Fifty years ago, the North Sea flooded, bringing widespread physical devastation and massive loss of life in the the UK and the Netherlands.

Ceri Wild looks at how it happened and examines the defensive moves made in its wake.

Fatal saturation

Fifty years ago, the North Sea flooded, bringing widespread physical devastation and massive loss of life in the the UK and the Netherlands.

Ceri Wild looks at how it happened and examines the defensive moves made in its wake.

"On the festival of St Martin (11 November), the sea flood sprung up to such a height and did so much harm as no man remembered that it ever did before."

This fragment from the Anglo Saxon Chronicle dated 1099, serves as the earliest record of a flood in London. It illustrates how even from Norman times, the southeast of England has been susceptible to catastrophic flooding. A more recent reminder of the capital's vulnerability to coastal flooding passed at the end of January, as the region marked the poignant fiftieth anniversary of the Great Flood of 1953, an event which claimed the lives of 1,900 people on the English and Dutch North Sea coasts.

On the freezing winter weekend of 31 January and 1 February 1953, the east of England and the Dutch coast were battered by 90mph northwesterly winds. These strong winds, coupled with a very low-pressure system, raised the sea level considerably, creating the greatest North Sea surge on record for the last century. (A surge is defined as the deviation of the observed tide at a given place and time from the tide which would normally occur free from meteorological influence.) According to the UK's Meteorological Office 1, the surge height reached 2.74m at Southend in Essex at the mouth of the Thames Estuary, 2.97m at King's Lynn in Norfolk and 3.36m in the Netherlands. In little more than 24 hours, 100,000 hectares of eastern England were flooded and 307 people died (this figure does not include a further 177 who perished at sea), with 58 fatalities in Canvey Island alone2. In the Netherlands, 50 dykes burst and 1,600 people drowned. The waters occupied 9% of all Dutch agricultural land and 3% of dairy pastures; salt water invaded over 200,000 hectares of reclaimed land.

Surge warning

The sophisticated satellite gadgetry, which nowadays enables the modern Met Office to make detailed weather forecasts, was just not around in the 1950s. Even so, the Met Office and its Dutch counterpart, the Surge Warning Service, were still able to successfully issue warnings of `dangerously high water' several hours before they occurred. Over the course of that fateful weekend, however, the timely receipt of detailed information was impeded by the weather conditions. Power and telephone lines were brought down in high winds and virtually no warnings of the storm's ferocity were relayed to the English counties further south until it was too late. Suffolk and Essex, on the exposed and low-lying east coast, reaped the appalling consequences.

Low-lying Canvey Island, on the north side of the Thames Estuary, bore the brunt in Essex, as sea walls collapsed and foaming water cascaded through homes and businesses. In London's East End, 100m of river defences collapsed, causing more than 1,000 homes to be deluged and 640,000 cubic metres of Thames water to flow through the streets of West Ham.

Modern Canvey Island now resembles a heavily defended fortress in terms of armoury against the sea. Buttressed by concrete and steel, the grim lessons from 1953 appear to have been heeded. The population of Canvey seems reassured and has grown from 11,000 before the flood to a present day figure of 37,0003. But do locations like Canvey still remain vulnerable?

Assessing the vulnerable

According to recent climatic studies conducted by the International Water Association (IWA) in 20024, the answer is a qualified `yes'. Research compiled on the wettest regions in northern Europe and southern Asia predicted that catastrophic floods would become significantly more frequent. Scientists from the Rossby Centre in Sweden and the European Centre for Medium-Range Weather Forecast in the UK suggested that winter rainfall in northern Europe will increase fivefold but countries within this region remain better equipped to protect lives, despite exposure to property and infrastructure development.

Brutal statistics from 2002's summer floods in eastern and central Europe, in which more than 90 people drowned and rainfall in some regions was the highest since records began, give further credence to the view that the risk from coastal and river flooding will deepen. Jane Toothill, natural hazard analyst at EQECAT Europe, was careful to stress, "the summer floods were triggered by unusual but not exceptional conditions"5. But against this increasingly bleak European picture, the question must be asked; what are the insurance and reinsurance ramifications?

According to the Association of British Insurers (ABI), UK homeowners are likely to experience a substantial rise in premiums as insurers confront a £15bn bill from the aftermath of 2002's European floods. Average premiums for buildings and home contents cover are estimated to rise by 10% in 2003, compared to last year's hike of 7-9%.

Floodplain folly

According to the Environment Agency, many householders face the unenviable position of failing to secure any cover for their property, after the agreement between insurers to provide household flood cover at a reasonable price expired at the end of 2002. David Crichton, Visiting Professor at the Benfield Greig Hazard Research Centre notes in his recent study, Flood risk & insurance in England & Wales: are there lessons to be learned from Scotland? 6that the "ABI has cited inadequate planning controls in England and restrictions on flood defence expenditure in England and Wales as the reasons for ceasing the guarantee of cheap flood insurance for all householders not only in England and Wales, but also in Scotland (even though planning controls have been tightened and flood defence spending has increased substantially in Scotland since devolution)". Professor Crichton also warns that households in flood plain regions will find it increasingly difficult to secure cover. Currently, 27% of new property by value across England and Wales, including £80bn worth of property in the London region, is built on floodplains. "The severe floods we have seen in recent years are consistent with climate change predictions," writes Professor Crichton. "Weather records for rainfall and temperature are being broken regularly, and yet we are still building in flood hazard areas, often against the advice of the Environment Agency." He continues: "This has been made possible by the market distortions caused by the insurance guarantee (expired in 2002), which has until now enabled properties in flood risk areas to obtain mortgages and insurance."

