Thames Water storm overflows
585 storm overflows · 543 with a live status feed · regulated by the Environment Agency.
Discharging now
From Thames Water's live monitor feed, longest-running first.
Year by year
Spills reported across all of Thames Water's monitored overflows.
More overflows were monitored each year (383 in 2021, 574 in 2025), so part of any rise is more monitors, not only more spilling.
Official Environment Agency Event Duration Monitoring returns, 12/24-hour counting method (the first 12 hours of a discharge count as one spill, each further 24 hours as one more). Earlier years are matched to today's overflows by name and location, because the EA's site IDs changed between returns; a site that could not be matched is left out of that year rather than guessed.
Most spills in 2025
The overflows that spilled most often. A red tag means discharging right now.
Rivers and seas it discharges into most
Spills in 2025 from Thames Water's overflows, by receiving water (names grouped approximately).
Concerned about an overflow?
Report pollution you can see to the Environment Agency on 0800 80 70 60 — they log and investigate incidents. Complaints about a company's service go to the company first.
Live status: © Thames 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. FloodRadar republishes the monitors' status and the published figures; it does not measure discharges itself, and a monitor reports a discharge, not its volume or its cause.