Forty years on from the floods of 1968

Forty years ago heavy thunderstorms were sweeping across South East England, flooding more than 14,000 properties, washing away bridges and shutting down roads and phone lines.

Towns across Surrey and South London including Guildford, Farnham, Leatherhead, Basingstoke, Gatwick, Lewisham, Greenwich and Croydon all suffered after many inches of rain fell in just a few hours on ground already saturated from a wet summer.

It was a year of records. The summer of 1968 was the wettest in South East England since 1931, and in some areas the rain that fell over the 14 and 15 September was the highest recorded amount for 100 years. Flows on the rivers Loddon, Wey and Mole were also the highest recorded at the time.

Flood risk manager Ian Tomes said: “The storms that swept through South East England brought devastation to many homes and businesses. As the rivers rose flood waters entered their properties, power and phone lines were cut, roads and railways were impassable.”

During the 14 and 15 September 1968, low pressure moved northwards into southern Britain and extended a frontal system from west to east across southern England. This system remained stationary for a number of hours causing heavy showers and thunderstorms.

In Guildford more than 4 inches of rain fell in just 48 hours, while Reigate received nearly 6 inches – this is twice the average rainfall for the month of September.

Guildford High Street was underwater, the bridge on Horsham Road between Shalford and Bramley was washed away and the local Yvonne Arnaud Theatre and St Nicholas Church were flooded.

Across Surrey a total of 14,000 properties were reported to have flooded from the rivers Wey, Mole, Blackwater, Loddon, and Addlestone Bourne. Around 10,000 of these were residential. Transport links were brought to a standstill, with major roads disrupted and extensive damage to many bridges. Gatwick airport was also closed to traffic for a number of hours.

In London, parts of Bromley, Greenwich and Corydon were flooded by the River Ravensbourne while the centre of Lewisham was brought to a standstill when the Quaggy River flooded. Immediately downstream the Ravensbourne Improvement Scheme was underway and the high flows knocked over the crane being used on the site.

Flooding was also reported in Sutton, Wandsworth, Merton, Wimbledon and Colliers Wood, including Wimbledon Stadium from the River Wandle and the Beverley Brook.

As well as some of the highest river flows ever recorded, the flooding was also caused by exceptional surface water runoff exacerbated by blockages of culverts and surface water sewers.

Forty years on

Ian continued: “Although much has changed in 40 years the rivers remain a threat to the homes and businesses. However, much has been done to protect these areas from an incident of this scale happening again.”

The flooding of 1968 prompted investigations into potential flood alleviation schemes across the region. Many progressed to schemes that today reduce the risk of flooding to thousands of homes and businesses.

These include:

In Surrey the Lower Mole Flood Alleviation Scheme was built following the 1968 floods, which included more than 3km of earth banks, and protected areas including Molesey, Esher, Hersham and Walton to a very high standard of protection (1 in 200 chance of flooding, or a 0.5 per cent chance in any year.)

In London the Quaggy River Flood Alleviation Scheme was completed between 2004 and 2007 in Greenwich and Lewisham to protect 586 properties from a 1 in 70 event. This £16 million scheme created flood storage areas at Sutcliffe Park and John Rohan School playing fields, which have become valuable environmental and community resources.

Work was undertaken in the River Ravensbourne, which runs through Bromley and Lewisham, during the 1970s before a flood relief channel was built in 1999.

“There have been many schemes built to protect homes and businesses from flooding, from major flood relief channels protecting hundreds or thousands of properties, to smaller flood storage areas which protects dozens,” Ian said.

“The Environment Agency will continue to investigate and develop schemes that will reduce the risk, although we can never eliminate this threat. This work, and the partnership between ourselves, the local authorities and emergency services, will become more important as scientists predict wetter winters in the future as we feel the impacts of climate change.”

In 1984/85 a culvert was built under the runway at Gatwick Airport and today there are plans to build an Upper Mole Flood Alleviation scheme to reduce the threat of flooding to 1,170 properties in Crawley, Horley and the airport.

A project is also underway to protect 2,600 properties in Sutton from flooding from the Beverley Brook which includes flood storage areas at Morden and Richmond Parks.

Floodline Warnings Direct

Since the major flooding, which affected large parts of the Thames Region, in 1968 the Flood Warning Service provided to members of the public has vastly improved. Many changes have been undertaken over the last 40 years to improve the way in which we inform members of the public, our professional partners and the media of flood risk.

Floodline Warnings Direct (FWD) is the UK’s first integrated multi-channel warning system, having replaced the old Automatic Voice System (AVM) on the 26 January 2006. It delivers flood warnings simultaneously via, telephone, mobiles, pager, fax, email and SMS text messaging, enabling large numbers of people to be effectively warned via a range of media.

Over the last two years the Environment Agency has been revising its Flood Warning Areas to warn people of the potential danger to life and property from flooding. By creating Flood Warning Areas based on communities, the Environment Agency aims to improve its free flood warning service.

“Living in the flood plain is never without risk, but there are ways we can reduce that threat. We will continue to look for ways to reduce the risk through schemes while homeowners can take some simple steps to protect their property,” continued Ian.

“This anniversary, the memories of last summer and the very recent flooding across the country, are a reminder that floods can happen at any time of year and we all need to be prepared. I would encourage everyone to check their level of risk and if possible sign-up to our free early warning system by calling Floodline or visiting our website”.