Storm discharge data

We want to be open and transparent about our storm discharge activity. That's why you can now access storm discharge data from event duration monitoring (EDM) in three ways: 

• An interactive map showing storm discharge activity as indicated by our EDM monitors
• Annual storm overflow activity reports showing you data from previous years
• A third party API, so you can integrate our data into your own systems

Storm discharge map

This map shows you near real-time storm discharge activity, as indicated by our EDM monitors.

You can use the map to see if our monitors indicate:

• That overflows are currently discharging into a watercourse
• The date, time and duration of the last recorded discharge

Although EDM gives us valuable insight to how our storm overflows are working, it isn't always accurate. The monitors are sensitive and can play up. Even the movement of a weed growing in front of the monitor could set it off, indicating that the overflow is active when it isn't.

So when a monitor triggers, we can’t say that a certain section of the watercourse definitely contains sewage, or promise that it’s safe to swim in. EDM doesn't confirm discharges, it only indicates them because the data received might not be accurate. We're being open and sharing our data exactly as we receive it, so you can make more informed choices.

See our storm discharge map

Data quality

We'll be open and transparent if we discover any issues with the quality of our data. See a list of data quality incidents here. 

Got any questions?

Take a look at our frequently asked questions page for further information. 

Annual reports

Our annual reports show the number of times storm overflows were active and for how long, as indicated by EDM monitors. This is updated by mid-March with data from the previous calendar year.

How to integrate our data

We're excited about the possibilities that open data provides for our customers and the water industry. We want to lead the way, so we've set up an application programme interface (API) to connect third parties to our publicly open storm discharge data. Our API can be used to integrate our data into your application.

Find out about our third party API.