Boscastle Flooding notes

The Boscastle Floods: August 16th 2004.

Causes:
Rain
A hot day in August (16th 2004)
Really torrential thunderstorm 60 mms in two hours
Really tall convectional clouds
The remnants of Hurricane Alex
Valley shape
Really steep sided deep valleys of the R. Valency and the R. Jordan
The valleys funnel the water down towards Boscastle
Small ‘flashy’ catchments that funnel water into rivers quickly. 23 sq. km.
Rivers run off the high ground of Bodmin Moor (relief rainfall)
Geology
Impermeable rocks (slates and granite) and clay soils
Human
Boscastle built beside the sea on a flood plain at the end of the narrow river valleys.

Effects:
. Around 1000 residents and visitors are believed to have been affected in this devastating event.
• Miraculously, there were no fatalities, with only 1 reported casualty - a broken thumb.
• 7 helicopters airlifted 100 people (including 6 firefighters) to safety.
• 29 out of the 31 Cornwall County Fire Brigade stations were involved in the incident. They remained at Boscastle for 7 days, assisting in the clean-up operation.
• 58 properties were flooded, 4 of which were demolished including The Visitor Centre,
• A further 40 properties were flooded in other villages
• 4 footbridges along the Valency Valley were washed away.
• 84 wrecked cars were recovered from Boscastle’s harbour and streets, 32 could still be out at sea.
• The infrastructure damage to buildings and services, could cost up to £2 million.

Future Prevention Measures
Seen as very exceptional – once in 400 year event – so less need to act!
No-one actually killed (unlike Lynmouth) – so less need to act!
Most of the inhabitants of Boscastle are under no illusion, from past experience the village may well witness further floods in the future, but hopefully not on this scale.
Preventative measures and improvements by the Environment Agency are already under way. They include a new culvert on the River Jordan, upstream of the Wellington Hotel, extending a further 80minto the River Valency.
Discussions concerning flood risk management in the upper Valency catchment area were also taking place, but no conclusions have yet been reached on further works in Boscastle.