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Tuesday 3 January 2017

Replacing Alma Bridge to secure a lifeline for both residents and visitors alike

Talk of doing something about Alma Bridge has been going on for some time:
Futures Forum: Alma Bridge: "lifeline" for residents and tourists alike

It's future is very much connected with that of Pennington Point:
Futures Forum: A replacement for Alma Bridge: 'scheme can only happen if cliff erosion is slowed'
Futures Forum: Alma Bridge and Pennington Point: "There’s no point putting a beautiful new bridge there if the eastern end is cut off because the cliff has eroded."

... and of the Eastern Town:
Futures Forum: New plans for Alma Bridge - and a sea defence wall to protect Sidmouth’s eastern town from flooding

The bridge had to be closed before Christmas:
Five-day closure plan for Sidmouth’s ‘vital’ Alma Bridge - News - Sidmouth Herald

But new, permanent plans are emerging:
New, ‘sloping’ replacement for Sidmouth’s Alma Bridge in 2018? - News - Sidmouth Herald

The County Council released this press statement just before Christmas:


Medium term solution sought to replace Alma Bridge in Sidmouth

Alma BridgeAlma Bridge
Posted on: 15 December 2016
Devon County Council is focusing attention on a medium term solution to replace the Alma footbridge in Sidmouth.
The temporary structure currently in place was only intended to have a very limited life expectancy and, due to ongoing cliff erosion, the bridge will be lost in the near future.
The authority is committed to ensuring this well used bridge is replaced if viable and has been exploring two options: one crossing 55 metres upstream of the existing bridge with ramps providing access to the bridge, and the other option using steps at each end of the bridge.
The ramp option includes a 30 metre long ramp on the west side from the pumping station, which would also form part of an upgraded coastal flood defence wall. The ramp was proposed to rise eight metres above the river to access a high level bridge and would require significant additional civil engineering work.
Flood modelling would be needed to design the west ramp to the correct standard of coastal flood defence. The modelling could be undertaken as part of East Devon District Council’s Beach Management Plan work, but it is anticipated this information would not be available for possibly up to 12 months. This would mean construction of a replacement bridge would be unlikely to commence for two or three years.
Extensive geotechnical investigation of the east cliff would also be required as there may also be considerable costs to stabilise the ground for a ramp structure on the east side. The scheme, which is anticipated to have a lifespan of more than 50 years, could cost up to £1.5 million.
The alternative option will provide a bridge with a flight of steps at either end of the bridge rather than extensive ramps. The original Hanger Path on the east side of Alma bridge was a series of steps close to the cliff edge before being abandoned for a very steep path realigned inland. As the cliffs erode it is likely that Hanger Path will have to be re-aligned again, possibly within the next five to 10 years. Due to very steep gradients the path may have to return to its original design using steps.
Councillor Stuart Hughes
Cllr Stuart Hughes
Councillor Stuart Hughes, Devon County Council Cabinet Member with responsibility for bridges and local member for Sidmouth, said: “Our teams have carried out a thorough examination of both options and at this time it makes sense to pursue a medium term solution until the preferred option from the Beach Management Plan is implemented. At that stage we could then look in more detail at longer term options with ramps to safeguard a crossing to the coast path which will also provide easier access.
“If the bridge option with ramps is pursued the coastal path could be diverted inland for up to three years until a new bridge is provided. It could also potentially be unviable for cost and engineering reasons. The second bridge option using steps could be considered more of a medium term solution but it’s a good compromise. It could be built sooner at a much lower cost, minimising the potential duration of the coastal path diversion. It will also keep the coast path in operation close to the sea front which will benefit both local residents and visitors alike.”
Martin Davies, Flood Risk Advisor from the Environment Agency said: “The River Sid defences currently provide a good standard of protection against flooding. We are aware that due to ongoing erosion of the cliffs to the east of the River Sid and the likely increase in storminess and sea level rise due to climate change these flood defences along the river upstream of Alma Bridge will need to be improved in the future. Although further improvements to manage flood risk along the river frontage are not justified at this time we are currently reviewing maintenance requirements along the River Sid wall and look forward to working with DCC to assist in developing their options for bridge access over the river.”
The County Council will target an opening for the new bridge during 2018. 

Medium term solution sought to replace Alma Bridge in Sidmouth | News centre

Which stimulated some discussion on the Streetlife site:


Alma Bridge replacement

Mary W-T  in Sidmouth

 
I am of course only going on the Herald article but I am confused about the two alternatives.

Surely the middle term alternative could be just upstream and reach the Hanger Path just a little higher than now. If the bridge was a greater number of feet above sea level it would not need steps at that end.

On the bottom end there is enough space around the turning circle to create a ramp in one direction or another.

It would be very strange if this hadn't been considered so is there anywhere we can see the options being considered and give input? Stuart?

