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Whaley Bridge Evacuated


furnessvale

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1 hour ago, Mike Todd said:

Whilst that is its function now, I have read that it was originally primarily to provide hydraulic power to industrial activities in the area below the dam, with canal feeder as a secondary purpose. I suspect that if that be the case then the canal feeder purpose would need much less capacity, in which case it may be that a reduced dam height or, perhaps more likely, a reduced 'normal' level would be sufficient. The reduction in the normal level would increase the ability to cope with extreme weather events which we are warned may increase in frequency and hence shift the cost benefit ratio.

 

I guess it would be fairly easy to do an order of magnitude calculation about the number of lockfuls per day needed as a canal reservoir. Does anyone local know how many boats pass through Marple each day (the crucial point for the feeder)

............  that's fine ...............  but then how will you manage when we get one of those drought years, possibly 3 in a row?  maybe about as likely as the extreme rainfall event we have just witnessed.

 

assuming the reservoir is critical to keeping the canal supplied with water, just imagine how the readers of this forum will react if CRT doesn't arrange sufficient capacity to keep the canal operating through the drought years 'in order to save money otherwise spent on investment and maintenance'.

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1 hour ago, Mike Todd said:

Whilst that is its function now, I have read that it was originally primarily to provide hydraulic power to industrial activities in the area below the dam, with canal feeder as a secondary purpose. I suspect that if that be the case then the canal feeder purpose would need much less capacity, in which case it may be that a reduced dam height or, perhaps more likely, a reduced 'normal' level would be sufficient. The reduction in the normal level would increase the ability to cope with extreme weather events which we are warned may increase in frequency and hence shift the cost benefit ratio.

 

I guess it would be fairly easy to do an order of magnitude calculation about the number of lockfuls per day needed as a canal reservoir. Does anyone local know how many boats pass through Marple each day (the crucial point for the feeder)

Given that on a number of occasions in recent years, the existing capacity has proved insufficient for the number of boats using the canal I don't think a reduction in capacity would go down well.  Don't forget it is also an important feeder for the summit level of the Cheshire ring, not just a minor branch canal.

 

George

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50 minutes ago, TheBiscuits said:

That's a very interesting point.  We were one of the very few boats that got through Marple Flight last year between the opening of lock 16 and the closing then reopening then closing again of  lock 11.

 

How deep are Marple locks? 14 feet or so for the deeper ones?

 

14 x 7 x 73 = 7154 cubic feet ~= 200,000 litres

 

1200 lock cycles at 200,000 litres = 240 million litres of water.

 

 

= 240,000 cubic metres of water.

 

Capacity according to Wikipedia is 1,288,000 cubic metres, so a year's lock fills (caveats: no leakage allowed for, etc) is 20% of the reservoir volume.

 

 

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Just now, Onionman said:

= 240,000 cubic metres of water.

 

Capacity according to Wikipedia is 1,288,000 cubic metres, so a year's lock fills (caveats: no leakage allowed for, etc) is 20% of the reservoir volume.

 

 

I have been on Bosley flight ...

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51 minutes ago, Chris Williams said:

Perhaps there should be a separate body to look after reservoirs and such like.  Entrusting it to a 'Charity' with all its other problems does not make sense.  I would not trust CaRT to look after the local duckpond.

Entrusting it to a private company would be worse. Their only responsibility is to their shareholders. Anyway, it would probably go to someone like Capita... 

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17 minutes ago, Onionman said:

= 240,000 cubic metres of water.

 

Capacity according to Wikipedia is 1,288,000 cubic metres, so a year's lock fills (caveats: no leakage allowed for, etc) is 20% of the reservoir volume.

 

 

Don't forget that the 1200 locks figure is only Marple flight - Bosley adds another 3000 lock fulls, so the reservoir looks like one year 's usage takes 60-70% of the reservoir (without leakage/evaporation etc) so it's probably the correct size!

Edited by TheBiscuits
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15 minutes ago, Arthur Marshall said:

Entrusting it to a private company would be worse. Their only responsibility is to their shareholders. Anyway, it would probably go to someone like Capita... 

I'm not recommending this route, but United Utilities do look after Gorton Reservoir even though it is redundant for their purposes, and they do a good job, including spending rather a lot on a new spillway not that long ago.

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6 minutes ago, magpie patrick said:

I'm not recommending this route, but United Utilities do look after Gorton Reservoir even though it is redundant for their purposes, and they do a good job, including spending rather a lot on a new spillway not that long ago.

They will have been told to do that, not volunteer

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38 minutes ago, LadyG said:

They will have been told to do that, not volunteer

err, yes, everyone who's got a reservoir, even private individuals, gets told how to maintain them.

