Environment Agency announces updated plans for York flood scheme
The Environment Agency says that after re-assessing a flood scheme in York a section of road will need to be closed, but for six months less than planned.
An aerial image of York during the winter 2015 floods
A spokesperson said that due to significant public safety concerns it will not be possible to keep a section of Terry Avenue open, between Skeldergate Bridge and Dukes Wharf, while flood defence work takes place.
The Environment Agency submitted a planning application in March 2019 with its proposals to better protect Clementhorpe from flooding. It forms part of the £45 million given to York by the government after the devastating flooding of Boxing Day 2015.
But concerns were voiced about the proposed closure of Terry Avenue for up to 18 months and the impact on local residents so an alternative solution was sought.
Under the original plans, the road needed to be closed because the machinery required to install an eight metre deep wall of concrete piles under Terry Avenue to stop water ingress during flooding was too large to safely keep access open.
The Agency recently investigated the viability of using a method known as grout injection to stop the water ingress and this was found to be a suitable solution.
This means that the work is expected to take one year, rather than 18 months, and will not require large pile driver machinery so will be less intrusive to residents living nearby.
Environment Agency project director Ben Hughes said:
It is great news that a new less invasive solution, and one that takes six months less time, has been found. This will cause significantly less disruption to people than would otherwise have been the case.
Mr Hughes added that significant preparatory work is needed before the underground grouting can take place, meaning large scale excavation is required along the narrow river frontage. He said:
During our investigations in October a number of incidents arose where work had to stop and members of the public needed to be escorted through the active working area.
This caused significant delay to even these minor works and to ensure Terry Avenue was fully reopened on time we had to impose a 24 hour road closure for vehicles.
Unfortunately these issues are out of our control and we can only conclude that it is not viable to safely accommodate the public in these areas during the main works.
To allow for the legal public consultation period, the planning application is expected to be heard in March/April, with the aim of work starting in late spring/early summer.
For further information, go to https://consult.environment-agency.gov.uk/yorkshire/yorkfas or contact the Environment Agency by emailing yorkfloodplan@environment-agency.gov.uk or speak to a member of staff directly at the hub on Wellington Row (YO1 6FZ), which is open 10am to 4pm on Mondays and Wednesday and 10am to 1pm on Thursday.
Further information:
Detail of work required While the proposed Clementhorpe flood alleviation scheme stretches from Skeldergate Bridge to Lovell Street (at the entrance to Rowntree Park), there are three key construction locations which will impact on access along Terry Avenue:
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Terry Avenue grout injection
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Clementhorpe floodgate
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Waterfront House floodwall
Terry Avenue grout injection To provide a below ground barrier to prevent water moving under our new flood defences and flooding properties, it will be necessary to excavate a trench along Terry Avenue between Skeldergate Bridge and Dukes Wharf. This will allow for:
• Excavation to identify services, sewer connections and finalise the route of the below ground barrier.
• Injection of grout into the ground to form barrier.
• Construction of a clay liner to connect above and below ground work ensuring the flood defences are not compromised from future work within the highway.
Clementhorpe floodgate
We have proposed installing a bi-fold flood gate at the bottom of Clementhorpe. Installation will require significant above and below ground work including:
• Excavation to remove the existing Aqua Barrier foundations.
• Identification and protection of existing buried services.
• Installation of bi-fold floodgate foundation, including piles.
• Diversion of existing buried services, by service providers, through ‘purpose built’ conduits within the gate foundation.
• Backfill of excavation and required road and footpath reinstatement/ reconfiguration.
• Installation of bi-fold floodgate and associated storage cabinets.
Waterfront House floodwall
To install the new floodwall, significant above and below ground work is required including:
• Identification, protection and diversion (by service providers) of existing buried services within the footpath to make space for the floodwall foundation.
• Injection of grout into the ground to form barrier.
• Installation of floodwall foundation, including piles.
• Construction of a clay liner to connect above and below ground work ensuring the flood defences are not compromised from future work within the highway.
• Backfill of excavation and required road and footpath reinstatement/ reconfiguration.
• Construction of concrete floodwall.
• Installation of flood resistant glass panels to ground floor balconies/windows plus new brick façade.
What does this mean for access?
Due to the extent of above and below ground work, and the lessons learnt from recent ground investigations, we have concluded that access along Terry Avenue for all users cannot be maintained safely once construction starts. It is expected that access will be compromised for 12 months.
Pedestrians and cyclists
Proposed diversions for pedestrians and cyclists have been outlined in our current construction traffic management plan (CTMP) which is available on the City of York Council planning portal under application reference 19/00570/FUL. Pedestrian access to the existing houseboats on Terry Avenue will be maintained.
Vehicles
Alternative routes for vehicles seeking access to areas south of Skeldergate Bridge will be required, including:
• Houseboats.
• Dukes Wharf residents.
• The Roomzzz Aparthotel.
• The Caravan and Motorhome Club – Rowntree Park.
• Rowntree Park car park.
The current construction traffic management plan outlines alternative vehicle access from the south via Butcher Terrace and Terry Avenue. Residents of Dukes Wharf have confirmed that they will utilise the private road to the rear of the property.