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Toddbrook report issued


Tim Lewis

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Canal & River Trust welcomes independent reports into Toddbrook Reservoir
 
The Canal & River Trust welcomes the Government-commissioned Independent Reservoir Review report from Professor Balmforth which examines the cause of the damage to Toddbrook Reservoir last summer and makes recommendations for the improvement of reservoir safety across England and Wales. 
 
Both the Balmforth report and a separate independent report by expert reservoir engineer Dr Andrew Hughes, commissioned earlier by the Trust and also published today, identify that serious hidden design flaws, inherent in the concrete auxiliary spillway from the time of its installation in 1970, caused its partial collapse on 1 August 2019 following several days of heavy rainfall.
 
Since the incident last August, the Trust has implemented measures to enhance reservoir inspection and maintenance and will now be fully reviewing both reports and acting on their findings to ensure the ongoing safe stewardship of the reservoirs in its care.
 
The events last summer, although happening after heavy rainfall, were unexpected.  At no point in the Toddbrook spillway’s 50-year history were design flaws identified; successive inspections by independent engineers - from the Government-appointed All Reservoir Panel, in accordance with the Reservoirs Act - did not raise any questions about its design until the most recent independent inspection report. This was received by the Trust only three months prior to the incident and did not identify an immediate threat to safety, or direct that any urgent precautionary measures be taken.
 
The Trust acknowledges that maintenance of the spillway in some periods of its 50 year life – including pre-2012 under Government-owned British Waterways – might have been more stringent; although both Professor Balmforth and Dr Hughes conclude that the inherent design flaws mean that it is very likely that the spillway would have failed in an extreme weather event regardless.
 
Richard Parry, chief executive of the Canal & River Trust, comments: “I welcome the publication of the independent report into the cause of the spillway failure at Toddbrook reservoir last summer, and its recommendations to enhance safety across all reservoirs in England and Wales.  Keeping people safe is always our top priority; we welcome any steps that reduce risks to local people and are fully committed to acting on all the lessons learnt from this incident and taking the actions arising from both these reports.
 
“Once again, I would like to thank the emergency services for their heroic efforts last summer, the residents of Whaley Bridge who have coped magnificently with the disruption, together with the Trust’s employees, volunteers and partners. The Trust has begun preliminary work on repairing Toddbrook reservoir prior to its full restoration, and we remain fully committed to liaising closely with the local community as our repair work progresses.”
 
Recent improvements made by the Trust include:
·       Reviewing the design features of all Trust-operated reservoirs and – as a precaution – managing water levels to remove any risk pending the completion of these reviews
·       Strengthening its reservoir team with an experienced reservoir engineer recruited to oversee the Trust’s reservoir management
·       Enhancing reservoir surveillance and vegetation management
·       Establishing a major investment programme to reduce any risks identified and ensure the highest levels of public safety; the Trust has set aside an additional £30m for reservoir works over the next three years, on top of its existing annual £25 million major works programme.
 
The Canal & River Trust’s reservoirs and waterways are a vital element of the UK’s infrastructure, and the reports published today provide an important opportunity for all reservoir owners to learn from what happened to ensure the highest standards of public safety in the future.

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Amazing where all the money comes from when Richard's in the mire.

Noted particularly "managing water levels" and "vegetation management", both of which were sadly lacking before the event.  And "reservoir surveillance" was withdrawn when the last watcher was removed from his cottage.

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1 hour ago, Tim Lewis said:

managing water levels to remove any risk pending the completion of these reviews

I was sort of hoping with the biblical deluges of this rainy season (formerly known as autumn, winter and spring) the canal system wouldn't run out of water during the hose pipe ban season (formerly known as summer). Maybe not then.

