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.

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.

Environment Agency 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.”

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

Ian Tomes 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.”

“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.”

“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.”

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.

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. The Agency is also recommending that householders start preparing before a flood by creating their own flood plan.