but it is particularly interesting to read that a clay layer beneath the spillway has been eroded. I’d be surprised if this clay layer was the main waterstop for the structure,

I suspect “clay layer” may be a guess by a journalist. As you say there is normally a clay core with other material making up the bulk of the embankment on either face. Not that it matters much what it is if it gets washed away. The spillway failure looks very much like the Oroville Dam failure in the States where water found its way down between the concrete floor and the side retaining wall of the spillway washing out the foundation. I suppose all that can be done now is to continue getting the water level down as quickly as possible to reduce load on the embankment and avoid any further overspill.

Disclaimer – Ex Civil Engineer, designed water retaining structures but never an earth embankment dam.

Its ok , the interent says there is a plug, its low down but there is a plug. Hope its got a long chain on it that reaches the top, I mean surely …

Loving the guy on the static line secured to the flimsy galvanised footbridge. Yes , when that dam gives way the static line will ensure your safety as the galvy footbridge is mounted onto the dam , which is on a soaking wet mud bank with some modelling clay whacked on the front,
by Irish Navvies in 1820 . Always time for safety whilst placing sandbags on top of a busted dam wall to divert the overtopping to a more stable run off area.

Its ok , the interent says there is a plug, its low down but there is a plug.

Yes I was intrigued by that.

Just found this in New Civil Engineer magazine. Sounds like it is primarily boulder clay construction after all.

The New Civil Engineer piece is good. There’s also a good collection of videos and comment in this link. The blogger is a pilot who has provided some of the best coverage of the 737 Max fiasco – he’s pretty level headed.

@DerbyshireFRS crews being assisted by RAF Chinook #WhaleyBridge pic.twitter.com/lHkseTIkPP

— Shirebrook Fire Station (@ShirebrookFire) August 2, 2019

They had a Chinook up there last night bringing in ballast.

They are currently dropping bags of aggregate into the ‘hole’ via a Chinook – it’s a ruddy big hole looking at some of the pictures on line with the bags already in there.

Been watching the Chinook on the local news this morning. What skill those pilots have dropping the gravel bags down.

We’re 6 miles away from the dam. It’s been a weird night. For some reasons a lot of house alarms have been going off.

I have friends and customers in Whaley Bridge,its a properly worrying situation for them. Some have businesses that they’ve taken years to build up.

Just screen grabbed this from Facebook. What a pilot!

Good update from the actual scene via the people who know. (Derbyshire constabulary)

A further update has been issued this morning regarding the ongoing incident at Toddbrook Reservoir in Whaley Bridge.

Officers have been assisted overnight by a wide number of partner agencies including the fire service who have sent firefighters from across the country, the Environment Agency, the ambulance service, local councils and emergency planning staff.

We were also assisted overnight by RAF crews who used a Chinook helicopter to move more than 50 tonnes of aggregate into the reservoir wall to reinforce it.

This work was done in conjunction with expert structural engineers, who have been advising the emergency response since yesterday afternoon.

Throughout the day, work will continue to further shore up the reservoir wall. The Chinook will also be dropping aggregate into other parts of the reservoir today, to stem the flow of water going into it.

There are also a total of 16 high volume water pumps which have been installed in the reservoir, in order to reduce the water levels. These have been provided by fire services from across the country and the Canal and River Trust.

Assistant Chief Constable Kem Mehmet, said: “Our message today remains the same as there is still a risk the dam will fail, please stay away from the area.

“If you are asked to leave, please heed emergency services and expert advice and do so. We understand that being asked to leave your home is an extremely difficult and worrying situation to find yourself in, however it is not a decision we have taken lightly and ultimately the safety of the public is our main concern.

“The evacuation point at Chapel High School, Long Lane, Chapel-en-le-Frith, High Peak, SK23 0TQ, will remain open today and residents will be accommodated if they are unable to make alternative arrangements.

“We have evacuated more than 1,000 people from the areas that would be immediately affected by floodwater should the wall fail.

“The majority have been able to find accommodation with family and friends. About 40 people have also been put up in a local hotel and they will be looked after today.

“We don’t know how long this operation will take to conclude but we and our colleagues in the emergency services, partner agencies, Environment Agency and military are doing everything humanly possible to save the reservoir wall and to protect the town.”

Let’s hope everything turns out ok like the previous scare of that dam wall (redmires?) in the Peak about 10 years ago

Of course, nothing can compare to the true horror of finding out that Edwina Currie has moved to your town.

Ulley, Houns.

