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Technical Excellence: Leaving floods at the door

Currently on the drawing board at UK Flood Barriers Droitwich HQ is what will be probably the most unusual conference room in the country. From the outside it will look like a conventional house, complete with doors, windows and the usual services, featuring brick and block and timber frame construction.

But the top storey will be missing – and it will sit inside a water tank.

UK Flood Barriers founder and chief executive officer Frank Kelly explains: “Once the visitors have been ushered inside, the door closed and the coffee served, the taps will be turned on and the tank filled to a depth of 600mm.

“This will be a graphic demonstration of how our Flood Angel range can keep homes and businesses safe from the ravages of flooding.”

Kelly started the business seven years ago with just one product, the anti-flood airbrick. “We noticed there was nobody specialising in flood defences, and world wide there were few products on the market. Coming from a construction background, we understood how buildings were constructed, so we were more interested in solutions than in products.”

Initial enthusiasm had to be tempered when Kelly discovered there was only one testing facility in the UK for his prototypes that could award the essential BSI Kitemark. “HR Wallingford could do the tests, but the costs they quoted were too much for us, given the number of products we planned,” Kelly says. “So we had to find an alternative.”

This turned out to be the construction of their own test tank, containing up to 40m3 of water, and its subsequent approval by BSI as a test facility. Kelly could now get down to developing the full Flood Angel range, which now includes 18 products holding ten Kitemarks, ranging from the original airbrick through barriers, walls and flood doors, to bungs and valves that prevent sewage backflow.

“The current tank can simulate the effects of waves and currents, all to the relevant British Standard,” Kelly explains. “We’re currently widening it by 3m to take the new meeting room building.”

Retrofitting property level protection is the biggest market for the company at the moment. The oldest building successfully protected dated from the 16th Century. Kelly says: “There’s only been two we couldn’t do anything for – and one of those was on an island between two rivers.” Thousands of homes have had the Flood Angel treatment, but Kelly is frustrated by what he sees as the blinkered attitudes of many developers, insurers and regulatory authorities. (See box).

On the larger scale, UK Flood Barriers can claim to be world leaders in passive flood defence technology, a claim backed up by an impressive string of high profile contracts in the UK and overseas. Star of the range is the self activating flood barrier (SAFB), which has been installed in locations as diverse as Cockermouth in Cumbria, a shopping mall in Monterrey, Mexico, and a zoo in Kemaman, Malaysia. The latest project is in New York, where a 78m SAFB will protect a medical centre against any incursions from the East River.

Simple in principle, the SAFB consists of a buoyant barrier up to 2.5m high, fabricated from Kevlar and GRP, housed in a concrete trough. It sits below ground level beneath a protective lid until water levels start to rise. Next to the barrier trough is a service pit, connected by an inlet pipe, which begins to fill with water as the water table rises and underground services are inundated.

When the water in the service pit reaches a pre-determined level, water flows through into the barrier trough, and the barrier rises, before any floodwater appears at the surface. As the floodwater reaches the barrier, water pressure forces the barrier against an angled support block, locking it into position and forming a watertight seal.

Once the flood has receded the barrier trough is drained and the barrier retracts. Kelly insists that the lifetime costs of a SAFB system compare very favourably with demountable systems, despite the slightly higher initial capital cost.

“The SAFB has zero operational costs. Once you add in the costs of erection, dismantling and storage, demountable barriers don’t look so cheap,” he says. “And there have been cases of demountable systems failing to make it from storage to their destinations due to traffic chaos caused by flooding.”

In 2009 the third major flood in four years inundated 900 properties in Cockermouth, triggering massive local demand for effective protection. Part of the Environment Agency’s £4.4M flood control project is the SAFB, the longest to date at 115m.

Protection: World's longest self activating flood barrier, Cockermouth, Cumbria

Protection: World’s longest self activating flood barrier, Cockermouth, Cumbria

UK Flood Barriers has a track record in protecting nuclear establishments, having installed two SAFBs at the Dounreay nuclear power station to protect nuclear waste storage bunkers during Dounreay’s protracted decommissioning. More possibilities were opened up when the SAFB was successfully tested for seismic resistance.

As a result, UK Flood Barriers will install SAFBs at no less than 17 French nuclear plants owned by EDF. Other prestigious clients include Crossrail, the US Government and the National Grid, although not all have needed an SAFB solution. Not surprisingly, the company is booming, with a workforce doubled in the last six months. Kelly also takes pride in the provenance of his specialised products.

“Everything is made locally, either by us or by nearby companies,” he says. “It’s taken us just four years to develop our current ‘toolkit’, with 14 products either patented or with patents pending.  

Counting the cost

“No home can be truly sustainable if it’s vulnerable to flooding,” Frank Kelly insists.

“The cost of flood protecting a new build house is usually less than the cost of replacing the kitchen after it’s been ruined by a flood.

“Planners are paying lip service to flood protection, developers don’t appear to care and new house buyers just don’t seem to understand the risks they could face.

“They seem to believe that if a I in 100 year flood happened last year, it won’t happen again for 99 years.”

Fitting a new four bedroom house with UK Flood Barriers’ Defender doors, barriers and airbricks along with non-return valves on the drainage and sewerage systems would add no more than £5,000 to the price, Kelly estimates.

“After all the major flood events we’ve had over recent years you would expect the Building Regulations to be updated to reflect the increased risks. But nothing has happened so far.”

He points out that New York amended its building codes in just seven months after Hurricane Sandy struck in 2012. Around 100,000 homes were destroyed or badly damaged: total cost of the disaster in the city was estimated to be £28bn.

“You would think the insurance companies here would be calling for the inclusion of flood mitigation in the Building Regulations, but they don’t seem to want to get involved.”

Kelly adds: “One of the problems we’re encountering is that local authority planning departments no longer have the skills needed to properly evaluate flood risks, thanks to all the cutbacks.

His company now offers “an affordable toolkit’ for flood protection and resilience, and progress is being made, with more than 3,000 homes now retrofitted as part of over 50 local authority schemes. But Kelly believes that until the insurance industry gets on board homes will still be needlessly damaged by inevitable flooding.

“Why don’t they offer reduced premiums to homeowners who retrofit their homes with flood mitigation measures?” he asks. 

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