflows 6 hours

© OpenStreetMap contributors
Contains OS Data © Crown copyright & database right 2021-2024
© Top of the Poops 2021-2024

Which Year?

Select Another Constituency

Select the constituency from the drop-down
✔ means we have live data (𝑥 if not)

View Annual Sewage Data

You're looking at the totals that we have calculated for sewage in Chippenham for 2025. It is an estimate, based on very poor quality live data from the Water Companies. This may not align with the 'official' reported sewage values from the water companies, which is reported in April following then end of the year - so 2025 numbers are reported in April 2026.

What's a potential overflow? If the CSO goes 'Offline' while its Overflowing, we don't know if it stopped overflowing until we get a 'Stop' event.

Take Action

Your local MP is Sarah Gibson (Liberal Democrat) - Find out more about their interests, donors, and voting at They Work For You

Share this page, post a message, and tell others about the huge problem of sewage pollution across the UK

Daily Data

Jan - 1,054 hours , 192 offline
Feb - 1,014 hours , 6 potential
Mar - 312 hours , 688 offline
Apr - 4 hours , 720 offline
May - 2 hours , 744 offline
Jun - 9 hours , 720 offline
Jul - 7 hours , 744 offline
Aug - 0 hours , 744 offline
Sept - 7 hours , 749 offline
Oct - 10 hours , 744 offline
Nov - 391 hours , 1,045 offline
Dec - 997 hours , 1,172 offline
We need your support!

Please consider a one-off or small recurring donation. We need your help to keep this site going.