That it is folly to build on vulnerable flood plain regions is an opinion shared by modeling agency Risk Management Solutions (RMS). As Robert Muir-Wood, managing director of global risk modeling at RMS, emphasises: "River flood has been the underestimated catastrophe peril in the UK." The portents appear bleak if development continues on floodplains and flood defence programmes receive nominal investment. The solution, according to Professor Crichton, is to embrace the `Scottish experience'.

The `Scottish experience'

Since devolution in 1999, when the responsibility for running Scotland moved from UK central government in London to a locally-elected assembly based in Edinburgh, the Scottish Executive has awarded grant aid for the construction of more flood defences than was awarded in the previous 40 years, and the budget for these types of projects continues to rise rapidly. By 2001 there were 60 new schemes approved, costing £29.5m.

Grant aid for flood protection in Scotland has never been rejected on the grounds of cost. According to Professor Crichton, this is one of the salient differences between England and Scotland; Scottish spending is effectively unlimited, as long as the flood project is properly costed, appraised and provides adequate protection. Built into this planning strategy is a stakeholder element, enabling input from across the community. Most Scottish local authorities, including all with a potentially serious flood hazard, have established flood appraisal groups, and these now represent 90% of the population. Scottish planning guidelines were drawn up with ABI consultation and include the ABI suggestion that flood appraisal groups invite an insurance representative to attend their meetings. Professor Crichton has been funded by insurers to represent insurance interests on these groups since 1996, and regularly attends flood appraisal group meetings the length and breadth of the country, from the Scottish Borders to the Shetland Islands.

The concept of flood defence is also enshrined in Scottish law, as the Flood Prevention and Land Drainage Act 1997 imposes a clear statutory duty on local councils to maintain water courses and initiate flood defence schemes. In short, Scotland remains a better flood risk than England and Wales.

In 1953, Scotland escaped relatively unscathed from the Great Flood, albeit with 19 fatalities at sea. But what measures are being taken across the UK to protect against such a storm - a storm which, if repeated on the scale of 1953, would nowadays result in insured losses of £20bn?7 This figure, according to Professor Crichton, does not include London, since the city is assumed to be adequately protected.

The events of 1953 led to the Thames becoming one of the most fortified rivers in the world. The flood barrier at Woolwich was completed in 1982, reinforced by 36 additional tidal barriers and gates, as well as 200 miles of floodwalls. Yet, in contrast, many of England's coastal defences built since 1953 are reaching the end of their life span. ABI research compiled in 1997 confirmed 60% of coastal flood defences in the south and east of England would fail in the type of storm anticipated every 50 years.

It is a sobering thought that the impact of the 1953 flood would have been far greater if, like a flood disaster in 1928, it had coincided with a spring tide, rapid snowmelt and heavy rainfall.

References

1. Source: www.metoffice.com/education/historic/flood.html

2. Source: Kelman, I. 2002. CURBE Fact Sheet 3: UK Deaths from the 1953 Storm Surge. Version 1, 10 December 2002. Downloaded from http://www.arct.cam.ac.uk/curbe/CURBEFactSheet3UK1953Deaths.doc

3. Source: www.guardian.co.uk/weather/Story/0,2763,868469,00.html James Meek: 50 years on, new menace of fatal flooding.

4. Source: www.iwahq.org.uk

5. Source: Global Reinsurance December 2002 p38 Jane Toothill, Flood of the millennium.

6. Source: Flooding Risks and Insurance in England and Wales: are there lessons to be learned from Scotland? A Research Report for the Benfield Greig Hazard Research Centre at University College London. By Professor David Crichton November 2002

7. Source: The Flooding disasters of 1928 and 1953. Are we ready for another? By Professor David Crichton January 2003.

Flood facts for England and Wales

  • Five million people in England and Wales are at risk from flooding every year, principally during the flood season (September to April) - but flooding can happen at any time, as it did in August 2002 in areas of north-east and north-west of England.

  • Two million homes and 185,000 businesses are at risk of flooding in England and Wales.

  • Property, land and assets to the value of £214bn are exposed to flood risks.

  • 10,000 properties were flooded in the severe floods of autumn 2000, but flood defences successfully protected 280,000 properties.

  • Scientists predict that climate change may lead to an increase in extreme and unpredictable weather - including floods.

  • Since 1999, 20 people have died as a direct result of flooding. Thousands have suffered shock, trauma and devastating damage to their homes and possessions.

  • Research by the insurance industry has shown that half a metre of floodwater in a modern semi-detached house will result in an average cost of £15,000-£30,000 to repair the building and £9,000 to replace damaged belongings.

    Source: Environment Agency, 23 September 2002.