Civil engineers have been working round the clock to restore the safe operation of services following Scotland’s recent severe weather which saw flooding, landslides, power outages and a breach of the Union Canal.
ICE Scotland members are already at the forefront of efforts to deliver robust and resilient infrastructure systems in Scotland. These assets however are being put under the spotlight to an almost unprecedented degree as the impact of climate change on our everyday lives is beginning to be more fully understood.
I was recently asked to take part on Radio Scotland’s Drivetime show for a discussion about whether our infrastructure is climate-change ready.
I was joined by ICE Fellow, Dr Andrew Black, a hydrologist with 30 years’ experience. Dr Black told the programme that one SEPA gauge in Aberdeenshire had measured 65mm of rainfall of 65mm in two hours whilst another revealed there had been 79mm in four hours.
“My calculations found this amount of rain is a once in 600-year occurrence,” said Dr Black. “But the concerns are clearly that these events are going to happen more frequently. And different parts of infrastructure are affected differently – some by intensive rain, as we have just experienced, others by rainfall over a longer duration.”
Mitigating the effects of extreme weather
The key question that all in the sector, and beyond, are now asking is: “What can be done to mitigate the effects?”
Design is clearly one aspect. At the early stages of project development, you must decide how much risk you are going to design for and what the effects of that risk will be and whether those risks are acceptable or not. If you take a simple house design the guttering might be designed to cope with 1 in 100-year rain fall for example.
Given last week’s events, gutters on houses across Scotland would have been overflowing – but the overall risk to cost ratio might be judged to be acceptable compared to the impact.
Infrastructure risk levels are of course more complex than house gutters, and as risk levels increase, understanding acceptable levels of risk becomes more of a challenge and brings into question the affordability of that level of design. Addressing this risk-to-cost ratio will be a key part of designing new infrastructure, future-proofed against the impact of climate change.
But design for new projects doesn’t preclude the work that needs to be done now. Things are changing – and we need to look at existing infrastructure as a matter of urgency to decide whether it will cope with what is being predicted for over the next 100 years.
Scotland’s existing infrastructure is already feeling the strain of climate-change pressures – severe rainfall, more frequent storms and rising temperatures. Key infrastructure networks, often dating back hundreds of years were simply not always built to withstand these new challenges.
An infrastructure retrofit
A programme of infrastructure retrofitting will be needed if we are to minimise the risk of climate-driven infrastructure failures.
Adapting infrastructure to withstand the impacts we now know are coming will lock-in the value we know our assets have and minimise the risk of disruption for infrastructure users. It also gives us an opportunity to future proof our assets in other ways too – embedding new technologies and using up to date materials.
This is no small challenge, but events of this summer have highlighted that we must act with urgency. Climate change was once thought of as something in the future, but it’s clear that the future is now.