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Heavy rain in Devon - flooding on the railways


Captain Kernow

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There's a lot more farther west with Looe closed again due to flooding and roads (other than the "long way round" via Pelynt) also closed due to more landslips and a collapsed house at Sandplace.

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There's a lot more farther west with Looe closed again due to flooding and roads (other than the "long way round" via Pelynt) also closed due to more landslips and a collapsed house at Sandplace.

Sadly, a lady was found dead in the collapsed house near Looe. Due to concerns over the rest of it collapsing, we were advised to keep the line closed today.

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I'm just on the way up to the smoke for the weekend including a visit to the Ally Pally and I noticed that there is an awful lot of water in the Exe and Culm after passing through Exeter.

 

SS

And I went up and back to Bristol today, and you're right, but everything is still OK at the moment, the rain is easing off here in the South Hams and we're watching the situation at Staffords Bridge and Cowley very closely.

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  • 1 year later...

An item on the BBC a few days ago; NR have announced their preferred solution to flooding at Cowley Bridge.  It includes removal of weirs and an additional culvert.  But work won't start for some time.  For now it is out for consultation.

 

Mike

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2016 headline in local newspapers 'Concern in Topsham as waters racing down the Exe flood the recreation ground'.

 

But in all sincerity I do wonder if NR's proposal has been assessed by the Hydraulics Research people (I think they now have a different name) at Wallingford.  Messing about with flow rates on the Thames by creating the Maidenhead Relief Stream (which has been given another fancy name) has seemingly resulted in more flooding downstream.  I appreciate that taking out weirs is not quite the same thing but the water has to go somewhere and the implication seems to be that it will go to wherever that is at a much faster rate which I would have thought could have an impact elsewhere either in terms of erosion, or flooding when it meets the sea coming the other way?

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I think it does (and it would seem from the NR page that it is so) need to be looked at in conjunction with impacts from the Exeter flood defence improvements being pushed through at present, the 60s/70s defences through Exeter have been close to overtopping in the last decade (and a 1/100 flood starts to sound a lot more likely when you start deducting how many years it's been there!) - so changes to prevent something really catastrophic were needed.

 

https://www.gov.uk/government/publications/exeter-flood-defence-scheme/exeter-flood-defence-scheme

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2016 headline in local newspapers 'Concern in Topsham as waters racing down the Exe flood the recreation ground'.

 

But in all sincerity I do wonder if NR's proposal has been assessed by the Hydraulics Research people (I think they now have a different name) at Wallingford.  Messing about with flow rates on the Thames by creating the Maidenhead Relief Stream (which has been given another fancy name) has seemingly resulted in more flooding downstream.  I appreciate that taking out weirs is not quite the same thing but the water has to go somewhere and the implication seems to be that it will go to wherever that is at a much faster rate which I would have thought could have an impact elsewhere either in terms of erosion, or flooding when it meets the sea coming the other way?

I'm not aware of the specifics just yet, but I do know that there has been a lot of joint working with other organisations like the E.A. etc.

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  • 2 years later...
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BREAKING NEWS.... here we go again...BBC Radio Devon reporter at Cowley Bridge (just north of Exeter) says "ballast has been washed away and track is 'dangling'"


 


https://twitter.com/...erp|twgr^author


 


Update: NR bloke in charge says that there are several washouts on the main line and also some on the Barnstaple line. The projected closure will be 48 hours.

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Not on the spot so I don't wish my comments to sound disingenuous but we were led to believe, as I recall, that the works and precautions from past events should have been enough to prevent inundation this time.  Not perhaps to avert a closure but certainly to avoid significant washouts and days of shut-down.  It's not as if this was an unexpected event.  The forecast proved quite accurate and timely.

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Ironically NR inflatable "barrier" was hanging around the Crowley Bridge junction for a very long time on the last occasion this happened but seemingly nothing this week even though it was forecast as predicted ?

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Not on the spot so I don't wish my comments to sound disingenuous but we were led to believe, as I recall, that the works and precautions from past events should have been enough to prevent inundation this time.  Not perhaps to avert a closure but certainly to avoid significant washouts and days of shut-down.  It's not as if this was an unexpected event.  The forecast proved quite accurate and timely.

