Thames Water plans to start a £3m scheme within weeks to stop sewage flowing through streets at Marston, Oxford.

The scheme has been welcomed, but described as long overdue.

As reported previously in the Oxford Mail, the work follows experiments in sewers across the city using CCTV and monitoring instruments to check the levels of waste water in pipes.

The scheme features two 18.5m-deep underground storage tanks which will take excess water that has previously flooded Ferry Road and Edgeway Road during heavy rainfall.

When water levels subside, they will activate a sensor to trigger pumps, which will transfer waste from the tanks to the sewerage network.

Thames Water experts believe the tanks, expected to be placed near Croft Road and Maltfield Road, will reduce the threat of flooding to 15 homes.

The company also hopes they will be big enough to cope with the extra capacity needed for extensions at the John Radcliffe Hospital, including the new Children's Hospital.

It is hoped they will also protect Bayswater Brook, Peasmoor Brook, the River Cherwell and New Marston Meadows, a nearby Site of Special Scientific Interest.

Council planning officer Paul Semple said: "The hospital is a prime reason why Thames Water had to look at these issues."

Mary Clarkson, a city councillor for Marston, said: "This is very welcome but long overdue. It's being done due to the constant nagging of local people and councillors."

Work is expected to start in September and take until June 2005. Andrew Baines, Thames Water's project manager, said: "This essential work will help ensure the sewer network can cope with the pressures of development for years to come."

Roy Darke, of Marston Residents' Association, said Edgeway and Ferry Roads had flooded on Thursday (July 8) during heavy rain. He said: "Thames Water have told me about their plans. We've needed this for 25 years."

Thames Water is continuing investigations into flooding in west Oxford, and will publish its findings later this year.