Storm Dennis - 15th/16th Feb 2020

[whole diary]

[Umberleigh]

"Network Rail have deployed their inflatable booms at Cowley Bridge to try to mitigate the effects of the flooding."
The Exeter /Taunton and N.Devon lines have been closed since start of Sunday.

At 1345 today I looked over the A377 main road bdge at Cowley to find about 6 men from NR^» (Network Rail - home page) Contractors Balfour Beatty in attendance with an UNinflated orange boom straddling the N.Devon and main lines lines in case the river flooded over the line later.
Heavy rainfall on Exmoor takes, via the river Exe, about 12 hours to reach Exeter.

This boom when inflated would thus stop most water going under the road bdge towards St D, but the floodwater would still flood across the lines and wash track ballast away.
There was apparently no flooding anywhere between Exeter and Taunton; not even at
flood prone Hele & B which has yet to have flood 'alleviation' works carried out.

At 1350 I found a queue of about 350-400 passengers waiting along the front of St D for coaches to Taunton...I dread to think how long some had been waiting (an empty IET^▸ (Intercity Express Train) was noted stabled in Exeter New Yard) .
A coach from the small family firm of Powells of Lapford, arrived at 1405 from Taunton having taken just over an hour from Taunton with Passrs off the 1103 Padd.
Passengers I collected off this coach remarked how professionally and carefully the driver had driven; who in this instance clearly 'knew the road' and how comfy the coach seats were compared to the hard seats on the ' New (IET) Trains' ...no surprises there then !

On Xmas Eve 2013 I had a more than 2 hour wait outside St David’s for a coach to TivertonParkway (flooding at H&B) after travelling up from Truro. Thankfully it was a sunny day, as there was no cover from any rain

[Umberleigh]

Is the old Cowley road-over-river bridge listed?

Seems to me that the road needs to be moved so that the railway be raised to allow water to run under it. Fairly major project but not as big as the new Barnstaple bridge

[Timmer]

The service at Pewsey and Westbury has been - to put it mildly - sparse today. Only three trains called at Pewsey (unless there were any unadvertised that don't show up on RTT^» (Real Time Trains - website)). From the passing times at Heywood Rd and Fairwood Junctions, it appears that the "fast" services did not call at Westbury to fill in the gaps - the only down trains recorded were 0920 and 1600; the only up trains at 1043 and 1115.

Thank you for reporting this Trowres. I was going to do a report on the second weekend of almost non existent service for Pewsey, Westbury and Castle Cary to/from London because for whatever reason GWR^▸ (Great Western Railway) didn’t stop Express services at these stations in place of the cancelled stoppers for the thread I started here:
http://www.firstgreatwestern.info/coffeeshop/index.php?topic=22891.0
But decided not to owing to a lack of interest with this thread. Probably not the right attitude to take I admit.

Fair play to GWR that because the service on the London-WoE line was a complete mess because of the line being closed between Taunton and Exeter meaning they had many hundreds of passengers to and from the SW to deal with that the service provided for these three stations was a lower priority.

I am however concerned that once again that once the semi fasts get cancelled nothing is done to serve these stations by stopping expresses, something the stations would have had when the old timetable operated.

I can only think that no one uses Pewsey station on the weekend to be concerned about this.

[Timmer]

From GWR^▸ (Great Western Railway) Help......


⚠️A diversionary route via Yeovil is now flooded so the last service from Paddington to Taunton will be at 15.30.
Replacement buses will run from Bristol Temple Meads to Taunton, Tiverton Parkway and Exeter St Davids but these are expected to get busier as the day progresses.⚠️

Why would that stop GWR operating services to Taunton?

Cross Country have been turning their trains around at Bristol Temple Meads,  so the service to Taunton has been just one stopper an hour.  Taking everyone arriving in Bristol for Exeter and beyond and putting them on the short stopper would be slow and overcrowded.  Then when they get to Taunton, they couldn't use the south side to transfer to buses because of all the works going on; really unsuitable for large volume rail to road transfer.

Apologies Graham, I should have been clearer in meaning services from London to Taunton.

Of course it made sense to bus those from XC^▸ (Cross Country Trains (franchise)) services terminating at Bristol down to Exeter rather than try and squeeze them onto local stopping services.

[grahame]

The service at Pewsey and Westbury has been - to put it mildly - sparse today. Only three trains called at Pewsey (unless there were any unadvertised that don't show up on RTT^» (Real Time Trains - website)). From the passing times at Heywood Rd and Fairwood Junctions, it appears that the "fast" services did not call at Westbury to fill in the gaps - the only down trains recorded were 0920 and 1600; the only up trains at 1043 and 1115.

Thank you for reporting this Trowres. I was going to do a report on the second weekend of almost non existent service for Pewsey, Westbury and Castle Cary to/from London because for whatever reason GWR^▸ (Great Western Railway) didn’t stop Express services at these stations in place of the cancelled stoppers for the thread I started here:
http://www.firstgreatwestern.info/coffeeshop/index.php?topic=22891.0
But decided not to owing to a lack of interest with this thread. Probably not the right attitude to take I admit.

; sticks hand up ... very interested in Pewsey.  Just that I don't "like" or reply every time ... my name pops up more than enough anyway

I am however concerned that once again that once the semi fasts get cancelled nothing is done to serve these stations by stopping expresses, something the stations would have had when the old timetable operated.

