New flood maps pinpoint risk areas

New maps of flood risks across the country which could cause a 15% drop in house values in vulnerable areas and large increases in insurance premiums, will be available for the first time today.

House owners will be able to find out whether their homes are at low, moderate, or high risk of flooding by pinpointing them on an internet map on the Environment Agency site.

For many the maps will be good news because new, more sophisticated techniques mean the information is no longer based just on postcodes. As a result 100,000 homes have been moved out of the at-risk zone - although there are still 1.8m homes in the one-in-100-year risk of a flood area.

It is those in the higher risk area, a one-in-75-year chance, who will find themselves having to negotiate for flood insurance and may face a drop in value of their house.

Peter Bolton King, the chief executive of the National Association of Estate Agents, found he was one of the lucky ones, his house having been moved out of a flood-prone area on the new maps. "It is a relief to me because I know that those who cannot get flood insurance cannot get a mortgage.

"What we have found is that the price of a house drops if it has been prone to flooding in the past, particularly the recent past ... Strangely, if the maps say there is a risk but there has not been a flood then it is ignored."

David Proverbs of the Flood Research Group at Wolverhampton University, said work in Shrewsbury this year showed that recent flooding lowered prices for individual properties by around 15%.

Work for a Royal Institution of Chartered Surveyors report showed there was a growing awareness among house buyers of the issues of global warming and flood dangers. Mortgage lenders would certainly make them aware of the risks.

"On the other hand in Bewdley in Worcestershire people pay a premium to live next to the river Severn even if they know it is probable that their properties might be flooded once a year. They cannot get insurance but they have adapted, they have tiled floors without carpets downstairs and all the electrics are above flood level on the walls. That might be the way that houseowners have to go."

The insurance industry welcomed the new flood maps as a helpful way of assessing risks. In practice, few people were left without insurance altogether but they may have to pay higher prices and face a large excess on their property. Those out of flood risk areas would be paying very little for flood insurance and those in the worst areas would have to enter into individual negotiation with their companies.

The chairman of the Environment Agency, Sir John Harman said: "Flooding is a natural phenomenon that will become more frequent as climate change leads to more extreme weather conditions. Find out whether or not you and your property, your family and friends are at risk from flooding and decide what action you need to take - don't leave it too late."

The Environment Agency site advises people on measures they can take to protect their homes. Ideas include devices to prevent flood water entering doors. Home owners can also apply to be put on the flood early warning system.

The new maps include areas prone to flooding but protected by flood defences, including large areas of London.

There is also a new category - a one-in-1,000-year risk. This is mainly aimed at preventing local authorities granting planning permission for new housing estates in flood-prone areas where, because of climate change, the risks can only get worse.

Among these areas is the proposed Thames Gateway development on the Thames estuary.

FInd out if you are at risk of flooding - Environment Agency