Donate Now

Totals so far

Company Site Name Receiving Waterway Overflow Days Total Duration (hours) Offline/Potential Pollution
Wessex Water COMPTON BASSETT THE POND Abberd Brook 53 1,145h 10m 6 h
Wessex Water CHIPPENHAM BLACKWELL HAMS STORM TANK River Avon 22 320h 6m -
Wessex Water CHIPPENHAM BLACKWELL HAMS STORM TANK River Avon 17 240h 2m -
Wessex Water THINGLEY COPPERSHELL LANE STORM TANK Byde Mill Brook/River Avon 13 213h 55m -
Wessex Water THINGLEY COPPERSHELL LANE STORM TANK Byde Mill Brook/River Avon 17 196h 37m -
Wessex Water LYNEHAM B SITE (MAIN STW) RAF LYNEHAM STORM TANK Springs Watercourse 12 164h 28m -
Wessex Water CALNE STORM TANK River Marden 14 138h 57m -
Wessex Water COMPTON BASSETT STORM TANK Rivers Brook 10 119h 29m -
Wessex Water ROYAL WOOTTON BASSETT STORM TANK Hancock'S Water 10 117h 44m -
Wessex Water CALNE STORM TANK River Marden 9 101h 19m -
Wessex Water CHIPPENHAM GASTONS ROAD Hardenhuish Brook 29 99h 15m -
Wessex Water ROYAL WOOTTON BASSETT STORM TANK Hancock'S Water 6 98h 20m -
Wessex Water CALNE MOSSES MILL X River Marden 25 93h 6m -
Wessex Water CHIPPENHAM GASTONS ROAD Hardenhuish Brook 18 90h 44m -
Wessex Water COMPTON BASSETT STORM TANK Rivers Brook 7 73h 8m -
Wessex Water LACOCK STORM TANK Bristol Avon 5 60h 22m -
Wessex Water CALNE MOSSES MILL X River Marden 17 51h 36m -
Wessex Water LYNEHAM B SITE (MAIN STW) RAF LYNEHAM STORM TANK Springs Watercourse 8 50h 3m -
Wessex Water CHIPPENHAM HIGH STREET O/S XX River Avon 31 46h 23m 29 h
Wessex Water CHIPPENHAM HIGH STREET O/S XX River Avon 16 45h 48m -
Wessex Water CHIPPENHAM WESTMEAD River Avon 2 38h 22m -
Wessex Water CHIPPENHAM BRISTOL ROAD Hardenhuish Brook 16 36h 4m -
Wessex Water LACOCK STORM TANK Bristol Avon 5 28h 58m -
Wessex Water COMPTON BASSETT THE POND Abberd Brook 3 27h 52m -
Wessex Water ROYAL WOOTTON BASSETT NEAR STW Hancock'S Water 9 26h 14m -
Wessex Water CHIPPENHAM BRISTOL ROAD Hardenhuish Brook 13 26h 10m -
Wessex Water CHIPPENHAM WESTMEAD River Avon 3 25h 39m -
Wessex Water CALNE INLET River Marden 8 24h 9m -
Wessex Water CALNE INLET River Marden 6 17h 13m -
Wessex Water CHIPPENHAM MONKTON PARK OFFICES River Avon 2 16h 12m -
Wessex Water CALNE MARDEN HOUSE CULVERT AT REAR River Marden 3 13h 36m -
Wessex Water LACOCK NETHERCOTE HILL Byde Mill Brook 2 12h 48m 753 h
Wessex Water ROYAL WOOTTON BASSETT NEAR STW Hancock'S Water 10 12h 46m -
Wessex Water TOCKENHAM INLET Cowage Brook, 3 11h 22m -
Wessex Water CHIPPENHAM BLACKWELL HAMS INLET River Avon 1 6h -
Wessex Water CHIPPENHAM XX LONG CLOSE River Avon Via Sws 6 5h 26m 6,976 h
Wessex Water CHIPPENHAM MONKTON PARK OFFICES River Avon 4 4h 26m -
Wessex Water CHIPPENHAM THE IVY River Avon 1 3h 34m -
Wessex Water CALNE MARDEN HOUSE CULVERT AT REAR River Marden 5 2h 54m -
Wessex Water THINGLEY COPPERSHELL LANE INLET Byde Mill Brook/River Avon 1 2h 9m -
Wessex Water CALNE STRAND / CHURCH STREET River Marden 5 1h 58m -
Wessex Water CALNE STRAND / CHURCH STREET River Marden 1 1h 6m -
Wessex Water CALNE RIVER MARDEN (RIVER BANK) SOUTH MARDEN HOUSE NEW ROAD River Marden 1 0h 58m -
Wessex Water CHIPPENHAM WOOD LANE River Avon 1 0h 46m -
Wessex Water TOCKENHAM INLET Cowage Brook, 2 0h 32m 192 h
Wessex Water LACOCK NETHERCOTE HILL Byde Mill Brook 1 0h 14m -
Wessex Water CHIPPENHAM WOOD LANE River Avon 1 0h 8m -
Wessex Water THINGLEY COPPERSHELL LANE INLET Byde Mill Brook/River Avon 1 0h 3m 1 h
Wessex Water CALNE OXFORD ROAD / WOOD STREET River Marden Via Sws 0 0h -
Wessex Water CALNE MOSSES MILL 1 River Marden 0 0h -
Wessex Water Unknown Unknown 0 0h -
Wessex Water Unknown Unknown 0 0h -
Wessex Water CALNE RIVER MARDEN (RIVER BANK) SOUTH MARDEN HOUSE NEW ROAD River Marden 0 0h -
Wessex Water CHIPPENHAM COMMONS SLIP River Avon 0 0h 335 h
Wessex Water CHIPPENHAM BLACKWELL HAMS INLET River Avon 0 0h -
Wessex Water CALNE OXFORD ROAD / WOOD STREET River Marden Via Sws 0 0h -
Wessex Water CHIPPENHAM DALLAS ROAD Hardenhuish Brook 0 0h 0 h
Wessex Water CALNE MARKET HILL / STRAND River Marden Via Sws 0 0h -
Wessex Water CHIPPENHAM DALLAS ROAD Hardenhuish Brook 0 0h -
Wessex Water CALNE MOSSES MILL 1 River Marden 0 0h -
Wessex Water CHIPPENHAM COMMONS SLIP River Avon 0 0h -
Wessex Water Unknown Unknown 0 0h -

Data Sources & Accuracy

EDM (Event Duration Monitoring) data and Consented Discharges to Controlled Waters with Conditions from Environment Agency & Data Map Wales, and Scottish Water

Experimental derived data from Thames Water API, Some data may be missing or inaccurate. Live sewage data from Stream Water API

Annual figures up to and including 2025 come from official water company returns. The 2026 figure is our own estimate, derived continuously from the companies' live data feeds.

Uses Environment Agency rainfall data from the real-time data API (Beta) - Rainfall data is delayed by up to two days.

This website is intended to provide an accurate representation of the Environment Agency data. The data is hard to use, and thus some errors may have been made. If you find something that is incorrect, please raise an issue at the GitHub issues page and we'll endeavour to fix it quickly.

This project is not associated, approved or endorsed by any of the companies whose logos you see here.