The Government has announced 93 new flood defence schemes that should be in place by 2015 to improve protection for some 64,000 homes and “unlock” up to £1 billion of new economic activity, says Jon Herbert.

 

The Government has unveiled plans for £120 million of new flood defence spending in addition to £2.3 billion already earmarked for flood and coastal erosion protection work up to 2015.

Ministers say they are being extremely prudent with the spending of taxpayers’ money and are bringing in an extra £148 million on top of the original total through partnership schemes with local councils, business and private partnership investors.

They point to £50.5 million to be spent in Leeds that the Department for Environment, Food and Rural Affairs (Defra) estimates will protect 495 businesses in the city and create some 18,000 new jobs.

However, they face criticism from Shadow Environment Secretary, Mary Creagh, who says that they have wasted two years looking for “shovel-ready” infrastructure opportunities to boost economic activity while 294 flood schemes have been cancelled or postponed.

More flooding forecast

Whatever the merits of the arguments, more flooding is here to stay. Retiring Government Chief Scientist, Sir John Beddington, has identified flood hazards as a major threat needing urgent action at many levels. As he left office in March, he warned that there is already enough CO₂ in the atmosphere to cause more flooding and droughts over the next 25 years.

The later Government leaves it, the tougher and more expensive it will be to combat, he said. The phenomenon the UK in particular is experiencing is uncertainty in normally quite stable seasonal weather conditions.

“The variation we are seeing in temperatures or rainfall is double the rate of the average,” said Sir John. “That suggests that we are going to have more droughts, more floods, more sea surges and more storms,” he added, noting that the effects would be on “quite a short timescale”.

The evidence that climate change is happening is “completely unequivocal, but partially masked by the slow rate at which the world’s climate system changes”, Sir John noted. He predicted a time horizon of 20 to 30 years.

Be prepared

The Environment Agency is already planning for changing weather patterns, with an emphasis on more flood warnings and defences. The agency’s Chairman, Sir Chris Smith, has noted that when the first big floods hit in the summer of 2007, not only homes and businesses but also vital infrastructure was badly affected, including electricity substations and water treatment plants.

This is reflected in the Government’s recent announcement of more flood defence spending.

Defra believes that 165,000 homes will be better protected by 2015. That would be some 20,000 above the previous target.

As a further example of the strategy at work, more than 1000 new jobs will be created in Exeter where 4700 existing jobs will be protected, according to the department.

Environment Secretary Owen Paterson says the improvements will be very welcome. “The 93 schemes given the green light today will bring huge relief to tens of thousands of homes and businesses that have lived with the fear of flood waters hitting their doors. They can get on with their daily lives and work knowing that there are well-built defences.”

The largest of the new schemes is an £80 million coastal defence at Rossell on the Wyre peninsular in Lancashire, which will give further protection to some 7000 valuable homes.

In addition to the £10.5 million being spent in Leeds, flood defences costing £14.5 million at Grimsby Docks in Lincolnshire will enhance protection for 4000 homes.

At Great Yarmouth in Norfolk, £28.6 million will be spent on sea defences, and new sea defences at Anchorsholme in Lancashire will cost £28.4 million. More than £16 million is also to be spent on River Thames tidal defences.

A further major scheme will spend £10 million to protect Littlehampton in West Sussex through improvements to the east bank of the River Arun.

Insurance cost rises

With one home in six now at flooding risk, part of the burden of flood damage is being borne by the insurance industry and a rise in household premiums. The Association of British Insurers predicts that “the exceptional is going to become the everyday”. It is concerned to see not only better flood defence management, but also no new houses built in high flood-risk areas.

Interestingly, the public has very practical views on the likelihood of more common and widespread flooding.

One concern is the prospect of new flood defences on flood plains shifting flooding patterns on to homes that are historically not at risk. Worries that un-dredged rivers will not be able to cope with peak flood flows is another. The fact that workmen are no longer employed to clear rural drainage ditches is noted, and other people put local flooding problems down to blocked drains.

At a more strategic level, some comment that the Government is using taxpayers’ money on civil engineering projects to undo the damage caused by tarmacing green land. The idea that public finance is being spent to repair damage caused by private building on flood plains is annoying to many.

Another view is that flood defences are so expensive that it is time to concentrate on making individual houses more flood-proof.

High-altitude winds

The cause of erratic UK weather has been studied by other scientists, including Professor Tim Palmer of the University of Oxford. The culprit seems to be more fluctuations in the jet stream, the high-altitude wind that circles northern latitudes. This could create a climate with many more extremes, he predicts.

“When the jet stream moves to the north, and then travels back down to the UK, it brings with it cold air, blizzards, and severe and unpleasant weather from that perspective,” Professor Palmer explained.

He noted that, alternatively, when the jet stream moves south, it brings periods of intense flooding of the type seen in the second half of 2012.

The concern is that, with climate change, jet stream variations could intensify. This is now the subject of very active research but, as yet, there are no clear answers. However, there is a high possibility that the jet stream will undergo “quite dramatic and erratic excursions”, according to Professor Palmer.

“I think it is a bit unwise, and possibly even a bit dangerous, to think that the climate of the UK will just gradually warm and we will transition to a balmier southern European climate.

“If the ideas about a more fluctuating jet stream are correct, then in fact what we will be seeing is a climate with many more extremes of both weather and flooding on the one hand, and extremes of dryness and possibly even coldness on the other.”

Storm surges

Another danger to coastal flooding is the phenomena of storm surges. Again, it is unclear what effect global warming will have on their frequency and severity. To date, the most destructive surge saw extensive damage to Britain’s east coast in 1953, killing more than 1700 people.

The danger arises from an upwelling of a large area of sea caused by intense low pressure at the centre of a storm that “pulls” the surface well above its normal level, creating a massive bulge that can be several metres high. On top of this platform, storm winds whip up waves that can be more devastating still if there is a high tide. In the North Sea, the narrowing English Channel has a further funnelling effect that can raise surge levels still further.

Planning defences against the unpredictability of future surges is another technical and financial challenge for government policy makers.

The fact that the south east of England is sinking slowly, while sea levels are rising, makes a tremendous difference. Even a few centimetres rise in mean sea levels adds significantly to the destructive pounding that coastal defences are expected to take. This, in turn, affects the strategy and cost of investing in long-term coastal stability.

Flooding infrastructure will be a UK problem for the indefinite future.

 

 

First published by Croner-i on 21 May 2013