Water companies launch new live sewage spill maps

Several water companies finally launched their own live sewage spill maps, an important step but we still have some way to go before we have a full picture of the storm overflows issue.

Matthew Woodard


You will remember that we have been reporting live sewage spill data on our Sewage Map from Thames Water for the last year.

This week, several other water companies finally launched their own live sewage spill maps. While this is an important step towards greater transparency and accountability, there is still some way to go before we have a full picture of the storm overflows issue. There are still problems with the data, some maps are currently only reporting spills near bathing water sites, the data is not in a standardised format making it hard to compare water companies and there is little transparency and openness about the process the data has been through before being shared.

Explore the live sewage spill maps that are now available:

Thames Water has had their Storm Discharge Map active for a year.

Water companies are publishing these live maps due to a requirement under The Environment Act 2021 to report on storm overflow discharges within an hour of them starting. Until recently, only Thames Water made their live data available, so it is good to see more companies stepping up to the mark. Disappointingly, there are still water companies dragging their feet on live reporting; we urge them to catch up with the pack.

In the State of Our Rivers Report 2024, we highlighted the significant impact that storm overflow discharges have on the health of our rivers in England and Wales; 11% of English river stretches failed to achieve good overall health due to untreated sewage spills. It’s therefore vitally important that we get a better picture of when and where these spills are happening through these live maps.

That being said, there are still significant gaps and missed opportunities in the data being published. We would like to see water companies collaborating on a single, centralised map that shows all spills in one place, rather than having individual maps tucked away in company websites. Additionally, all the maps are using different language to describe spills and some maps make it hard for users to see individual overflow points. A single map, using consistent language, would be more transparent and accessible to the public. The Rivers Trust is working to update our map to compile this live reporting, but a lack of standardised and openly available data sets across water companies makes this a complicated process.

The data that is being reported on in these maps is relatively surface level, only telling us when and for how long storm overflows are operating. Without any information about the contents of the spill and its volume, we can’t say much about the severity of the spill itself and how it may impact the environment, or public health. Some water companies have started adding extra information to their maps, for example about weather conditions, which helps us to understand why overflows are spilling and should become the norm. If we are to truly tackle the impact of untreated sewage spills on our rivers, we need more complete data about what is making up these spills, how they are impacting receiving waters, and what effect they are having on river health.

Live sewage spill data from all water companies in England and Wales would be a significant step forward in the debate about sewage pollution that has captured both public and political attention in recent years. The Rivers Trust plans to update our Sewage Map later this year to bring live data from all water companies together in one place; we will continue to urge companies to provide their data in an open format to make this possible. In the meantime, we will maintain pressure on lagging water companies to publish their complete live sewage spill data (not just for bathing water sites). We will engage with the companies themselves, regulators, and Government, around the importance of publishing water quality data for sewage spills.

What you can do right now:

You can check out your water company maps and let them know that you care on their websites.

You can also contact your locally elected representative using the helpful tool on our website and let them know how much you care about the state of our rivers.

Email your political representative

Back to top