 

Jen

  • Greenie 1
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https://www.gov.uk/government/publications/toddbrook-reservoir-incident-2019-independent-review

 

"In his report of his 2018 inspection, submitted to CRT in April 2019, the Inspecting Engineer correctly identified the risk posed by the spillway, and recommended measures that would likely have addressed the deficiencies in the longer term. The incident occurred before work had started, however. He required CRT to complete an investigation of the spillway over the following 18 months and required full maintenance of the spillway to be undertaken. However, in wording his requirements, he did not convey any sense of urgency or require any precautionary measures, such as a draw down of the reservoir. Where significant and credible risks are identified that threaten the safety of a reservoir then the seriousness of that should be unequivocal in the wording and timeliness of measures in the interests of safety (MIOS) and/or statutory maintenance."

 

https://canalrivertrust.org.uk/refresh/media/thumbnail/41505-report-on-toddbrook-reservoir-by-dy-andrew-hughes.pdf

 

"I conclude, admittedly with the benefit of hindsight, that there were indications, that an experienced reservoir engineer should have identified, of the flaws in the design and the potential for a problem to exist and develop. The Canal & River Trust could reasonably expect to rely upon this expertise to identify and alert them to any risks and the warning signs could have been recognised by those reservoir engineers earlier; indeed the latest Inspecting Engineer should have required more urgent action to investigate the spillway than he specified in his formal report, submitted in April 2019. If that had happened, then the failure/ incident could well have been avoided."

 

Both reports say that the external Inspecting Engineer had failed to draw CRT's attention to the urgency of dealing with the identified deficiencies in the spillway.

Edited by David Mack
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I got into an awful lot of trouble on YouTube for pointing out that Richard Parry knows an awful lot about trains... I mean, the idea that a team dealing with the safety of reservoirs should have an engineer who knows about reservoirs in charge of it? Ridiculous. They probably cost more than just getting some bloke to look over it every now and then...

After all, that's why I've currently got the milkman fixing the oil leak in my Lister. He's only on nine quid an hour, the guy down the bloody boatyard wanted fifty!

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From one of three reports by Graham Aldred which I understand was made available to the Government investigation last December (also leaked to CRT)

 

Quote

I am confident that there are significant water erosion channels under some Apron
panels because on occasions I have seen pulses of water mixed with air, hiss and
bubble and burst out of the spillway panel gaps at the LH corner where the first panels
were lifted. It happens when the reservoir is high enough for strong waves to be hitting
the underside of the Apron with enough pumping power to provide these observable
pulses on the spillway. This is the fundamental evidence for the cause of last month’s
near catastrophe....there were water erosion channels underneath the concrete Apron.
Forensic examination after careful lifting of various panels will confirm their existence.

But will that happen?

Further evidence is provided by numerous local users of the Dam footway who, like me,
have also seen that the top panels in the LH corner of the spillway are very often wet
when all of the Apron and other Spillway panels are dry, evidence of erosion channels
underneath the panels. There is another pair of panels in the centre, halfway down the
spillway which are wet when all others are dry. This is even visible on recent media
video and photos.

Bearing in mind that the dam is inspected twice per week, it is difficult to understand why the government report does not make more of this.

 

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1 hour ago, David Mack said:

Who is Graham Aldred and what are his reports?

Graham Aldred is an engineer and a local resident. He has strong connections to the reservoir and surrounding area and experience of dealing with CRT.

His reports are -

Toddbrook Reservoir Dam Report - Sept. 2019
Analysis of the Damage to the Toddbrook Dam - Dec 2019

Toddbrook Reservoir Incident - Proposed Modifications and Repairs - Feb 2020

As far as I am aware these reports have been circulated to local MP's, Councillors, local newspapers, the Balmforth team and some Whaley Bridge locals.

 

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  • 2 weeks later...

Having read the Balmforth report, I find the overall conclusion of value.

 

The cause of failure at Toddbrook Reservoir on the 1 August 2019 was the poor design of the spillway, exacerbated by intermittent maintenance over the years which would have caused the spillway to deteriorate. It has not been possible to say whether it was the poor design or the intermittent maintenance that was the primary cause of failure on the day. With consistent good quality maintenance over the years leading up to the event the spillway may not have failed. However, it would have been unlikely to survive the probable maximum flood which is many times greater than the flood in which it failed.

