What are trunk mains?

Trunk water mains are described in the industry as the 'motorways' of the water network, carrying a significant amount of water at high pressure. Unfortunately, in 2016 we suffered eight separate bursts on our trunk main network which caused significant damage to homes and businesses, traffic disruption, and temporary loss of water supply.

What happens when they burst

As they’re our own pipes, we do everything we can to repair the damage that was caused as a result of the bursts and to minimise the risk of any future burst mains on our water supply network. We're extremely sorry customers were flooded and lost their water supply in 2016, we understand how upsetting and disruptive this has been and as it was caused by our pipes. We work closely with those directly affected for as long as they need us and we're also committed to ensuring we play our part in engaging with the wider local community when these incidents do happen. Our main priority after any burst is to get people’s lives and businesses back to normal as quickly as possible.

How we’re working to prevent them from bursting in future

We have made some significant steps building on the recommendations from the external and internal reviews. We have delivered some of the key changes in our approach to preventing, predicting and responding better to trunk mains bursts:

• We now assure the information gathered from our front line / operational teams, and so that we can better plan work where work needs to be done now and in the future.
• We have improved our modelling working with stakeholders such as railway companies to understand more the impact of a burst trunk main.
• We have provided additional training to our operational staff so they can track alarms and alerts on the systems in place to better predict a potential burst.
• We are also piloting a new visibility tool to improve this understanding further.
• We have now put in place rapid response night shift teams available for 1 hourly response in areas where trunk main bursts have the most impact on customers.
• We have developed our plans to ensure if the worse happens we have plans in place to minimise disruption to our customers.
• We have increased the number of high consequence valve checks we do so if there is a burst we can turn the water off quickly.
• We will continue to monitor our progress ensuring minimal disruption while engaging with our customers throughout.

Trunk water mains review

Since the incident in 2016, we’re committed to undertaking an independent Forensic Review and a Trunk Mains Strategic Review. Below is a summary of what happened, the findings of the reviews, and an update on our progress so far.

The forensic and strategic review

Our Chief Executive ordered an immediate forensic analysis of all our trunk main bursts looking back over the 12 month period which was led by Paul Cuttill OBE, a leading voice in the utility sector. Paul has over 30 years’ experience in utilities, including as EDF Power Networks’ Chief Operating Officer. The report highlighted 86 areas of improvement which we then built on and addressed in the strategic review attached above.