IT’S November. And there’s a storm surge heading down the North Sea straight for Norfolk. That’s the scenario today as emergency services across the county take part in Britain’s biggest-ever civil defence drill.

Exercise Watermark is designed to test how well the Environment Agency and other bodies can put lessons learned from the 2007 floods which engulfed parts of the Midlands into action.

Climate change, rising sea-levels and increasingly-frequent storms mean Norfolk’s low-lying coastline and areas like the Fens and Broads will become increasingly vulnerable.

As well as the EA the police, fire service, councils, coastguards, the army, RNLI, Maritime Coastguard Agency, Met Office, power commpanies and the NHS will all be taking part today.

“It’s the biggest civil defence exercise ever to take place in the UK,” said Nick Hesp, the EA’s operations delivery manager for Norfolk and Suffolk.

“It’s about how we work alongside emergency responders and the various people who are involved so everybody’s ready when a flood event happens.

“We’ve got 10,000 people taking part in Exercise Watermark this week. For us in the Anglian region, we’ll be simulating a 1953-style tidal event.”

More than 80 people died around the Norfolk coast on the night of January 31, 1953.

A freak mixture of low pressure, high tides and a high winds drove the sea through defences around Snettisham, Heacham, Hunstanton and Sea Palling.

Forecasting and communications have greatly improved over the last half-century. The conditions which cause North Sea surges can now be spotted days in advance, as weather systems develop north of Scotland.

Closer to home today the EA will be showing flood wardens, parish councillors and police how to operate the flood defences at Sea Palling, which help protect 1,200 homes from flooding.

Mr Hesp said those taking part would also rehearse how they might deal with a missing person.

At Wells the flood gates will be tested using both mains power and a back-up generator to simulate a power failure. EA staff will be on-site from 9.30am - 1pm to explain how the defences work and give qadvice on flood prevention.

At Great Yarmouth, the EA will be testing how quickly staff can close the flood gates protecting more than 6,000 homes from a tidal surge up the River Yare.

A report out on Monday, from the Joesph Rowntree Foundation, said the town was one of a number of “disadvantaged” coastal communities most at risk from climate change.

And at Potter Heigham, staff will be demonstrating the barrier which protects coarse fish in the River Thurne from salt tides.

Norfolk County Council resilience manager, John Ellis said: “It is only by working and practising together that we will be ready to protect people’s lives, homes and livelihoods when flooding hits.

“As well as the different agencies exercising their response to flooding, we are asking members of the public to ensure they know what to do if their home was flooded – from knowing how to turn off gas, water main supplies, and what to do if water enters their home.”

A free booklet to help people prepare for a flood is available from libraries in Norfolk. It shows how to check whether you are in a flood risk area and how to cope with an emergency.