BBC Radio Somerset came calling this week, wanting an engineering opinion on how much it would cost to raise a 3km stretch of the A361 across the flooded Somerset Levels.
Engineering judgement please, not political hysteria
Best estimates suggested that the road in question could be protected for anything from £5M to £50M. It’s not a huge sum and wouldn’t be a difficult project to complete. But to what end? Perfectly adequate diversion routes exist, no lives are being threatened, and no businesses are being disrupted.
Much hysteria surrounds the Somerset Levels at the moment with everyone from the prime minister down promising immediate action to… do what exactly? Dredging seems to be the favourite for those seeking instant action, even though it is costly, environmentally damaging, and, for this latest flood incident at least, utterly ineffective.
As any engineer worth his salt knows, the river channels in question are too small to contain extreme floods, even after dredging. Yes, you can increase the flow of a river by dredging, but that is likely to cause faster and more dangerous floods downstream when the water hits the nearest urban bridge (something the residents of Taunton and Bridgwater should be very worried about).
And it’s not just dredging. All kinds of wild solutions are being proposed, not least the raising of the A361. Many railways run on embankments, I was told, so why not the A361? Well of course it could. But why? On what rational grounds?
My argument was that the government has a £377bn infrastructure pipeline featuring 646 projects and programmes all of which have sound benefit to cost ratios and as a result must be better bets than attempting to hold back the tides on the Somerset Levels. One such scheme is the £100M Boston Barrier in Lincolnshire.
This would protect over 15,000 properties but has yet to get an official start date despite years of planning.
Implementation of the plan - and schemes like Boston’s - hinges on a lot of private investment being found and on the government holding true on its public investment promises. The reality is that there is not going to be enough money to respond, knee-jerk style, to every crisis.
So our job as engineers is first to talk sense; give a dispassionate, reasoned response to all the hysteria. Already I think we’ve been too quiet on that. And then we’ve got to get smarter and start selling our vision for the infrastructure of the future.
Last week University College London launched an executive leadership programme that aims to build a powerful, influential network of leaders who will develop a built environment fit for the future. It did so by calling on London mayor Boris Johnson to set out his vision for 2050. It was typically bold an d zany stuff. But I sense he was deliberately goading us traditional engineer-types to think bigger; to think outside the box.
Can we think big? Can we devise and then sell a better solution than dredging rivers and raising roads across the Somerset Levels?
Let’s do it.
- Mark Hansford is NCE’s interim editor