Dorking and Horley

Polluted by sewage 643 times in 2024 lasting 7,704 hours

Monitoring fell below 50% in some locations so could be more

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

Select Constituency

Select the constituency from the drop-down
✔ means we have experimental daily data since 2023

Live data for Dorking and Horley in 2025

So far this year (as of May 8, 2025, 5:15 PM) there has been 1,813 hours of sewage overflows

Totals for Dorking and Horley in 2024

18 Sites polluted by Thames Water
643 sewage dumps
7,704 hours duration
That's 10.7 months. On average 1.8 times a day

Change Over Time

Take Action

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

Daily Data

We get information about overflowing CSOs since January 2025. Here is a chart of the last three months of data for Dorking and Horley, here you can see overflows in red, the darker the red, the more the CSO overflowed that day.

Each CSO has a row, the most recent data is on the right hand side.

Monitoring Online
Monitoring Offline
Polluting
Potentially Polluting
Unknown
We need your support!

We managed to raise £150 in 2024. That's not enough to keep the site running. Please consider a one-off or small recurring donation.

Donate Now

Pollution Summary 2024

Here are all the reported sewage overflow totals for Dorking and Horley in 2024. Sometimes sewage can be being dumped for months at a time.

Reporting refers to how much of the time the monitoring was active. In this constituency 1 of the total 19 CSO locations had reporting enabled for less than half the year.

Company Waterway Site Sewage Dumps Duration (Hours) Reporting %
Thames Water Burstow Stream BURSTOW STW, HATHERSHAM ROAD, SMALL 133 1,758 99.6
Thames Water Holmwood Stm Leigh Brk HOLMWOOD SEWAGE TREATMENT WORKS 107 1,630 99.9
Thames Water Mole LEE STREET 91 1,444 99.7
Thames Water River Mole DORKING STW (STORM) 69 978 99.5
Thames Water River Mole IRONSBOTTOM (SIDLOW) WWTW 63 858 86.2
Thames Water Mans Brook CHARLWOOD, SURREY 35 268 98.5
Thames Water River Mole Brockham Bridge 15 122 99.9
Thames Water Thornhurst Brook Canfold Wood 26 122 99.9
Thames Water River Mole COACH ROAD CSO ON STONEBRIDGE SEWER 11 121 36.3
Thames Water Mole CASTLE GARDENS SPS 12 119 100
Thames Water Deanoak Brook CSO AT CAPEL SPS 22 89 99.4
Thames Water Into Land Box Hill 9 46 90.6
Thames Water Bookham Brook Commonside 13 37 99.8
Thames Water Tanners Brook SPOOKS HILL, NORTH HOLMWOOD, SURREY 12 36 99.9
Thames Water Salfords Stream SALFORDS SEWAGE PUMPING STATION 8 35 99.9
Thames Water Cobbler'S Brook Ockley Road 7 17 100
Thames Water Mole RIVER LANE PUMPING STATION, FETCHAM 6 10 99.5
Thames Water Tanners Brook SURFACE WATER SEWER 4 8 100
Thames Water Deanoak Brook Dean Oak Lane 0 0 100

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. This 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.