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Dorking and Horley was polluted by sewage 596 times in 2023
lasting 7,120 hours
- but monitoring was disabled in some locations, so could be more

© OpenStreetMap contributors
Contains OS Data © Crown copyright & database right 2021-2023
© Top of the Poops 2021-2023
✔ means we have experimental daily data since 2023
Totals for Dorking and Horley in 2023
19 Sites polluted by Thames Water
596 sewage dumps
7,120 h duration
That's 9.89 months. On average 1.6 times a day
Change Over Time
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Daily Data Since 2023
     Monitoring Online      Monitoring Offline      Polluting      Potentially Polluting      Unknown
Daily data is experimental and data is not guaranteed to be accurate. Please inform us of any issue, we will fix.

Pollution Summary 2023

Here are all the reported sewage overflow totals for Dorking and Horley in 2023. 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 3 of the total 22 CSO locations had reporting enabled for less than half the year, of which 3 had zero reporting.

Company Waterway Site Sewage Dumps Duration (Hours) Reporting %
Thames Water Holmwood Stm Leigh Brk HOLMWOOD SEWAGE TREATMENT WORKS 118 1,997 99.8
Thames Water Burstow Stream BURSTOW STW, HATHERSHAM ROAD, SMALL 126 1,370 99.9
Thames Water Mole LEE STREET 80 1,240 97.7
Thames Water River Mole DORKING STW (STORM) 71 920 100
Thames Water River Mole IRONSBOTTOM (SIDLOW) WWTW 34 623 99.2
Thames Water Mans Brook CHARLWOOD, SURREY 41 328 87.3
Thames Water River Mole COACH ROAD CSO ON STONEBRIDGE SEWER 19 154 50.4
Thames Water Deanoak Brook CSO AT CAPEL SPS 24 138 75.3
Thames Water Thornhurst Brook Canfold Wood 23 124 97
Thames Water River Mole Brockham Bridge 8 50 97.3
Thames Water Cobbler'S Brook Ockley Road 9 45 92
Thames Water Mole CASTLE GARDENS SPS 5 32 76.1
Thames Water Salfords Stream SALFORDS SEWAGE PUMPING STATION 7 25 99.3
Thames Water Into Land Box Hill 11 20 70.1
Thames Water Mole RIVER LANE PUMPING STATION, FETCHAM 4 18 99.8
Thames Water Deanoak Brook Dean Oak Lane 7 12 100
Thames Water Tanners Brook SPOOKS HILL, NORTH HOLMWOOD, SURREY 6 9 97.1
Thames Water Bookham Brook Commonside 2 8 96.1
Thames Water Tanners Brook SURFACE WATER SEWER 1 1 99.3
Thames Water Bents Brook Bentsbrook Road, Dorking 0 0 0
Thames Water Burstow Stream Burstow 0 0 0
Thames Water Mole Horley Road, Charlwood 0 0 0

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.