Trunk water mains review

After a series of bursts on our trunk water main network in 2016, we committed to undertake 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.


Trunk water mains have been described as the 'motorways' of the water network. They are large pipes (18" diameter or larger) and carry significant volumes of water at high pressure.

We suffered eight separate bursts on our trunk main network towards the end of 2016. These caused significant damage to homes and businesses, traffic disruption, and temporary loss of water supply.

We're extremely sorry customers were flooded and lost their water supply. We understand how upsetting and disruptive this has been - it was caused by our pipes and it is our responsibility to put everything right.

What happens when there is a burst

Our main priority after any burst is to get people’s lives and businesses back to normal as quickly as possible.

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 work closely with those directly affected for as long as they need us. We're also committed to ensuring we play our part in engaging with the wider local community when these incidents do happen.

The forensic and strategic review

Our Chief Executive, Steve Robertson, ordered an immediate forensic analysis of all our trunk main bursts looking back over 12 month period. The independent Forensic Review 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.

Our progress so far

We have made some significant steps building on the recommendations from the external and internal reviews. At a high level we have delivered some the key changes in our approach to:

Preventing 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.

Predicting bursts

  • 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.

Responding to bursts

  • 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.