03 November 2011, UK -- The water industry must be careful to avoid climate change ‘tunnel vision’ when considering the challenges facing water sector planning, said Graydon Jeal, chief consultant at Atkins.
Graydon, who spoke at the Water 2011 conference in London last month, has identified a raft of other significant threats, and is urging senior UK water sector decision makers to establish smarter, more flexible approaches to future asset design.
Outlining the planning difficulties posed by ambiguity relating to climate change as well as a myriad of other variables such as population growth and water demand, he said: “The UK climate projections give us a much better appreciation of the uncertainty we are facing rather than just viewing climate change as deterministic – but climate change impacts are still not as set in stone as you might think. There are other unknown factors that must also be recognised.”
Graydon highlighted that the uncertainty in the climate change projections is multiplied when considered in the wider context of other key variables. He highlighted that:
- The 2008 UK national population projections estimate anything from a 5% increase in population in the next 50 years to as much as a 50% increase;
- The Environment Agency’s water resources strategy developed scenarios ranging from a 15% reduction in water demand through to a 35% increase over the same time period.
“These are really chunky statistical variables,” explained Graydon. “We are building assets now such as reservoirs, pipelines and treatment works that we hope to still be around in 50 years and they need to be able to cope with this magnitude of uncertainty.”
Urging water industry leaders to not suffer inertia and be tempted to take no action at all in the face of such enormous ambiguity, he said: “We have to do something. We need to take a two-fold flexible and adaptive approach. Short and medium term assets where capacity can easily be increased retrospectively should be designed with less conservative assumptions and shorter design horizons. For assets that we can’t easily go back and upsize, we should adopt a precautionary approach with conservative assumptions on things like climate change and population growth.”
Considering the complications and costs posed by carrying out an economic justification for each single asset on a design-by-design basis, Graydon said: “It would be sensible to adopt some general pragmatic principles and best practice based on the risk of failure of certain types of asset. Flexible, adaptive designs and approaches will play a useful part in how we respond to the challenges ahead.”