I suspect that a 'complete' solution would be very expensive, and outside the complete control of Network Rail anyway.

 

The River Exe has changed its route along the valley over the years and the railway passes more or less down the middle of the flood plain.

Although the line crosses the Exe twice you can still see the remains of oxbow lakes to the south of the line in the immediate vicinity of Cowley Bridge, any overspill from the river into this area ends up trapped between the railway the hillside and Cowley Bridge. Following previous flooding events, like in 2000, work has been carried out including drainage ditches and culverts near Pynes Weir which partly alleviate the problem, perhaps these need to be more substantial.

Also I suspect Cowley Bridge itself which carries the A377 would need rebuilding to increase water capacity from the Exe and the Creedy though this itself might create problems round the corner in Exeter where increased water management work is already planned or underway.

 

cheers

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These events made a mess of my sister's trip to visit us yesterday, commencing from Liskeard, where in an unrelated incident the train she should have boarded before 09:00 failed before she was able to board. In the ensuing chaos that finally saw her arrive at BTM just after 4pm (!) we enjoyed a telephone conversation in the course of which she said that the train she was in was even more uncomfortable than 'that awful thing' of enduring family memory that she rode in when she was five. That was a Gresley Quad Art, packed to the gunnels. So, no progress there then.

 

Having reached BTM, thereafter the journey went reasonably well, and she got to us 'only' six hours later than expected. Will she dare the train for the homeward run on Friday?

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I suspect that a 'complete' solution would be very expensive, and outside the complete control of Network Rail anyway.

 

The River Exe has changed its route along the valley over the years and the railway passes more or less down the middle of the flood plain.

Although the line crosses the Exe twice you can still see the remains of oxbow lakes to the south of the line in the immediate vicinity of Cowley Bridge, any overspill from the river into this area ends up trapped between the railway the hillside and Cowley Bridge. Following previous flooding events, like in 2000, work has been carried out including drainage ditches and culverts near Pynes Weir which partly alleviate the problem, perhaps these need to be more substantial.

Also I suspect Cowley Bridge itself which carries the A377 would need rebuilding to increase water capacity from the Exe and the Creedy though this itself might create problems round the corner in Exeter where increased water management work is already planned or underway.

 

cheers

There was a plan announced by NR earlier this year, albeit after I had retired, outlining new flood relief channels to be built at Cowley Bridge Jct. This is clearly not a 5 minute job, but I would expect it to be prioritised and certainly completed by next winter.

 

I remember the work done in 2000, which involved digging part of the railway embankment away after the flooding, and installing some large diameter pipes to act as additional culverts. We thought at the time that it would be sufficient, but you live and learn, eh?

 

Incidentally, I recall hearing earlier today that the NR 'inflatable sausages' had been 'washed away' at Cowley Bridge Jct, which implies that they had been deployed, whereas on the lunchtime news, the NR 'spokesman' intimated that the flooding 'hadn't been expected'. 

 

It's at times like this that you sometimes wish you were still there, 'on the inside' (albeit without all the hassle, cr*p and not getting home until late).

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I suspect the SR main is also still prone to flooding around the Axe area, however don't they bother diverting stuff down through Yeovil these days or Basingstoke if Somerset is having problems? Maybe there isn't line capacity these days?

Phil 

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I suspect the SR main is also still prone to flooding around the Axe area, however don't they bother diverting stuff down through Yeovil these days or Basingstoke if Somerset is having problems? Maybe there isn't line capacity these days?

Phil 

The water seemed to recede quite quickly last night/this morning.

 

Diverting up trains isn't too difficult so long as they come off Exeter at times that fit into the SWT schedule - if they don't, they just have to get held somewhere until they do! This often entails holding a down train to cross two ups, one Paddington and one Waterloo, but with careful regulating that doesn't have to cause huge delays to the down service. Consistency is all and, this morning, things were recovered very well once the very late 1L09 was "got rid of".  

