Half a million homes could be swamped by Thames surge

MORE than half a million London properties are at risk of flooding.

Hundreds of thousands of homes could be left underwater if rivers burst their banks or a tidal surge hit the Thames, the Environment Agency said.

The research provides the most detailed picture yet of the flood dangers facing London.

Experts from the Agency revealed that nine out of 10 homes in Hammersmith and Fulham could be left underwater.

In Southwark almost seven out of 10 buildings could be submerged and at least half of all properties in Newham are vulnerable.

In total 563,783 London buildings are in danger from floods, according to the State of the Environment report.

It comes two weeks after torrential downpours triggered almost 100 flood warnings across the capital.

An agency spokesman said: "Londoners need to be prepared as floods can occur at any time from prolonged rainfall to storms."

He added: "The risk of flooding can be reduced by adapting buildings."

He warned that just five per cent of the properties in the flood "danger zone" have signed up to the agency's warning service, which sends advance alerts by phone, text, email, pager or fax. Flood warnings are also broadcast on local radio stations. A spokesman for Hammersmith and Fulham council said the figures were "worrying".

Less than one per cent of the borough's buildings in danger are registered for flood warnings.

The report does not include homes on higher land that could be swamped by surface water if heavy downpours block drains.

It means the true number of properties at risk could be far higher than the 563,783 figure.

Jeff Hook, Southwark council's executive member for the environment, said: "An incident involving a breach in our Thames flood defences could have a severe impact on the borough.

"The council has a tried and tested emergency scheme in operation and regularly trains and exercises with our emergency services partners."

About 1.25million people live in London's flood plain - an area of 57sqmiles which lies below the high-tide line.

Most of these homes are classed as low-risk, which means they could be flooded on average once every 200 years. The Environment Agency said defences such as the Thames Barrier helped reduce danger but could not eliminate the risk.

The barrier has been raised 114 times since the Eighties, but 75 of these have been since 2000.

In 2007/08, £29million was invested in improving the barrier and other flood defences, reducing the flood risk for 8,450 properties.