FOR several days and nights our television screens have been filled with images of devastation on a scale seldom seen on these shores.

The heaviest rainfall ever recorded in Britain over 24 hours fell on Cumbria last Thursday, plunging swathes of the county into an almost apocalyptic nightmare of collapsing bridges and high streets turned to rivers.

Search and rescue helicopters were scrambled as more than 200 people in Cockermouth were rescued from their homes by the emergency services.

Waters from the raging River Derwent deluged 900 properties in the region and tragically claimed the life of PC Bill Barker, who was swept away when a bridge where he was directing traffic crumbled beneath his feet.

Several members of the Environment Agency's Leeds-based team have been drafted in to help with the operation and the event now throws the city's own flood defence plans into even sharper focus.

The ambitious scheme – which covers a near 11 mile stretch of the River Aire – was put out to public consultation in May this year and approved by Leeds City Council at the end of August.

The design now has to pass a series of rigorous internal checks by the Environment Agency before being put before its directors, chief executive and board next spring.

After that it must be submitted to the Department of Environment, Food and Rural Affairs (DEFRA) and the Treasury for central government approval.

If it passes that final hurdle work could begin in the early part of 2011.

With an estimated cost of £167 million it represents the biggest river-based flood defence scheme in the country.

But then with the cost to Leeds of flooding on a comparable scale to that seen in Cumbria put at £480m it's clearly viewed by many as money that would be well spent.

Should such a severe weather event as a one in every 200-year flood occur here, water from an overflowing River Aire could crash down Kirkstall Road, paralysing a key route that handles 45,000 cars every day.

The train station and the rail lines in and out of the city may be high enough to escape relatively unscathed.

However, the 100,000 passengers who use the station on a daily basis would still be stranded if the floodwaters overwhelmed the electricity substation in the Dark Arches that supplies its power.

It's a grim picture and one Martin Slater is keen to do everything in his power to prevent.

As the Environment Agency's development manager for the Leeds flood alleviation scheme he's convinced of the plan's worth, even if its chances of being made reality still hang in the balance.

As usual, everything hinges on money.

"If the scheme is approved we then have to find the funding for it," he told the YEP, sitting in an office at Rivers House, the Environment Agency's regional headquarters in Leeds.

"The approval doesn't come with a cheque attached to it. There's a finite supply of government funding and almost an infinite demand.

"The cost of the scheme represents a large proportion of our annual budget. We're all well aware of the state of public sector finances and the economic situation so we've got to work as hard as we can to try to find other sources of funding."

The Environment Agency has £620m to spend nationally on flood risk management this year, rising to £670m in 2010/11. In addition, just under £90m is allocated to local authorities through the revenue support grant.

The agency will ask the Government for the full amount of £167m to finance the scheme but, if funding falls short, the rest will have to be made up with a combination of cash from other sources.

The city council has pledged £10m to the plans, with regional development agency Yorkshire Forward and Yorkshire Water among those expected to contribute, along with the city's business community.

One thing that could work against the scheme in winning government backing is that it protects relatively few homes at risk of flooding, with businesses making up the vast majority of the 4,500 properties it would safeguard.

However, the geographical make-up of the city means cutting corners is not an option.

"Leeds is what we call a one flood cell," said Martin.

"So if the water gets out in one place it can go right across the flood plain. That's why the defences have to be continuous across the entire river as it runs through the city."

Along some stretches of the river the defence could take the form of simple walled embankments.

However, Martin's plan would see more subtle measures put in place elsewhere.

"The principle of the scheme is to build a defence that doesn't look like a defence," he said.

"Billions of pounds of investment has gone into the waterfront in Leeds in the last 10 years.

"We want to build a scheme that's going to fit in with the waterfront and actually enhance it."

Outline plans have been approved by council architects including seating terraces and ampitheatres that will help protect the city from flooding without spoiling the look of the riverside.

Among these so-called 'hotspots' are Sovereign Place, Water Lane and Brewery Wharf.

