1. BOSCASTLE MEDC FLOODING- CAUSES/EFFECTS AND MANAGEMENT STRAGIES
Causes:Physical
-Stormy weather up to flood meant saturated ground
-Steep saturated sides of Valency Valley meant
increased surface run off and therefore discharge
volume
-Impermeable rock at Bodmin moor prevented
infiltration so water reached channel faster
-Over 60mm (typically a month’s rainfall) fell in 2
hours on already saturated land
-Boscastle is at confluence of 3 rivers:Valency, Jordan
& Paradise
- Flooding coincided with high tide makingmatters
worse
Background:
A small north Cornish town popular with tourists.Approximately 800 permanent residents but more
affected due to influx of tourists. Hit by catastrophic floods on 16th
August 2004
Causes:Human:
-Less significant
-Lack of any flood control eg raised
banks around river or emergency
drainage ditches
-Old sewer and drainage system
with low capacity
-Small, low bridges over river
trapped material and cars acting as
dam and causing water to flow
round the bridge causing more
flooding
Flood Defence Scheme: Cost £4.6 million and completed by 2008.
-Widening channel and lowering bed by 0.7m to increase discharge capacity
-Raising car park to work as flood defence and make cars safer
-Car park new permeable surface
-New river/flood defence wall to reduce impact (hard engineering)
-Relocated lower bridge with raised arch to prevent debris build up
-Clearing vegetation from river bed- active management every summer
- New gauging station to measure flow/speed of water to aid flood protection
-Drainage improvements
Sustainability of defence scheme:
-Area protected so people don’t move away so no job losses
-Less property damage so tourist industry can continue..Last a long time so no large on-going costs
-£4.6million small in comparison to £20million insurance pay out
Effects:
-25 business properties destroyed. (loss of jobs & cost of repair)
-50 buildings damaged (owner cost of repair, insurance pay out causes future premiums to rise)
-4 footbridges washed away (cost of rebuild for council)
-Pavements and gardens damaged by weight of water
-Roads blocked so rescue by helicopter only
-Burst sewage left Boscastle inaccessible for a few days
-£20 million insurance pay out so premiums will now rise
-Visitor centre destroyed and mud/debris covered large parts of the town. This devastated local economy, 90%
of which comes from tourists
