Climate data models are helping Anglian Water identify and upgrade the weakest links in their pipe network, says Dr. Tim Farewell, Director, MapleSky.
As our climate continues to warm, many across the industry are beginning to recognise the risks posed by extreme weather events. However, what may not first come to mind is the stress hotter, drier conditions are placing on our water networks and wider critical infrastructure thanks to changing soil conditions.
Understanding these effects has been central to a MapleSky research project for the past four years. Working with Anglian Water, we have been gathering insights into how changes in temperatures and rainfall, and the subsequent changes in soil conditions, have wider impacts on water networks that can lead to burst pipes and disruption to supply.
As temperatures change, so do the challenges
Whilst changes in soil condition may appear to be fairly benign on the surface, the reality is that soil expansion and shrinkage can damage water network infrastructure just as subsidence does your house. At the beginning of our partnership with Anglian Water our priority was modelling how extreme heat or cold might cause bursts on the company’s pipe network. From here, we then dug into the data to identify the most at-risk assets so those risks could be mitigated.
Whilst many companies are well versed in the potential impact that cold temperatures can have on metal pipes, our climate models show that cold winters are becoming more intermittent. The increasing risks come from how hotter temperatures are driving failures on old, cement-based pipes. These are the materials that fail most when temperatures soar and soils shift.
From research to action with the Climate Vulnerable Mains project
Hotter summers are, clearly, already a challenge for water companies. Higher temperatures mean higher consumption of water as people tend to their gardens and try to stay cool. That these same temperatures could also lead to an increase in network failures is something that all water companies should be paying close attention to.
Our initial research demonstrated that changing temperatures would have a significant weakening effect on the network. The East Anglian region’s clay and peat soils are especially aggressive to pipes, being very shrinkable and highly corrosive. Through our modelling, we then identified the most vulnerable assets in the Anglian Water network that required urgent attention. Typically, these pipes were characterised as older, small-diameter pipes which were buried in clay and peat soils and made up 10-to-20% of the network.
Once these assets were identified, the partnership moved from being one that was research-based to what is now known as Anglian Water’s Climate Vulnerable Mains project. Informed by MapleSky’s research, Anglian Water has drawn up plans to invest £1.64 billion to identify and upgrade at-risk infrastructure and implement other climate resilience measures.
This goes beyond business-as-usual maintenance: polyethene pipes, which are flexible and resilient to shifting soil conditions are being used to replace vulnerable pipes, whilst those yet to be replaced but likely to fail each season are being proactively identified and monitored to reduce impact on customers.
Understanding the broader implications
As is the case with the Climate Vulnerable Mains project (and as stipulated by the National Infrastructure Commission and Competition & Markets Authority recommendations on forward-looking risk assessment strategies), water companies need to understand the potential issues that will come from climate change, and extreme weather conditions.
This is not just an issue for those in regions with clay and peat soils. We have applied our climate-adjusted models to other regions and forecast that similar types of effects will be seen elsewhere. Even areas that currently experience more rainfall will experience these issues.
Whilst the ultimate solution is to achieve net zero globally as fast as possible, we cannot wait until that happens. It is crucial that water companies and other utilities take an evidence-based, forward-looking approach to risk assessment so they understand how our changing climate can and will affect critical services. It is only by making research-informed investments that we will be able to ensure that the services we rely on every day will be resilient to the coming changes.
