Whaley Bridge Evacuated

[furnessvale]

2 hours ago, system 4-50 said:

Shouldn't every reservoir have a plughole so that it can be emptied fairly quickly and independently of the normal path into a well-maintained run-off?  Or stop planks? I am prepared to donate a universal travel bath plug that I have not used in years.

As required by law, every reservoir has such a plug, or valve.

 

George

[Boater Sam]

12 minutes ago, furnessvale said:

As required by law, every reservoir has such a plug, or valve.

 

George

Aye, and they probably retired/cast off the guy who knows where it is.

 

Good to see that they are clearing the weed, trees and crap from the overflow, finally. Bit tardy though as it turns out. The guy who lives next to it reckons its been overgrown for years.

Wonder if the dam superintendent man who used to live in that house left any instructions about the plug in the house?

 

Pleased to see Julie squirm a bit on camera, did better than Dick Parry though.

Edited August 2, 2019 by Boater Sam
huge correction

[Naughty Cal]

1 hour ago, crossley said:

Was in Furness this afternoon on other business, called in to the marina tocheck on the boat. After going through the roadblock on the A6 where police are cautioning people, it was eerie. No trains on the Buxton line, or hope valley line, no road noise, the incessant stream of tipper trucks, nothing. Never realised how noisy it was up there. The levels up a few inches that's all. Hopefully the worst is over now, if it had rained heavily overnight and continued undercutting the embankment, they would have been in real trouble. So hopefully we got off lightly this time. 

More potentially heavy rain is forecast for sunday so that are not out of the woods just yet.

[Jerra]

14 minutes ago, Boater Sam said:

Good to see that they are clearing the weed, trees and crap from the overflow, finally. Bit tardy though as it turns out. The guy who lives next to it reckons its been overgrown for years.

Presumably this isn't something the dam inspector has to inspect or wasn't concerned about?

[frangar]

17 minutes ago, Boater Sam said:

Aye, and they probably retired/cast off the guy who knows where it is.

 

Good to see that they are clearing the weed, trees and crap from the overflow, finally. Bit tardy though as it turns out. The guy who lives next to it reckons its been overgrown for years.

Wonder if the dam superintendent man who used to live in that house left any instructions about the plug in the house?

 

Pleased to see Julie squirm a bit on camera, did better than Dick Parry though.

You are a cock aren’t you. At least Julie is on the ground...there’s many a COO who would be hiding in an office letting some minion deal with the press. 

[roland elsdon]

My friends just said boris is in whaley bridge to plug the leak. Things are looking up. 

‘dude look at that wall of water’

[Graham Davis]

2 hours ago, Boater Sam said:

Aye, and they probably retired/cast off the guy who knows where it is.

 

Good to see that they are clearing the weed, trees and crap from the overflow, finally. Bit tardy though as it turns out. The guy who lives next to it reckons its been overgrown for years.

Wonder if the dam superintendent man who used to live in that house left any instructions about the plug in the house?

 

Pleased to see Julie squirm a bit on camera, did better than Dick Parry though.

As has been pointed out by those on this forum that do know what they are talking about, unlike you, there are experts who know EXACTLY how this dam works, where all the valves are, and inspect it regularly. 
I am surprised that with your expert knowledge of dam dynamics and construction you haven't been up there sharing this. 

[zenataomm]

3 hours ago, blackrose said:

I love this thread. Suddenly everyone's an expert in civil engineering! ? 

For Civil engineering this thread has a lot of dam language in it.

[Guest]

1 hour ago, roland elsdon said:

My friends just said boris is in whaley bridge to plug the leak. Things are looking up. 

‘dude look at that wall of water’

Haven't they suffered enough?

[alan_fincher]

7 minutes ago, catweasel said:

Haven't they suffered enough?

If Boris is in Whaley Bridge, many residents might actually be grateful they have been evacuated from it!

[IanD]

4 hours ago, blackrose said:

I love this thread. Suddenly everyone's an expert in civil engineering! ? 

Some of us are engineers...

[Machpoint005]

2 hours ago, roland elsdon said:

My friends just said boris is in whaley bridge to plug the leak. Things are looking up. 

