Experian releases the industry's first groundwater flood map

Experian, the global information services company, has launched the first Groundwater Flood Model to give insurers greater confidence in their underwriting process.

Until recently, groundwater flooding received little attention from insurers in the UK.

However, the potential for this type of flooding has grown due to the increase in extreme downpours and Sir Michael Pittan's interim report on the causes and consequences of the floods released earlier this week has highlighted groundwater as an area that needs monitoring.

It is now estimated that it can affect several hundred thousand properties in the UK, making the issue more urgent and highlighting a need for further work in this area.

Groundwater flooding occurs following sustained excessive rainfall, which can cause the water tables to rise up and interact with buildings and other infrastructure.

This leads to flooding, in some cases away from those areas, such as flood plains, where flooding is normally expected.

Often, groundwater flooding has been overshadowed by more visible surface water events, which is why it had not been acknowledged until the wet winter of 2001 when the need to understand groundwater flooding became more apparent.

As a result, the British Geological Survey (BGS) began developing the first national data set of groundwater flooding susceptibility.

However, this information on its own is of limited use to insurers, so Experian incorporated the BGS data into its existing flood risk data.

Experian's Groundwater Flood Model is currently the first of its kind on the market to highlight the level of susceptibility to groundwater flooding for every postcode in England and Wales by identifying areas where geological conditions could enable groundwater flooding to occur and also where groundwater may come close to the ground surface.

Experian has added further value to the product by overlaying it with its own extensive property and demographic datasets.

This enables insurers not only to see where groundwater flooding could occur, but enables them to assess the likelihood of an insurance claim being made from a given postcode, taking into account the lifestyle and financial status of the people living there.

It also gives insurers an estimate of the potential cost for that particular postcode, taking into account factors such as property type, size and regional construction costs, which can significantly affect the cost of claims.

Avis Easteal, Managing Director of Experian's Insurance Services division, said: "Until the last few years, groundwater flooding was not recognised as a distinct event as it was often masked by surface water.

Previously, local knowledge of these events was the only guide to an area's susceptibility to this kind of flooding, but this was often patchy and unreliable.

"However, groundwater flooding has played its part in the rising costs of meeting flood claims over the years, so we welcomed the BGS development of the first national data set of groundwater flooding susceptibility.

"A key aspect of Experian's risk data is the ability to lay our own demographic and lifestyle data onto flood information.

For example, two households with the same flood risk, but in different postcodes could react very differently in the event of a flood.

A postcode containing a number of old properties with cellars is far more likely to see claims as a result of groundwater flood, than a postcode which has many new build properties.

This could affect the premiums charged by insurers.

Experiana's Groundwater Flood Model can also be used by local authorities, public utility and retail businesses in order to help with, for example, store planning and other infrastructure decisions.

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