Repairs to bridge over Rea Brook

Shropshire County Council has just started urgent work to stabilise Kingfisher Valley number two bridge in Shrewsbury which has been severely damaged by flooding.

The bridge, which carries the Pritchard Way to Sutton Road cycleway over the Rea Brook, is an old railway arch thought to be about 150 years old.

On 25 January (2008) engineers discovered a large hole in the side of the arch and closed the cycleway for safety reasons. Since then, their contractor, Enterprise, has been busy diverting the Rea Brook through another nearby bridge.

Diverting the brook has involved excavating an estimated 4000 cubic metres of soil to form a new river channel which crosses land maintained by Shrewsbury & Atcham Borough Council who have been working closely with the County Council to solve the problem.

The brook was diverted into its new channel last Thursday (14 February). Since then workers from the Environment Agency have been helping by rescuing fish from pools in the cut-off part of the brook. This process involved using specialist electro-fishing equipment to lightly stun the fish, making them easier to catch.

Now that the brook has been diverted, engineers have been able to get close enough to the damaged bridge to assess the damage.

John Williams, Shropshire County Council’s principal bridge engineer, said: “The damage is considerable and parts of the bridge are very unstable. In order to stabilise it, it is proposed to slide a 1.2m diameter steel pipe under it and then concrete the void between the pipe and the underside of the arch.

“It is appreciated that the closure of the cycleway is causing inconvenience and we will do all that we reasonably can to re-open it as soon as possible. In the meantime, people are asked to honour the closure for their own safety as parts of the bridge are very unstable.”

The stabilisation work started last weekend (16 February) with the building of a temporary haul road from Pritchard Way to the bridge and is expected to continue for a period of two to three months.

After the bridge has been stabilised, the County Council will be commissioning consultants to carry out flood modelling to assess the impact that the work may have on future flood levels and to establish whether it will be necessary to carry out further improvement work. This will be done in liaison with the Environment Agency.

Further information

The damage is believed to have been caused by flood water undercutting the bridge’s foundations. Although engineers cannot be certain, it is thought to have happened during the summer 2007 flooding and then aggravated further by last month’s flooding (January 2008).

As recommended in national Codes of Practice, the County Council has its highway bridges inspected by experienced inspectors at two year intervals. This bridge was last inspected in summer 2006 and found to be is a reasonable condition given its age.

In addition to carrying the cycleway, the bridge also carries a multitude of services which include a gas main and sewers. As yet these have not been affected; however engineers are monitoring the situation on a regular basis.

Although it is too early to be precise, it is estimated that the cost of diverting the Rea Brook and stabilising the bridge will be in the region of £450,000.

21 February 2008