Culverts could relieve threatened bridges

The extreme rain and floods seen in the UK in recent years may see increased demand for the type of flood-saving culverts such as Tubosider supplied for the River Eden at Carlisle in Cumbria.

Northside Bridge in Workington, also in Cumbria, was completely washed away in the floods of 2009, and now English Heritage is to review the suitability of the 7000 listed bridges in its care.

Ancient stone bridges with water pouring over the parapets, their narrow arches choked by fallen trees and debris washed down swollen rivers, have been recurring images in flood reporting.

With the bridges often been blamed for damming the rivers’ flow and causing misery to nearby communities, English Heritage is launching a pilot study to establish whether the bridges in its care are the villains or the victims.

Many bridges built more than 500 years ago for pack horses and wagons still carry cars and trucks every day. The massive stone slabs of Tarr Steps, a pedestrian bridge over the river Barle in Somerset believed to be more than 1000 years old, were washed away in floods in December, and engineers are now studying how to rebuild it.

English Heritage first began to assess bridges across the country after the floods of 2009, when in Cumbria alone, several collapsed or were left so structurally unsafe that they were demolished. The county has 350 listed bridges, and many more which are not listed but regarded as of historic local interest.

A pilot project is being launched along the River Aire, in parts of Yorkshire and Lancashire, assessing the importance and vulnerability of scores of road, rail and footbridges, and measures to protect them in case of flooding. Nationally, the plan aims to highlight areas where historic bridges are at the highest risk, due to the rate at which flood water rises, and the speed of its flow.