I am not asking in the spirit of interferring or mischief-making but from the position of having a degree and career in design and so being interested in such things.


Stuart H  
Mary
The simple answer to your question is that
Devon County Council has already obtained EA Flood Defence consent for this option and it is anticipated works could commence next year and be complete in 2018.
This link as you know is so important to the economy of Sidmouth and a lifeline for those living east of the river.
Mary W-T 
Thank you Stuart.
The article gave me the impression that the mid-term option was forced to have steps even though the preferred option would be a ramp.

If it is all agreed then that is that.
Stuart H  
We've just got to get on with it now Mary .... We can't afford to wait for a Beach Management Plan scheme that is at least 4 years and possibly 5/6 years away.
The Environment Agency will be carrying out some important work on the river wall during 2017 which will cost at least £100,000 .... We can make sure that the full blown Bridge scheme is worked up ready for the future.
Mary W-T 
Thanks again for the further info.
I suddenly realised that I have no idea if bridges have to get planning permission in the same way buildings do.

If they do need planning permission would it be DCC or EDDC who dealt with it? If not, then what mechanism is there for making sure bridges and such structures are a suitable design for their setting?

Will the EA work be to the east or west bank of the river, and is it near where the new bridge will be?
Stuart H  
Hi Mary and re your further questions can confirm that EA are carrying out work on the scouring of the river training wall which is in the ownership of the Town Council.
As for planning County will carry out consultation with both the town and district councils but have deemed consent.
There are also other hoops to jump through including permission from Natural England however when I met with their Chairman Andrew Sells he indicated their support .... Then there is the MMO and the Environment Agency who have already given their support.
Hope this helps.
Stuart H  
And what we can't and don't want to do is divert any funding away from Government for the Beach Management Plan Scheme.... Without protection of the cliffs to stem the erosion the bridge would be surplus to requirement.
Mary W-T 
Thank you Stuart, I realise it is a very complex negotiation which has to occur.

So am I correct in understanding that County planning is ultimately responsible for making sure it is suitable for a conservation area but that EDDC and STC will be allowed to comment?

The scouring of the training wall I find a bit confusing as the recent rains had, I thought, cleared loads of stuff out to sea from there. Is it that the tail end of the high water flow deposited more?

On an historical note, the training wall seems to have been very much a mixed blessing!
Stuart H  
Hi Mary
Correct on first point that you raise.

Scouring isn't shingle deposits ... It's where the sea is undermining the river wall that is scouring and it is quite considerable. Whilst the Town Council own this wall the Environment Agencyare to carry out the work b
Stuart
Mary W-T 
Ah, so they are working on the scouring which has occurred not working to scour! I understand now.
Paul Wright  
Have you seen that you can now create 3D printed steel bridges? Alma bridge was pretty boring IMHO. Creating a 3D printed bridge gives you scope for amazing designs. An artist could let their creative juices flow.  A landmark bridge with an incredible design would create a tourist attraction that would draw visitors for years. If Sidmouth had the 1st 3D bridge in the UK, think of the visitors that would draw in. Have a look here:

https://www.theguardian.com/technology/2015/jun/17/dutch-startup-plans-first-3d-printed-steel-bridge...
Barnacle Bill 
A competition, open to designers and engineers worldwide is needed - just like the Port Royal one.
Stuart H  
Not sure where the funding would come from. A great idea though ...... Let's get the interim bridge in first and then who knows.
Mary W-T 
I agree that a really nice bridge would be excellent. The Alma Bridge created by Sampson was art of its time, then it was changed in design a couple of times only retaining the brick pillars and so ended up looking a bit of a dogs dinner.

I find the one in the link from Paul beautiful.

I don't see why a competition would need funding? Or are you thinking of the funding needed for creating the bridge Stuart?
Real Sidmouthian  
I'm sure if there is a chance of a new bridge being built once or twice SH will be on hand to cut the ribbon with a photographer!
Polarising Plebeian 
Q: How many years does it take to build a new bridge?  A: Wrong question, you just declare the status quo as being perfectly OK.
Paul Wright  
Stuart, who is funding the current proposed bridge? I'm sure extra funding could be found for a landmark bridge. As the gateway in to sidmouth from the costal path, it would set the tone for the whole Port Royal redevelopment.
Stuart H  
I think as usual on this site people get carried away and then start throwing insults.
So let's go back to where we started. We Devon County Council have secured the necessary permissions to install a temporary bridge with a lifespan of 25/30 years depending on the success of the Beach Management Plan Scheme.
A bridge further upstream would take 5/6 years to achieve and by that time the scaffolding bridge that's there now would be gone and the lifeline for those east of the Sid would be severed and then the only way to town would be via Milford Road.
Let's get the bridge we can achieve in first and then look to the future.


Streetlife | Alma Bridge replacement
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