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9 minutes ago, Heartland said:

Having read the Balmforth report, I find the overall conclusion of value.

 

The cause of failure at Toddbrook Reservoir on the 1 August 2019 was the poor design of the spillway, exacerbated by intermittent maintenance over the years which would have caused the spillway to deteriorate. It has not been possible to say whether it was the poor design or the intermittent maintenance that was the primary cause of failure on the day. With consistent good quality maintenance over the years leading up to the event the spillway may not have failed. However, it would have been unlikely to survive the probable maximum flood which is many times greater than the flood in which it failed.

Absolutely!

Many boaters have been misled by reading CRT's press release paying scant attention to the government report.

Here is what the Sunday Times had to say -
 

Quote

 

The owners of a dam above Whaley Bridge were repeatedly warned about safety issues before heavy rain caused it to fail last year, putting thousands of lives at risk.

An independent report shows how the Canal & River Trust (CRT) failed to carry out essential maintenance to keep the dam safe for residents of the picturesque Peak District town.

The CRT released public statements after the Whaley Bridge incident about the dam being in a “sound condition”, said the report. However, following an engineer’s 2018 inspection, the condition of the reservoir was quietly downgraded by the trust from C to D. Grade D is classed as “poor” with “structurally significant defects leading to loss of stability” generally in five to 10 years.

More than 1,500 people were forced to leave Whaley Bridge when the spillway section of the reservoir, a concrete slope used as an emergency overflow, began to crumble last August.

The incident triggered a meeting of the government’s Cobra committee. A rescue operation was launched by the RAF and emergency services to save the town, which was in danger of being washed away by 300 million gallons of water.

The dam wall was shored up with sandbags from a Chinook helicopter and the reservoir drained by the fire brigade.

Government sources are understood to be “highly concerned” about the condition of the other 71 reservoirs across the UK currently maintained by the CRT. One Whitehall source said: “This report shows a worrying lack of urgency for important repairs that were recommended, in some cases for years, by inspection engineers.

“We are taking steps to ensure this is not the case with the other reservoirs maintained by the Canal & River Trust.”

There are about 2,000 dams in England and Wales and 800 in Scotland. They create reservoirs for drinking water, fill local canals, help farms or are used for recreation. Many are above towns and cities.

The report’s author, Professor David Balmforth, warned of a gap between owners of reservoirs being “compliant with the current legislation” and “what is actually safe” for communities living in the shadow of the UK’s dams.

“Despite Toddbrook reservoir [next to Whaley Bridge] being compliant in terms of the legislation, it wasn’t actually safe,” said Balmforth. “We are now looking at how we can better improve the safety of our reservoirs across the country.”

All UK reservoirs with a capacity more than 5.5 million gallons (25,000 cubic metres) must comply with the Reservoirs Act. A civil engineer has to file an annual safety report to the Department for Environment, Food & Rural Affairs (Defra).

Katie McRoberts, 26, who has a baby boy, lives in Whaley Bridge in one of the closest houses to the dam wall. She bought the house weeks before the disaster. “I moved in about a month before it happened,” she said. “I’m still worried about it, especially now I have the baby.”

Balmforth’s report found that Toddbrook Reservoir’s spillway had a “poor design” and intermittent maintenance”, which led to its failure.

The report, published last week, revealed:

 

  • From 2015 to 2018, the supervising engineer at Toddbrook stated in four separate reports that vegetation on the dam could cause cracks and create weaknesses in the joints.
  •  No action was taken on recommendations to seal joints and cracks despite warnings before the dam’s failure, which were “material to the failure of the spillway”
  •  An inspecting engineer identified “key safety issues” in 2018 and gave 18 months for joints to be properly sealed, but no work was carried out
  • The original design of the spillway section, built in 1969-70, was flawed because the concrete slabs were thin and lacked “sufficient reinforcement”


The Sunday Times has previously used the Freedom of Information Act to obtain safety inspection reports from the CRT. They were returned heavily redacted with negative comments from inspectors obscured.

