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Environment Agency - 1947 floods Thames

  • ️Chris Mitchell
  • ️Invalid Date

Environment Agency says check your flood risk using our flood maps

Author:

Chris Mitchell

Date published:

14-Mar-2007

Keywords:

On the 60 year anniversary of the 1947 floods - some of the most devastating floods to hit the Thames Valley in living memory - the Environment Agency is urging those at risk to take the necessary action to reduce the impact flooding can cause.

The floods of 1947 affected thousands of homes, forcing many war-weary to evacuate their homes, and leaving many more without electricity or heating. The floods followed a particularly harsh winter with weeks of frost and snow. In early March much of this snow was melted by heavy rainfall, and with a frozen, impermeable ground, these elements combined to produce an estimated of 117mm of rainfall, which quickly overwhelmed the area's rivers and streams.

"Although floods on the scale of 1947 are very rare on the Thames, history shows they do happen, and could happen again," Steve Naylor, from the Environment Agency's Flood Forecasting said. "We endeavor to reduce flood risk where we can, however living in the floodplain is never without risk, so it's vital to ensure people take action to protect themselves and ensure that they have done all they can to limit the damage, difficulties and misery flooding can cause."

After 1947, numerous schemes were carried out on rivers and tributaries of all sizes throughout the Thames Region. Such schemes include the River Lee flood relief channel which protects properties in north east London and the Maidenhead, Windsor and Eton flood relief scheme, which includes the Jubilee River, and was built to protect Maidenhead and Windsor from floods as severe as those in 1947.  A few months after it was opened, it succeeded in protecting more than 1,000 properties in January 2003.  These were the biggest since 1947, causing flooding in Oxford, Reading, and many other towns and villages on the Thames.

However, the most effective way to reduce flood risk is not to build in flood risk areas, and to take the opportunity in any redevelopment to ensure that the potential for flood damage is reduced or eliminated by designing flood resistant buildings.

In recent years the Environment Agency has made strides in defining areas at risk by using recorded flooding information and simulations to produce detailed flood maps. These maps are a valuable tool in limiting inappropriate development in the floodplain, and are also an important resource for homeowners to check their level of risk online at www.environment-agency.gov.uk/flood

"We would urge everyone to check whether they are at risk of flooding by looking up their address on our floodmaps," Steve Naylor added. If you are at risk there are a lot of things you can do to protect yourself such as signing up to our free Floodline Warnings Direct service which sends automatic flood warnings over the phone. We would also urge you to ensure you have a flood plan in place so you know what needs to be done in the event of a flood. For information and advice, please contact Floodline on 0845 988 1188 or log onto our website."

10 Flood Facts:

  1. A staggering 117mm (4.6inches) of rainfall (rain combined with snow melt) caused the 1947 floods.
  2. There are now approximately 215,000 properties at risk today in the Thames Valley.
  3. Floodplains in the Thames Valley area cover 10,000km2, equivalent to 10 per cent of the region's land.
  4. The snow was up to 1.5m deep in some areas of the Chilterns, with snow drifts of between 3-5m
  5. The 1947 floods are rated from a 1/56 - 1/100 year event.
  6. An estimated 715 cubic metres of water rushed over Teddington Weir. This is the equivalent to 61.7 billion litres of water per day. In 2003 the recorded peak flow was around 470 cubic metres per second.
  7. Other significant floods to hit the Thames Valley since 1947 were 1968, 1993, 1998, 2000, 2003 and 2006 at varying magnitude.
  8. The 1947 floods cost the UK a total £12 million - equivalent to nearly £300million in today's money.
  9. Almost 300,000 hectares (approximately 700,000 acres) of land across the UK - a total area equivalent to the size of Kent was inundated.
  10. Current estimates are that peak river flows in Britain could be 20 percent higher by 2080.