In deep water?

Environment Business talks to Environment Agency Thames Estuary Strategy Manager Peter Borrows about the flood risk to development in the Thames Gateway

Deputy prime minister John Prescott hasn’t had an easy time of it over the last couple of years. His plans for regional assemblies collapsed in a wave of apathy, and ODPM’s plans to meet the UK’s demand for more housing – dubbed Sustainable Communities – has been constantly sniped at as being anything but.

Plans to build tens of thousands of houses in the Thames Gateway, which stretches from East London to the mouth of the River Thames, have been attacked as a recipe for the destruction of the countryside, and as a reckless scheme to build in areas prone to flooding. But is the risk as high as has been claimed?
It appears that the Association of British Insurers, which represents about 400 companies, thinks so. The latest to put the boot in has published a report claiming that with up to 108,000 planned homes in floodplains, up to 10,000 face the risk of significant flooding without proper planning.

This was certainly a blow for housing and planning minister Keith Hill, who accused MPs who questioned the plans in the House of Commons last year, of scaremongering. When questioned by the Conservative MP for Rayleigh in Essex Mark Francois on the subject he erupted: “Every possible measure is being taken to increase the already high levels of flood defence in the Thames Gateway.”

Lib Dem Ed Davey had claimed protecting the newly developed areas could cost up to £5 billion, prompting a further angry reply from Hill. Davey was “simply wrong to conjure the expression ‘floodplain’ out of the firmament and imagine that is in itself a threat”, he insisted. “It is not, and he is doing wrong in even ventilating the possibility of a threat arising from the existing flood plain in its own right.”

A complex decision

While environmental groups, which are inclined to oppose development as a matter of course, have latched onto the flood risk as a weapon in the fight against the Gateway plan, Hill may well be right.

Environment Agency Thames Estuary strategy manager Peter Borrows says: “The government has to take all sorts of things into account. The pressure for housing is in the south east, and there are positive aspects such as areas of natural beauty which will be further protected as part of the plans.

“Transport’s good, and the area is close to Europe. And the fact remains that in the Thames Gateway, the area that’s potentially at risk from flooding has the highest levels of protection in the United Kingdom. This must have helped the government come to the decision it has, although it doesn’t mean that there is no risk.”

Mitigation measures

There are three forms of flooding to which the Thames Gateway is vulnerable. Tidal flooding from the North Sea up the estuary, fluvial flooding from rivers as a result of heavy rainfall, surface water flooding caused by drainage systems failing to cope, and run-off from impermeable surfaces such as roads.

Borrows says: “In terms of river flooding, in the Gateway area it’s not a major problem, apart from in the lower River Lea, where the standards of protection are just about what the ABI would like to see. And there is a very high standard of protection from tidal flooding.

“We use the jargon ‘once in a thousand years’, but what we mean is that the chance of something happening to the defences are on average 0.1% in any one year.”
While this still represents a risk, and one which clearly would be aggravated by the huge number of houses covering the affected areas, there are mitigation measures that can and should be put in place.

“You have to think about just what sort of building types and what sort of occupancy you have,” Borrows says. “And that depends very much on what depths of water you might be likely to experience. Clearly if you are right behind the flood defences the chances are that you are going to have to contend with higher depths of water than if you’re on the fringes of the floodplain.

“So you’re not going to want to put single storey buildings occupied by vulnerable groups like children, the elderly or infirm in areas where potentially their lives would be at risk in the event of something happening, however remote that might seem.”

Planning problems

Carefully prepared drainage plans are also essential, and government is proposing that the Agency has a role in making sure this happens. However, communication with local authorities on flood risk has been less than perfect.

In January the Agency warned that while “local planning authorities are taking on board the message about not developing inappropriately in the flood plain”, it was concerned that “some are not always following clear government policy which is designed specifically to ensure that development needs can be met without creating unnecessary flood risk”.

Agency chief executive Barbara Young said: “We are concerned that, three years after the publication of Planning Policy Guidance 25, some local authorities are not consulting the Agency on all applications in flood plains. There is a persistent core of applications being approved contrary to our advice, including a small but significant number of major developments, many of which are for homes.
“In view of climate change and the growth in housing needs, it is all the more important that we avoid planning decisions that create new flood risks to people or property.”

However, Borrows says that authorities in the Thames floodplain are not the worst culprits. “Within the Thames region there are very few developments that proceed against the Agency’s advice, although it would be nice if there were none,” he says.

“Ultimately we are not the planning authority – the local authority has to make that decision and has to consider a whole range of circumstances. I don’t think we should be too despondent in the Thames region about the actions of local authorities. By and large they’ve taken on the principles of PPG25. There are debates about just how far you go to manage flood risk and that’s inevitable. It’s the job of local authorities and the Agency to insist on high standards.”

But ultimately it will be those living in the Thames Gateway who will have perhaps the greatest role to play. Sustainable drainage means householders refraining from paving over their front yards to park their cars on, and taking measures to mitigate climate change, be it through installing energy efficient appliances in their new homes, or using public transport to travel to work in London rather than drive.

Partnership for the future

“Climate change is probably the number one issue facing this planet, and ultimately that comes down to individual behaviours,” Borrows says. “We all want to fly off to remote places, we all want to get in our cars and drive everywhere, we all want more and more possessions, all of which take energy to produce, yet no one wants to be flooded.”

Developers and housebuilders also have an extremely important role to play in making the Thames Gateway a success. Energy and water efficient devices can be installed in the new houses, and sustainable drainage can be taken into account.
Government can ensure that transport systems are sustainable, that flood defenses are adequate, and that local authorities make informed and sensible decisions. The Agency too has a role to play, as do water companies.

Demand for housing is a reality, and one that must be addressed. The Thames Gateway has the potential to develop into a truly sustainable community, but without partnership Prescott’s plans may not become a reality.

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