Boscastle Floods 2004 - Lecture notes PDF

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Flooding in the UK - 2004 Boscastle Floods On the 16th of August 2004, Boscastle was almost completely destroyed in the space of two hours when a flash flood occurred at around 3pm. Boscastle is located in southwest England less than a kilometre from the coastline. The River Valency flows directly through the town and meets the River Jordan at a confluence in the town.

Causes • In two hours over 60mm of rain fell and by the end of the flood, nearly 200mm had fallen. • The rain fell over Bodmin Moor, an area composed of impermeable shale and has sparse vegetaKon cover. This increased surface runoff due to a lack of both infiltraKon and intercepKon, increasing the volume of water entering the River Valency. • The ground had been saturated by previous rainfall, reducing infiltraKon and increasing surface runoff. • The River’s floodplain had been urbanised reducing infiltraKon and increasing surface runoff. Effects ECONOMIC • Insurance claims came in between £15,000 and £30,000 per property. • Businesses were badly damaged with property destroyed or filled with silt, sewage and debris. • ASer the events of the flood, people were less willing to travel to Boscastle because of the risk of another flood occurring resulKng in less tourism, which is one of their main sources of income. SOCIAL • Some people suffered from broken bones & hypothermia. • Houses were flooded and silt, sewage & debris was deposited inside of them. • Water & power supplies were taken out during the flood. ENVIRONMENTAL • Raw sewage was washed out to sea and into the River Valency. • 75 cars & 6 buildings were washed out to sea. Responses SHORT TERM • A flood warning was issued for parts of Cornwall at 3:30pm but Boscastle wasn’t specifically warned. • Over 150 people were saved by search and rescue operaKons. • 11 Days aSer the flood people were allowed to return to their homes to salvage their belongings. • Prince Charles visited the town 2 days aSer the flood and donated a large sum of money to the town. • A few days aSer the flood, geologists flew over to assess the risk of landslides triggered by heavy rain. • 100 people used the Camelford leisure centre as a refuge. LONG TERM • By early 2005, power and water was back up. • The council invested money into improving Boscastle’s flood defences. • In 2006, the channel was widened and deepened to increase its capacity and ability to handle sudden increases in discharge....