WaterWatch — Thames CSO Monitor

WaterWatch

Thames Water Region · Live Intelligence

Live data on

WaterWatch surfaces every Combined Sewer Overflow in the Thames Water region in real time — discharge history, site rankings, live alerts, river levels, and a weekly roundup with rainfall context. All sourced directly. Nothing added.

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New2025 annual discharge data is now available · View rankings →

·Network dashboard now live · Explore →

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Sites discharging now

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Discharged past 48hrs

Thames CSO sites monitored

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EA data update interval

What WaterWatch does

One platform. Every overflow. All the data.

Live now

Complete visibility from day one.

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Live discharge map

Every active CSO event plotted in real time, sourced directly from Thames Water EDM sensor data. Updated every 15 minutes.

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Per-site history

Drill into any overflow point for a full record of discharge events — start time, duration, and total hours spilling by month and year.

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Instant alerts

Get notified by email or SMS the moment a discharge event is recorded at a site you follow. Free, no spam, unsubscribe anytime.

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CSV export

Download raw discharge data for any site or date range for your own analysis.

Live

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Site rankings

Every Thames Water CSO site ranked by total spill hours and event count. Sort by year, time window, or river.

See whether each site is improving or worsening. Year-on-year percentage change, colour-coded clearly.

A Monday morning email with total spill hours, worst sites, most-impacted rivers, and rainfall context.

Explore →

Live

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River & rainfall data

Live river levels and rainfall from EA gauging stations put every discharge event in environmental context.

Explore →

How it works

From sensor to your inbox in minutes.

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Thames Water logs it

EDM sensors at each CSO site record when discharge starts and stops, reporting to us every 15 minutes.

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We ingest it

WaterWatch pulls the latest readings continuously and detects the moment a site transitions to discharging.

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Map updates live

The discharge map reflects the current state of every monitored site in real time — no refresh needed.

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You get notified

If you're subscribed to a site, we fire an alert the moment we find it starts or stops discharging.

Our approach

Data as it is. Nothing added.

WaterWatch does not editorialise or layer interpretation on top of the numbers. All data originates from Thames Water's EDM sensor network — the same data they are legally required to submit to regulators. We display what is recorded. You draw your own conclusions.

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Source-attributed

Every data point links back to the Thames Water EDM sensor and permit reference it originated from.

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Numbers, not narratives

We show spill counts, durations, and cumulative hours. No severity scores or hidden weightings.

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Timestamped as reported

Events are shown with the timestamp Thames Water logged them — not when WaterWatch ingested them.

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Limitations disclosed

EDM sensors have documented failure rates. We surface missing or flagged readings rather than silently filling gaps.

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Know the moment it happens.

Subscribe to any CSO site and get an instant alert when discharge starts or stops. Email and SMS supported. Free, no spam, unsubscribe any time.

Or browse the map and click any site to subscribe