The Environment Agency expects the risks of flooding to rise significantly during this century.

Climate change is being blamed, as well as poor maintenance of the flood prevention system and dabbling in nature, such as concreting over the countryside which acts as a natural drainage system and trying to re-route rivers.

Lax planning permission has also resulted in half the new housing since World War Two being built on flood-prone land.

Dr Kevin Hiscock, hydrologist at the University of East Anglia, said: "Climate change scenarios for the future indicate that rainfall intensity will increase: there will be fewer rain days but when it rains it will fall in larger volumes.

"Storm water drainage systems in our older cities may not be able to cope with increased rainfall intensities."

Failure to tackle flooding could result in more misery for hundreds of thousands of homeowners.

Dr Dave Reay, of the School of GeoSciences at the University of Edinburgh, said: "The risk of flooding and climate change will put more and more homes at risk. If we fail to address climate change, by the year 2075 flooding could be costing us an extra one billion pounds a year."

Professor Richard Hey, at the University of Birmingham, said it was essential to return the function of natural rivers by recreating river meanders and reconnecting them with their flood plains.

A lack of money is also cited by experts as detrimental.

"The amount of maintenance money allocated by (the government) to the Environment Agency to maintain its flood defence assets is not sufficient," said Dr Jean Venables, chief executive of the Association of Drainage Authorities.

Spending on flood risk management increased by 40 percent to about 900 million pounds between 2001 and 2007, the National Audit Office (NAO) reported in mid-June.

During that time, a number of improvements were implemented, including the completion of 169 projects and improved early warning systems, it said.

But it also pointed out that the agency had not met its target to maintain 63 percent of England's flood defence systems. Less than half, 46 percent of high risk systems, such as those protecting urban areas, had achieved their target condition.

The agency, which has seen a cut in resources during recent years, said it needs a further 150 million pounds a year to bring all flood defence systems up to their target condition.