Study launched into new £20bn barrier, amid fears that the existing system is not enough to hold back future floods

Government ministers are studying plans for a second Thames barrier to save London from potential flooding. The plan is part of a wider initiative to protect vital infrastructure from flood damage, including all major police, fire and power stations.

Flood experts have warned that the current Thames barrier may not be able to cope with rising tides by 2030. And since its completion in 1983, the chances of London flooding has doubled, from a one in 2,000 estimate to one in 1,000.

The second barrier would be positioned farther east than the existing system at Woolwich, which has had a dramatic increase in the number of times it has been put into use recently. It was initially used on average every couple of years, but following the bad weather conditions to have hit Britain, the defence system was operated a 19 times in 2003.

The minister for environment, Phil Woolas, told the Sunday Telegraph that the feasibility study into the second barrier by the Environment Agency was due to report in a matter of weeks and that a decision would be made "some time next year".

Woolas also revealed that during the July floods this year, the Welham sub power station in Gloucestershire was one and a half inches from flooding. He said: "Had it flooded it would have been the biggest peace time evacuation in this country in history." But he added that recent flooding disasters will force the public to wake up to the threat, "The public need to understand that the point of no return is seven and a half years away," he said. "People accept that it is a real threat but they don't realise the imminence of it. Hopefully if there is any good that comes out of the floods it will be that recognition."