Sewage is continuing to spill into a tributary of the Thames from a water treatment works for the 16th day in a row.

The discharge from the Witney Sewage Treatment Works into the River Windrush was confirmed last night. The company has failed to reveal whether sewage is continuing to be released today.

The update was announced in an alert posted on social media site Twitter by @oxthamessewage, which uses information from water company Thames Water, Oxford City Council and charities Thames 21 and The Rivers Trust.

The tweets are posted by Mid-Thames End Sewage Pollution Group who are working with Thames Water, and tweet the notifications the company emails to local community groups as part of its Oxfordshire notifications trial.

Treatment works are only allowed to put sewage into waterways after wet weather and when they are close to capacity.

Foraging group Oxfordshire Wild commented: "Super poopers! Impressive 16 day streak from Thames Water."

There are plans for a protest on Port Meadow on January 23 to put pressure on Thames Water to invest in improved infrastructure.

Over the Christmas period sewage discharges from the works resulting in a Boxing Day swim downstream in Wolvercote being cancelled.

A Thames Water spokesperson said at the time: “We are very sorry to those people who have been unable to swim following sewage discharges, which have been due to our treatment works being at full capacity following heavy rainfall over the Christmas period and more recently.

"These weather events can result in more groundwater entering our sewer network in the area and while unacceptable to us, discharges are sometimes necessary and permitted to prevent flooding to homes, gardens, streets and open spaces."

Thames Water is currently increasing sewage treatment capacity in the area including sites in Oxford and Witney, and at Fairford and Ampney St Peter in neighbouring Gloucestershire.

Between 2020 and 2025 the company intends to spend £1.25 billion on maintaining and improving sites across the Thames Valley and in London.

The spokesperson added: “Our aim will always be to try and do the right thing for rivers and for the communities who love and value them. We’ll also work with the Government, Ofwat and the Environment Agency to accelerate work to stop discharges of untreated sewage being necessary.

“We have a long way to go – and we certainly can’t do it on our own – but the ambition is clear.”

The group of outdoor swimmers from Wolvercote, Oxford, were informed about the release into the River Windrush in an email from Thames Water.

Swimmer Dr Fiona Palumbo Tolan said the group found it "deeply distressing".

Dr Tolan said: "Every week we have to check for notifications of sewerage releases before being sure that it's safe to swim.

"It seems that what should be a very last resort in the case of extreme emergency has become a very common tactic of convenience for the water companies."

The Department for Environment, Food and Rural Affairs said: "Environment Agency staff respond to pollution incidents 24/7 to contain pollution and protect water quality.

"We would urge anyone who notices a pollution incident to call our hotline."