As well as four reservoirs in the Peak District, the CRT has reservoirs that feed Huddersfield Narrow Canal at Sparth, Slaithwaite & Diggle, while in the West Midlands it has Windmill Pool, Terry’s Pool, Engine Pool, Cofton, Upper Bittell, Rotton Park and Chasewater, feeding Birmingham’s canals.

Richard Parry, CRT chief executive, said that keeping people safe was its “top priority”.

“We welcome any steps that reduce risks to local people and are fully committed to acting on all the lessons learnt from this incident,” he said.

Sir James Bevan, chief executive of the Environment Agency, said: “Our reservoirs have an excellent safety record, but any incident is one too many.

“The EA will act quickly to implement these recommendations. We will continue to work closely with all reservoir owners to ensure they are maintaining and monitoring their reservoirs in line with our high safety standards.”

 

 

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Yes,

 

The report does show there are issues that CRT must address, and yes their report did not truly reflect the 22 recommendations by David Balmforth.

 

Should the CRT re focus on its responsibilities and duties and not continue to wander into the tangential worlds that often accompany Trusts where all forms of diverse issues are brought into the fold distracting from a principal purpose of running and maintaining the waterway. 

Edited by Heartland
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1 hour ago, Heartland said:

Yes,

 

The report does show there are issues that CRT must address, and yes their report did not truly reflect the 22 recommendations by David Balmforth.

 

Should the CRT re focus on its responsibilities and duties and not continue to wander into the tangential worlds that often accompany Trusts where all forms of diverse issues are brought into the fold distracting from a principal purpose of running and maintaining the waterway. 

CRT have been rather naughty with its 'independent' report. Unlike Defra, who published TOR before the the report was commissioned, CRT's terms of reference appear to have adapted to provide a counter to the Balmforth report.

From  CRT board minutes, September 2019 -
 

Quote

Dr Andrew Hughes will take on the external investigation into Toddbrook and the Trust’s management of it’s reservoirs ...as

 

However, Dr Hughes, in his report, gives his TOR as -
 

Quote

I was commissioned by the C&RT to undertake the following task:

  • Investigate the nature and root cause of the Toddbrook Reservoir auxiliary spillway failure on 1st August 2019 including a review of the history of the installation and development of the spillway from 1st December 1964 to 1st August 2019

The Balmforth report says -
 

Quote

It has not been possible to say whether it was the poor design or the intermittent maintenance that was the primary cause of failure on the day

but guided by the 'new' TOR Dr Hughes had to make a choice.

Is anyone surprised that he chose the 'cause' that was less damaging to CRT?

I would agree that CRT should concentrate on discharging its statutory duties as a Navigation Authority. I'm not sure the Toddbrook wake up call will achieve that.


 

 

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That’s a blast from the past for me. Professor Balmforth was the head of the School of Engineering at Sheffield City Polytechnic/Hallam University when I was an undergraduate. Was a political animal, never had the pleasure of being taught by him. In fact I’m not sure in three years I ever saw him.

 

JP

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  • 2 weeks later...
1 hour ago, Tim Lewis said:

Sounds like a sensible plan - the full repair is clearly going to be a large project.

 

A rail and bogey system has been introduced along the top of the dam wall to reduce manual handling.

 

Hope that they really mean bogie!

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  • 1 month later...
3 hours ago, Tracy D'arth said:

The information request referred to in the article can be found at -

 

Trust454


Following another information request, CRT has now published the Graham Aldred reports mentioned earlier on this thread. The information request can be found at -

Causes of damage to the Toddbrook Reservoir Spillway and resulting actions
 

If you just want to read the reports -

CRT response

 

 


 

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