Whaley Bridge Spillway Failure. 6000 folk evacuated.

[MCN]

https://www.google.com/amp/s/www.telegraph.co.uk/news/2019/08/01/whaley-bridge-dam-collapse-latest-news-derbyshire-town-evacuated/amp/

https://youtu.be/Zm_MMRA9Szk
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[stinkwheel]

Three things occurr to me.

1) Having a top-overspill seems like a stupid design.

2) Why are they using pumps to empty it? They could stick a properly big fuck-off pipe in there with a gate-sluice on the end, close the gate, prime the pipe with the pumps and syphon the bastard in no time flat. Thirlmere reservoir feeds Manchester by syphon.

3) If it's for passively feeding a canal (I don't know the geography but that's what the news reports suggest), open all the fucking lock gates to flood position and let rip. It'll empty in no-time flat. People have totally emptied canals before today by accidentally the lock gates.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Howling Terror]

[Howling Terror]

[MCN]

Juan Brown does not too bad as a news guy.
Anyway.
The damage to the Spillway is probably due to what Juan suggested. Cracks in the concrete (where the weeds are growing.)
He highlights this point as there was a massive washout of the Oroville Dam Spillway in the states. (On the Oroville Canal. 🤣)
It's similar to pot holes where water finds cracks in the waterproof cover.

https://hackaday.com/2019/05/17/repairing-a-catastrophic-failure-the-oroville-dam-update/

Links help.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[doggone]

[MCN]

[Howling Terror]

I've walked around there for decades and when old bids say they've not experienced rainfall like that in their lifetime that could be called unprecedented.


There were no cracks in the concrete panels.

It could have been caused by water getting through and under the joints or there may have been existing leakage through the headbank that aided the collapse.

Until water levels drop it's guesswork at the mo.
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The Harry Turner Project

[Tracey Suntan-King]

I'm sure it must be terrible to have your home threatened by flooding but is it wrong of me to giggle smuttily everytime the R4 newreader mentions the "24 hour pumping operation"?


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Whether you think you can, or think you can't, you're probably right

[Howling Terror]

[MCN]

[Howling Terror]

Cracks and joints are different are they not.

You'll have to take my word that the concrete panels had no cracks, there are a few areas where summer weeds get a hold and a small bush growing near the base. Ironically the area of failure was weed free.

I can say this as somebody who goes there on a regular basis and stands on that footbridge. Reads the graffiti on the side wall and sees where kids have rolled stones down it....and wondered if I could ride a bike down it.

You could be right, you could be wrong you could be somewhere between the two.
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Diabolical homemade music Bandcamp and Soundcloud
Singer songwriter, Artist and allround good bloke Listen to Andrew Susan Johnston here
The Harry Turner Project

[MCN]

[Pete.]

I don't see a single bit of rebar hanging out of any of those broken panels. That means that either there is none or what there is is so thin that it's all sheared along every break. When large flat panels break like that you normally see evidence of rebar especially where a corner has crunched. If it's heavy then the broken piece will hang off the larger piece on the bars. If it's light it usually stretches then shears.

IMO it's inconceivable that those panels could have no cracks in them after so many baking and freezing cycles over the years. I wish someone could have got in there with a drone and taken some close-up photos.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[doggone]

On one of the News clips yesterday they were pretty close filming with a helicopter and there was a Mavic-looking drone much nearer to the damaged bit.
I would assume it was being flown officially but it was still surprising the helicopter was in such close proximity, even allowing for zoom lenses.

[Sister Sledge]

I reckon frost damage and gradual settling of the dam over the decades. There are mentions of inspections by engineers but so what? Just takes one or two lazy / complacent ones and there's a disaster looming.
When the floods hit at Newburn on Tyneside (Mill Vale Estate - houses on stilts being demolished) it was actual culvert surveyors who'd carried out two separate surveys during construction who had quite literally left survey marks on top of visible damage and not made a note of it.
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CCM 404 DS

[MCN]

https://www.bbc.com/news/uk-england-derbyshire-49196766
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[Riejufixing]

I used to be interested in dams, as part of another interest. There are several possible problems at play; try this from "Wikipedia", which has links to further information (especially the first, which I have added for convenience):

Dam works

High rainfall levels resulted in damage to the dam’s spillway in December 1964.[1] The damage was repaired in 1965, but flood studies judged the spillway to be inadequate.[1] As a result in 1971 a new concrete spillway was added to the centre of the dam.[1][3]

In the 1980s, British Waterways carried out significant repair works to the dam to deal with leaks involving the mining shafts located around the dam. This resulted in a culvert being constructed under the current beach/launching area for the reservoir. A stone marker could be seen on the main beach showing the location of this for many years, but was relocated to the footpath opposite Toddbrook Lodge during access work for the 2009 draining.

It was known that the local coal mining industry had been a challenge for the dam's integrity for many years. The original builders were forced to purchase a block of coal below the dam in situ in order to ensure its mining did not cause structural issues.

The reservoir was also partially drained in 2009 for re-alignment works on the dam, and again in 2010.



[1] https://evidence.environment-agency.gov.uk/FCERM/Libraries/FCERM_Project_Documents/Lessons_from_Historical_Dam_Incidents.sflb.ashx

[MCN]

[Ste]

Three years ago Whaley Bridge dam looked like this:

https://i.imgur.com/qMv5e5D.jpg

[doggone]

All the joints packed with weeds and even small trees growing, no wonder water got in - lack of maintenance.
Blame global warming for making rain rainier.

[MCN]

[MCN]

https://youtu.be/f16a-9SKPwo


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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[Kris]

[MCN]