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River health

We want to do the right thing for our rivers and the communities that love them. We're committed to protecting and enhancing them.

Putting untreated sewage into rivers is unacceptable to us, to our customers and to the environment. But after heavy rain, it is sometimes necessary, and permitted, as a last resort to prevent it from flooding homes, gardens, streets, and open spaces. We're working hard to make these discharges unnecessary, with the help of the government, Ofwat and the Environment Agency.

Future plans

Our plans for the next few years to reduce the harm to river water quality from our wastewater activities are set out in this summary document. You can also read the full report.

Our plans include ensuring that we discharge high-quality treated effluent that meets all required standards, work towards eliminating polluting discharges to our rivers and work with partners to improve river water quality.

The investment that the Environment Agency and Natural England requires us to make through the Water Industry Environmental Programme (WINEP) is summarised in this report. Further detail can be found in this spreadsheet.

Also included in our plans is increasing the treatment capacity of many of our sewage treatment works, including in Oxford and Witney, increasing the storage capacity of some of our storm tanks and updating our sewer network in areas where it is affected by groundwater flowing into it.

You can learn more about these proposals in our groundwater plans and our Drainage and Waste Water Management Plan.

What we’re doing to help river users

While we work on those plans, we want to help river users know when we're having to make releases, so they can make informed decisions about their activities. We’re currently trialling notifications in Oxfordshire and we have a manual system in place for part of the River Thames.

To learn more about how we treat wastewater, look at our sewage treatment process.

Oxfordshire notification trial

We’re testing automatic release notifications to local community groups in the Oxfordshire area.

These notifications use information from the Event Duration Monitors (EDMs) on our network to send a daily email whenever the data indicates there's likely to have been a release. We’re working to make the notifications as close to ‘real time’ as possible.

Sign up for notifications

See the locations covered by the notifications on our map:

River Thames rower notifications

We have a manual alert system in place on the River Thames.

The notifications cover Mogden Sewage Treatment Works and Hammersmith Pumping Station. They let river users know when we’re releasing sewage, due to heavy rain.

Email us to register for these alerts.

Once the Thames Tideway Tunnel is completed, the number of releases from Hammersmith Pumping Station will be significantly reduced.

Using rivers safely

There are several safety factors to think about when swimming in rivers.

If you've had a notification that we've made a discharge, then this could take up to four days to clear. This should be considered if you’re planning when and where to enter the water.

There's more advice in the Swim Healthy leaflet from Public Health England and the Environment Agency.

Annual data

You can see our annual report showing the number of times sewage has been released and for how long. This is based on data from monitors on our network.

If you would like to know more about this data, you can email us.