👍🏻

Blimey, was 2007. Interesting read

https://www.hydroworld.com/articles/print/volume-18/issue-4/articles/hydraulic-_structures/rebuilding-ulley-dam.html

Best wishes to all and stay safe from an ex New Mills and Furness resident. I understand Furness Vale was evacuated too.

I find it amazing that they can lower the volume using pumps. There must be some serious volumes being shifted.

@franksinatra if they have big 24″ pumps there, they can move about 1.4 cumecs.

I find it amazing that they can lower the volume using pumps. There must be some serious volumes being shifted.

Yep. I guess you need a big pipe (or 16) and just enough oomph to prime the pipe to its high point and back down below the water level, then the siphon will do the rest

The Goyt’s going to be rather full. I’ve seen a video from down near Roman Lakes and it’s full to the brim already. Might take a look at the Goyt near me this weekend (I’m less than half a mile from it, but on the top of a hill).

@fossy: Goyt levels have dropped considerably from their high point on Tuesday. Which is good because it gives a bit more leeway for pumping a shitload of reservoir water into it.

A couple of my old oppos are involved in the RAF operation to help shore up the dam, one is on the Chinook and one is on the ground supporting them.

Aye, I rode over the Goyt at marple on the way home lasty night and again this morning on the way to work. last night I crossed at chadkirk where the river is already about 60 feet wide – it was up to about 80 feetwide, and a good two or three feet deeper than normal. there’s normally an exposed weir there, it was completely submerged.

this morning I crossed at Brabyn’s Park, river is much narrower there (it’s just above the point where the etherow joins) and it as about 2 feet up on normal, width up from 20 feet to 25. You could see though from the vegetation it has been a good three or four feet higher in the past day

Some amazing shots of the Chinook in the press.

The scary thing for me was not the water over the top of the spillway, but there was a video showing water coming out of the area that has collapsed.
which says to me the breach was round the outside of the concrete structure or through the main dam bank.

wrightyson

Member

Just screen grabbed this from Facebook. What a pilot!
Posted 2 hours ago

I’m pleased to see they found some bigger sand bags.

Chinooks in action on Long Hill

Posted by Robin Sharp on Thursday, August 1, 2019

Posted by Robin Sharp on Thursday, August 1, 2019

Indeed, just seen an image from slightly above and to the side – of the Chinook dropping aggregate bags.
Penalty for failure: high!

see if link works –

I love Chinooks. What an incredible bit of kit.
Also, note to self – do not attempt to ride over Long Hill today.

Those vids of the chinook are amazing – that is some control of a beast like that! Very impressive

A couple of years ago I’d ridden the Whaley Bridge mtbike loop. After the ride I walked into the local Co-op to gorge on munchies. I reached for the only almond tart left at the bakery section at exactly the same time as Edwina Curry. She grabbed it, I was just a second too slow. I wanted to shout – ‘Edwina you have absolutely no idea how hungry I am at this moment in time’. There won’t be a next time, I’ll wrestle her to the ground, wearing sheep poo smeared riding gear.

Fingers are crossed that there won’t be any more rain for the next few days. Although some is forecast for Sunday.

Nice pic in the Grauniad…

https://www.theguardian.com/uk-news/2019/aug/02/whaley-bridge-dam-raf-helicopter-collapse-peak-district#img-1

One walked the dam area a good few times – and we used to raft on there with work groups.

Scary stuff.

Chinooks in action on Long Hill

I used to love Under Slung Load operations, except in the desert!

Apparently some residents are refusing to leave, prompting others to call them selfish because in the event it does go it puts emergency services at risk to rescue them.

Can’t see why the emergency services wouldn’t just leave them to make their own arrangements if the worst happened and they chose to stay.

Trying to get my head around this one…

https://www.bbc.co.uk/news/live/uk-england-derbyshire-49196445 @1446

Couple go to Stockport for the day, but on return cannot go back home due to the dam. Later in evening, they are let through cordons to rescue their pets. They get their two dogs, but leave their rabbits behind without food.

How the heck does that happen?

How the heck does that happen?

Because panicky or stressed people being told to run in, run out.

These boys are well fast, but they do it every day.

Christ, they don’t hang about. That’s some impressive flying

Second picture down, beneath the “How Dangerous is it?” subtitle – https://www.bbc.co.uk/news/uk-england-derbyshire-49201467 shows earth to the outside of the spillway wall to have been washed away as well. Possibly due to spillway water eventually undercutting the wall – no way of telling for sure.

One of the videos yesterday which I can’t find now shows water at the top of the spillway jumping over the sidewall onto the earth embankment probably scouring the embankment from the top, not under the sidewall.