HS2 Resilience to Flooding

[Nottingham59]

For better or worse HS2 Ltd has decided to put the line into deep cuttings and tunnels along most of its route, rather than say using viaducts over obstructions. How have these alignments fared in the recent heavy rains? Has the drainage been adequate? Or are there worksites on the route that are currently under water?

I know it's early days, and work is ongoing. Green tunnels will not yet be complete; Old Oak Station has still to be covered over and sealed; drainage channels will still to be dug; etc. etc., but it would be reassuring to know if the design is showning good resilience against flooding.

 

[andyjhatton]

I would take a bit of issue with the phrase "...HS2 Ltd has decided..."

They were pushed into this by various NIMBYs and environmental groups.

 

[Nottingham59]

They were pushed into this by various NIMBYs and environmental groups.

Totally agree with you. But it does raise the question of whether they have been pushed into building a line that it now vulnerable to flooding. Hence this thread.

 

[stuu]

Lots of the route isn't actually in cuttings, what they are doing is redesigning the landscape so that the land around the line is built up to give the impression of being in a cutting.

Given that most of it is nothing like finished, the current state of flooding or otherwise doesn't offer much in the way of insight

 

[318 Ayrline]

For better or worse HS2 Ltd has decided to put the line into deep cuttings and tunnels along most of its route, rather than say using viaducts over obstructions. How have these alignments fared in the recent heavy rains? Has the drainage been adequate? Or are there worksites on the route that are currently under water?

I know it's early days, and work is ongoing. Green tunnels will not yet be complete; Old Oak Station has still to be covered over and sealed; drainage channels will still to be dug; etc. etc., but it would be reassuring to know if the design is showning good resilience against flooding.

Having been criss crossing the line around the Banbury area on local roads the extent of flooding is clearly evident

 

[Nottingham59]

Having been criss crossing the line around the Banbury area on local roads the extent of flooding is clearly evident

Yes. It was this BBC item of the A421 underpass in Bedford being blocked that made me wonder about HS2 cuttings.

Watch: A421 submerged by flood water in Bedfordshire

The road is closed in both directions and a diversion is in place.

www.bbc.co.uk

 

[zwk500]

but it would be reassuring to know if the design is showning good resilience against flooding.

The current state of works will give zero idea about the capability of the final design. After all, it will have been designed to drain a concrete slab track railway, not a muddy haul road.

 

[GRALISTAIR]

I would take a bit of issue with the phrase "...HS2 Ltd has decided..."
They were pushed into this by various NIMBYs and environmental groups.

Totally agree with you. But it does raise the question of whether they have been pushed into building a line that it now vulnerable to flooding. Hence this thread.

I think modern civil engineering and knowledge of Soil Mechanics etc has so improved that I doubt this will be the case. Time will tell of course.

 

[fgwrich]

The current state of works will give zero idea about the capability of the final design. After all, it will have been designed to drain a concrete slab track railway, not a muddy haul road.

I really do hope the drainage is maintained well enough though, having seen the effects when slab track is flooded. Ballast may have resulted in a slightly lower top speed but at least it has the advantage of being freely draining. But otherwise, fully in agreement.

 

[Nunners]

On the parts of the design I've seen, it's been designed to be operational in a 1 in 1000 year flood event. Obviously there's a size of storm that could render it non-operational but it will be much more resilient than the "classic" railway

 

[zwk500]

I really do hope the drainage is maintained well enough though, having seen the effects when slab track is flooded. Ballast may have resulted in a slightly lower top speed but at least it has the advantage of being freely draining. But otherwise, fully in agreement.

Do agree re maintenance.