The central timetable meeting last week came up with some questions concerning practises with the new timetable when things aren't going right.   It wasn't really on that agenda but a couple of points were taken away 

[grahame]

Apologies Graham, I should have been clearer in meaning services from London to Taunton.

Of course it made sense to bus those from XC^▸ (Cross Country Trains (franchise)) services terminating at Bristol down to Exeter rather than try and squeeze them onto local stopping services.

I actually got both ... but even with just the London traffic, I suspect Taunton will struggle with the south side area closed (see "where's the AGM^▸ (Annual General Meeting) thread and link to https://www.gwr.com/plan-journey/stations-and-routes/taunton-upgrades )

[Timmer]

http://www.firstgreatwestern.info/coffeeshop/index.php?topic=22891.0

The central timetable meeting last week came up with some questions concerning practises with the new timetable when things aren't going right.   It wasn't really on that agenda but a couple of points were taken away 

Pleased to hear this was raised in the timetable meeting Graham as the last two weekends have not been the first time the semi fasts have been cancelled with no substitute calls on other services offered.

This goes back to the first day of the new timetable on the 15th of December when shortage of train crew affected in the semi fasts in the run up to Christmas.

[froome]

I'm using this thread due to the discussion about Cowley Bridge flooding. I am due to be travelling from Bath to Exeter this Saturday (Feb 29) for a meeting and need to be certain of being able to return home to Bath that evening. I'm aware that the forecast for Saturday is grim with rain heaviest in the south-west.

How likely is it that the line north from Exeter will get flooded again and closed during Saturday? If that is the case, can I rely on alternative transport being made available? Will alternative routes be available to use, assuming they are not flooded as well?

[TaplowGreen]

I'm using this thread due to the discussion about Cowley Bridge flooding. I am due to be travelling from Bath to Exeter this Saturday (Feb 29) for a meeting and need to be certain of being able to return home to Bath that evening. I'm aware that the forecast for Saturday is grim with rain heaviest in the south-west.

How likely is it that the line north from Exeter will get flooded again and closed during Saturday? If that is the case, can I rely on alternative transport being made available? Will alternative routes be available to use, assuming they are not flooded as well?

I'd suggest following Met Office advice.

[ellendune]

Try this flood forecast:

https://flood-warning-information.service.gov.uk/5-day-flood-risk

Looks OK for Saturday at the moment

[froome]

Try this flood forecast:

https://flood-warning-information.service.gov.uk/5-day-flood-risk

Looks OK for Saturday at the moment

Thanks. It looks like it should be ok, although the forecast is still for much rain in the south-west.

However, my question was more to do with what people's perception of the susceptibility of Cowley Bridge to flooding is, especially from those of you who have more local knowledge. Given its importance, as the main route from the south-west to much of the rest of the country, how susceptible is it? I have been caught out there before, but can also remember being on trains where the whole Exe valley was under water and there was water on the tracks, but the train got through, albeit slowly.

And given the experience I had yesterday of rail replacement, which I've outlined elsewhere, how much can I rely on that being provided and providing the service of getting passengers to their destinations in a timely way?

[IndustryInsider]

I guess we'll have to wait for the answer to that for several years until the effectiveness of the recent flood alleviation work becomes clear.  Those responsible estimated that the railway would have to be closed only once every ten years instead of once every two years.

That work was finished only 18 months ago, so not a good start seeing it close already - however the flooding associated with the storm and rainfall was very extensive so perhaps it will indeed be another ten years before something similar comes along?

[CyclingSid]

Oh that 10--year return periods in flood data were that simple!

[ellendune]

Oh that 10--year return periods in flood data were that simple!

Yes I have lost count of the number of times I have had to explain that during my career.  The Environment Agency prefers to use the term a probability of flooding of 10% every year rather than once in 10 years, but even this does not give the whole picture. 

Estimates of flood frequency can only be based on long term observations of flow and rainfall data.  If you are estimating the frequency of something that happens fairly randomly but on average every 10 years you will need not just 10 years of data but several decades of data to get a reasonably reliable estimate of the frequency. 

However that assumes a stable system, and we know the climate is changing and the catchment may have changed as well. The catchment changes we can at least see and make allowance for, the the climate is more difficult. Because climate is long term and we are dealing with frequencies, we don't even know with any certainty what it has changed to at the moment, let alone where it will end up.  So we apply uplifts to the design rainfall based on the predictions of climate models. The government has published uplift values for river flows If I were to say that for the south west region these uplifts are estimated to be between 30% and 85% for the 2080's you might get a sense of the uncertainty here. 

The climate models are thought to be reasonably good for longer periods of rain like those that cause river flooding of the type we have at the moment. But for short intense storms like those that cause the Boscastle floods a few years back or even shorter intense periods that cause a lot of surface water flooding in urban areas there is still even more uncertainty which the uplift figures do not reflect. 

Then there is the catchment wetness that affects how much of the rain runs off.  The problem on the Severn and the Wye at the moment is that the ground is no so wet rain does not soak into the ground, so more of the rain runs off into the rivers. This is to do with how far apart the storms are. I am not sure how well the climate models have captured this aspect at the moment but I suspect not that well.