 

Diverting down WR trains is a bit more tricky than it used to be "in my time". Since the WoE recontrol, the position of the relocated Down Main starter at Honiton makes it impossible to create an overlap for the Down Home. Signallers can no longer have the driver trundle down to the starter and accept another down off Axminster West before the first has departed.

 

The loss of the ability to conveniently cross two down trains with one up at Honiton meant that the diverted 1C77 caught some serious delay at Axminster West this morning, though the reactionary delay it in turn caused to 1L48 at Honiton was fairly modest.  

 

John

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I suspect the SR main is also still prone to flooding around the Axe area, however don't they bother diverting stuff down through Yeovil these days or Basingstoke if Somerset is having problems? Maybe there isn't line capacity these days?

Phil 

 

Looks like they might be diverting that way Phil (probably a trimmed' service) but there was a flood warning earlier for the Axe so best to cross fingers I reckon.

 

The real problem at Cowley Bridge is the shape of the river and flood plain upstream (as noted above by Kenny) and the only real answer I think is to do proper flow study the way the Hydraulics Research people at Wallingford used to do them and then bite the very expensive bullet which will emerge from that study.  With water it is always very easy to under estimate the quantities and force involved and of course the scientists simply can't forecast how much rain will come down in future weather events although it's likely to be more.

 

The real answer?  Probably lift the railway by several feet onto a viaduct which allows free water movement underneath it and which doesn't channel it into a fairly narrow stream.  Will that happen?  Probably not as the cost will be huge but in reality it's just as important as the seawall/cliff face situation a bit further west.

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I suspect the SR main is also still prone to flooding around the Axe area, however don't they bother diverting stuff down through Yeovil these days or Basingstoke if Somerset is having problems? Maybe there isn't line capacity these days?

Phil 

 

The line was closed at Whimple last night due to flooding, and it was close to flooding the line at Chard Junction as well.  Trains were terminating at Crewkerne and Honiton and I don't know if any bus replacement was running as the A35 at Honiton had flooding as well as the road from Axminster to Kilmington which the line runs by, as well as road closures at Weycroft Bridge just outside Axminster and at Donyatt on the A358 last night.

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I suspect the SR main is also still prone to flooding around the Axe area, however don't they bother diverting stuff down through Yeovil these days or Basingstoke if Somerset is having problems? Maybe there isn't line capacity these days?

Phil

 

I suspect that capacity is part of the reason and probably route knowledge or lack of, also plays a part.

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Just seen on tonights Spotlight a NR spokesman was asked about the barrage and he said that the warning came at around 10.30 last night and it was decided that under the prevailing conditions at the time it was decided that it was to dangerous to deploy them.

Yes, I saw that too.

 

I'm not persuaded by that argument. Controversially, perhaps, my take on this is that the flooding could have been predicted and equipment deployed. Arc lighting in sufficient quantities could have been deployed in advance and watchmen stationed at strategic (and safe) locations to watch out for flooding.

 

Putting those inflatable sausages out requires a firm decision to be taken to suspend the train service in advance of the deployment happening. Good information is necessary to inform that decision.

 

I'm not aware that any less rain fell on Exmoor over the last few days as compared with anywhere else in the SW. As such, it isn't rocket science (no, it really isn't!) to make an approximate estimate as to what this will do to the River Exe a few hours later. My view is that perhaps too much reliance is put on the Environment Agency these days.  This actually appears to be what Mr Gallop implied on live TV to Justin Leigh (and I think he regretted saying that as soon as it left his mouth).

 

For the last couple of years or so before I retired, no one in NR was keen to make a weather-based decision, unless the Duty Met Office forecaster (or whoever was contracted to provide NR with their weather forecasts at the time) came on to the inevitable telephone conference. There was (hopefully still is) a clerical officer in one of the local NR maintenance offices who was/is so good at weather interpretation, that on the (relatively few) occasions that he was invited to take part in the telephone conferences, he actually gave the Meteo Group forecaster (as it was then) a run for his money on one or two occasions, pointing out things that the Meteo Group forecaster had overlooked, but our guy had checked several different sources and just had a brilliant knack for getting it right.

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