Existing buildings will form part of the defence too, with work carried out to strengthen and waterproof them without altering their appearance.

There are also a number of waterfront developments that have not yet been built that will incorporate flood defence measures in their construction.

"It's a very complicated scheme because you're working in a very crowded urban area," said Martin.

"It's like putting pieces into a jigsaw. That's why it's so expensive.

It's a very complicated, structural design that needs to fit into existing buildings."

However, if the city's defences do clear the hurdles ahead it may be another eight or nine years before they are in place.

And even then there is no guarantee that they will be sufficient to keep Mother Nature at bay.

"The circumstances that occurred in Cumbria last week were a combination of meteorological events," said Martin. "In theory that could happen anywhere.

"There have been some big floods in Leeds in the past, such as in 1946/7, and we've had a number of near misses since 2000. We've got to be vigilant but we can't always prevent flooding.

"Cockermouth had flood defences but they were simply overwhelmed.
"This scheme will go a long way to safeguarding Leeds, but you can never say never."

Find out if your home is at risk of flooding and sign up to the Environment Agency's flood warning system at
www.environment-agency.gov.uk.


City's bridges could go the same way...

SIX bridges have been washed away by the Cumbrian floods and a Leeds expert today warned some of our city's bridges may also be susceptible.

Steve Garrity, professor of architectural engineering at Leeds University, said bridges may need to be strengthened or even replaced to cope with the increased risk of collapse due to severe weather conditions.

Workington's Victorian Northside bridge had its routine check last July and was found to be in good order, but it collapsed in the early hours of last Friday, killing PC Bill Barker as he directed motorists away from the scene.

"Masonry arch bridges of the type that collapsed in Cumbria have been around for 150 to 200 years," said Steve. "They have experienced many examples of flooding but none as extreme as what happened last week.

"The problems arise because of the shape of the arch. As floodwaters rise more of the bridge acts as an obstacle to prevent the water from passing along the water course.

"Modern bridges don't tend to be arched, they tend to be flat and so you don't have the same obstructions. But back then they didn't have concrete or steel so they built them that way out of necessity."

All public sector bridges are inspected by the local authority every two years.

Because of the increased risk of flooding in recent years many have had the foundations of their supports, or piers, strengthened.

However, many of the bridges that collapsed in Cumbria were fatally undermined when the water levels reached a point where it was the arches themselves, rather than just the piers, that bore the brunt of the water.

The mortar that binds the stones together was also systematically washed away, weakening the structures and causing their collapse.

"Any bridge is always potentially susceptible to the effects of very extreme climatic conditions," said Professor Garrity, who previously ran his own consultancy practice specialising in the inspection, repair and strengthening of bridges, particularly masonry arch structures similar to those that collapsed in Cumbria.

"However, these bridges have lasted for many years, they are regularly inspected, there are well-defined procedures for looking after our infrastructure generally and the risk should be very low.

"But, as is the case with all these things, the risk is never zero and when you're dealing with extreme climatic events that risk tends to rise.

"We're trying to fight against the extreme forces of nature and it's nature, when it wants to, that tends to win."

Steve said it often comes down to a matter of quantifying the level of risk and deciding how much taxpayers' money should be spent dealing with the potential hazards.

"I suspect that a combination of flood defence, water management and a limited amount of strengthening may be sufficient in the short term.

"Beyond that it's difficult to say but it's possible that some of these bridges may need to be replaced or very seriously strengthened to cope with increasing levels of risk.

"What I would say is that it's important for people not to panic.

"Inevitably when you get these incredible pictures of people dying and communities affected in such a terrible way people tend to ask could it happen to them and is central government and the local authority doing enough.

"It's important to get a realistic perspective of what's happening.

Yes, these extreme climatic events are likely to happen more frequently but they're still comparatively rare.

"Our bridges have performed very well up to now and we have procedures in place that can cope with managing and dealing with the risk.

"The city council and other local authority engineers in our region have their fingers on the pulse. As long as central government funding isn't withdrawn with public spending cuts we should be able to cope with future scenarios."