CASE STUDY: BOSCASTLE FLOOD Flashcards
(Boscastle) Basic profile of the flood (Date, Place etc.)
16th August 2004
Southwest England
200mm of rainfall in 24h, saturated ground and impermeable rock lead to surface runoff down steep v shaped valley.
River valency confluences with rivers Jordan and Paradise, increasing discharge.
3 meter flash flood, 440 million gallons of water
(Boscastle) Why did the flood happen? (Human reasons)
Lack of trees for interception of rainfall
Channelisation of River lead to increased flow speed and reduced width
Boscastle was built on a floodplain
Bridges with small arches became blocked due to cars and this worsened the flood as the water had nowhere to go.
(Boscastle) What were the effects of the flood?
Trees, Cars and Debris carried through village causing damage - Artificial dams that blocked bridges and caused flow on main street.
Over 80 cars wrecked, 4 footbridges destroyed across river
1000 residents affected, 42 properties flooded, 4 demolished
Shop Owners lost business
Lack of tourism as a primary source of income (90%)
(Boscastle) How was management during and after the flood?
150 people airlifted in biggest airlift since WW2
POST FLOOD: £10mil management scheme
Afforestation to increase interception
Removal of potentially damaging trees closer to banks
River widened
New drainage system drained water to a lower part of valency out of village.
Protects against 1 in 75 year flood, used to be 1 in 10
Car Parks Raised
(Boscastle) How did the flood affect the economy?
No compensation for residents who lost 70-80% of income
Loss of income and repair cost totaled £300mil by 2006
Damage to tourist economy
Houses Lost Value, Flood risk.
(Boscastle) What was the date of the flood?
16th August 2004.
(Boscastle) How much water came through the village?
440 Million Gallons
(Boscastle) Was the improvement to defence sustainable?
Yes - Boscastle did not flood again in 2007 and 2012 despite national flooding
Defended against similar levels of precipitation
Arguably damaged tourism aesthetics
