The review is being led by David Balmforth, technical director of consulting engineer MWH, who is also a visiting professor of Imperial College London and former president of the Institution of Civil Engineers (2014/15).
David Balmforth’s team has been tasked with determining: what might have led to the damage; if it could have been prevented or predicted; any lessons to be learned from the failure.
An interim report is expected to be made to the environment secretary by the end of the year. Following this, the review may be extended to consider any wider improvements needed to current reservoir safety or amendments to the 1975 Reservoirs Act.
Residents of Whaley Bridge had to be evacuated after high water levels on 1st August damaged the spillway of Toddbrook reservoir. The Canal & River Trust, which owns and operates the reservoir, worked with its contractor Kier as well as the Environment Agency, fire and rescue service and the Royal Air Force to reduce water levels and to repair damage to the spillway to make it safe for residents to move back in.
How the various parties responded to the incident and the current integrity and future repairs to Toddbrook Reservoir are outside the scope of the inquiry. But how well the Canal & River Trust has been maintaining this and other structures around England and Wales is now very much under the spotlight.
The Canal & River Trust was formed as a charity in 2012, taking ownership of public assets from British Waterways.
The trust says that Toddbrook reservoir was visually inspected twice weekly by Canal & River Trust operatives and inspected twice year by reservoir engineers. It also undergoes a detailed 10-yearly inspection by an independent inspecting engineer – the last one at Toddbrook took place in November 2018 and this did not identify any immediate repairs needed to the spillway.
Environment secretary Theresa Villiers said: “I’m pleased that the independent review into the incident at Toddbrook reservoir, which I commissioned last month, is now well underway.
“I expect this review to provide valuable insight into how this incident came about, and I hope it will also offer peace of mind to local residents. The outcome of the review will help inform how we can further improve this country’s excellent reservoir safety record.”
David Balmforth said: “England has an excellent reservoir safety record and the speedy action of many organisations helped keep the community around Toddbrook reservoir safe during the highly unusual incident earlier this year.
“However, it is important that we uncover the causes of the damage to the dam and identify any lessons which can be learned, and I look forward to taking that work forward.”
Since the summer the Environment Agency has ensured that water levels at Toddbrook Reservoir are monitored and remain at a safe level until full repairs are completed. The Canal & River Trust is still assessing the damage and identifying how the reservoir should be permanently repaired in the longer term.