As the York floods subside Stephen Lewis asks are we still at risk?

FOR the crowds who gathered on Skeldergate Bridge on Monday evening to gawp at the swollen River Ouse, the floods in York were little more than a sideshow.

True, the poor old King's Arms on King's Staith was under water again, South Esplanade was almost nowhere to be seen, and the villagers of Naburn had suddenly become the inhabitants of Britain's newest island.

But for most of York's residents, the flooding was a bit of fun: something different to liven up humdrum everyday life.

It may not always be so. Since the York floods of 1982, something like £10 million has been pumped into York's flood defences. Flood walls and embankments protect large areas of lower Bootham, Clifton Green and Leeman Road, as well as North Street on the opposite bank of the river from the Guildhall.

Floodgates normally buried beneath Marygate can be raised in the event of heavy water levels, linking up with flood embankments protecting the Museum Gardens.

And the River Foss barrier prevents water 'backing up' from the Ouse along the Foss and flooding whole areas of the city bordering the Foss right up to Layerthorpe.

The barriers are designed to cope with a 'once in a 100 years event', says Bob Parry of the environment agency. That sounds fine and certainly this week's floods came nowhere near really testing the city's defences. There is even plenty of warning: because the water which causes the Ouse to flood will have fallen normally two or three days earlier up on the Pennines.

What keeps emergency planners in the city awake at night, though, is the thought of what would happen if a freak combination of conditions occurred which overwhelmed the city's flood defences - or if those defences were breached.

John Simmons, emergency planning co-ordinator at City of York Council, says hundreds of homes in the city whose owners think they are safe behind flood barriers could be at risk in the event of a catastrophic flood or failure of the defences.

"It is very important that the defences hold," says John. "A failure is something that will hopefully never occur - but we cannot give a 100 per cent guarantee and a worst case scenario is something we have to plan for. The thought is always in the back of our minds what if they don't hold. That would be fairly catastrophic."

Bob Parry says that is very unlikely. The defences were built to a high standard and are adequately maintained. But even he concedes there is a risk. And that risk may not be quite as small as many of us would like to think.

There was, this week, a minor glitch with the Marygate floodgates which meant they didn't come into use as quickly as they should have done.

It didn't cause a disaster this time: but it was evidence that defences are not infallible.

What the emergency planners really fear, though, is a freak combination of events such as that which caused last year's North Yorkshire floods.

"If we had say four inches of snow up in the dales, followed by a thaw and heavy rainfall, that would put our defences to a severe test," admits John.

This week's floods rated an Amber Two warning, meaning they ranked with the 1995 and 1982 floods in severity.

At the height of the floods at 10.30pm on Monday, water levels were more than 14ft above normal.

That was enough for full-scale emergency plans to be readied. Members of the York Flood Group - which includes the city council, the police, fire and ambulance services - met at Fulford police station on Monday morning as water levels were still rising.

By then, they were fairly confident they knew the water levels would peak before there was a major problem: but there was always that niggling doubt about the defences.

A detailed emergency plan is already in place and ready to swing into action in the event of a sudden break in the defences or in case water levels were to rise to such levels the defences were overwhelmed.

Police would take the lead, co-ordinating a massive evacuation of all the homes at risk. Transport would be laid on, temporary evacuation centres set up in schools, leisure centres and even at the racecourse, hot food would be prepared.

As the flooding began to recede, environmental health officers would be on hand and there would be advice about dealing with insurers. People whose homes were not fit to be lived in would be temporarily rehoused, and if necessary a flood appeal along the lines of that in North Yorkshire last year would be launched.

Hopefully it will never come to that. But ominously there are signs that the weather in the UK is, slowly but steadily, getting warmer and wetter.

Over the last 140 years, the average temperature in the UK has risen by 0.7C - and there has also been a small increase in rainfall.

Radio 5 Live weatherman Philip Eden admits there has been a 'tendency' to warmer, wetter weather in Britain: but insists it is still too early to attribute this to global warming.

Sean Clarke of the Met Office, though, has few such doubts.

"We are very confident that global warming is a reality," he says.

Part of the global rise in temperature up to the 1950s was probably down to increased solar activity, he says, with some being the result of industry. But since the 1950s almost all the continued warming was down to man.

The concern is that even a global rise of less than one degree to the world's temperature could still have a large effect on the world's weather systems. In the UK, we would have more summers where the temperature topped 30C - and fewer frosts in the winter. Computer models have shown that rain patterns would also be affected - with paradoxically less rain in summer but far more in winter.

John Simmons likes to say that in York we've been learning to prepare for floods ever since 1625 - the city's worst recorded inundation. If global warming continues to muck about with our weather patterns, those preparations may one day prove to be in vain.

PICTURE: A Selby-bound bus tackles the Cawood floods