New wetlands have been created as part of plans sponsored by Thames Water to protect and enhance the River Evenlode.

However, concerned local residents say sewage pollution from the water company itself is causing many of the problems.

The River Evenlode is one of the headwaters of the River Thames, running through the rural communities of the Cotswolds.

The Smarter Water Catchments Initiative was launched at Magpie Farm in Chipping Norton with community leaders, developers and councillors.

The new wetland habitats were created by the partners of the Evenlode Catchment Partnership, including Thames Water, Atkins, the landowner, the Environment Agency and Natural England.

They have been designed to help reduce phosphorus run-off from farmland, create natural flood management and boost biodiversity and recreational opportunities.

The Smarter Water Catchments Initiative is a £3 million project that aims to bring together organisations, community groups and residents to improve ecological status of the River Evenlode and other rivers in the area, said Thames Water.

Richard Aylard, Thames Water sustainability director, said: “We are keen to play our full part in protecting and enhancing our precious rivers and streams – while there is still a long way to go, the ambition is clear.

“Working in partnership with local stakeholders we’ve set out our collective plans to improve the Evenlode’s Ecological Status by reducing pollution, restoring physical habitats and improving water quality."

However, concerned local residents say that data they have collected suggests that sewage pollution from the water company itself is causing many of the problems.

Local volunteers have been monitoring its impact and measuring phosphorus across the Evenlode catchment since early 2019.

Vaughan Lewis, of the Evenlode Catchment Partnership – a group of organisations who work together to protect the river – said: “The data they have collected shows significant and consistent changes in water quality between locations upstream and downstream of several of the sewage treatment works.

“Additional study by volunteers has shown more than 100 times the recommended maximum limit of the gut bacteria E.coli downstream of the sewage treatment works in Church Hanborough.

“High levels of phosphorous have consequences for the whole river ecosystem, affecting biodiversity and causing algal blooms that deprive other species of nutrients.”

At Milton-Under-Wychwood, one volunteer collected evidence that poor water quality is impacting insect populations.

He said: “Current actions in place to reduce raw sewage pollution are totally insufficient given the extent of the problem and projected local development - according to Thames Water, every 100 new houses will add an extra 30 tonnes of raw sewage to the network.

“Thames Water has allowed its sewage network to deteriorate over time due to lack of investment. We are now faced with a water quality emergency in our rivers with raw sewage regularly entering them, often illegally.

"The current investment plans from Thames Water are totally inadequate to turn this problem around, with the lack of robust regulation and enforcement by the Environment Agency compounding the problem.

"Change is urgently needed, and Thames Water need to step up.”