‘dude look at that wall of water’

The RAF didn't manage to drop a bags of rocks on him. I'm sure my bro-in-law would have done so when he was in that mob.

8 minutes ago, IanD said:

Some of us are engineers...

Indeed we are - but not that particular flavour, in my case.

[Guest]

[Nightwatch]

8 hours ago, Tonka said:

says a man whose boat is rotting away due to lack of maintenance

Does it effect your daily life or just my own? No need for that remark. Git!

[Naughty Cal]

According to the news this morning (which granted may not be the best source of information) they have lowered the water level in the reservoir by 0.5m in three days.

 

They need to lower it by several metres for it to be deemed safe for people to return to their homes. So it is going to be a long wait for the people of the town to return home.

 

Hopefully the storms forecast for tomorrow wont drop too much more water in the area and delay things further.

[Tim Lewis]

12 hours ago, frangar said:

You are a cock aren’t you. At least Julie is on the ground...there’s many a COO who would be hiding in an office letting some minion deal with the press. 

 

[Heartland]

Yes, it is good to see Julie Sharman has visited the danger area and given an update on progress. More pumps and aggregate. The pumps to assist with reducing water levels and the aggregate to assist with the work.

[Murflynn]

May I suggest that the 1971 spillway design was fundamentally flawed? 

The spillway should be designed to take a shallow and evenly spread sheet of water which would have a relatively limited velocity and would never amount to much in the way of turbulence and undermining flow, and would not cause any wash-out, a bit like a shower of rain running across your patio slabs.  Tapering the spillway at one side concentrated a large flow adjacent to the vertical wall which was the straw that broke the camel's back.    I haven't seen the design of any overflow structure prior to 1971 or 1964, but if there was one I expect it would follow the same footprint.

It would be interesting to find what the underlying material comprises. 

I was the senior site engineer for the contractor when constructing Wraysbury Reservoir in 1965.  There was a vertical clay core about 2m thick, supported on both sides by compacted coarse gravel, finished with topsoil planted with coarse grasses.   Of course such a structure was not designed for over-topping, but in both cases the integrity of the dam relied on the grading of the gravels and the degree of compaction.  Good compaction was achieved by placing the gravels in very shallow layers and arranging for heavy rubber-tyred earthmoving equipment to travel at relatively high speeds while placing the material, to the extent that the vehicles loaded with about 50 tonnes of gravel would actually bounce on their rubber tyres, imparting huge compacting forces to the gravel layers.   Such techniques would not have been available to 19th century contractors.

The use of unsuitable materials under the spillway slabs, and a lack of compaction of such material would reduce the ability to resist wash-out if there was any significant turbulence resulting in undermining. 

It will be interesting to see what the Inquiry findings are.

 

B.Sc. (civil engineering), C.Eng, M.I.C.E.

Edited August 3, 2019 by Murflynn

[soonguy]

I guess that the pumping operation will be stepped up as they get more pumps in. But there will be a limit to the rate they can dump water, since it all has to end up in the River Goyt, and too much will cause river damage and flooding in New Mills and further downstream. If the dam even has an emergency plug, which I doubt being so old, then them same maximum flow issue would apply. You can't empty it quickly.

 

Despite Boris making empty promises about rebuilding it, long before any survey or costings, here's a question I'd like to see discussed:

 

Unlike most canal feeder reservoirs, Todbrook is indeed scarily situated in a high narrow valley right above a small town. When it was built nearly 200 years ago, this was the only way to keep the top level of the Peak Forest Canal topped up. But now, at its current rate of usage, surely it would be possible to keep it topped up with all the streams flowing from above it off the hills, all the way to Marple locks, topped up if needed by water electrically pumped up from the Goyt. In other words, is the reservoir actually needed? A shame for the boat club who use it, but I think a lot of people would feel a lot safer if it wasn't there. Having seen the damage that even a canal bank breach on the Llangollen did, a catastrophic breach of Todbrook would destroy half of Whaley Bridge, probably demolish more than one farm in the valley, plus the New Mills railway viaduct and road bridge, destroy a number of low lying houses in New Mills, and cause havoc all the way to the Mersey and beyond.