 

Edited as that's a little unfair on @LadyG my point is UU have done everything very thoroughly, gold plated even, including maintaining public access in a reservoir that is not needed at all

 

They do have the choice of draining them instead, which does happen although not very often

Edited by magpie patrick
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We Moor in New Mills opposite the marina. It is very quiet. Residents in Furness Vale have now been told to walk out and in because vehicles are no longer allowed up the A6 past New Mills. Shops here are out of bread and there is no public transport after Marple. I have had to get special dispensation from the police to allow my dialysis transport Ithrough. (One patient in Hayfield has had 45 mins added to his journey and two in Chapel en le Frith an hour) so I have got off remarkably lightly. 

The Goyt has died down a little but the flow is quadtlruple what it normally is - the first photo is the Torrs where the Sett and Goyt meet. The second is the railway viaduct where the sensors were destroyed 

 

Edited to add that stop planks are in at Bridge 29, before New Mills Marina, the canal is closed from 26 onwards and all boats that wished to were brought through yesterday to New Mills 

IMG_20190803_191537_458.jpg

IMG_20190803_191957_485.jpg

Edited by StarUKKiwi
To add a point
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11 hours ago, magpie patrick said:

I'm not recommending this route, but United Utilities do look after Gorton Reservoir even though it is redundant for their purposes, and they do a good job, including spending rather a lot on a new spillway not that long ago.

Thanks to Allan Richards for the following 

"As with C&RT's other assets, high risk reservoirs have the equivalent of  Principal Inspections (at least every 10 years) and  Annual Inspections every year. The difference is that these inspections are not carried out by C&RT staff because the Reservoir Act 1975 (as amended) stipulates that engineers from a panel are appointed.

There is also third inspection which equates to C&RT's Length Inspections. This is called a Reservoir Surveillance Inspection (RSI). These are held once a week at least."

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19 minutes ago, StarUKKiwi said:

To feed the Peak Forest Canal, which can get very low if locks are in use 

Just to add it is also a major feeder to the summit pound of the Cheshire Ring (should anyone get the idea it is only a feeder to a minor canal branch).

 

George

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Just looking at the map, if that dam were to breach, would it send a surge of water along the upper peak forest canal? and since there are no locks until Marple if it did, would it go that far? I ask because I see that the branch leading to the Whaley Bridge water/sanitary station is in direct line from the dam.

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I was interested to see a Civil Engineer (funny how none claim to be uncivil engineers) on TV pointing out that emptying the dam too quickly could damage the dam on the side towards the water.   So clearly it isn't just a case of getting the water out as quick as you can.

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10 minutes ago, Wanderer Vagabond said:

Just looking at the map, if that dam were to breach, would it send a surge of water along the upper peak forest canal? and since there are no locks until Marple if it did, would it go that far? I ask because I see that the branch leading to the Whaley Bridge water/sanitary station is in direct line from the dam.

Theve put stop planks in at bridge 29 so I’m guessing that’s a precaution against the canal breaching due to overtopping or or to slow a wave....not sure it would help that much tho. 

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9 minutes ago, Wanderer Vagabond said:

Just looking at the map, if that dam were to breach, would it send a surge of water along the upper peak forest canal? and since there are no locks until Marple if it did, would it go that far? I ask because I see that the branch leading to the Whaley Bridge water/sanitary station is in direct line from the dam.

Various people have raised this possibiliy but the canal is on a shelf on the side of the valley.  Any surge of more than 2ft or so would quickly overtop the towpath and fall into the valley below.

 

I would hazard a guess that by Furness Vale a "Severn Bore" of about a foot would be in the canal and by New Mills it would be all but spent.

 

George

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If you want to find out more about water supplies to canals, the attached paper is probably the best introduction. It was written by Mike Hyde, who was BWs principal water engineer, for the PIANC Conference in 1977. Mike was always happy to share his extensive knowledge of canal water supply. He could also sing the Polish national anthem, though without knowing what the words meant.

water supply.pdf

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1 hour ago, Wanderer Vagabond said:

Just looking at the map, if that dam were to breach, would it send a surge of water along the upper peak forest canal? and since there are no locks until Marple if it did, would it go that far? I ask because I see that the branch leading to the Whaley Bridge water/sanitary station is in direct line from the dam.

First off, the Basin, Transhipment Shed, houses, Railway Station, then The aquaduct next to B&M/Tesco on the Bugsworth Arm would go, the next major structure is the A6 bridge, then the main viaduct carrying the Sheffield Line at New Mills, plus the two bridges over the Goyt in New Mills. (hence they're all closed). 

There is a command meeting at 11am but the BBC shared this 

https://www.bbc.co.uk/news/amp/uk-england-derbyshire-49231384?__twitter_impression=true

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On ‎02‎/‎08‎/‎2019 at 15:26, Tuscan said:

Richard Parry stated on Newsnight that CRT were not short of funds for reservoir works so there should be no problem.............

I suspect that the point he was making was that there was no question that a lack of funds had led to a failure to properly maintain the reservoir

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