The Flood Warning and Dissemination Problem
An important way to reduce the risk to life from a flood event is by the actions taken to warn the public before the flood. Flood warnings can also reduce the damage to property by more than 25% if communicated in sufficient time. Of course it needs to be stressed that for some types of flood, it is not feasible to give an early warning. This is particularly the case for steeply sloping catchments, as was seen at Lynmouth in 1952 and Boscastle in 2004. It should be noted that the insurance template (see Appendix 1) makes special provision for such circumstances and requires a higher standard for new developments at risk of flooding from "Flashy Catchments".

Flood Line, a customer dial up telephone service, was set up with funds earmarked for the purpose after the Easter 1998 floods. It was introduced in England and Wales in 1999, and extended to Scotland in 2001.

New codes are used for warnings: Flood Watch, Flood Warning and Severe Flood Warning. These are backed by clear graphic symbols, which are used on television and on printed warning material. Flood Line provides a single national number (0845 988 1188) for the public to ring on any matter associated with flooding throughout Britain . All calls are charged at local rates, and during the Autumn 2000 event, Flood Line received 467,200 calls, costing the EA £300,000.

The current Floodline system is excellent, but it could be better. There are two main problems:

Lack of sufficient rain gauges and river flow gauges with appropriate telemetry for monitoring. Remote gauges are prone to vandalism and can be expensive to maintain. However more gauges can mean earlier warnings and fewer false alarms.

Problems with disseminating warnings. Flood victims report that there is still some confusion about the meaning of the new warning codes, and that warnings do not always reach those who need them. Also the media often issue conflicting or incorrect information.

As regards dissemination, for many years, flood warnings were disseminated by the police, using loudspeaker vans and even door to door calling. This service was unilaterally withdrawn by the police in England and Wales in 1997, and was one of the main drivers for the EA's original flood warning service, which had to be introduced in some haste to fill the gap. The police continued to disseminate warnings in Scotland until 2001, waiting until the Scottish Flood Line service was introduced and operational.

Dissemination of flood warnings is provided by telephone to pre registered properties at risk of flooding using Automatic Voice Messaging (AVM), but this relies on people answering the telephone (if they have registered their number). In Scotland , there is also an informal use of "rings" of people organised by local businesses and emergency services. The leader of the first "ring" is telephoned manually by SEPA, and undertakes to telephone everyone in the ring. Each of them in turn telephones their own ring of people, and in this way information can be rapidly disseminated.

This is not the end of the problems; in areas where flats are rented, there tends to be a mobile population who may not be aware of the AVM service and do not register. People living in ground floor flats are particularly vulnerable as there is no where safe for them to go or to take their valuables. There is also some anecdotal evidence that landlords do not repair such properties adequately after a flood.

In addition, there are many people who decide not to register either because they refuse to believe they are at risk or because they fear that their insurer will find out and charge more premium, or withdraw cover. The author suggested some years ago that those insurers which support the Neighbourhood Watch system, might encourage local co-ordinators to also act as flood wardens to disseminate warnings and assist the elderly and infirm. This suggestion has been implemented to some extent through the flood warden scheme.

Another idea that the author suggested some years ago is for insurance company call centres and helplines to become proactive during a flood event by calling their customers to see if they need any help. Insurers have said they are reluctant to do this in case it is a false alarm and the customer sues them for additional expenses incurred in taking precautions. This seems to be a rather spurious argument, and there seems to be no reason not to try it out on an experimental basis, perhaps even offering physical help to people who are elderly or infirm.

Most people in Britain are still inadequately prepared for floods, and do not realise just how much damage even a small flood event can cause. (see table).

Table 4 Cost of damage caused by a flood depth of 0.6m. Building sum insured £100,000, Contents sum insured £30,000
National Flood Insurance Claims Database, 1999.

In an effort to raise awareness, both the EA and SEPA have annual "Flood Awareness Weeks". During these weeks, press releases are issued, and exhibitions organised to help to inform the public of the hazards of flood and what they can do about it.

The Environment Agency spends around £2 million a year showing people how to take action to protect themselves and their property - like fitting flood boards or airbrick covers.

As part of the EA activities for 2002, they commissioned research into flood awareness, and an extract from their findings is contained below.

The survey found that while there was a big increase in awareness that there were things that could be done to prepare for a flood, only 5% of respondents would actually take any action in advance of a flood. The Environment Agency think this could be not just apathy, but also fears that acknowledging the risks and taking steps to protect against flooding could in some way have a negative affect on the value of properties.

In launching the 2002 flood awareness week, the Environment Agency Chief Executive Barbara Young said:

"This is very worrying. Floods are extremely dangerous. They can be a threat to life as well as property. If you can take precautions to reduce the risk you should. Pretending you're not at risk is not a defence - it's a delusion. The Agency works extremely hard to protect and warn people and Government has announced extra investment for defences. But, as recent events in Europe and around the world show, no country can guarantee absolute protection against the forces of nature. In addition to our work, individuals need to take action of their own."

There has been considerable research into this subject in Australia . In March 2001, a flood warning was issued for the town of Grafton in New South Wales . The potential threat was so serious that it was decided to evacuate all 12,000 residents in the flood hazard area. Fewer than ten percent of residents left the city during the nine hours the evacuation was in effect. Following this, a research project was set up to discover why so many people remained in the danger area. The researchers used interviews combined with telephone samples. The research also examined the different methods used to disseminate the warnings to see how effective they were. Space does not permit a full description of the results, but one outstanding feature was that 75% of the residents believed that the city would not be flooded. It was not that they expressed any great faith in the local flood defences, but because they had not experienced the direct effects of flood since the defences had been constructed, a huge level of inertia had built up, with a very low perception of the risk. Many aspects of life in Grafton continued as normal; people went to the pub to discuss the evacuation with their friends, some went to the local river flow gauge to check the readings for themselves, several logged onto the internet to get the latest projections. Many asked older residents for advice.

In the event, the flood defences held, although water came within 0.2m of the top of the levee. The question is, whether flood defences, by protecting against most floods, give rise to a feeling of complacency which could lead to loss of life in a really big flood where the defences fail?

More natural, non-structural measures would perhaps be safer; flooding would happen more gradually and people would be more likely to evacuate if they could see the water getting closer. Also of course, people would be less likely to live in the danger area in the first place.

There have been a number of papers published in Australia regarding research into the effectiveness of various types of flood warning dissemination methods using large scale surveys and sophisticated analyses methods. It is to be hoped that the authorities in Britain will take into account such results in their future strategies.

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