 

I grew up looking over the Goyt Valley towards Furness Vale, and can easily imagine what floodwater would do there.

[Detling]

20 hours ago, carlt said:

We can be fairly sure that when the emergency is over the rebuild bill will come out of CRT's coffers as there is no surplus in boris' Brexit battle budget for such fripperies. 

 

Maybe CRT could apply for a European grant... Oh... Hang on... 

Will the inhabitants of Whaley Bridge allow a rebuild, or will they try to prevent a rebuild and have a small lake in a landscaped valley instead. I am sure the question will be raised, thousands of people at risk of flood, or a few pleasure boaters having some water.

[Guest]

29 minutes ago, soonguy said:

I guess that the pumping operation will be stepped up as they get more pumps in. But there will be a limit to the rate they can dump water, since it all has to end up in the River Goyt, and too much will cause river damage and flooding in New Mills and further downstream. If the dam even has an emergency plug, which I doubt being so old, then them same maximum flow issue would apply. You can't empty it quickly.

 

Despite Boris making empty promises about rebuilding it, long before any survey or costings, here's a question I'd like to see discussed:

 

Unlike most canal feeder reservoirs, Todbrook is indeed scarily situated in a high narrow valley right above a small town. When it was built nearly 200 years ago, this was the only way to keep the top level of the Peak Forest Canal topped up. But now, at its current rate of usage, surely it would be possible to keep it topped up with all the streams flowing from above it off the hills, all the way to Marple locks, topped up if needed by water electrically pumped up from the Goyt. In other words, is the reservoir actually needed? A shame for the boat club who use it, but I think a lot of people would feel a lot safer if it wasn't there. Having seen the damage that even a canal bank breach on the Llangollen did, a catastrophic breach of Todbrook would destroy half of Whaley Bridge, probably demolish more than one farm in the valley, plus the New Mills railway viaduct and road bridge, destroy a number of low lying houses in New Mills, and cause havoc all the way to the Mersey and beyond.

 

I grew up looking over the Goyt Valley towards Furness Vale, and can easily imagine what floodwater would do there.

Boris's normal knee-jerk reaction to everything.

Some interesting points that you have raised.

[Heartland]

Murflynn has made a valuable point concerning the spillway. The original canal engineer who designed the reservoir, will no doubt be traced through Peak Forest Canal Records at the TNA. 

 

On a related point, the nearby Combs Reservoir also supplied the Peak Forest Canal. This was built earlier and was probably to Benjamin Outram's plans. Todd's Brook is a later reservoir to meet increased water supply needs.   

[furnessvale]

5 minutes ago, Heartland said:

Murflynn has made a valuable point concerning the spillway. The original canal engineer who designed the reservoir, will no doubt be traced through Peak Forest Canal Records at the TNA. 

 

On a related point, the nearby Combs Reservoir also supplied the Peak Forest Canal. This was built earlier and was probably to Benjamin Outram's plans. Todd's Brook is a later reservoir to meet increased water supply needs.   

Combs has also had its problems in the past resulting in the dam height being increased with a concrete return wall.

 

Incidentally, both dams were fairly recently fitted with quick release valves to drain them quickly in the event of an occurance such as this.  This was to comply with new legislation.  I wonder why the one at Toddbrook is not being used and many pumps are being brought in?  Four more went up there last night about 7pm.

 

George

[PaulD]

13 minutes ago, furnessvale said:

Combs has also had its problems in the past resulting in the dam height being increased with a concrete return wall.

 

Incidentally, both dams were fairly recently fitted with quick release valves to drain them quickly in the event of an occurance such as this.  This was to comply with new legislation.  I wonder why the one at Toddbrook is not being used and many pumps are being brought in?  Four more went up there last night about 7pm.

 

George

Valves were replaced during major works in 2010 / 2011.

[WotEver]

5 hours ago, soonguy said:

I guess that the pumping operation will be stepped up as they get more pumps in. But there will be a limit to the rate they can dump water, since it all has to end up in the River Goyt, and too much will cause river damage and flooding in New Mills and further downstream.

They reported in this morning’s news that they already have problems with the discharge and are looking for alternative routes for the pumped water to go.