Oxford Rivers Project

For up-to-date information on rivers in Oxfordshire, including sewage spills, river levels, flood warnings, water quality and more, check out the Oxford Rivers Portal!

Oxfordshire is a county interlaced with numerous waterways, from trickling Thames headwaters, to bubbling Cotswold rivers, clear chalk streams and smooth straight canals linking us with the Midlands and beyond.

Oxford is a city threaded with two rivers (the Thames and the Cherwell) and many other streams. Thousands of people – residents, tourists and students alike – take to the rivers for swimming, rowing, kayaking, punting and boat trips every year, and many more regularly walk, run or picnic on riverbanks.

The Oxford region has numerous nature reserves and has been identified as an “important freshwater area” for its freshwater biodiversity. Its floodplain meadows are protected nationally as a “special area of conservation”. Over 70% of our drinking water comes from our rivers.

Yet despite this, our rivers and waterways are in a bad state, with only 2 out of 48 waterbodies classed as in good ecological health (4%).

Like many other areas of the country, the rivers are struggling due to pollution from both untreated and treated sewage, agriculture, road run-off, plastic and ‘forever’ chemicals. River barriers prevent fish migrating, and inappropriate development, habitat loss and invasive species lead to declines in freshwater wildlife and plants.

Thames21 in Oxfordshire brings together people who love their local rivers and streams to take action. The three aims of the project are:

To increase the community’s awareness and understanding of rivers and what makes them healthy;
Monitor river health and pollution using citizen science;
Improve local rivers and streams through direct habitat improvements or working with others to stop pollution (e.g. raw sewage).

We currently have three active projects:

Cherwell and Ray Water Watchers (since September 2023)

Our water watchers go out once a month to monitor the health of their local river or stream in the Cherwell & Ray catchment. The data they collect is used to identify sources of pollution and focus on areas which need to be improved, and help us advocate for our river.

Do you think you could join them? The test itself only takes around 20 minutes a month. All equipment and training provided, and you get access to a community of like-minded people and events.

If you live in or around Marston, Kidlington, Bicester or Banbury, we would love to hear from you! Contact Claire at claire.robertson@thames21.org.uk.

Find out more about the Cherwell & Ray catchment partnership in our storymap.

View all our citizen science results from the Banbury area and the lower Cherwell & Ray.

Ock, Abingdon & Oxford Water Watchers (since January 2025)

If you live in central, East & South Oxford, Abingdon, Didcot or the Vale of White Horse, this is the scheme for you!

Water watchers go out once a month to monitor the health of their local river or stream in the Ock catchment. The data they collect is used to identify sources of pollution and focus on areas which need to be improved, and help us advocate for our river.

At some sites on the Thames, we test for bacteria in the river which helps people know how clean the river is for swimming and other watersports.

Do you think you could join them? The test itself only takes around 20 minutes a month. All equipment and training provided, and you get access to a community of like-minded people and events. Contact Claire at claire.robertson@thames21.org.uk if you want to take part.

View our results here: Ock, Abingdon & Oxford Water Watchers.

Sustainable governance for rivers (GOVAQUA)

Thames21 is part of a Europe-wide project to improve river governance: who makes decisions about how rivers are used, how they make those decisions, and who benefits.

Oxfordshire is a “Living Lab” for this project and is supported by the Rivers Trust and the UK Centre for Ecology and Hydrology.

The aim of our project is to increase accountability for river pollution through digital tools and open data.

We have created the Oxford Rivers Portal to help everyone who lives in the area, from dog-walkers to local councillors to environmental managers, better understand the water quality in the rivers and how it changes day to day and over the course of years.

We run regular webinars and events explaining water quality and how to use the portal: check out our events page here.

Oxford and the surrounding area straddles five different river catchments. Thames21 co-hosts the Cherwell and Ray catchment partnership, and we currently also work in the Ock Catchment. We actively work with other local catchment partnerships, such as the Evenlode, Windrush and Thame as well.

We partner with many other environmental charities & organisations, including Berks, Bucks & Oxon Wildlife Trust, Earthwatch Europe, the Freshwater Habitats Trust, Community Action Groups Oxfordshire and the UK Centre for Ecology and Hydrology.

Past projects

In 2020, a concerned group of locals formed a campaign group after realising how frequently sewage was being discharged into the Thames upstream of Oxford.

By October 2020, more than 5,000 residents had signed a petition calling for a ‘designated bathing water area’ in Oxford, regular testing for bacteria, alerts of raw sewage spills, and improvements to the wastewater system.

Oxford City Council, The Rivers Trust and Thames Water all provided funding and in-kind support for the project, which ran throughout 2021, and Thames21 hosted the project.

The project kept the original aims of the petition, which, we are proud to say, have now all been achieved or are promised:

A designated bathing water area: in April 2022, Wolvercote Mill Stream at Port Meadow, Oxford, was only granted bathing water designation: only the second river site in the UK to achieve this. The designation puts a legal duty on the Environment Agency to test for bacteria pollution every week in the summer, and on Thames Water to stop sewage spills and improve water quality upstream.
Regular testing for bacteria: from January to December 2021, volunteer citizen scientists collected river water samples from 18 locations in and around Oxford, including 8 popular recreational areas. The levels of bacteria were then tested at Thames Water labs. Only 1 site passed the standards for bacteria pollution. Read a summary and download the full report here: https://endsewagepollutionthames.wordpress.com/water-quality-testing/
Alerts of raw sewage spills: after testing sewage alerts at six Oxford sites in 2021, Thames Water rolled out live sewage spill alerts across its region in January 2023, and now gives alerts for 619 sites.
Improvements to local wastewater treatment works: in November 2023, Thames Water released plans to put UV disinfection on 3 sewage treatment works upstream of Port Meadow (Cassington, Stanton Harcourt and Church Hanborough) to decrease the bacteria load going into the river. Thames21 are advocating for nature-based solutions like treatment wetlands as well.

If you have any questions about Thames21’s work in Oxford, past, present or future, please contact claire.robertson@thames21.org.uk