Thames Water is in the dock after admitting to releases of sewage and polluted storm water into the Thames at Hammersmith, Isleworth and Petersham.

The privatised water giant said high rainfall over the weekend meant its sewer system could not cope.

As a result, it tweeted a warning to rowers and other river users on Sunday evening, saying : "Following the recent rainfall, Hammersmith Pumping Station has in the last hour discharged untreated sewage into the River Thames, due to lack of capacity in the existing sewer network."

The release of the untreated sewage took place for over four hours on Sunday afternoon through to the evening.

Given the tidal nature of the river through Brentford, there is a risk that pollution would have been carried down stream towards Hounslow.

In a separate alert, Thames Water, revealed a release of sewage storm water from the Mogden water treatment works, which has an outlet into the Thames on the Isleworth bank opposite Old Deer Park. This ran for more than 10 hours – from 5.45pm on Sunday through to around 4am on Monday.

Thames Water's live event duration monitoring (EDM) storm discharge map reveals pollution incidents.

Thames Water said: "Following recent persistent rainfall, Mogden Sewage Treatment Works is continuing to discharge heavily diluted storm water into the River Thames."

In the past, storm water releases from Mogden have caused serious pollution in the Duke of Northumberland river, which runs towards the Thames.

Thames Water's live event duration monitoring (EDM) storm discharge map also revealed that storm water was discharged into the Thames at Petersham for 1hr and 45mins in the early hours of Monday.

Horrified residents hit out at the discharges in response to the announcements.

One said described the releases as 'absolutely awful' and another said it was a 'disgusting example' of a failure by Thames Water and the government to protect rivers.

The river clean-up campaigner, Feargal Sharkey, has been critical of Thames Water and accuses the government of allowing water companies to get away with routine pollution of waterways and beaches.

He pointed to a large number of sewage and storm water discharges over the weekend across the company's area, saying: "Remember, this government … has made this legal so long as the water company can argue that they are doing something to 'Reduce the adverse impacts'."

Thames Water said: "Taking action to improve the health of rivers is a key focus for us, but we also need to explain what is happening, and why.

"After a successful trial in the Oxford area, we have decided to provide close to real-time information about storm discharges from all of our 468 permitted locations. This is a key part of our River Health Action Plan to radically improve both performance and transparency in order to protect and improve the environment.

"We are absolutely committed to protecting and enhancing our rivers and the communities who love them."

The sewage discharge map can be found here – https://www.thameswater.co.uk/edm-map