Utility Week Live: what we learned about resilience

The past year has seen Ofwat placed under a new duty to ensure the resilience of the water sector, and a task group under the chairmanship of Waterwise’s Jacob Tompkins has explored the definition, scope and challenges of building resilience.

The threat of climate change and more extreme weather events has placed a growing spotlight on the extent to which the sector can maintain and restore service in the face of unexpected challenges.

So here’s what Utility Week Live taught us about resilience:

Increasing resilience is not simply about reducing risk.

While minimising the risk of failure is an important aspect of designing water and wastewater systems, resilience is more than this because it is all about the response and recovery when failure occurs – it can be thought of as ‘bouncebackability’ or making systems ‘safe to fail’ according to Professor David Butler, Professor of Water Engineering at Exeter University.

Resilience as a property of a system needs therefore to be distinguished from the performance of that system, he added.

This chimes in with the definition of resilience that emerged from Ofwat’s Task and Finish Group, which was: “Resilience is the ability to cope with, and recover from, disruption, and anticipate trends and variability in order to maintain services for people and protect the natural environment now and in the future.”

Cost-benefit analysis may not be reliable with resilience projects. While everybody agrees that more resilient networks and systems are a good thing, the real difficulty is establishing the level of protection that needs to be invested in – and basing a cost-benefit calculation on a ‘1 in 50 year drought’ or a ‘1 in 100 year storm’ is problematic because these climatic events are becoming so much more frequent.

“Because we can no longer rely on a stable climate, we can’t rely on return periods to establish the value of an investment,” Trevor Bishop, Deputy Director of Water Resources at the Environment Agency, said. “We don’t know how climate change will affect these probabilities – we only have the direction of travel.”

For this reason, if failure of a particular asset would represent a catastrophe, then a much higher level of protection may be justified. For example, the Dutch have determined that some key assets in the Netherlands must be protected against a 1-in-10,000-year storm, an almost unimaginable event.

Catastrophic scenarios might be low probability but they are very high cost: for example, it was estimated that the cost of a total failure of water supply to London would be £7-10 billion a week.

Non-household retail competition may help promote resilience, Ofwat believes. The regulator’s Nikki Russell said that the example of Scotland had shown that businesses had changed supplier on the basis that retailers could help them manage down their water demand, reducing bills but also boosting system resilience.

Finally, the behaviour and response of customers could be the missing ingredient in creating a more resilient water network, according to Jacob Tompkins.

He said that “social infrastructure” was just as important as hard assets, and that customer awareness could make the key difference in reducing water use and in protecting sewerage. Rainwater harvesting was also given as an example of how individuals or communities could make water supplies in their immediate area more resilient.