North Cornwall District Council has deferred a decision on whether to demolish a historic, listed bridge in Boscastle which is part of the Environment Agency’s solution to reducing flood risk.
The agency has £4.5-5M available to better protect the town following the damage wreaked when 200mm of rain fell in 24 hours, two Augusts ago, increasing the peak flow of the River Valency to 140m3/sec.
It has submitted three planning applications, including demolition of the 19th century Lower Bridge, which carries a private road and the South West Coast Path across the lower harbour.
The 1887-built bridge was seen as a particular bottleneck in the devastating 2004 flood and the grade two-listed structure was extensively damaged and its parapets demolished. But, although it was patched up with temporary parapets, the agency believes the National Trust-owned structure will have to be replaced – a move some residents have expressed concern about to local media.
‘It is felt necessary to demolish the remains of the structure and provide a replacement bridge to span a wider and deeper river bed at a point some 3.5m downstream from its present position,’ the council’s planning and development committee was told.
The intended replacement would have a single 11m span to be built in blue-grey dressed arch stones with blue grey rough rubble stone parapets, both similar to the existing bridge. Silver grey granite copings are proposed.
The works, proposed by the agency, will provide one in 75-year protection – the 2004 flood was assessed as a one in 400-year event, with 200mm of rain falling in 24 hours and the River Valency flooding 42 properties. ‘Clearly such improvements will, in turn, reduce the severity of damage in less frequent but more significant events,’ the committee was told.
The proposed works, to be spread over two years, include reconstruction of a car park with raised flood defence levels, and widening of the river channel above and through the car park.
Downstream of the car park, the river bed will be widened and lowered, involving modifications to adjacent gardens, and a large replacement pedestrian bridge provided. An upstanding sewer crossing would be replaced beneath the surface of the lower river bed.
The sudden downpour on the 16 August 2004 caused the Valency and Jordan to burst their banks, prompting what was described as the UK’s largest peacetime rescue operation. Fifty-eight properties were flooded, more than 100 cars wrecked, and there was £1.2M worth of damage to the town’s highways and bridges.