The UK is relying on a legacy of a victorian engineering and is reluctant to spend what is needed to improve its water management network. Richard Stirling hears from concrete pipe makers about the state of British Infrastructure.

THE DIFFERENCE between Victorian engineers and their 21st Century counterparts is that the former built infrastructure as a monument to their own skills and ingenuity while the latter are hampered by
tight budgets, framework agreements and lightweight materials.

The brick-built sewers left behind by the Victorians still transport our waste water but Richard Raymond, vice chair of the Concrete Pipeline Systems Association, says the infrastructure going into the ground these days suffers from short-termism and a lack of understanding when it comes to specifying materials.

“We seem to design at a cost these days,” he says. “We do get asked what the design life
of a pipe is, but customers are not interested in the long-term. They’re interested in the end of their framework agreement in five years’ time. “If Isambard Kingdom Brunel had built the London to Bristol railway to the cost constraints that we have it wouldn’t have been built at all.”

Ripples of disapproval
Raymond says much of the recent flooding across the UK was caused because the pipes used for water management are too small. He says the short-term attitude of many designers towards infrastructure projects hampers their judgement when it comes to specifying sufficient capacity to cope with freak conditions.

“The size of pipe needed isn’t just governed by the numbers of houses and roads,” he says. “It’s also governed by the nature of the flood and whether we experience a one–in–100-year or 60-year storm.”

Whereas the Victorians used brick to build their solid water infrastructure, engineers today don’t have the same pool of skilled labourers. As an exponent of precast concrete, it will come as no surprise that Raymond wants specifiers to consider precast as an alternative material for its robustness and speed of installation.

“The concrete pipe will offer the right design because it starts from 300mm upwards,” he says. “Once it’s built, we have got a very sound system. The joints are good and the pipe is inherently strong. Also if we’re talking about waterlogged ground it’s not susceptible to floatation and it will stand up to
the maintenance regimes and take the jetting pressures.”

Stemming the flood
Designers, particularly of small to medium sized developments, are using large attenuation tanks to manage flood water. The mechanics of these huge tanks aren’t complicated; they store the water that runs off the paved areas of developments and releases it slowly into local water courses.

As a fervent backer of building in concrete, Raymond is suspicious of lightweight plastic attenuation tanks. “If you’re going to store water in these tanks you’ve got to make sure they are safe and secure,” he says. “In the US, Australia and South Africa they have had problems with fuel spillages getting into the tanks and then setting alight. If you’ve got attenuation tanks made from plastic, they will melt and then you have further problems because the void you created just isn’t there anymore so you end up with land slippages.”

He says this could potentially be an issue for projects such as airports where safety and security are top of the list.

Rainwater harvesting is also proving popular with designers as a way of managing the water that comes off the increasingly large paved areas.

“This is one issue that’s coming to the forefront,” Raymond says. “Here we are in the 21st Century and what we flush our loo with is fully treated drinking water, which is a total waste. We don’t need to do it.”

He recommends the UK looks across the Channel to how other European countries manage rainwater for domestic use. It is used for flushing toilets and in washing machines where rainwater is better at getting clothes clean.

“Concrete tanks are excellent for rainwater harvesting,” Raymond says. “The issue isn’t loading but more to do with land slippage. With concrete you’ve got a sustainable item that’s not going to crack and break.”

If the UK is to avoid a repeat of the devastation it experienced in the wake of the recent floods it will have to invest heavily in its infrastructure. And when it does, it will have to take a long-term approach to flood defences. With the advent of climate change and the disruption of our weather patterns, what were once one in 100-year storms will become more frequent. The odds of the infrastructure failing again will rise along with the water around the homes of the hapless victims of flooding.

If we don’t have the resources at our disposal of our Victorian predecessors, then perhaps precast concrete will come to our aid.

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