Boscastle Flood Defence System, River Jordan Catchment, Cornwall
About the Project
- Principal designer: Halcrow Group
- Client: Environment Agency
- Principal contractor: Mowlem Engineering
- Principal engineer: Halcrow Group
- Contract value: £900,000
Boscastle, North Cornwall, was the scene of a flash flood in 2004 which led to the evacuation of 50 people from rooftops as a three-metre wall of flood water swept down the steep-sided River Valency valley.
A scheme designed to defnd the River Jordan, a Valency tributary, had been due to be signed off the day after the flood; a redesign took two weeks, and construction started the following Monday.
The scheme features a concrete culvert running behind a row of eight terraced cottages. This converts to a concrete pipe running down a road to an outfall into the river Valency, downstream of the main bridge through the village. The outfall incorporates a baffle wall to dissipate energy before releasing flood flows. Great efforts were made to integrate works with the village's historical features.
The scheme was completed one week ahead of schedule and 18 per cent under budget. But the vital component was the clear benefit of partnership working, delivering flood protection to a community shattered by events in August 2004.
The Judges said:
"This project is a good example of essential flood alleviation, produced in a discreet and well-designed manner."